JP7700532B2 - POWER CONVERSION DEVICE, INFORMATION PROCESSING DEVICE, AND INFORMATION PROCESSING METHOD - Google Patents

Description

This disclosure relates to power conversion devices, etc.

For example, a technology has been disclosed that notifies the user of the predicted time until cooling performance is predicted to seriously deteriorate when a cooling structure, such as a cooling fin for dissipating heat from a heat generating element, becomes blocked (clogging) (see Patent Document 1).

JP 2009-295644 A

However, in a power conversion device including a power device, operation may be forcibly stopped when the temperature of a cooling structure, such as a cooling fin for dissipating heat from the power device, reaches a predetermined standard. Therefore, from the standpoint of, for example, continuous operation of the power conversion device and planning of maintenance of the power conversion device related to the cooling structure, it is desirable to notify the user of the time when the power conversion device will be forcibly stopped.

In view of the above problem, the objective of the present invention is to provide a technology that can notify the user when the power conversion device will be forced to shut down due to a rise in temperature of the cooling structure.

In order to achieve the above object, in one embodiment of the present disclosure,
Power devices,
a cooling structure for dissipating heat from the power device;
A blower that blows air to the cooling structure;
a stop control unit that forcibly stops the operation of the power conversion device when the temperature of the cooling structure unit reaches a predetermined standard;
an estimation unit that estimates an operable time of the power conversion device until the temperature of the cooling structure reaches the predetermined standard based on a tendency of a change over time of the temperature of the cooling structure ,
the estimation unit estimates an operable time of the power conversion device during an entire period from a state where the cooling structure has been maintained until the temperature of the cooling structure reaches the predetermined standard, based on measurement data of the temperature of the cooling structure in a time series from the first start of use of the power conversion device after shipment from a factory to a predetermined timing;
A power converter is provided.

In another embodiment of the present disclosure,
An information processing device for an electric power conversion device, the information processing device comprising: a power device; a cooling structure for dissipating heat from the power device; and an air blower for blowing air to the cooling structure , the information processing device for estimating an operable time of the electric power conversion device until the temperature of the cooling structure reaches a predetermined standard based on a tendency of a time change in the temperature of the cooling structure, the information processing device comprising :
an operating time of the power conversion device during the entire period from a state where the cooling structure has been maintained until the temperature of the cooling structure reaches the predetermined standard based on measurement data of the temperature of the cooling structure in a time series from the first start of use of the power conversion device after shipment from a factory to a predetermined timing;
An information processing device is provided.

In still another embodiment of the present disclosure,
An information processing method for estimating an operable time of a power conversion apparatus, the power conversion apparatus having a power device, a cooling structure for dissipating heat from the power device, and an air blower for blowing air to the cooling structure, the operation of which is forcibly stopped when a temperature of the cooling structure reaches a predetermined standard, based on a tendency of a time change in temperature of the cooling structure, the method comprising :
an operating time of the power conversion device during the entire period from a state where the cooling structure has been maintained until the temperature of the cooling structure reaches the predetermined standard based on measurement data of the temperature of the cooling structure in a time series from the first start of use of the power conversion device after shipment from a factory to a predetermined timing;
A method for processing information is provided.

According to the above-described embodiment, it is possible to notify the user when the power conversion device will be forced to shut down due to a rise in temperature of the cooling structure.

FIG. 1 illustrates an example of a configuration of a cooling abnormality diagnosis system. FIG. 2 is a schematic diagram illustrating an example of a cooling structure of a power conversion device. FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device. FIG. 2 is a functional block diagram illustrating an example of a functional configuration of a control device. 11 is a diagram showing an example of a method for estimating a reference value (reference operable time) of an operable time from a state where maintenance has been completed on a cooling structure unit until a forced shutdown of a power conversion device; FIG. 10 is a flowchart illustrating an example of a process for estimating a reference operable time. 10 is a flowchart illustrating an example of a notification process of a remaining operable time until a forced stop of a power conversion device. 13 is a diagram showing an example of the relationship between the cumulative operating time from a state in which maintenance has been completed for the cooling structure and the notification content of the remaining operable time. FIG. 13 is a block diagram showing another example of the functional configuration of the control device. FIG. 11 is a diagram showing an example of a change over time in the temperature difference between the fin temperature and the inside air temperature when a cooling abnormality occurs in the power conversion device. FIG. 1 is a diagram illustrating an example of a method for diagnosing a cooling abnormality in a power conversion device; 5 is a flowchart illustrating an example of a process for acquiring reference data of a temperature difference between a fin temperature and an inside air temperature. 4 is a flowchart illustrating an example of a process for diagnosing a cooling abnormality in a power conversion device. 10 is a flowchart illustrating another example of a notification process of a remaining operable time until a forced stop of a power conversion device. 13 is a diagram showing another example of the relationship between the cumulative operating time from the maintenance-completed state of the cooling structure unit and the notification content of the remaining operable time. FIG.

The following describes the embodiment with reference to the drawings.

[Configuration of cooling abnormality diagnosis system]
The configuration of a cooling abnormality diagnosis system 1 according to this embodiment will be described with reference to FIG.

Figure 1 is a diagram showing an example of the configuration of a cooling abnormality diagnosis system 1 according to this embodiment.

The cooling anomaly diagnosis system 1 according to this embodiment diagnoses abnormalities in the cooling performance of the power conversion device 100.

As shown in FIG. 1, the cooling abnormality diagnosis system 1 includes a power conversion device 100, a computing device 200, and a terminal device 300.

The power conversion device 100 converts three-phase AC power (e.g., R phase, S phase, and T phase) input from a commercial power source PS into three-phase AC power (e.g., U phase, V phase, and W phase) having a predetermined voltage and a predetermined frequency, and drives the electric motor M.

The electric motor M electrically drives a specific machine, such as a winding machine installed in a spinning factory, based on the three-phase AC power output from the power conversion device 100.

The power conversion device 100 may generate three-phase AC power to drive the motor M based on three-phase AC power input from a power source other than a commercial power source. The power conversion device 100 may also generate three-phase AC power to drive the motor M based on power input from a DC power source. In this case, the DC power is input to a DC link section (positive line PL and negative line NL) between the rectifier circuit 110 and the inverter circuit 130 described below.

The power conversion device 100 includes a rectifier circuit 110, a smoothing circuit 120, an inverter circuit 130, a control device 140, a sensor 150, a display device 160, a communication device 170, and a cooling fan 180.

The rectifier circuit 110 is configured to be able to rectify three-phase AC power of R, S, and T phases input from the commercial power source PS and output DC power. The rectifier circuit 110 has positive and negative output terminals connected to one end of the positive line PL and the negative line NL, respectively, and can output DC power to the smoothing circuit 120 through the positive line PL and the negative line NL. The rectifier circuit 110 is, for example, a bridge-type full-wave rectifier circuit including six semiconductor diodes SD (an example of a power device) (see FIG. 4), in which three sets of two semiconductor diodes SD connected in series to form upper and lower arms are connected in parallel.

The smoothing circuit 120 suppresses and smoothes pulsations in the DC power output from the rectifier circuit 110 and the DC power regenerated from the inverter circuit 130.

The smoothing circuit 120 includes, for example, a smoothing capacitor.

The smoothing capacitor may be provided in parallel with the rectifier circuit 110 and the inverter circuit 130 in a path connecting the positive line PL and the negative line NL.

The smoothing capacitor is repeatedly charged and discharged as appropriate to smooth out the DC power output from the rectifier circuit 110 and the DC power output (regenerated) from the inverter circuit 130.

There may be one smoothing capacitor. Alternatively, multiple smoothing capacitors may be arranged, and the multiple smoothing capacitors may be connected in parallel or in series between the positive line PL and the negative line NL. Alternatively, the multiple smoothing capacitors may be configured in such a way that two or more series-connected smoothing capacitors are connected in parallel between the positive line PL and the negative line NL.

The smoothing circuit 120 also includes, for example, a reactor.

The reactor may be provided on the positive line PL between the rectifier circuit 110 and the smoothing capacitor (specifically, the branch point from the path in which the smoothing capacitor is located).

The reactor generates a voltage to appropriately prevent changes in the current, smoothing the DC power output from the rectifier circuit 110 and the DC power output (regenerated) from the inverter circuit 130.

The inverter circuit 130 has its positive and negative input terminals connected to the other ends of the positive line PL and the negative line NL. The inverter circuit 130 converts the DC power supplied from the smoothing circuit 120 into three-phase AC power (e.g., U phase, V phase, and W phase) having a predetermined frequency and a predetermined voltage by the switching operation of a semiconductor switch SW (an example of a power device) (see FIG. 3), and outputs the converted power to the electric motor M. The semiconductor switch SW may be, for example, an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET) made of silicon (Si). The semiconductor switch SW may also be, for example, a semiconductor element using a wide band gap semiconductor such as silicon carbide (SiC) or gallium nitride (GaN).

