JP2005237148A - Inverter inspection device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology that makes it possible to use electromagnetic contactors whose permissible switching voltage is lower than a voltage that is impressed to a connecting circuit that applies a DC voltage to an inverter, in a technology of inspecting an inverter. <P>SOLUTION: An inverter inspection device includes a DC power supply 4 that converts AC power into DC power that is input into the inverter, the connecting circuit 6 that connects the DC power supply 4 to the inverter 102 to be inspected, the electromagnetic contactors 36, 38 provided on the connecting circuit 6, and a means 10 that regulates the release timing of the contactors. The permissible switching voltage of the contactors 36, 38 is lower than an output voltage of the DC power supply 4, while the permissible conducting voltage and a permissible non-conduction maintaining voltage of the contactors 36, 38 are higher than the output voltage of the DC power supply 4. The timing regulating means 10 allows the contactors 36, 38 to be released only when the voltage of the connecting circuit 6 is lower than the permissible switching voltage of the contactors 36, 38. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for inspecting an inverter. In particular, the present invention relates to a technique for inspecting an inverter that inputs DC power, switches a built-in semiconductor switch group, and supplies driving power to an electrical device.

2. Description of the Related Art An inverter that supplies driving power to an electrical device by inputting DC power and switching a built-in semiconductor switch group is known. For example, the inverter 102 in FIG. 1 inputs DC power using the input terminals 104 and 106, and switches the built-in semiconductor switch group to drive electric power (in this case, the three-phase motor 8) to drive power (this 3 phase AC power). 1 incorporates semiconductor switches 116 and 118 such as IGBTs connected in series, semiconductor switches 120 and 122, and a group of semiconductor switches in which semiconductor switches 124 and 126 are connected in parallel. By switching the switch group, the magnitude and direction of energization supplied to the three coils 46, 48, 50 of the three-phase motor 8 are switched. By using the inverter 102, the output torque, rotation direction, and rotation speed of the three-phase motor 8 can be adjusted.
As the electrical equipment controlled by the inverter becomes larger in capacity, the DC power input to the inverter is also being increased in voltage.

If there is a malfunction in the operation of the inverter, the electrical equipment will not be driven normally. Therefore, it is necessary to inspect the completed inverter before actually using it.
In order to inspect the inverter, DC power input to the inverter is required. Connect the inverter to be inspected between the DC power supply that supplies the DC power for inspection and the electrical equipment controlled by the inverter (or a load that has equivalent electrical characteristics), and assume actual use The inverter can be inspected by switching the semiconductor switch group of the inverter and measuring the output waveform (for example, voltage, current, frequency, phase difference, etc.) of the inverter.
Commercial AC power is supplied to the DC power supply device. The DC power supply device rectifies input AC power and converts it into DC power, transforms it as necessary, and outputs DC power input to the inverter.

At the end of an inspection or at an emergency stop, it is necessary to electrically isolate the DC power supply device and the operator, or the DC power supply device and the inverter. In such an inspection device, the contact circuit connecting the DC power supply device and the inverter is electromagnetic contact A vessel is inserted. It is necessary to create a state in which a DC voltage is not applied to the terminal on the inverter side of the connection circuit by opening the electromagnetic contactor.
If the inverter to be inspected is normal, the switching of the semiconductor switch group built in the inverter should be stopped, and it should be possible to create a state where no current is flowing in the connection circuit. Can be inserted into the connection circuit. However, if there is an abnormality in the inverter to be inspected, it cannot be said that there is no fear that current will continue to flow even if all switching of the semiconductor switch group is stopped. Further, when there is an abnormality in the inspection apparatus, the electromagnetic contactor may be opened by operating the emergency stop function of the inspection apparatus even during energization. Therefore, an electromagnetic contactor that can be opened while being energized with the maximum voltage output from the DC power supply device must be inserted in the connection circuit.
In the conventional inspection device, an electromagnetic contactor that can be opened while being energized with the maximum voltage output from the DC power supply device is selected and inserted into the connection circuit. However, as the inverter voltage increases, the DC voltage output from the DC power supply also increases, and it is necessary to select a large and expensive electromagnetic contactor, which increases the size and cost of the inspection device. It has become.

  The present invention relaxes the conditions required for the electromagnetic contactor inserted in the connection circuit in order to create a state in which no DC voltage is applied to the terminal on the inverter side of the connection circuit connecting the DC power supply device and the inverter, The purpose is to reduce the size and cost of the inspection device.

