JP3788591B2 - Inverter device failure diagnosis method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a failure diagnosis method for an inverter device that supplies alternating current power having a desired frequency and voltage to a load by turning on and off each of a plurality of semiconductor switching elements constituting an inverter main circuit.
[0002]
[Prior art]
In this type of conventional inverter device, in particular, there is no one having a diagnostic function for determining whether or not a plurality of semiconductor switching elements constituting the inverter main circuit are normal, and therefore In general, a serviceman checks whether or not the semiconductor switching element is normal.
[0003]
[Problems to be solved by the invention]
When a failure occurs in a conventional inverter device, when it becomes necessary to determine whether or not each of the plurality of semiconductor switching elements constituting the inverter main circuit is normal, the corresponding components of the inverter device are disassembled in advance. In general, this disassembling work requires a skillful technique and takes time to elucidate a failed part.
[0004]
An object of the present invention is to provide a fault diagnosis method for an inverter device that eliminates the above-mentioned difficulties.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a failure diagnosis method for an inverter device for supplying AC power having a desired frequency and voltage to a load by turning on and off each of a plurality of semiconductor switching elements constituting the inverter main circuit.
A gate driving circuit for turning on and off the semiconductor switching element and a state detection circuit for detecting an on / off state of the semiconductor switching element are provided in each of the plurality of semiconductor switching elements,
A drive signal for failure diagnosis to each of the semiconductor switching elements is generated, an on / off state of the semiconductor switching element corresponding to the drive signal is detected, and the detected on / off state and the drive for failure diagnosis are detected. A comparison operation with a signal is performed.
[0006]
According to a second aspect of the present invention, a plurality of semiconductor switching elements constituting the inverter main circuit are turned on and off to supply alternating current power having a desired frequency and voltage to the load, while driving signals to the semiconductor switching elements are supplied. In the failure diagnosis method for an inverter device that also performs an operation of correcting the waveform of each of the drive signals based on the on / off states of the semiconductor switching elements corresponding to the respective semiconductor switching elements,
A gate driving circuit for turning on and off the semiconductor switching element and a state detection circuit for detecting an on / off state of the semiconductor switching element are provided in each of the plurality of semiconductor switching elements,
A drive signal for failure diagnosis to each of the semiconductor switching elements is generated, an on / off state of the semiconductor switching element corresponding to the drive signal is detected, and the detected on / off state and the drive for failure diagnosis are detected. A comparison operation with a signal is performed.
[0007]
According to the present invention, since the inverter device has a function of determining whether or not each of the plurality of semiconductor switching elements constituting the inverter main circuit is normal, the malfunctioning semiconductor switching element is activated by operating this function. The disassembling work when specifying the is no longer necessary.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a circuit configuration diagram of an inverter device showing a first embodiment of the present invention. In FIG. 1, in order to simplify the following description, some components related to the present invention are shown. The other components are not shown.
[0009]
That is, in FIG. 1, this inverter device includes, as an example, a three-phase bridge-connected inverter main circuit 1 in which each of IGBT1 to IGBT6 is a semiconductor switching element, a microprocessor, and the like. A CPU circuit 11 that controls the monitoring operation, a gate drive circuit 12 for turning on and off the IGBT 2 based on a drive signal from the CPU circuit 11, and a state detection circuit 13 for detecting the on / off state of the IGBT 2 are provided. .
[0010]
This state detection circuit 13 is composed of a level shift circuit for converting the collector potential of the IGBT 2 to the logic level of the CPU circuit 11. For example, when the IGBT 2 is in the ON state, the state detection circuit 13 has a logic “H” level. In addition, when the IGBT 2 is in the OFF state, the state detection circuit 13 outputs a logic “L” level. Similarly, when the drive signal from the CPU circuit 11 to the IGBT 2 is at a logic “H” level, the IGBT 2 is turned on, and when the drive signal from the CPU circuit 11 to the IGBT 2 is at a logic “L” level, the IGBT 2 is turned off. Shall be.
[0011]
In FIG. 1, only the IGBT 2 is provided with the gate drive circuit 12 and the state detection circuit 13, and only the IGBT 2 is described above. However, the gate drive circuit 12 and the state detection circuit 13 are also provided for the remaining IGBTs 1, IGBT3 to IGBT6. And an equivalent circuit, and the same operation as that of the IGBT 2 is performed.
[0012]
Accordingly, when some failure occurs in the inverter device shown in FIG. 1 and it is necessary to determine whether each of the IGBTs 1 to 6 constituting the inverter main circuit 1 is normal, the failure is caused by operating a touch panel (not shown). By operating the diagnosis function, a drive signal for failure diagnosis is output from the CPU circuit 11 to each of the IGBT1 to IGBT6. At this time, the IGBT2 outputs the logic level output by the state detection circuit 13 corresponding to this drive signal and the above-described logic level. The CPU circuit 11 performs a comparison operation with the logic level of the drive signal, and displays the result of the failure diagnosis on the display of the touch panel. Here, since the repetition rate of the pulse of the drive signal is high during normal operation, it is difficult to compare the two logic levels. Therefore, the drive signal for failure diagnosis is, for example, the drive signal during normal operation. It is assumed that the pulse width is wider than the pulse width, and that for all the IGBTs, a drive signal for failure diagnosis is sequentially given to perform a comparison operation of both logic levels. That is, if all the IGBTs constituting the inverter main circuit 1 are sequentially operated by the CPU circuit 11, for example, the check can be made without removing the connections of the IGBTs 1 to 6.
[0013]
FIG. 2 is a circuit configuration diagram of an inverter device showing a second embodiment of the present invention. In FIG. 2, in order to simplify the following description, some components related to the present invention are shown. The other components are not shown.
[0014]
That is, in FIG. 2, this inverter device is composed of a microprocessor and the like in addition to the inverter function circuit 1, the gate drive circuit 12, and the state detection circuit 13 having the same functions as the components shown in FIG. The pulse widths of the drive signal from the CPU circuit 21 to the IGBT 2 and the detection signal from the state detection circuit 13 are substantially equal to improve the control performance of the CPU circuit 21 that controls, protects, and monitors, and the inverter device. A pulse width correction circuit 22 that generates a new drive signal corrected in this way and outputs the new drive signal to the gate drive circuit 12 is provided.
[0015]
Further, when the drive signal from the CPU circuit 21 to the pulse width correction circuit 22 shown in FIG. 2 is at the logic “H” level, the IGBT 2 is turned on, and the drive signal from the CPU circuit 21 to the pulse width correction circuit 22 is turned on. Assume that IGBT2 is turned off when is at a logic "L" level.
[0016]
In FIG. 2, only the IGBT 2 is provided with the pulse width correction circuit 22, the gate drive circuit 12, and the state detection circuit 13. In the above description, only the IGBT 2 is described. However, the remaining IGBTs 1, IGBT 3 to IGBT 6 also have a pulse width. The correction circuit 22, the gate drive circuit 12, and the state detection circuit 13 are each provided with an equivalent circuit, and the same operation as the IGBT 2 is performed.
[0017]
Accordingly, when some failure occurs in the inverter device shown in FIG. 2 and it is necessary to determine whether or not each of the IGBTs 1 to 6 constituting the inverter main circuit 1 is normal, the failure is caused by operating a touch panel (not shown). By operating the diagnostic function, a drive signal for failure diagnosis is output from the CPU circuit 21 to each of the IGBT1 to IGBT6. At this time, in the IGBT2, the logic level output by the state detection circuit 13 corresponding to this drive signal and the above-mentioned The CPU circuit 21 performs a comparison operation with the logic level of the drive signal, and displays the result of the failure diagnosis on the display of the touch panel. Here, since the repetition rate of the pulse of the drive signal is high during normal operation, it is difficult to compare the two logic levels. Therefore, the drive signal for failure diagnosis is, for example, the drive signal during normal operation. It is assumed that the pulse width is wider than the pulse width, and that for all the IGBTs, a drive signal for failure diagnosis is sequentially given to perform a comparison operation of both logic levels. That is, for all IGBTs constituting the inverter main circuit 1, if the CPU circuit 21 sequentially performs the above-described operation, for example, it is possible to check without removing the connections of the IGBT1 to IGBT6, In the case of this inverter device, it is not necessary to install new hardware components.
[0018]
In the above description of the circuits of the first and second embodiments, the case where a failure has occurred in the inverter device has been described. However, every time an operation command is given to this inverter device, prior to normal startup. The diagnosis method of the present invention that outputs a drive signal for failure diagnosis is performed. As a result, if a failure of the inverter device is found, the failure can be displayed.
[0019]
【The invention's effect】
According to the present invention, when a failure occurs in the inverter device and it is necessary to determine whether or not each of the plurality of semiconductor switching elements constituting the inverter main circuit is normal, failure diagnosis for each of the semiconductor switching elements is performed. For example, the semiconductor switching element can be automatically checked based on the drive signal.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of an inverter device showing a first embodiment of the invention. FIG. 2 is a circuit configuration diagram of an inverter device showing a second embodiment of the invention.
DESCRIPTION OF SYMBOLS 1 ... Inverter main circuit, 11 ... CPU circuit, 12 ... Gate drive circuit, 13 ... State detection circuit, 21 ... CPU circuit, 22 ... Pulse width correction circuit