The inverter circuit 130 includes, for example, six semiconductor switches SW, and is configured to include a bridge circuit in which three sets of series-connected semiconductor switches SW (switch legs) constituting upper and lower arms are connected in parallel between a positive line PL and a negative line NL. The inverter circuit 130 may output three-phase AC power through a U-phase wire, a V-phase wire, and a W-phase wire drawn from the connection points of the three sets of upper and lower arms. In addition, a free-wheeling diode may be connected in parallel to each of the six semiconductor switches SW.

The control device 140 (an example of an information processing device) controls the power conversion device 100. The functions of the control device 140 may be realized by any hardware or any combination of hardware and software, etc.

In addition, some or all of the functions of the control device 140 may be transferred to an external device outside the power conversion device 100, such as a calculation device 200 or a terminal device 300 (both of which are examples of information processing devices).

The sensor 150 acquires measurement data related to the operating state (operating state) of the power conversion device 100. The sensor 150 is connected to the control device 140, for example, via a one-to-one communication line, and a signal corresponding to the measurement data is input to the control device 140. This allows the control device 140 to control the power conversion device 100 based on the output signal of the sensor 150, and to calculate the operating time until the power conversion device 100 is forcibly stopped, as described below.

The sensor 150 includes, for example, various temperature sensors. The temperature sensor may include, for example, a fin temperature sensor that detects the temperature of the cooling fin section 194 (hereinafter, "fin temperature") Tf. The temperature sensor may also include, for example, an inside air temperature sensor that detects the temperature of the air inside the housing of the power conversion device 100 (hereinafter, "inside air temperature") Ta.

The sensor 150 may include, for example, various current sensors and voltage sensors. The current sensor may include, for example, a load current sensor that detects the load current output to the electric motor M.

The display device 160 (an example of a notification unit) is provided, for example, on the outer surface of the housing of the power conversion device 100. The display device 160 displays information related to the operating state (operating state) of the power conversion device 100 under the control of the control device 140.

The display device 160 may be provided outside the housing of the power conversion device 100, for example, on the surface (outer surface) of the housing of a specific machine electrically driven by the electric motor M.

The communication device 170 (an example of a notification unit) communicates with devices external to the power conversion device 100, such as the computing device 200 and the terminal device 300, via a specified communication line.

The predetermined communication line may be, for example, a one-to-one communication line. The predetermined communication line may include, for example, a local network (LAN: Local Area Network) such as a field network constructed in a facility (factory) where a predetermined machine electrically driven by an electric motor M is installed. The local network may be constructed as a wired network, may be constructed as a wireless network, or may include both. The predetermined communication line may also include, for example, a wide area network (WAN: Wide Area Network) outside the facility (factory) where a predetermined machine electrically driven by an electric motor M is installed. The wide area network may include, for example, a mobile communication network with a base station as an end, a satellite communication network using a communication satellite, an Internet network, etc. The predetermined communication line may also include, for example, a short-distance communication line according to a predetermined wireless communication standard such as Bluetooth (registered trademark) or WiFi.

The functions of the communication device 170 may be incorporated into the control device 140 (interface 144).

The cooling fan 180 (an example of an air blower) blows air to the cooling structure 190 (specifically, the cooling fin section 194) described below, promoting heat dissipation by the cooling structure 190.

The housing of the power conversion device 100 is provided with an intake port (intake port) for outside air and an exhaust port (exhaust port), and the cooling fan 180 may be provided upstream of the cooling structure 190 in the path of the air flow from the intake port to the exhaust port. In this case, the cooling fan 180 draws in outside air from the intake port and sends it out toward the cooling structure 190, thereby blowing relatively low-temperature outside air onto the cooling structure 190 and discharging the air heated by heat exchange with the cooling structure 190 from the exhaust port. The cooling fan 180 may also be provided downstream of the cooling structure 190 in the path of the air flow from the intake port to the exhaust port. In this case, the cooling fan 180 draws in air around the cooling structure 190 and creates an air flow from the upstream intake port toward the cooling structure 190, thereby blowing relatively low-temperature outside air onto the cooling structure 190.

The calculation device 200 is provided outside the power conversion device 100 and performs various calculation processes.

The arithmetic device 200 may be communicatively connected to the power conversion device 100 via a predetermined communication line, and may perform arithmetic processing related to the control of the power conversion device 100 in response to a command from the control device 140. Specifically, the arithmetic device 200 may perform part or all of the arithmetic processing related to the determination of cooling anomalies, which will be described later, in response to a command from the control device 140.

The arithmetic device 200 may be, for example, a PLC (Programmable Logic Controller) or an edge controller for controlling a specific machine electrically driven by an electric motor M. The arithmetic device 200 may also be, for example, a computer terminal such as a PC (Personal Computer).

The computing device 200 may also be, for example, a server device. The server device may be a cloud server or an on-premise server installed outside the facility (factory) where the specific machine electrically driven by the electric motor M is installed. The server device may also be, for example, an edge server installed inside the facility (factory) where the specific machine electrically driven by the electric motor M is installed, or in a communication facility (for example, a base station or station building) near the facility.

The terminal device 300 is provided outside the power conversion device 100 and is used by a user of the power conversion device 100 (cooling abnormality diagnosis system 1). The terminal device 300 provides various information to the user through, for example, the display unit 310, and receives various inputs from the user and transmits them to the power conversion device 100.

The terminal device 300 may include, for example, a stationary terminal device such as a desktop computer terminal. The terminal device 300 may also include, for example, a portable terminal device (mobile terminal) such as a smartphone, a tablet terminal, or a laptop computer terminal.

[Cooling structure of power conversion device]
Next, the cooling structure 190 of the power conversion device 100 will be described with reference to FIG.

Figure 2 is a schematic diagram showing an example of a cooling structure 190 of a power conversion device 100.

The cooling structure 190 corresponds to, for example, a heat sink and includes a fin base 192 and a cooling fin portion 194.

The fin base 192 has a flat plate shape with a predetermined thickness. A cooling fin section 194 is provided on one surface (the lower surface in the figure) of the flat plate shape of the fin base 192, and circuit boards 110A and 130A corresponding to the rectifier circuit 110 and the inverter circuit 130, respectively, are placed on the other surface (the upper surface in the figure).

The fin base 192 is made of a material with relatively high thermal conductivity. This makes it easier for thermal energy generated by losses when the semiconductor diode SD or semiconductor switch SW is energized to escape to the fin base 192. The fin base 192 may be made of a metal such as aluminum, iron, or copper. The same may be true for the cooling fin portion 194 below.

As described above, the cooling fin section 194 is provided on one surface of the flat plate shape of the fin base 192. The cooling fin section 194 includes a plurality of fins 194A that are provided so as to protrude in a direction away from the surface of the fin base 192 (in the negative Z-axis direction in the figure).

Each of the multiple fins 194A has a very thin flat plate shape and is arranged at approximately equal intervals along a predetermined direction (the X-axis direction in the figure) on one surface of the fin base 192.

The multiple fins 194A are each made of a material with relatively high thermal conductivity. This makes it easier for thermal energy generated by losses when the semiconductor diode SD or semiconductor switch SW is energized to escape from the fin base 192 to the multiple fins 194A. In addition, the multiple fins 194A have a relatively large surface area. This makes it possible to relatively increase the contact area between the multiple fins 194A and the air, making it easier to dissipate thermal energy into the surrounding air. Therefore, it becomes easier to dissipate thermal energy generated by losses when the semiconductor diode SD or semiconductor switch SW is energized to the air, improving the cooling performance of the power conversion device 100.

In addition, the cooling fan 180 causes the cooling air CA to flow in a direction (Y-axis direction in the figure) perpendicular to the direction (X-axis direction) in which the multiple fins 194A are arranged. This allows the cooling air CA to pass between the multiple fins 194A, and the temperature of the air around the multiple fins 194A is maintained at a relatively low temperature. This makes the temperature difference between the fins 194A and the surrounding air relatively large, making it easier to dissipate the thermal energy of the fins 194A to the surrounding air. This makes it easier to dissipate the thermal energy generated by losses when the semiconductor diode SD and semiconductor switch SW are energized to the air, further improving the cooling performance of the power conversion device 100 and ensuring the cooling performance required of the power conversion device 100.

On the other hand, depending on the environment in which the power conversion device 100 is installed, foreign matter may get stuck between the fins 194A. Also, depending on the size of the foreign matter, the foreign matter may get stuck in the air intake of the housing of the power conversion device 100. For example, in a spinning factory, not only dust but also cotton may be contained in the air, and the cotton or the like may get stuck between the fins 194A or in the air intake of the housing of the power conversion device 100. Then, the cooling air CA may not hit the fin 194A corresponding to the part where the foreign matter is stuck, or the amount of outside air sucked in from the air intake may decrease, causing the temperature of the air supplied to the cooling fin section 194 to increase. Therefore, the cooling performance of the semiconductor diode SD and the semiconductor switch SW by the cooling structure section 190 and the cooling fan 180 is deteriorated. As a result, an abnormality in the cooling performance of the power conversion device 100 (semiconductor diode SD and semiconductor switch SW) by the cooling structure section 190 and the cooling fan 180 (hereinafter, "cooling abnormality") may occur.