In the present invention, paying attention to the fact that the allowable energization voltage and allowable non-conducting sustain voltage of the magnetic contactor are higher than the allowable switching voltage of the magnetic contactor, it is possible to configure the inspection apparatus with a smaller electromagnetic contactor. . Here, the permissible switching voltage refers to a voltage that can open and close the electromagnetic contactor while energized. The allowable energization voltage refers to a voltage that can continue to energize the magnetic contactor. The allowable non-conducting maintaining voltage refers to a voltage that can be insulated by the magnetic contactor even if a high voltage is applied after the electromagnetic contactor is opened. Due to the characteristics of the magnetic contactor, the allowable energizing voltage and the allowable non-conducting voltage are higher than the allowable switching voltage.
By controlling the output voltage of the DC power supply device and combining the control operation with the switching operation of the magnetic contactor, even if the allowable switching voltage of the magnetic contactor is less than the maximum output voltage of the DC power supply device, inspection It is possible to realize the device.

The inspection apparatus of the present invention inputs DC power, switches a built-in semiconductor switch group, and inspects an inverter that supplies driving power to an electrical device. The inspection device of the present invention includes a DC power supply device that converts AC power into DC power input to the inverter, and a connection circuit that connects the DC power supply device and the inverter to be inspected. The connection circuit is provided with an electromagnetic contactor, and the opening timing of the electromagnetic contactor is regulated by regulating means.
The allowable switching voltage of the magnetic contactor is lower than the output voltage of the DC power supply device, and the allowable energization voltage and allowable non-conducting sustain voltage of the magnetic contactor are higher than the output voltage of the DC power supply device. Since the allowable switching voltage of the magnetic contactor is lower than the output voltage of the DC power supply device, the electromagnetic contactor cannot be opened while the current is being supplied with the output voltage of the DC power supply device. Therefore, timing regulating means is prepared, and the timing regulating means permits the opening operation of the magnetic contactor only when the voltage of the connection circuit is lower than the allowable switching voltage of the magnetic contactor. Since the allowable energizing voltage and allowable non-conducting sustain voltage of the magnetic contactor are higher than the output voltage of the DC power supply device, it is possible to continue supplying DC power to the inverter, and once the electromagnetic contactor is opened, the DC Even if the power supply device starts to output a DC voltage, the magnetic contactor maintains an insulated state and prevents the DC voltage from being applied to the terminal on the inverter side of the connection circuit.

In the inspection apparatus of the present invention, the DC power supply device stops operation when the inspection ends or at an emergency stop. When the DC power supply device stops operating, the voltage of the connection circuit also decreases. The magnetic contactor inserted in the connection circuit may be opened after the voltage of the connection circuit decreases, and can be opened even by an electromagnetic contactor having an allowable switching voltage lower than the output voltage of the DC power supply device. . There is no need to use an electromagnetic contactor having an allowable switching voltage higher than the output voltage of the DC power supply.
The magnetic contactor inserted in the connection circuit is required to have an allowable energization voltage and an allowable non-conducting sustain voltage higher than the output voltage of the DC power supply device. Since the non-conducting maintaining voltage is higher than the allowable switching voltage, electromagnetic contactors having an allowable energizing voltage and an allowable non-conducting maintaining voltage that are higher than the output voltage of the DC power supply device are widely used. According to the inspection device of the present invention, since the allowable switching voltage of the magnetic contactor may be lower than the output voltage of the DC power supply device, the conditions required for the magnetic contactor are greatly relaxed, and a smaller electromagnetic It is possible to employ a contactor.
The present invention provides an output of a DC power supply device by using it in combination with a DC power supply device even though it is an electromagnetic contactor used to create a state where a DC voltage is not applied to a terminal on the inverter side of a connection circuit connected to the inverter. It is possible to adopt an electromagnetic contactor that only has an allowable switching voltage that cannot be opened and closed when the voltage is energized, and that the allowable energizing voltage and the allowable non-conducting maintaining voltage need only be higher than the DC voltage. It was realized by wisdom. It should be noted that the concepts of allowable switching voltage, allowable energization voltage, and allowable non-conducting sustain voltage are novel concepts recognized in the present invention and are not existing terms.

