JP7622822B2 - Information processing device, short circuit determination method and program - Google Patents

Description

The present invention relates to an information processing device, a short circuit determination method, and a program.

For short circuit protection in indoor DC power supply systems (cable lengths of several hundred meters or less), large-capacity electrolytic capacitors and fuses built into the current distribution device are used. In the event of a short circuit, an electric charge is supplied from the large-capacity capacitor to the fuse, causing it to melt. In outdoor DC power supply systems with long cable lengths (several thousand meters or so), large-capacity capacitors cannot be used, so short circuit protection is provided at two stages: the DC/DC converter gate block and the fuse.

Non-patent document 1 discloses a system design method that takes into account the effects of short-circuit faults in a high-voltage DC power supply system.

"Toward the realization of a high-voltage DC power supply system", NTT Technical Journal, August 2009, [online], Internet <URL: https://www.ntt.co.jp/journal/0908/files/jn200908018.pdf>

In conventional technology, in DC power supply systems with long cable lengths, such as outdoor DC power supply systems, if only the gate block of the DC/DC converter is stopped and the fuse is not blown, it is difficult to determine whether the DC/DC converter has failed or is short-circuited, and it takes time to determine the cause.

The disclosed technology aims to assist in identifying the cause of a fault in the power supply system.

The disclosed technology is an information processing device that includes a data acquisition unit that acquires data indicating characteristics of a power supply system, and a short circuit possibility determination unit that determines whether or not there is a possibility that a short circuit has occurred in the power supply system based on the data, and the data acquisition unit acquires as the data at least one of an operation time of a gate block of a DC/DC converter included in the power supply system, a capacitance of an X capacitor of the DC/DC converter, an impedance of a power supply cable, and a melting characteristic of a fuse included in the power supply system .

We can assist in identifying the cause of a malfunction in the power supply system.

FIG. 2 is a diagram illustrating a system configuration of a power supply system to be determined. FIG. 2 is a functional configuration diagram of an information processing device. 10 is a flowchart showing an example of the flow of a short circuit determination process. FIG. 1 is a diagram showing an outline of an equivalent circuit. FIG. 2 is a first diagram showing an example of a current waveform. FIG. 13 is a second diagram showing an example of a current waveform. FIG. 2 illustrates an example of a hardware configuration of a computer.

Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applicable is not limited to the following embodiment.

Figure 1 shows the system configuration of the power supply system to be evaluated.

The power supply system 1 that is the subject of the determination process according to this embodiment is an outdoor DC power supply system, and is a system in which the length of the power supply cable is several thousand meters. The power supply system 1 includes a rectifier (or AC/DC converter) 901, a distribution board 902, a DC/DC converter 903, a fuse 906, a cable impedance 907, and an apparatus 908.

The DC/DC converter 903 also includes a gate block 904 and an X capacitor 905.

Outdoor DC power supply systems cannot use large-capacity capacitors like indoor DC power supply systems, so fuse 906 is less likely to blow. Furthermore, as the length of the power supply cable increases, the cable impedance increases and the short-circuit current decreases, making fuse 906 less likely to blow.

DC/DC converter 903 also has the function of detecting the flow of an overcurrent due to a short circuit, etc., and opening gate block 904 to stop the power supply. However, even after gate block 904 is opened, the charge stored in X capacitor 905 (approximately several hundred to several thousand uF/kW) built into the output filter of DC/DC converter 903 continues to flow toward the short-circuit point. As a result, even if gate block 904 operates quickly, fuse 906 may be blown by the current flowing from X capacitor 905.

Below, we will explain a method for determining whether or not a short circuit may have occurred using an information processing device according to this embodiment in such a situation where gate block 904 is stopped and fuse 906 is not blown.

Figure 2 is a functional configuration diagram of an information processing device.

The information processing device 10 comprises a data acquisition unit 11, a current waveform calculation unit 12, a judgment reference value calculation unit 13, a short circuit possibility judgment unit 14, and an output unit 15.

The data acquisition unit 11 acquires data indicating the characteristics of the power supply system 1. Specifically, the data acquisition unit 11 acquires data indicating the operating time of the gate block 904 of the DC/DC converter 903 provided in the power supply system 1, the capacitance of the X capacitor 905 of the DC/DC converter 903, the impedance of the power supply cable, and the melting characteristics of the fuse 906 provided in the power supply system 1. The data acquisition unit 11 may acquire data by a user's input operation, or may receive data from another device, etc.