In addition, if an abnormality occurs in the cooling fan 180, causing the rotation speed of the cooling fan 180 to decrease or the cooling fan 180 to stop, the temperature of the air around the cooling fin portion 194 (fins 194A) becomes relatively high. This deteriorates the cooling performance of the cooling structure portion 190 and the cooling fan 180 for the semiconductor diode SD and the semiconductor switch SW. As a result, there is a possibility that an abnormality in the cooling of the power conversion device 100 (semiconductor diode SD and semiconductor switch SW) by the cooling structure portion 190 and the cooling fan 180 may occur.

Depending on the severity of the cooling abnormality, the fin temperature Tf may reach the overheating temperature Tferr, which may result in the need to forcibly shut down the power conversion device 100, potentially affecting the operation of the factory in which a specific machine electrically driven by the electric motor M is installed.

The cooling structure 190 may have any shape as long as it can promote the dissipation of heat energy generated by losses when the semiconductor diode SD or the semiconductor switch SW is energized into the surrounding air. For example, the fin 194A may be one instead of multiple. Also, instead of the fin 194A, the fin base 192 may be provided with one or more rod-shaped or needle-shaped protrusions made of a material with relatively high thermal conductivity.

[Example of the configuration of the control device]
Next, an example of the configuration of the control device 140 will be described with reference to FIGS.

Figures 3 and 4 are diagrams showing an example of the configuration of the control device 140 in the cooling abnormality diagnosis system 1 according to this embodiment. Specifically, Figure 3 is a block diagram showing an example of the hardware configuration of the control device 140, and Figure 4 is a block diagram showing an example of the functional configuration of the control device 140.

As shown in FIG. 3, the control device 140 includes, for example, a CPU 141 (Central Processing Unit), a memory device 142 such as a RAM (Random Access Memory), an auxiliary storage device 143 such as a ROM (Read Only Memory), and an interface 144, all of which are connected to one another via a bus B. The control device 140 performs various controls by loading a program installed in the auxiliary storage device 143 into the memory device 142 and having the CPU 141 execute the program. The control device 140 also receives external signals and outputs (transmits) signals to the outside through the interface 144.

As shown in FIG. 4, the control device 140 includes, as functional units, a drive control unit 1401, a recording unit 1402, a memory unit 1403, a maintenance judgment unit 1404, and an operable time estimation unit 1405. The functions of the drive control unit 1401, the recording unit 1402, the maintenance judgment unit 1404, and the operable time estimation unit 1405 are realized, for example, by a program installed in the auxiliary storage device 143 being loaded into the memory device 142 and executed on the CPU 141. In addition, the function of the memory unit 1403 is realized, for example, by a memory area defined in the auxiliary storage device 143.

The drive control unit 1401 controls the drive of the electric motor M through the inverter circuit 130. Specifically, the drive control unit 1401 outputs a drive signal to the inverter circuit 130 (specifically, to the gates of each semiconductor switch SW) and uses the inverter circuit 130 to drive the electric motor M so as to satisfy specified operating conditions. In other words, the drive control unit 1401 generates a control signal for driving the electric motor M in accordance with the specified operating conditions and outputs it to the inverter circuit 130.

In addition, when the fin temperature Tf reaches an overheat temperature Tferr, which indicates an overheated state of the cooling fin section 194, the drive control section 1401 (an example of a stop control section) activates the protection function of the power conversion device 100 and forcibly stops the operation of the power conversion device 100.

The recording unit 1402 records the predetermined measurement data acquired from the sensor 150 in chronological order in the memory unit 1403. Details of the recording unit 1402 will be described later (see Figures 6 and 12).

The memory unit 1403 stores the specified measurement data recorded in chronological order through the recording unit 1402. For example, the memory unit 1403 may store record data including the specified measurement data and time data when the measurement data was acquired.

The maintenance determination unit 1404 determines whether maintenance has been performed on the cooling structure unit 190. Maintenance on the cooling structure unit 190 means maintaining the function of the cooling structure unit 190, i.e., the cooling function of the power conversion device 100 by the cooling structure unit 190, in a normal state. Maintenance on the cooling structure unit 190 includes, for example, cleaning of the cooling structure unit 190 (cooling fin unit 194) and the air intake of the housing of the power conversion device 100.

For example, the maintenance determination unit 1404 may determine that maintenance of the cooling structure unit 190 has been performed when a specific input indicating that maintenance of the cooling structure unit 190 has been performed is received from a user. The specific input from the user is received, for example, through an input unit installed in the power conversion device 100 or a specific machine on which the power conversion device 100 is mounted. In addition, the specific input from the user is received, for example, when a signal representing the specific user input to an input unit installed in the calculation device 200 or terminal device 300 is transmitted from the calculation device 200 or terminal device 300 and received by the communication device 170.

For example, the maintenance determination unit 1404 may compare the measurement data of the sensor 150 during the previous and current operation of the power conversion device 100 to determine whether or not maintenance of the cooling structure unit 190 has been performed. Specifically, the maintenance determination unit 1404 may compare the measurement data or the time change of the temperature (fin temperature Tf) of the cooling fin unit 194 during the previous and current operation of the power conversion device 100 to determine whether or not maintenance of the cooling structure unit 190 has been performed. When maintenance (cleaning) of the cooling structure unit 190 is performed, the heat dissipation efficiency of the cooling structure unit 190 is improved, and a difference may occur in the fin temperature Tf or its time change compared to the previous operation of the power conversion device 100. The maintenance determination unit 1404 may also compare the measurement data or the time change of the air temperature (internal air temperature Ta) inside the housing of the power conversion device 100 during the previous and current operation of the power conversion device 100 to determine whether or not maintenance of the cooling structure unit 190 has been performed. When the maintenance of the cooling structure 190 is performed, as described above, the heat dissipation efficiency of the cooling structure 190 improves, and the temperature of the air (inside air temperature Ta) to which the thermal energy of the cooling structure 190 is transferred and its change over time may differ from the previous operation of the power conversion device 100. The maintenance determination unit 1404 may compare the measurement data of the temperature difference Y between the fin temperature Tf and the inside air temperature Ta during the previous and current operation of the power conversion device 100, or the change over time, to determine whether or not the maintenance of the cooling structure 190 has been performed. When the maintenance of the cooling structure 190 is performed, as described above, the heat dissipation efficiency of the cooling structure 190 improves, and the temperature difference Y between the fin temperature Tf and the inside air temperature Ta and its change over time may differ from the previous operation of the power conversion device 100.

The operable time estimation unit 1405 (an example of an estimation unit) estimates the operable time of the power conversion device 100 until the temperature (fin temperature Tf) of the cooling structure unit 190 (cooling fin unit 194) reaches the overheat temperature Tferr and is forcibly stopped. Details of the operable time estimation unit 1405 will be described later (see Figures 5 and 7).

[Overview of the method for estimating driving time]
Next, an outline of a method for estimating the operable time of the power conversion device 100 until the fin temperature Tf reaches the overheat temperature Tferr by the control device 140 will be described with reference to FIG.

Figure 5 shows an example of a method for estimating the reference value of the operable time OTcr from the state where maintenance has been completed for the cooling structure 190 until the power conversion device 100 is forcibly stopped (hereinafter, the "reference operable time").

The standard operable time OTcr is a reference value for the operable time of the power conversion device 100 from a state in which maintenance has been completed for the cooling structure 190 until a forced shutdown occurs due to an increase in the fin temperature Tf caused by the presence of foreign matter such as a clogged cooling fin section 194 or the air intake of the housing.

The control device 140 (recording unit 1402) records the measurement data of the fin temperature Tf in a range where the fin temperature Tf is somewhat lower than the overheat temperature Tferr in a chronological order in the memory unit 1403, starting from the start of use of the power conversion device 100 after shipment from the factory. For example, the recording unit 1402 records the measurement data of the fin temperature Tf in a chronological order in the memory unit 1403 from the start of use of the power conversion device 100 after shipment from the factory until the fin temperature Tf reaches a predetermined temperature (hereinafter, "recording end temperature") Tfover corresponding to the end condition. The recording end temperature Tfover is set to a temperature somewhat lower (lower) than the overheat temperature Tferr. As a result, as shown in FIG. 5, the control device 140 can acquire reference data (hereinafter, for convenience, "reference data of the fin temperature Tf") 501 that indicates the tendency of change in the fin temperature Tf over the cumulative operation time OT starting from the start of use of the power conversion device 100 after shipment from the factory.