The timing regulating means preferably includes voltage measuring means for measuring the voltage of the connection circuit and means for comparing the measured voltage with an allowable switching voltage of the magnetic contactor. In this case, the relationship of opening the electromagnetic contactor after the voltage of the connection circuit is reduced is directly secured.
Alternatively, the opening operation of the electromagnetic contactor may be regulated by a device that measures the elapsed time since the output of the DC power supply device is stopped and a means that compares the measured elapsed time with a predetermined time. When the DC power supply stops outputting, the voltage of the connection circuit decreases according to the time constant. If the predetermined time is set with a margin, the relationship of opening the magnetic contactor after the voltage of the connection circuit falls below the allowable switching voltage of the magnetic contactor is substantially secured.

The electromagnetic contactor is preferably a mechanical lock type electromagnetic contactor. A mechanical lock type electromagnetic contactor here means that once excitation power is applied and turned on, it is mechanically locked in that state, and keeps contact of the contact even if the supply of excitation current is stopped. Of the type.
When a mechanical lock type magnetic contactor is used, the magnetic contactor is not opened even if a power failure occurs. It is possible to prevent the electromagnetic contactor from being opened while the connection circuit is energized by a DC voltage that is higher than the allowable switching voltage. As a result, the contact of the magnetic contactor is prevented from being significantly damaged or ignited from the electromagnetic contactor.

The present invention provides a method for testing new and useful inverters. The inspection method of the present invention is a method for inspecting an inverter that inputs DC power, switches a built-in semiconductor switch group, and supplies driving power to an electrical device. The inspection method of the present invention includes a step of converting AC power into DC power to be input to the inverter, a step of inputting the DC power to the inverter to be inspected through an electromagnetic contactor, and an opening timing of the electromagnetic contactor. It has a regulation process.
The allowable switching voltage of the magnetic contactor is lower than the maximum voltage input to the inverter, and the allowable energization voltage and allowable non-conducting sustain voltage of the magnetic contactor are higher than the maximum voltage input to the inverter. Since the allowable switching voltage of the magnetic contactor is lower than the maximum voltage input to the inverter, the electromagnetic contactor cannot be opened while the maximum voltage is applied to the inverter. Therefore, a process for regulating the opening timing of the electromagnetic contactor is prepared. In this timing regulating step, the opening operation of the magnetic contactor is permitted only when the voltage applied to the inverter is lower than the allowable switching voltage of the magnetic contactor. Since the allowable energizing voltage and allowable non-conducting sustain voltage of the magnetic contactor are higher than the maximum voltage input to the inverter, it is possible to continue supplying DC power to the inverter, and once the electromagnetic contactor is opened The magnetic contactor maintains an insulated state to prevent a DC voltage from being applied to the inverter.
According to the inspection device of the present invention, since the allowable switching voltage of the magnetic contactor may be lower than the maximum voltage input to the inverter, the conditions required for the magnetic contactor are greatly relaxed, and a smaller electromagnetic It is possible to employ a contactor.

  According to the present invention, conditions required for an electromagnetic contactor inserted in a connection circuit that supplies a DC high voltage to an inverter can be relaxed, and the inspection apparatus can be reduced in size and cost.

The best modes for carrying out the invention are listed below.
(Mode 1) An inverter inspection apparatus includes an inspection load connected to an output terminal of the inverter.
(Mode 2) The inverter inspection device includes an inspection program that inputs control signals of various conditions to the inverter, measures the output waveform of the inverter, and inspects the characteristics of the inverter.
(Mode 3) The inverter inspection apparatus includes a control program for controlling the inspection apparatus. The control program stops the switching command to the inverter every time the inspection of the inverter is finished, stops the DC power supply device, and when the voltage applied to the connection circuit falls below the allowable switching voltage of the magnetic contactor Open the magnetic contactor.
(Mode 4) The inverter inspection device includes a control program for controlling the inspection device. The control program stops the switching command to the inverter every time the inspection of the inverter is finished, stops the DC power supply device, and then the electromagnetic contactor inserted in the connection circuit after a predetermined time has elapsed. Is released.

Hereinafter, an inverter inspection apparatus of the present invention will be described in detail with reference to the accompanying drawings.
Example 1 FIG. 1 shows a circuit diagram of an inspection apparatus 2 of this example. The inspection device 2 inspects the inverter 102. Of the circuits shown in FIG. 1, all of the circuits other than the inverter 102 are built in the inspection apparatus 2.
The inspection device 2 has the same electrical characteristics as the DC power supply device 4, the connection circuit 6 that connects the DC power supply device 4 and the inverter 102 to be inspected, and the electrical equipment to which the inverter 102 to be inspected supplies drive power. The test load 8 that is present, the control device 10 that controls the test device 2, and the inverter 102 are instructed to send a test signal, the output waveform to the test load 8 is measured, and the inverter 102 is judged to be normal or abnormal A device 12 is provided. The control device 10 and the determination device 12 can be configured by the same computer.