The current waveform calculation unit 12 calculates the current waveform when the power supply system 1 is short-circuited based on the operation time of the gate block 904, the capacitance of the X capacitor 905, and the impedance of the power supply cable, which are data acquired by the data acquisition unit 11.

Specifically, when the operation time of the gate block 904 is equal to or less than a predetermined threshold, the current waveform calculation unit 12 calculates the current waveform when the power supply system 1 is short-circuited based on the capacity of the X capacitor 905 and the impedance of the power supply cable, and when the operation time of the gate block 904 exceeds the threshold, the current waveform when the power supply system 1 is short-circuited based on the capacity of the X capacitor 905, the impedance of the power supply cable, and the operation time of the gate block 904.

In addition, the current waveform calculation unit 12 calculates the current waveform when the power supply system 1 is short-circuited by simulating a circuit equivalent to the power supply system 1.

The judgment reference value calculation unit 13 calculates a value (judgment reference value) that serves as a reference for judging the possibility of a short circuit, based on the current waveform calculated by the current waveform calculation unit 12. Specifically, the judgment reference value calculation unit 13 calculates the total charge (It) and Joule integral value ( ^I2t ) that flow through the circuit when a short circuit occurs.

The short circuit possibility determination unit 14 determines whether or not there is a possibility that a short circuit has occurred based on the calculated determination reference value and the melting characteristics of the fuse 906. Specifically, the short circuit possibility determination unit 14 determines whether or not there is a possibility that a short circuit has occurred based on whether or not the calculated total charge amount (It) exceeds the limit value of the total charge amount obtained from the melting characteristics of the fuse 906, or whether or not the Joule integral value (I ² t) exceeds the limit value of the Joule integral value obtained from the melting characteristics of the fuse 906.

The output unit 15 outputs the judgment result of the short circuit possibility judgment unit 14. The output unit 15 may transmit information indicating the judgment result to another device, or may display a screen indicating the judgment result.

(Operation of information processing device 10)
Next, a description will be given of the operation of the information processing device 10. Fig. 3 is a flowchart showing an example of the flow of a short circuit determination process.

When a fault occurs in the power supply system 1, the short circuit determination process is started in response to an operation by a user, such as an administrator of the power supply system 1.

The data acquisition unit 11 acquires data indicating the characteristics of the power supply system 1, which is an outdoor DC power supply system (step S101). The data indicating the characteristics of the power supply system 1 includes the operating time of the gate block 904 of the DC/DC converter 903 provided in the power supply system 1, the capacitance of the X capacitor 905 of the DC/DC converter 903, the impedance of the power supply cable, and the melting characteristic of the fuse 906 provided in the power supply system 1.

Next, the current waveform calculation unit 12 determines whether the operation time of the gate block 904 is 100 μs or less (step S102). Note that 100 μs is a value that is preset as a predetermined threshold value.

When the current waveform calculation unit 12 determines that the operation time of the gate block 904 is 100 μs or less (step S102: Yes), it calculates the current waveform (time constant) during a short circuit by a simulation based on the capacitor capacitance and cable impedance (step S103). This simulation is a simulation using an equivalent circuit, which will be described later.

Next, the judgment reference value calculation unit 13 calculates the total charge (It) and Joule integral ( ^I2t ) flowing through the circuit when a short circuit occurs (step S104). Then, the short circuit possibility judgment unit 14 judges whether the calculated total charge is smaller than the limit value of the total charge obtained from the melting characteristics of the fuse 906, or whether the calculated Joule integral is smaller than the limit value of the Joule integral obtained from the melting characteristics of the fuse 906 (step S105).

If the short circuit possibility determination unit 14 determines that the calculated total charge amount is smaller than the limit value of the total charge amount obtained from the melting characteristics of the fuse 906, or that the calculated Joule integral value is smaller than the limit value of the Joule integral value obtained from the melting characteristics of the fuse 906 (step S105: Yes), it determines that there is a possibility of a short circuit (step S106).