Then, the control device 140 (operable time estimation unit 1405) uses the acquired reference data 501 of the fin temperature Tf to extrapolate the timing 502 at which the fin temperature Tf reaches the overheat temperature when the fin temperature Tf changes according to the trend of the reference data 501. Specifically, the recording unit 1402 estimates the reference operable time OTcr until the power conversion device 100 is forced to stop by extrapolating from the start of use after the power conversion device 100 is shipped from the factory, which corresponds to the state in which the cooling structure unit 190 has been maintained. At this time, any known extrapolation method such as linear extrapolation, polynomial extrapolation, or least squares method may be applied. As a result, the operable time estimation unit 1405 can estimate the remaining operable time OTrem of the power conversion device 100 until it is forced to stop due to a rise in the fin temperature Tf based on the reference operable time OTcr after acquiring the reference operable time OTcr.

Specifically, when the maintenance determination unit 1404 determines that maintenance has been performed on the cooling structure unit 190, the operable time estimation unit 1405 measures the cumulative operating time OTa of the power conversion device 100 starting from the state in which maintenance has been completed on the cooling structure unit 190. Then, the operable time estimation unit 1405 subtracts the cumulative operating time OTa of the power conversion device 100 from the reference operable time OTcr to estimate the remaining operable time OTrem of the power conversion device 100 (OTrem = OTcr - OTa).

The operable time estimation unit 1405 may estimate the remaining operable time OTrem of the power conversion device 100 by a simpler method without acquiring reference data for the fin temperature Tf. For example, the operable time estimation unit 1405 may estimate the remaining operable time OTrem by extrapolation based on the past history of measurement data of the fin temperature Tf, starting from the most recent time point when the maintenance determination unit 1404 determined that maintenance was performed on the cooling structure unit 190.

[Estimation process of reference operable time]
Next, the process of estimating the reference operable time OTcr by the control device 140 will be described with reference to FIG.

Figure 6 is a flowchart that shows an example of the estimation process of the reference operable time OTcr by the control device 140. This flowchart is executed repeatedly at a predetermined interval, for example, during the operation of the power conversion device 100 from power on to power off.

In this example, a flag F1 is used to indicate whether the reference operable time OTcr has been acquired. The flag F1 is stored, for example, in the auxiliary storage device 143, and is set as an initial value at the time of factory shipment of the power conversion device 100 to "0", which indicates that the reference operable time OTcr has not been acquired. The flag F1 may be read from the auxiliary storage device 143 to the memory device 142 when the power conversion device 100 is powered on, and used or updated, and the latest state may be stored in the auxiliary storage device 143 when the power conversion device 100 is powered off.

As shown in FIG. 6, in step S102, the recording unit 1402 determines whether the flag F1 is "0", i.e., whether the reference operable time OTcr has not yet been acquired. If the flag F1 is "0", the recording unit 1402 proceeds to step S104, and if the flag F1 is not "0", i.e., is "1", which indicates that the reference operable time OTcr has been acquired, the recording unit 1402 ends the processing of this flowchart.

In step S104, the recording unit 1402 determines whether the latest measurement data of the fin temperature Tf is greater than the maximum fin temperature Tfmax.

The maximum fin temperature Tfmax represents the maximum value among the measurement data of the fin temperature Tf already recorded in the memory unit 1403. The maximum fin temperature Tfmax is set to a predetermined initial value at the time of shipment from the factory.

If the measurement data for the latest fin temperature Tf is greater than the maximum fin temperature Tfmax, the recording unit 1402 proceeds to step S106; otherwise, it ends the processing of this flowchart.

In step S106, the recording unit 1402 records the latest measurement data of the fin temperature Tf and the cumulative operating time OT of the power conversion device 100 from the start of use after shipment from the factory when the measurement data was obtained in association with each other in the memory unit 1403. Specifically, the recording unit 1402 creates record data including the latest measurement data of the fin temperature Tf and the cumulative operating time OT when the measurement data was obtained, and stores the record data in the memory unit 1403.

When the control device 140 completes processing of step S106, it proceeds to step S108.

In step S108, the recording unit 1402 determines whether the end condition for recording the measurement data in a time series of the fin temperature Tf, which corresponds to the reference data of the fin temperature Tf, is met.

The termination condition may be, for example, that the fin temperature Tf reaches a recording end temperature Tfover that corresponds to the termination condition. The termination condition may also be, for example, that the number of times that measurement data is recorded reaches a predetermined number.

If the end condition for recording the reference data for the fin temperature Tf is met, the recording unit 1402 proceeds to step S110, and if the end condition is not met, the recording unit 1402 ends the processing of this flowchart.

In step S110, the recording unit 1402 sets flag F1 to "1".

When the control device 140 completes processing of step S110, it proceeds to step S112.

In step S112, the operable time estimation unit 1405 estimates the reference operable time OTcr by extrapolation based on the reference data of the fin temperature Tf stored in the memory unit 1403.

When the control device 140 completes the processing of step S112, it ends the processing of this flowchart.

In this way, the control device 140 obtains reference data for the fin temperature Tf, which indicates the tendency of time-dependent change in the fin temperature Tf, starting from the state in which the power conversion device 100 starts to be used after being shipped from the factory, which corresponds to the state in which the cooling structure 190 has been maintained. This allows the control device 140 to use the reference data for the fin temperature Tf to obtain the reference operable time (reference operable time OTcr) from the state in which the cooling structure 190 has been maintained until the power conversion device 100 is forcibly stopped due to an increase in the fin temperature Tf.

[Example of a process for notifying remaining operable time]
Next, an example of a notification process of the remaining operable time OTrem until the forced shutdown of the power conversion device 100 by the control device 140 will be described with reference to Figs.

Figure 7 is a flow chart showing an example of a notification process of the remaining operable time OTrem until the forced shutdown of the power conversion device 100 by the control device 140. Figure 8 is a diagram showing an example of the relationship between the cumulative operating time OTa from the maintenance completed state for the cooling structure unit 190 and the notification content of the remaining operable time OTrem.

The flowchart in FIG. 7 is executed repeatedly at a predetermined cycle, for example, during operation of the power conversion device 100 from when it is turned on to when it is turned off. The flowchart in FIG. 7 is also executed, for example, when an input is received from a user requesting notification of the remaining operable time OTrem via an input unit or terminal device 300 installed in the power conversion device 100 or a specific machine on which the power conversion device 100 is mounted. The same may be true for the flowchart in FIG. 14 described below.

As shown in FIG. 7, in step S202, the drivable time estimation unit 1405 determines whether flag F1 is "1", i.e., whether the reference drivable time OTcr has been acquired. If flag F1 is "1", the drivable time estimation unit 1405 proceeds to step S204, and if flag F1 is not "1", i.e., is "0", which indicates that the reference drivable time OTcr has not been acquired, the processing of this flowchart is terminated.

In step S204, the drivable time estimation unit 1405 estimates (calculates) the remaining drivable time OTrem by subtracting the current accumulated drivable time OTa from the reference drivable time OTcr.

When the control device 140 completes processing of step S204, it proceeds to step S206.

In step S206, the operable time estimation unit 1405 notifies the user of the remaining operable time OTrem estimated in step S204. This allows the control device 140 to notify the user of the remaining operable time OTrem, which is sequentially subtracted from the reference operable time OTcr as the cumulative operating time OTa elapses, starting from the state in which the power conversion device 100 has been maintained with respect to the cooling structure unit 190 (see FIG. 8).

The drivable time estimation unit 1405 notifies the remaining drivable time OTrem in a visual manner, for example, through the display device 160 or the display unit 310 of the terminal device 300. The visual display content representing the remaining drivable time OTrem may be, for example, character information such as numbers representing the remaining drivable time OTrem, or a bar graph, etc. The drivable time estimation unit 1405 may also notify the remaining drivable time OTrem in an auditory manner, i.e., as audio information, through a sound output unit installed in the power conversion device 100 or a specific machine on which the power conversion device 100 is mounted.

When the processing of step S206 is completed, the control device 140 ends the processing of this flowchart.

In this way, in this example, the control device 140 estimates the remaining operable time OTrem until the power conversion device 100 is forced to shut down due to an increase in the fin temperature Tf, based on the time series measurement data of the actual fin temperature Tf.

As a result, the control device 140 can notify the user of the time when the power conversion device 100 will be forcibly stopped based on the remaining operable time OTrem until the power conversion device 100 is forcibly stopped. This makes it easier for the user to operate the power conversion device 100 by continuous operation and to plan maintenance of the power conversion device 100 related to the cooling structure 190.

In this example, the control device 140 notifies, via the display device 160 and the communication device 170, the estimated remaining operable time OTrem until the power conversion device 100 is forced to shut down due to an increase in the fin temperature Tf. Specifically, the control device 140 notifies, via the display device 160 and the communication device 170, the remaining operable time OTrem to be subtracted over time starting from the state in which maintenance has been completed for the cooling structure 190.

This allows the control device 140 to notify the user of the remaining operable time OTrem, which is sequentially subtracted from the maintenance completed state of the cooling structure 190.