Claims (2)

In a failure diagnosis method for an inverter device that supplies AC power of a desired frequency and voltage to a load by turning on and off each of a plurality of semiconductor switching elements constituting the inverter main circuit,
A gate driving circuit for turning on and off the semiconductor switching element and a state detection circuit for detecting an on / off state of the semiconductor switching element are provided in each of the plurality of semiconductor switching elements,
A drive signal for failure diagnosis to each of the semiconductor switching elements is generated, an on / off state of the semiconductor switching element corresponding to the drive signal is detected, and the detected on / off state and the drive for failure diagnosis are detected. A method for diagnosing a fault in an inverter device, comprising performing a comparison operation with a signal. The semiconductor switching corresponding to each drive signal to the semiconductor switching element while supplying AC power of a desired frequency and voltage to the load by turning on and off each of the plurality of semiconductor switching elements constituting the inverter main circuit In the failure diagnosis method for an inverter device that also performs an operation of correcting the waveform of each of the drive signals based on the on / off state of each element,
A gate driving circuit for turning on and off the semiconductor switching element and a state detection circuit for detecting an on / off state of the semiconductor switching element are provided in each of the plurality of semiconductor switching elements,
A drive signal for failure diagnosis to each of the semiconductor switching elements is generated, an on / off state of the semiconductor switching element corresponding to the drive signal is detected, and the detected on / off state and the drive for failure diagnosis are detected. A method for diagnosing a fault in an inverter device, comprising performing a comparison operation with a signal.

Images