Furthermore, if the short circuit possibility determination unit 14 determines that the calculated total charge amount is not smaller than the limit value of the total charge amount obtained from the melting characteristics of fuse 906 and that the calculated Joule integral value is not smaller than the limit value of the Joule integral value obtained from the melting characteristics of fuse 906 (step S105: No), it determines that there is no possibility of a short circuit (step S107).

Furthermore, in the processing of step S102, if the current waveform calculation unit 12 determines that the operation time of the gate block 904 is not 100 μs or less (step S102: No), it calculates the current waveform (time constant) during a short circuit by simulation based on the capacitor capacitance, cable impedance and operation time of the gate block (step S108).

Next, the judgment reference value calculation unit 13 calculates the total charge (It) and Joule integral ( ^I2t ) flowing through the circuit when a short circuit occurs (step S109).Then, the short circuit possibility judgment unit 14 judges whether the calculated total charge exceeds the limit value of the total charge obtained from the melting characteristics of the fuse and whether the calculated Joule integral exceeds the limit value of the Joule integral obtained from the melting characteristics of the fuse (step S110).

If the short circuit possibility determination unit 14 determines that the calculated total charge exceeds the limit value of the total charge obtained from the melting characteristics of the fuse and that the calculated Joule integral value exceeds the limit value of the Joule integral value obtained from the melting characteristics of the fuse (step S110: Yes), it determines that there is no possibility of a short circuit (step S107).

Furthermore, if the short circuit possibility determination unit 14 determines that the calculated total charge does not exceed the limit value of the total charge obtained from the melting characteristics of the fuse, or that the calculated Joule integral does not exceed the limit value of the Joule integral obtained from the melting characteristics of the fuse (step S110: No), it determines that there is an error and displays the error on a screen or the like (step S111). Then, the process returns to step S101, and the data acquisition unit 11 acquires the corrected data.

Figure 4 shows an outline of the equivalent circuit. The equivalent circuit 800 is used in steps S103 and S108 shown in Figure 3.

The equivalent circuit 800 includes a DC/DC converter 803, a fuse 804, an RL series circuit 805, and a short-circuit switch 806. The DC/DC converter 803 includes a gate block 801 and an X capacitor 802.

In step S103, the current waveform calculation section 12 calculates the total amounts of charge It and ^I2t flowing through the fuse 804 without taking into account the operation time of the gate block, since the operation time of the gate block is short.

In addition, in step S108, since the operation time of the gate block is long, the current waveform calculation unit 12 assumes that the charge from the X capacitor 802 and the charge from the gate block 801 flow to the fuse 804, and calculates the total charges It and ^I2t flowing through the fuse 804 in accordance with the operation time of the gate block.

Figure 5 is a first diagram showing an example of a current waveform.

Graph 701 is an example of a current waveform calculated in step S103. Shown is a current waveform 702 indicating the current flowing through fuse 804, and a current waveform 703 indicating the current flowing through gate block 801. In this case, since there is almost no current flowing through gate block 801, current waveform 702 matches the current waveform indicating the current flowing through X capacitor 802.

Figure 6 is a second diagram showing an example of a current waveform.

Graph 711 is an example of a current waveform calculated in step S108. Shown is a current waveform 712 indicating the current flowing through fuse 804, and a current waveform 713 indicating the current flowing through gate block 801. In this case, the current waveform indicating the sum of the current flowing through X capacitor 802 and the current flowing through gate block 801 becomes the current waveform indicating the current flowing through fuse 804.

According to the information processing device 10 of this embodiment, in an outdoor DC power supply system with a long cable length, if only the gate block of the DC/DC converter is stopped and the fuse is not blown, the presence or absence of the possibility of a short circuit is determined. This can assist in identifying the cause of whether the DC/DC converter is broken or has a short circuit.

(Example of hardware configuration of information processing device 10)
The information processing device 10 can be realized, for example, by making a computer execute a program in which the processing contents described in this embodiment are described. Note that this "computer" may be a physical machine or a virtual machine on the cloud. When a virtual machine is used, the "hardware" described here is virtual hardware.

The above program can be recorded on a computer-readable recording medium (such as a portable memory) and can be stored or distributed. The above program can also be provided via a network such as the Internet or e-mail.

Figure 7 is a diagram showing an example of the hardware configuration of the computer. The computer in Figure 7 has a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, etc., which are all connected to each other via a bus B.