[Another example of the configuration of the control device]
Next, another example of the configuration of the control device 140 will be described with reference to Fig. 9. Below, the description will be centered on the parts that are different from the above-mentioned example (Figs. 3 and 4), and the description of the same or corresponding contents as the above-mentioned example may be omitted.

Figure 9 is a block diagram showing another example of the functional configuration of the control device 140.

In this example, the hardware configuration of the control device 140 is the same as the example described above. Therefore, the example described above (FIG. 3) is used and illustrations are omitted.

9, the control device 140 includes, as functional units, a drive control unit 1401, a recording unit 1402, a memory unit 1403, a maintenance judgment unit 1404, and an operable time estimation unit 1405, as in the above example. The control device 140 also includes a diagnosis unit 1406, unlike the above example. The functions of the drive control unit 1401, the recording unit 1402, the maintenance judgment unit 1404, the operable time estimation unit 1405, and the diagnosis unit 1406 are realized, for example, by a program installed in the auxiliary storage device 143 being loaded into the memory device 142 and executed on the CPU 141. The function of the memory unit 1403 is realized, for example, by a memory area defined in the auxiliary storage device 143.

The diagnostic unit 1406 diagnoses abnormalities in the cooling performance of the power conversion device 100. Specifically, it diagnoses abnormalities in the cooling performance of the cooling structure 190 for dissipating heat generated by losses when the semiconductor diode SD and semiconductor switch SW are energized, and the cooling fan 180 for blowing cooling air to the cooling structure 190. Details will be described later (see Figures 11 and 13).

[Outline of cooling abnormality diagnosis method]
Next, an overview of a method for diagnosing cooling abnormalities in the power conversion device 100 by the control device 140 (diagnostic unit 1406) will be described with reference to Figs. 10 and 11 .

Figure 10 is a diagram showing an example of the change over time of the temperature difference Y between the fin temperature Tf and the inside air temperature Ta when a cooling abnormality occurs. Specifically, Figure 10 is a diagram showing an example of the change over time of the temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object (graph 1001), and an example of the change over time of the temperature difference Y when a cooling abnormality occurs due to an abnormality (failure) of the cooling fan 180 (graph 1002). Figure 11 is a diagram showing a schematic diagram of an example of a method for diagnosing a cooling abnormality in the power conversion device 100.

As shown in FIG. 10, when a cooling abnormality occurs, the temperature difference Y between the fin temperature Tf and the inside air temperature Ta increases over time. This is because a decrease in the amount of heat dissipated from the cooling structure 190 to the air causes the rate of increase of the fin temperature Tf relative to time to become relatively large, while the rate of increase of the inside air temperature Ta relative to time to become relatively small. Therefore, the diagnosis unit 1406 can determine whether or not a cooling abnormality has occurred based on the magnitude of the measurement data of the temperature difference Y and the trend of time change.

In addition, the rate of increase in temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object is relatively small (gentle), whereas the rate of increase in temperature difference Y when a cooling abnormality occurs due to an abnormality in the cooling fan 180 is relatively large. Therefore, the diagnosis unit 1406 can distinguish between an abnormality in cooling performance due to the presence of a foreign object and an abnormality in cooling performance due to an abnormality in the cooling fan 180 based on the rate of increase in temperature difference Y.

For example, as shown in FIG. 11, the diagnosis unit 1406 uses reference data 1100 (hereinafter, for convenience, "reference data for temperature difference Y") that indicates the tendency of time-dependent change in temperature difference Y when cooling performance is abnormal due to the presence of a foreign object, to determine whether or not there is a cooling abnormality while distinguishing between cooling abnormalities due to the presence of a foreign object and cooling abnormalities due to an abnormality in the cooling fan 180.

The reference data 1100 represents the change over time in the temperature difference Y with the passage of the cumulative operating time OTa of the power conversion device 100 from a state in which the cooling structure 190 has been maintained when an abnormality in cooling performance occurs due to the presence of a foreign object. The cumulative operating time OTa of the power conversion device 100 from a state in which the cooling structure 190 has been maintained is the cumulative operating time of the power conversion device 100 starting from a state in which maintenance was performed on the cooling structure 190. The control device 140 can calculate the cumulative operating time OTa by subtracting the cumulative operating time OT from the cumulative operating time OT from the start of use after shipment from the factory until just before maintenance was performed on the cooling structure 190.

The diagnostic unit 1406 may determine that there is an abnormality in cooling performance due to the presence of a foreign object when the deviation of the measurement data of the temperature difference Y from the reference data 1100 of the temperature difference Y is relatively small. Specifically, the diagnostic unit 1406 may determine that there is an abnormality in cooling performance due to the presence of a foreign object when the coordinates defined by the measurement data of the temperature difference Y and the cumulative operating time OTa from the maintained state when the measurement data was acquired are in the region 1101 including the reference data 1100 of the temperature difference Y. More specifically, the diagnostic unit 1406 may determine that there is an abnormality in cooling performance due to the presence of a foreign object when the difference between the measurement data of the temperature difference Y and the reference value Ycr at the same timing starting from the maintained state of the cooling structure unit 190 is smaller than the threshold value ΔYth (>0). For example, the region 1101 is set to a range of ±30% of the value of the reference data 1100 of the temperature difference Y (hereinafter, the "reference value") Ycr. In this case, the threshold value ΔYth corresponds to 30% of the reference value Ycr at the same timing when the measurement data of the temperature difference Y was obtained, starting from the state in which the cooling structure 190 has been maintained.

On the other hand, when the deviation of the measurement data of the temperature difference Y from the reference data 1100 of the temperature difference Y is relatively large in the direction in which the temperature difference Y increases, the diagnosis unit 1406 determines that there is an abnormality in the cooling performance due to an abnormality in the cooling fan 180. Specifically, when the coordinates defined by the measurement data of the temperature difference Y and the cumulative operating time OTa from the maintenance-completed state when the measurement data is acquired are in the region 1102, the diagnosis unit 1406 may determine that there is an abnormality in cooling due to an abnormality in the cooling fan 180. The region 1102 is an adjacent region on the side where the temperature difference Y is larger than the region 1101. More specifically, the diagnosis unit 1406 may determine that there is an abnormality in cooling due to an abnormality in the cooling fan 180 when the value obtained by subtracting the reference value Ycr at the same timing starting from the maintenance-completed state for the cooling structure unit 190 from the measurement data of the temperature difference Y is equal to or greater than the threshold value ΔYth.

In addition, when there is a cooling abnormality due to an abnormality in the cooling fan 180, this may include a case where in addition to an abnormality in the cooling fan 180, there is also a cooling abnormality due to the presence of a foreign object.

Furthermore, the diagnosis unit 1406 may determine that there is no cooling abnormality when the deviation of the measurement data of the temperature difference Y from the reference data 1100 is relatively large in the direction in which the temperature difference Y is smaller. Specifically, the diagnosis unit 1406 may determine that there is no cooling abnormality when the coordinates defined by the measurement data of the temperature difference Y and the cumulative operating time OTa from the maintained state when the measurement data was acquired are in the region 1103. The region 1103 is an adjacent region on the side where the temperature difference Y is smaller than the region 1101. More specifically, the diagnosis unit 1406 may determine that there is no cooling abnormality when the value obtained by subtracting the measurement data of the temperature difference Y from the reference value Ycr at the same timing starting from the maintained state for the cooling structure unit 190 is equal to or greater than the threshold value ΔYth.

In this way, in this example, the control device 140 determines whether or not there is an abnormality in the power conversion device 100 using the reference data 1100 for the temperature difference Y, which represents the change over time in the temperature difference Y when a cooling abnormality occurs due to the presence of a foreign object.

As a result, the control device 140 can determine whether or not there is a cooling abnormality while distinguishing between a cooling abnormality due to the presence of a foreign object and a cooling abnormality due to an abnormality in the cooling fan 180, depending on the degree of deviation of the measurement data of the temperature difference Y from the reference data 1100.

[Process for acquiring reference data for temperature difference between fin temperature and inside air temperature]
Next, the process of acquiring reference data by the control device 140 will be described with reference to FIG.

Figure 12 is a flowchart that shows an example of a process for acquiring reference data for the temperature difference Y between the fin temperature Tf and the inside air temperature Ta by the control device 140. This flowchart is executed repeatedly at a predetermined interval, for example, during operation of the power conversion device 100 from when the power is turned on to when the power is turned off.

In this example, flag F3 is used to indicate whether acquisition of reference data for temperature difference Y has been completed. Flag F3 is stored, for example, in auxiliary storage device 143, and is set as an initial value at the time of factory shipment of power conversion device 100 to "0", which indicates that reference data has not been acquired. Flag F3 may be read from auxiliary storage device 143 to memory device 142 when power is turned on for power conversion device 100, and used or updated, and the latest state may be stored in auxiliary storage device 143 when power is turned off for power conversion device 100.