The DC power supply 4 receives commercial AC power (in this case, three-phase 440 volts) from terminals 14, 15, 16, rectifies by a rectifier 32, transforms by an output chopper circuit 30, and DC power from terminals 18, 20. Is output. The output voltage (maximum voltage that can be output) of the DC power supply device 4 is approximately 600 volts.
The drive circuit 28 of the DC power supply device 4 controls the operation of the output chopper circuit 30 based on a command from the control circuit 10. The drive circuit 28 controls the operation of the output chopper circuit 30 so that the output voltage of the DC power supply 4 is adjusted between zero volts and approximately 600 volts.
A voltmeter 34 is provided between the DC voltage output terminals 18 and 20, and the output voltage of the DC power supply device 4 is monitored. The output voltage of the DC power supply device 4 monitored by the voltmeter 34 is read by the control device 10.

The connection circuit 6 connects the output terminals 18 and 20 of the DC power supply device 4 and the input terminals 104 and 106 of the inverter 102 to be inspected. Electromagnetic contactor pairs 36 and 38 are inserted into a connection line 6a connecting the output terminal 18 and the input terminal 104 and a connection line 6b connecting the output terminal 20 and the input terminal 106.
The electromagnetic contactor pair 36, 38 is switched on / off according to the control device 10. The electromagnetic contactor pairs 36 and 38 are normally open types that continue to be opened unless the excitation coil is energized. Once energized, even if the energization to the excitation coil stops, a mechanical latch type electromagnetic that holds the energized state. It is a contactor.
A maximum DC voltage of 600 volts is applied between the connection line 6a and the connection line 6b. The magnetic contactor pairs 36 and 38 cannot be opened when a 600 volt DC voltage is applied, but can continue to be energized with a 600 volt DC voltage. Those that continue to be insulated even when a voltage is applied are selected. That is, the allowable switching voltage of the magnetic contactor pair 36, 38 is lower than the output voltage (600 volts) of the DC power supply device 4, and the allowable energizing voltage and the allowable non-conducting sustain voltage of the electromagnetic contactor pair 36, 38 are DC It is higher than the output voltage (600 volts) of the power supply device 4.
In the inspection apparatus 2, the magnetic contactor pairs 36 and 38 are energized with a maximum DC voltage of 600 volts. However, it is necessary for the electromagnetic contactor pairs 36 and 38 to be able to be opened while the 600 volt DC voltage is energized. And not. Thereby, the selection conditions of the electromagnetic contactor pairs 36 and 38 are relaxed, and a small electromagnetic contactor is employed for the output of the inspection apparatus 2.
At the end of the inspection or at the time of emergency stop, the electromagnetic contactor pair 36, 38 is opened to create a state in which no DC voltage is applied to the terminals of the connection lines 6a, 6b connected to the input terminals 104, 106 of the inverter.

The inverter 102 of this embodiment includes six transistors (specifically IGBTs) 116, 118, 120, 122, 124, 126. A circuit 128 in which the IGBT 116 and the IGBT 118 are connected in series, a circuit 130 in which the IGBTs 120 and 122 are connected in series, and a circuit 132 in which the IGBTs 124 and 126 are connected in series are connected in parallel in the inverter 102. A connection point provided between the IGBT 116 and the IGBT 118 and an output terminal 112 of the inverter are connected. A connection point provided between the IGBT 120 and the IGBT 122 and the output terminal 110 of the inverter are connected. A connection point provided between the IGBT 124 and the IGBT 126 and the output terminal 108 of the inverter are connected.
The IGBTs 116 to 126 of the inverter 102 are switched by a gate voltage applied to each of them, and outputs voltages having phases different from each other by 120 ° from the output terminals 128, 130, and 132. Three-phase alternating current is output from the output terminals 128, 130, and 132, and a load 8 such as a three-phase alternating current motor can be driven.