The program that realizes the processing on the computer is provided by a recording medium 1001, such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 via the drive device 1000 into the auxiliary storage device 1002. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

When an instruction to start a program is received, the memory device 1003 reads out and stores the program from the auxiliary storage device 1002. The CPU 1004 realizes the functions related to the device in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network. The display device 1006 displays a GUI (Graphical User Interface) based on a program, etc. The input device 1007 is composed of a keyboard and mouse, buttons, a touch panel, etc., and is used to input various operational instructions. The output device 1008 outputs the results of calculations.

(Summary of the embodiment)
This specification describes at least the information processing device, the short circuit determination method, and the program described in the following sections.
(Section 1)
A data acquisition unit that acquires data indicating characteristics of the power supply system;
and a short circuit possibility determination unit that determines whether or not there is a possibility that a short circuit has occurred in the power supply system based on the data.
Information processing device.
(Section 2)
the data acquisition unit acquires the data indicating an operation time of a gate block of a DC/DC converter included in the power supply system, a capacitance of an X capacitor of the DC/DC converter, an impedance of a power supply cable, and a melting characteristic of a fuse included in the power supply system.
2. The information processing device according to claim 1.
(Section 3)
a current waveform calculation unit that calculates a current waveform when a short circuit occurs in the power supply system based on an operation time of the gate block, a capacitance of the X capacitor, and an impedance of the power supply cable;
and a judgment reference value calculation unit that calculates an amount of charge (It) or a Joule integral value ( ^I2t ) flowing in the circuit when a short circuit occurs based on the calculated current waveform.
the short circuit possibility determination unit determines whether or not there is a possibility that the short circuit has occurred based on the calculated charge amount or the Joule integral value and melting characteristics of the fuse.
3. The information processing device according to claim 2.
(Section 4)
the current waveform calculation unit calculates a current waveform when the power supply system is short-circuited based on a capacitance of the X capacitor and an impedance of the power supply cable when the operation time of the gate block is equal to or less than a predetermined threshold, and calculates the current waveform when the power supply system is short-circuited based on the capacitance of the X capacitor, the impedance of the power supply cable, and the operation time of the gate block when the operation time of the gate block exceeds the threshold.
4. The information processing device according to claim 3.
(Section 5)
the judgment reference value calculation unit calculates the amount of charge and the Joule integral value,
The short circuit possibility determination unit is
When the operation time of the gate block is equal to or less than the threshold value,
determine that there is a possibility of a short circuit when the calculated amount of charge is smaller than a limit value of the amount of charge obtained from the melting characteristics of the fuse, or when the calculated Joule integral value is smaller than a limit value of the Joule integral value obtained from the melting characteristics of the fuse, and determine that there is no possibility of a short circuit when the calculated amount of charge is not smaller than the limit value of the amount of charge obtained from the melting characteristics of the fuse and when the calculated Joule integral value is not smaller than the limit value of the Joule integral value obtained from the melting characteristics of the fuse,
When the operation time of the gate block exceeds the threshold value,
if the calculated amount of charge exceeds the limit value of the amount of charge obtained from the melting characteristics of the fuse and if the calculated Joule integral value exceeds the limit value of the Joule integral value obtained from the melting characteristics of the fuse, it is determined that there is no possibility of a short circuit, and if the calculated amount of charge does not exceed the limit value of the amount of charge obtained from the melting characteristics of the fuse or if the calculated Joule integral value does not exceed the limit value of the Joule integral value obtained from the melting characteristics of the fuse, it is determined that an error has occurred.
5. The information processing device according to claim 4.
(Section 6)
the current waveform calculation unit calculates the current waveform when the power supply system is short-circuited by a simulation in a circuit equivalent to the power supply system.
6. The information processing device according to any one of claims 3 to 5.
(Section 7)
1. A computer-implemented method comprising:
obtaining data indicative of a characteristic of a power supply system;
and determining whether or not there is a possibility that a short circuit has occurred in the power supply system based on the data.
Method for determining short circuit.
(Section 8)
A program for causing a computer to function as each unit in the information processing device according to any one of claims 1 to 6.