As shown in FIG. 12, in step S302, the recording unit 1402 determines whether flag F3 is "0", i.e., whether the reference data has not yet been acquired. If flag F3 is "0", the recording unit 1402 proceeds to step S304, and if flag F3 is not "0", i.e., is "1", which indicates that the reference data has already been acquired, the recording unit 1402 ends this flow chart.

In step S304, the recording unit 1402 determines whether the measurement data for the temperature difference Y between the latest fin temperature Tf and the inside air temperature Ta is greater than the maximum temperature difference Ymax.

The maximum temperature difference Ymax represents the maximum value of the measurement data of the temperature difference Y already recorded in the memory unit 1403. The maximum temperature difference Ymax is set to a predetermined initial value at the time of shipment from the factory. The initial value of the maximum temperature difference Ymax functions as the lower limit value of the temperature difference Y when recording the temperature difference Y as reference data.

If the latest measurement data of the temperature difference Y is greater than the maximum temperature difference Ymax, the recording unit 1402 proceeds to step S306; otherwise, it ends the processing of this flowchart.

In step S306, the recording unit 1402 records the latest measurement data of the temperature difference Y and the cumulative operating time OT of the power conversion device 100 from the start of use after shipment from the factory when the measurement data was obtained in association with each other in the memory unit 1403. Specifically, the recording unit 1402 creates record data including the latest measurement data of the temperature difference Y and the cumulative operating time OT when the measurement data was obtained, and stores the record data in the memory unit 1403.

When the control device 140 completes processing of step S306, it proceeds to step S308.

In step S308, the recording unit 1402 determines whether the end condition for recording the measurement data in the time series of temperature difference Y, which corresponds to the reference data for temperature difference Y, is met.

The termination condition may be, for example, that the fin temperature Tf reaches a recording end temperature Tfover that corresponds to the termination condition. The termination condition may also be, for example, that the number of times that measurement data is recorded reaches a predetermined number.

If the end condition for recording the reference data for temperature difference Y is met, the recording unit 1402 proceeds to step S310, and if the end condition is not met, the recording unit 1402 ends this flowchart.

In step S310, the recording unit 1402 sets flag F3 to "1".

When the control device 140 completes the processing of step S310, it ends the processing of this flowchart.

In this way, in this example, the control device 140 acquires time-series measurement data that indicates an upward trend in the change in temperature difference Y over time over the cumulative operating time OT, starting from the state in which the power conversion device 100 begins to be used after being shipped from the factory, which corresponds to the state in which the power conversion device 100 has been maintained. This allows the control device 140 to acquire reference data for the temperature difference Y based on the acquired time-series measurement data. This is because the likelihood of an abnormality occurring in the cooling fan 180 at an early stage after the power conversion device 100 begins to be used after being shipped from the factory is extremely low, and the increase in temperature difference Y at this point is considered to be due to the presence of a foreign object.

At this time, the control device 140 (diagnosis unit 1406) may use the record group of the measurement data stored in the memory unit 1403 as the reference data as is, or may generate an approximation formula or table data equivalent to the reference data based on the record group of the measurement data.

In addition, instead of acquiring the reference data for the fin temperature Tf and the reference data for the temperature difference Y separately, integrated reference data for the fin temperature Tf and the temperature difference Y may be acquired. In this case, the integrated reference data for the fin temperature Tf and the temperature difference Y may be acquired as a record data group including the measurement data for the fin temperature Tf and the temperature difference Y and the cumulative operating time OT at the time the measurement data was acquired.

[Diagnosing cooling abnormality]
Next, a process of diagnosing a cooling abnormality in the power conversion device 100 by the control device 140 will be described with reference to FIG.

Figure 13 is a flowchart that shows an example of a process for diagnosing cooling abnormalities in the power conversion device 100 by the control device 140. This flowchart is executed repeatedly at a predetermined interval, for example, during operation of the power conversion device 100 from power-on to power-off.

In this example, a flag F4 is used to indicate whether or not maintenance was performed on the cooling structure 190 immediately before the current operation start (power on) of the power conversion device 100. The flag F4 is set to "1" indicating that maintenance was performed on the cooling structure 190 as an initial value at the first start of use (power on) after shipment from the factory, and is retained in the memory device 142 from power on to power off of the power conversion device 100. The flag F4 may be set according to the determination result of the maintenance determination unit 1404 at the second or subsequent power on of the power conversion device 100 after shipment from the factory, and the state may be maintained until the power is turned off. Specifically, when the maintenance determination unit 1404 determines that maintenance was performed on the cooling structure 190, the flag F4 is set to "1", and the state may be maintained until the power is turned off of the power conversion device 100. On the other hand, if the maintenance determination unit 1404 determines that maintenance has not been performed on the cooling structure unit 190, the flag F4 is set to "0", which indicates that maintenance has not been performed on the cooling structure unit 190, and this state may be maintained until the power conversion device 100 is turned off.

Furthermore, in this example, flag F5 is used to indicate the presence or absence of a cooling abnormality due to the presence of a foreign object. Flag F5 is, for example, held in memory device 142 from when power is turned on to when power is turned off of power conversion device 100, and is set as an initial value to "0" when first used (power is turned on) after shipping from the factory, indicating that there is no cooling abnormality due to the presence of a foreign object. Flag F5 may be read from auxiliary storage device 143 to memory device 142 when power is turned on for use or update, and the latest state may be stored in auxiliary storage device 143 when power is turned off for power conversion device 100.

As shown in FIG. 13, in step S402, the diagnosis unit 1406 determines whether or not the flag F3 is "1", i.e., whether or not the reference data has been acquired. If the flag F3 is not "1", i.e., if the flag F3 is "0", which indicates that the reference data has not been acquired, the diagnosis unit 1406 proceeds to step S404, and if the flag F3 is "1", which indicates that the reference data has been acquired, the diagnosis unit 1406 proceeds to step S408.

In step S404, the diagnosis unit 1406 determines whether the measurement data of the temperature difference Y (= Tf - Ta) between the latest fin temperature Tf and the inside air temperature Ta exceeds a predetermined threshold value Yth.

The threshold value Yth is predefined as a lower limit value of the temperature difference Y for determining that a cooling abnormality has occurred in the power conversion device 100. Furthermore, the threshold value Yth is set to a value that is somewhat smaller than the value of the temperature difference Y that corresponds to the timing at which the fin temperature Tf reaches the overheat temperature Tferr. This allows the diagnostic unit 1406 to determine that a cooling abnormality has occurred in the power conversion device 100 at a timing before the power conversion device 100 is forcibly stopped.

If the latest measurement data of temperature difference Y exceeds the threshold value Yth, the diagnosis unit 1406 proceeds to step S406, and if the measurement data does not exceed the threshold value Yth, the diagnosis unit 1406 proceeds to step S424.

In step S406, an alert is output to the user indicating that a cooling abnormality has occurred in the power conversion device 100.

The alert may be output to the user in a visual manner, for example, through the display device 160. The alert may also be output to the user in a visual manner through the display unit 310 of the terminal device 300, for example, by transmitting a signal corresponding to the alert from the communication device 170 to the terminal device 300. The display device 160 or the display unit 310 may display only the fact that a cooling abnormality has occurred, or in addition to that fact, data on the operating state (operating state) of the power conversion device 100, including the fin temperature Tf, the inside air temperature Ta, and the temperature difference Y, and data representing the history of these may be displayed as numerical values. The data representing the history may be, for example, data representing the change in the temperature difference Y. The alert may also be output to the user through a sound output device such as a speaker provided in the power conversion device 100, a specific machine on which the power conversion device 100 is mounted, or the terminal device 300. The same may be true for the alerts in steps S412, S418, and S422 described below.

When the processing of step S406 is completed, the control device 140 proceeds to step S414.

When the control device 140 completes the processing of step S406, it may skip the processing of step S414 and simply end the processing of this flowchart.

On the other hand, in step S408, the diagnosis unit 1406 determines whether flag F4 is "1", i.e., whether maintenance on the cooling structure 190 was performed immediately before the current start of operation (power on) of the power conversion device 100. If flag F4 is not "1", i.e., if flag F4 is "0", which indicates that maintenance on the cooling structure 190 has not been performed, the diagnosis unit 1406 proceeds to step S410, and if flag F4 is "1", which indicates that maintenance on the cooling structure 190 has been performed, the diagnosis unit 1406 proceeds to step S420.

In addition, in step S410, it may be determined whether the cumulative operating time OTa of the power conversion device 100 since the most recent maintenance on the cooling structure 190 is less than or equal to a predetermined time. The predetermined time is set to a value somewhat smaller than the lower limit of the time required for the power conversion device 100 to develop a cooling abnormality due to a foreign object from a state in which maintenance on the cooling structure 190 has been completed. In this case, if the cumulative operating time OTa is not less than or equal to the predetermined time, the diagnosis unit 1406 proceeds to step S410, and if it is less than or equal to the predetermined time, the diagnosis unit 1406 proceeds to step S420.