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

REFERENCE SIGNS LIST 1 Power supply system 10 Information processing device 11 Data acquisition unit 12 Current waveform calculation unit 13 Judgment reference value calculation unit 14 Short circuit possibility judgment unit 15 Output unit 801 Gate block 802 X capacitor 803 DC/DC converter 804 Fuse 805 RL series circuit 806 Short circuit switch 901 Rectifier (or AC/DC converter)
902 Distribution board 903 DC/DC converter 904 Gate block 905 X capacitor 906 Fuse 907 Cable impedance 908 Device 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU
1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims (8)

A data acquisition unit that acquires data indicating characteristics of the power supply system;
a short circuit possibility determination unit that determines whether or not there is a possibility that a short circuit has occurred in the power supply system based on the data,
the data acquisition unit acquires, as the data, at least one of an operation time of a gate block of a DC/DC converter included in the power supply system, a capacitance of an X capacitor of the DC/DC converter, an impedance of a power supply cable, and a melting characteristic of a fuse included in the power supply system;
Information processing device. A data acquisition unit that acquires data indicating characteristics of the power supply system;
a short circuit possibility determination unit that determines whether or not there is a possibility that a short circuit has occurred in the power supply system based on the data,
the data acquisition unit acquires the data indicating an operation time of a gate block of a DC/DC converter included in the power supply system, a capacitance of an X capacitor of the DC/DC converter, an impedance of a power supply cable, and a melting characteristic of a fuse included in the power supply system.
Information processing device. a current waveform calculation unit that calculates a current waveform when a short circuit occurs in the power supply system based on an operation time of the gate block, a capacitance of the X capacitor, and an impedance of the power supply cable;
and a judgment reference value calculation unit that calculates an amount of charge (It) or a Joule integral value ( ^I2t ) flowing in the circuit when a short circuit occurs based on the calculated current waveform.
the short circuit possibility determination unit determines whether or not there is a possibility that the short circuit has occurred based on the calculated charge amount or the Joule integral value and melting characteristics of the fuse.
The information processing device according to claim 2 . the current waveform calculation unit calculates a current waveform when the power supply system is short-circuited based on a capacitance of the X capacitor and an impedance of the power supply cable when the operation time of the gate block is equal to or less than a predetermined threshold, and calculates the current waveform when the power supply system is short-circuited based on the capacitance of the X capacitor, the impedance of the power supply cable, and the operation time of the gate block when the operation time of the gate block exceeds the threshold.
The information processing device according to claim 3 . the judgment reference value calculation unit calculates the amount of charge and the Joule integral value,
The short circuit possibility determination unit is
When the operation time of the gate block is equal to or less than the threshold value,
determine that there is a possibility of a short circuit when the calculated amount of charge is smaller than a limit value of the amount of charge obtained from the melting characteristics of the fuse, or when the calculated Joule integral value is smaller than a limit value of the Joule integral value obtained from the melting characteristics of the fuse, and determine that there is no possibility of a short circuit when the calculated amount of charge is not smaller than the limit value of the amount of charge obtained from the melting characteristics of the fuse and when the calculated Joule integral value is not smaller than the limit value of the Joule integral value obtained from the melting characteristics of the fuse,
When the operation time of the gate block exceeds the threshold value,
if the calculated amount of charge exceeds the limit value of the amount of charge obtained from the melting characteristics of the fuse and if the calculated Joule integral value exceeds the limit value of the Joule integral value obtained from the melting characteristics of the fuse, it is determined that there is no possibility of a short circuit, and if the calculated amount of charge does not exceed the limit value of the amount of charge obtained from the melting characteristics of the fuse or if the calculated Joule integral value does not exceed the limit value of the Joule integral value obtained from the melting characteristics of the fuse, it is determined that an error has occurred.
The information processing device according to claim 4. the current waveform calculation unit calculates the current waveform when the power supply system is short-circuited by a simulation in a circuit equivalent to the power supply system.
The information processing device according to claim 3 . 1. A computer-implemented method comprising:
A data acquisition step of acquiring data indicative of characteristics of the power supply system;
and a short circuit possibility determination step of determining whether or not there is a possibility that a short circuit has occurred in the power supply system based on the data,
In the data acquisition step, the computer acquires, as the data, at least one of an operation time of a gate block of a DC/DC converter included in the power supply system, a capacitance of an X capacitor of the DC/DC converter, an impedance of a power supply cable, and a melting characteristic of a fuse included in the power supply system.
Method for determining short circuit. A program for causing a computer to function as each unit of an information processing device according to any one of claims 1 to 6.

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