In step S410, the diagnosis unit 1406 determines whether the absolute value of the subtraction value ΔY (=Y-Ycr) obtained by subtracting from the measurement data of the latest temperature difference Y the reference data (reference value Ycr) of the same accumulated operating time OTa as when the measurement data was acquired is smaller than the threshold value ΔYth.

For example, when the reference data is expressed by an approximation formula, the diagnosis unit 1406 can calculate the reference value Ycr corresponding to the cumulative operation time OTa when the measurement data of the temperature difference Y is acquired by the approximation formula. Also, for example, when the reference data is expressed by a discretized data group such as a record group of measurement data or table data, the reference value Ycr of the cumulative operation time OTa that is the same as when the measurement data of the latest temperature difference Y is acquired may or may not exist in the memory unit 1403. If the reference value Ycr of the cumulative operation time OTa that is the same as when the latest temperature difference Y is acquired exists in the memory unit 1403, the diagnosis unit 1406 can use the reference value Ycr as it is. On the other hand, if the reference value Ycr of the cumulative operation time OTa that is the same as when the latest temperature difference Y is acquired does not exist in the memory unit 1403, the reference value Ycr of the target cumulative operation time OTa can be interpolated using the reference value Ycr at the cumulative operation time OTa adjacent to the front and rear of the target cumulative operation time OTa.

If the absolute value of the subtraction value ΔY is smaller than the threshold value ΔYth, the diagnosis unit 1406 proceeds to step S412; otherwise, the diagnosis unit 1406 proceeds to step S416.

In step S412, the diagnosis unit 1406 outputs an alert to the user indicating that a cooling abnormality has occurred in the power conversion device 100 due to the presence of a foreign object (foreign object clogging the cooling fin section 194 or the air intake).

When the control device 140 completes processing of step S412, it proceeds to step S414.

In step S414, the diagnosis unit 1406 sets flag F5 to "1", indicating that there is a cooling abnormality due to the presence of a foreign object.

Note that a situation in which acquisition of the standard operable time OTcr has not been completed corresponds to a situation in which the cumulative operating time OT since the start of use of the power conversion device 100 is relatively short, and the possibility of an abnormality occurring in the cooling fan 180 is extremely low. Therefore, even if the condition of step S404 is met and an alert for a cooling abnormality is output in step S406, flag F5 is set to "1".

When the control device 140 completes the processing of step S414, it ends the processing of this flowchart.

On the other hand, in step S416, the diagnosis unit 1406 determines whether the subtraction value ΔY (= Y-Ycr) is equal to or greater than the threshold value ΔYth. If the subtraction value ΔY is equal to or greater than the threshold value ΔYth, the diagnosis unit 1406 proceeds to step S418; otherwise, the diagnosis unit 1406 determines that there is no cooling abnormality in the power conversion device 100 and proceeds to step S424.

In step S418, the diagnosis unit 1406 outputs an alert to the user indicating that a cooling abnormality has occurred in the power conversion device 100 due to an abnormality in the cooling fan 180.

When the processing of step S418 is completed, the diagnosis unit 1406 proceeds to step S424.

On the other hand, in step S420, the diagnosis unit 1406 determines whether the subtraction value ΔY (=Y-Ycr), obtained by subtracting the reference data (reference value Ycr) of the same cumulative operating time OTa as when the measurement data was acquired from the latest measurement data of the temperature difference Y, is equal to or greater than the threshold value ΔYth. If the subtraction value ΔY is equal to or greater than the threshold value ΔYth, the diagnosis unit 1406 proceeds to step S422, otherwise proceeds to step S424. As a result, when the power conversion device 100 is operating immediately after maintenance on the cooling structure unit 190 has been performed, the control device 140 can determine only the presence or absence of the latter cooling abnormality, between a cooling abnormality due to the presence of a foreign object and a cooling abnormality due to an abnormality in the cooling fan 180.

In step S422, the diagnosis unit 1406 outputs an alert to the user indicating that a cooling abnormality has occurred in the power conversion device 100 due to an abnormality in the cooling fan 180.

When the processing of step S422 is completed, the diagnosis unit 1406 proceeds to step S424.

In step S424, flag F5 is set to "0", indicating that there is no cooling abnormality due to the presence of a foreign object.

When the processing of step S424 is completed, the control device 140 ends the processing of this flowchart.

In this way, in this example, the control device 140 uses reference data that represents the change over time in the temperature difference Y between the fin temperature Tf and the inside air temperature Ta when a cooling abnormality occurs due to the presence of a foreign object.

This allows the control device 140 to distinguish between cooling abnormalities caused by the presence of a foreign object and cooling abnormalities caused by an abnormality in the cooling fan 180.

In addition, in this example, when the cumulative operating time of the power conversion device 100 after maintenance on the cooling structure 190 is relatively short, the control device 140 determines whether there is a cooling abnormality due to the presence of a foreign object or a cooling abnormality due to an abnormality in the cooling fan 180.

This allows the control device 140 to suppress erroneous determination of cooling abnormalities due to the presence of foreign matter. This is because the possibility of a cooling abnormality due to the presence of foreign matter occurring is extremely low for a certain period of time after maintenance on the cooling structure 190 is performed.

In addition, in this example, when the control device 140 has not yet acquired the reference data, it determines whether there is a cooling abnormality in the power conversion device 100 based on the magnitude of the temperature difference Y between the fin temperature Tf and the inside air temperature Ta.

As a result, although the control device 140 cannot distinguish between a cooling abnormality due to the presence of a foreign object and a cooling abnormality due to an abnormality in the cooling fan 180, it can determine whether or not there is a cooling abnormality in the power conversion device 100 even in a situation where the reference data has not yet been acquired.

The control device 140 may use reference data prepared in advance in addition to the reference data acquired in accordance with the actual use environment of the power conversion device 100. The data prepared in advance may be, for example, registered (stored) in the auxiliary storage device 143 during inspection before shipment from the factory, or may be downloaded from an external device (for example, the computing device 200) and stored in the auxiliary storage device 143 after shipment from the factory. In this case, if the reference data has not been acquired (NO in step S402), instead of the processing of steps S404 and S406, the same processing as steps S410 to S424 may be performed using the reference data prepared in advance. In addition, the control device 140 may use the reference data prepared in advance instead of the reference data acquired in accordance with the actual use environment of the power conversion device 100. In this case, the processing of FIG. 7 is not performed, and the processing of steps S402 to S406 may be omitted. In addition, there may be multiple types of reference data prepared in advance. For example, multiple types of reference data may be prepared in advance according to the usage environment, and may be selectable by a specific input received from the user. Also, the control device 140 may diagnose a cooling abnormality in the power conversion device 100 without distinguishing between a cooling abnormality due to the presence of a foreign object and a cooling abnormality due to an abnormality in the cooling fan 180. For example, the processes of steps S402, S408 to S412, and S416 to S422 may be omitted.

[Another example of the remaining driving time notification process]
Next, another example of the notification process of the remaining operable time OTrem until the forced shutdown of the power conversion device 100 by the control device 140 will be described with reference to Figs. 14 and 15 .

Figure 14 is a flow chart showing another example of the notification process of the remaining operable time OTrem until the forced shutdown of the power conversion device 100 by the control device 140. Figure 15 is a diagram showing another example of the relationship between the cumulative operating time OTa from the maintenance completed state for the cooling structure unit 190 and the notification content of the remaining operable time OTrem.

As shown in FIG. 14, step S502 is the same as the processing in step S202 in FIG. 7, so detailed explanation is omitted.

If flag F1 is "1", the drivable time estimation unit 1405 proceeds to step S504, and if flag F1 is not "1", i.e., is "0", it ends the processing of this flowchart.

In step S504, the operable time estimation unit 1405 determines whether flag F5 is "1", i.e., whether a cooling abnormality due to the presence of a foreign object has occurred. If flag F5 is "1", the operable time estimation unit 1405 proceeds to step S506, and if flag F5 is "0", indicating that a cooling abnormality due to the presence of a foreign object has not occurred, the operation proceeds to step S508.

Step S506 is the same as the processing in step S204 in FIG. 7, so detailed explanation will be omitted.

When the control device 140 completes processing of step S506, it proceeds to step S510.

On the other hand, in step S508, the drivable time estimation unit 1405 estimates (calculates) the reference drivable time OTcr as the remaining drivable time OTrem (OTrem = OTcr).

When the control device 140 completes processing of step S508, it proceeds to step S510.

In step S510, the operable time estimation unit 1405 notifies the user of the remaining operable time OTrem estimated in step S506 or step S508. This allows the control device 140 to maintain the remaining operable time OTrem at the reference operable time OTcr, starting from the state in which the power conversion device 100 has been maintained for the cooling structure unit 190, until a cooling anomaly related to the presence of a foreign object occurs. Then, when a cooling anomaly related to the presence of a foreign object occurs, the control device 140 can notify the user of the remaining operable time OTrem, which is sequentially subtracted from the reference operable time OTcr as the cumulative operating time OTa elapses (see FIG. 15).

When the control device 140 completes the processing of step S510, it ends the processing of this flowchart.

In this way, in this example, when a cooling abnormality occurs in the power conversion device 100, the control device 140 notifies the remaining operable time OTrem via the display device 160 and communication device 170 so that it is subtracted over time.

This allows the control device 140 to notify the remaining operable time OTrem, which is sequentially decremented over time, only when a cooling abnormality occurs in the power conversion device 100.

[Effect]
Next, the operation of the power conversion device 100 (control device 140) according to this embodiment will be described.

In this embodiment, the power conversion device 100 includes a power device such as a semiconductor diode SD or a semiconductor switch SW, a cooling structure 190, a cooling fan 180, a drive control unit 1401, and an operable time estimation unit 1405. Specifically, the cooling structure 190 is used to dissipate heat from the power device. The cooling fan 180 blows air to the cooling structure 190. When the temperature of the cooling structure 190 reaches the overheat temperature Tferr, the drive control unit 1401 forcibly stops the operation of the power conversion device 100. The operable time estimation unit 1405 estimates the operable time of the power conversion device 100 until the fin temperature Tf reaches the overheat temperature Tferr based on the tendency of the time change of the temperature (fin temperature Tf) of the cooling structure 190.

This allows the control device 140 to notify the user of the time when the power conversion device 100 will be forcibly stopped, using the estimated operation time of the power conversion device 100 until the fin temperature Tf reaches the overheating temperature Tferr.

In addition, in this embodiment, the operable time estimation unit 1405 may estimate the operable time (reference operable time OTcr) of the power conversion device 100 for the entire period from when the cooling structure 190 has been maintained until the temperature of the cooling structure 190 reaches the overheat temperature Tferr, based on the measurement data of the fin temperature Tf in a time series from the first start of use of the power conversion device 100 after shipment from the factory to a specified timing.

This allows the control device 140 to estimate the time when the power conversion device 100 will be forcibly stopped based on the operational time of the power conversion device 100 over the entire period from when the cooling structure 190 has been maintained until the temperature of the cooling structure 190 reaches the overheat temperature Tferr.

In addition, in this embodiment, the power conversion device 100 may include a maintenance determination unit 1404. Specifically, the maintenance determination unit 1404 may determine that maintenance has been performed on the cooling structure unit 190. The operable time estimation unit 1405 may estimate the remaining operable time OTrem of the power conversion device 100 until the fin temperature Tf reaches the overheat temperature Tferr by subtracting the cumulative operating time OTa of the power conversion device 100 from the time when the maintenance determination unit 1404 determined that maintenance has been performed on the cooling structure unit 190 from the estimated operable time of the power conversion device 100 for the entire period (reference operable time OTcr).

This allows the control device 140 to specifically estimate the remaining operable time OTrem.

In addition, in this embodiment, the power conversion device 100 may include a notification unit such as a display device 160 or a communication device 170. Specifically, the notification unit may notify the user of the remaining operable time OTrem of the power conversion device 100 until the temperature of the cooling structure unit 190 reaches the overheat temperature Tferr, as estimated by the operable time estimation unit 1405.

As a result, the power conversion device 100 can notify the specific time when the power conversion device 100 will be forcibly stopped based on the estimated remaining operable time OTrem of the power conversion device 100.

In addition, in this embodiment, the power conversion device 100 may include a diagnosis unit 1406. Specifically, the diagnosis unit 1406 may perform a diagnosis regarding an abnormality in the cooling performance of the cooling structure unit 190. Then, when the diagnosis unit 1406 determines that there is an abnormality in the cooling performance of the cooling structure unit 190, the notification unit may notify the user of the remaining operable time OTrem of the power conversion device 100 so that it is subtracted in accordance with the lapse of the cumulative operating time of the power conversion device 100.

As a result, the power conversion device 100 can notify the remaining operable time OTrem, which is sequentially decremented in accordance with the lapse of the accumulated operating time of the power conversion device 100, only when an abnormality occurs in the cooling performance of the cooling structure unit 190.

In addition, in this embodiment, the power conversion device 100 may include a maintenance determination unit 1404. The notification unit may notify the user of the remaining operable time OTrem of the power conversion device 100, which is subtracted in accordance with the lapse of the cumulative operating time of the power conversion device 100, starting from the time when the maintenance determination unit 1404 determines that maintenance related to the cooling structure unit 190 has been performed.

This allows the power conversion device 100 to notify the user of the remaining operable time OTrem, which is sequentially subtracted from the maintenance completed state of the cooling structure 190 in accordance with the lapse of the accumulated operating time of the power conversion device 100.

Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the invention as described in the claims.

REFERENCE SIGNS LIST 1 Cooling abnormality diagnosis system 100 Power conversion device 110 Rectifier circuit 110A Circuit board 120 Smoothing circuit 130 Inverter circuit 130A Circuit board 140 Control device (information processing device)
141 CPU
142 Memory device 143 Auxiliary storage device 144 Interface 150 Sensor 160 Display device (notification unit)
170 Communication device (notification unit)
180 Cooling fan 190 Cooling structure 192 Fin base 194 Cooling fin section 194A Fin 200 Computing device (information processing device)
300 Terminal device (information processing device)
310 Display unit 1401 Drive control unit (stop control unit)
1402 Recording unit 1403 Storage unit 1404 Maintenance judgment unit 1405 Operational time estimation unit (estimation unit)
1406 Diagnostic unit M Motor NL Negative line PL Positive line PS Commercial power supply SD Semiconductor diode (power device)
SW Semiconductor switch (power device)

Claims (7)

Power devices,
a cooling structure for dissipating heat from the power device;
A blower that blows air to the cooling structure;
a stop control unit that forcibly stops the operation of the power conversion device when the temperature of the cooling structure unit reaches a predetermined standard;
an estimation unit that estimates an operable time of the power conversion device until the temperature of the cooling structure reaches the predetermined standard based on a tendency of a change over time of the temperature of the cooling structure ,
the estimation unit estimates an operable time of the power conversion device during an entire period from a state where the cooling structure has been maintained until the temperature of the cooling structure reaches the predetermined standard, based on measurement data of the temperature of the cooling structure in a time series from the first start of use of the power conversion device after shipment from a factory to a predetermined timing;
Power conversion equipment. a maintenance determination unit that determines whether maintenance has been performed on the cooling structure,
the estimation unit estimates a remaining operable time of the power conversion device until the temperature of the cooling structure reaches the predetermined standard by subtracting a cumulative operating time of the power conversion device from a time when the maintenance determination unit determines that maintenance on the cooling structure has been performed, from the estimated operable time of the power conversion device for the entire period.
The power conversion device according to claim 1 . a notification unit that notifies a user of a remaining operable time of the power conversion device until the temperature of the cooling structure unit reaches the predetermined standard, the remaining operable time being estimated by the estimation unit.
The power conversion device according to claim 1 or 2 . a diagnostic unit that diagnoses an abnormality in the cooling performance of the cooling structure,
When the diagnosis unit determines that there is an abnormality in the cooling performance of the cooling structure unit, the notification unit notifies a user of a remaining operable time of the power conversion device until the temperature of the cooling structure unit reaches the predetermined standard, the remaining operable time being subtracted in accordance with the lapse of operation time of the power conversion device.
The power conversion device according to claim 3 . a maintenance determination unit that determines whether maintenance has been performed on the cooling structure unit,
the notification unit notifies a user of a remaining operable time of the power conversion device until the temperature of the cooling structure unit reaches the predetermined standard, the remaining operable time being subtracted in accordance with the lapse of operation time of the power conversion device from a point in time when it is determined by the maintenance determination unit that maintenance on the cooling structure unit has been performed.
The power conversion device according to claim 3 . An information processing device for an electric power conversion device, the information processing device comprising: a power device; a cooling structure for dissipating heat from the power device; and an air blower for blowing air to the cooling structure , the information processing device for estimating an operable time of the electric power conversion device until the temperature of the cooling structure reaches a predetermined standard based on a tendency of a time change in the temperature of the cooling structure, the information processing device comprising :
an operating time of the power conversion device during the entire period from a state where the cooling structure has been maintained until the temperature of the cooling structure reaches the predetermined standard based on measurement data of the temperature of the cooling structure in a time series from the first start of use of the power conversion device after shipment from a factory to a predetermined timing;
Information processing device. An information processing method for estimating an operable time of a power conversion apparatus, the power conversion apparatus having a power device, a cooling structure for dissipating heat from the power device, and an air blower for blowing air to the cooling structure, the operation of which is forcibly stopped when a temperature of the cooling structure reaches a predetermined standard, based on a tendency of a time change in temperature of the cooling structure, the method comprising :
an operating time of the power conversion device during the entire period from a state where the cooling structure has been maintained until the temperature of the cooling structure reaches the predetermined standard based on measurement data of the temperature of the cooling structure in a time series from the first start of use of the power conversion device after shipment from a factory to a predetermined timing;
Information processing methods.

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