The input terminal 40 of the inspection load 8 is connected to the output terminal 108 of the inverter 102. The input terminal 42 is connected to the output terminal 110. The input terminal 44 is connected to the output terminal 112. A coil 46 is connected to the input terminal 40, a coil 50 is connected to the input terminal 42, and a coil 48 is connected to the input terminal 44. End portions not connected to the input terminals of the coils 46, 48 and 50 are connected to each other.
Each coil 46, 48, 50 incorporates ammeters 46 a, 48 a, 50 a that measure the magnitude of the energized current, and the magnitude of the energized current flowing through the coils 46, 48, 50 is input to the determination device 12. It has come to be. Although not shown in the drawings, voltages at various locations necessary for measuring the characteristics of the inverter 102 are input to the determination device 12.

  The determination device 12 includes power supplied from the output terminal 108 of the inverter 102 via the input terminal 40 to the coil 46, power supplied from the output terminal 110 of the inverter 102 via the input terminal 42 to the coil 50, The power supplied from the output terminal 112 to the coil 48 via the input terminal 44 is measured, and it is determined whether or not the characteristics of the inverter 102 match the intended characteristics. The determination device 12 is configured by a computer operating according to a determination program.

  In order to be inspected by the inspection device 2, the DC voltage supplied from the DC power supply device 4 is supplied to the circuits 128, 130, and 132 of the inverter 102 through the connection circuit 6 and the input terminals 104 and 106. Further, an inverter drive signal is input from the determination device 12 to the IGBTs 116 to 126. The determination device 12 outputs voltage pulses of various patterns to the gates of the IGBTs 116 to 126. The determination device 12 measures the power value output from the inverter 102 to the input terminals 40, 42, and 44 of the test load 8 in response to fluctuations in the gate voltage of the IGBTs 116 to 126, and determines the characteristics of the inverter 102.

If the inverter 102 to be inspected is abnormal, the inverter 102 may malfunction during the inspection. At this time, even if the switching command to the IGBTs 116 to 126 is stopped, it cannot be said that there is no fear that current will continue to flow from the DC power supply device 4 to the inverter 102. If an attempt is made to open the electromagnetic contactor pair 36, 38 in this state, the electromagnetic contactor pair 36, 38 is opened while a current of DC 600 volts is flowing. For this reason, conventionally, a large-sized electromagnetic contactor having an allowable switching voltage of 600 volts or more has been required.
The diagnostic device 2 uses small electromagnetic contactor pairs 36 and 38 having an allowable switching voltage of 600 volts or less, and the electromagnetic contactor pairs 36 and 38 in a state in which DC 600 volts flows through the connection lines 6a and 6b. Cannot be released. Therefore, in the diagnostic device 2, the opening operation of the electromagnetic contactor pairs 36 and 38 is performed in combination with the control of the output chopper circuit 30 of the DC power supply device 4.

The inspection device 2 for the inverter 102 according to the present embodiment proceeds with the inspection according to the flow shown in FIG. 2 in the case where the abnormal inverter 102 is inspected or during an emergency stop, and after the voltage applied to the connection circuit 6 is lowered, the electromagnetic contact The device pair 36, 38 is opened, and a state in which a DC voltage is not reliably applied to the terminal on the inverter side of the connection circuit 6 is created. Hereinafter, according to a flowchart, the control content performed by the control apparatus 10 and the test | inspection apparatus 12 is demonstrated in detail.
When the inspection of the inverter 102 is started, the control device 10 turns on the electromagnetic contactor pairs 36 and 38 of the connection circuit 6 (that is, closes the contacts) so as to enable energization (step S2). In order to energize the connection circuit 6 after the electromagnetic contactor pair 36, 38 is securely closed, the control device 10 leaves an interval of 2 seconds until the next processing is performed (step S4). When two seconds elapse after the electromagnetic contactor pair 36, 38 is closed, the control device 10 instructs the drive circuit 28 to cause the drive circuit 28 to start controlling the output chopper circuit 30 (step S6). The drive circuit 28 controls the output chopper circuit 30 to start energization, and the output of the DC voltage from the DC power supply device 4 is started (step S8). The control device 10 issues a test start command to the determination device 12, and the determination device 12 starts to issue a test signal to the IGBTs 116 to 126 of the inverter 102. That is, various pulse voltages are applied to the gates of the IGBTs 116 to 126 in accordance with a temporal change pattern determined in advance for inspection (step S10). The determination device 12 measures the output power of the inverter 102 that changes in response to the change in the gate voltage, and inspects the characteristics of the inverter 102 (step S12). When the characteristic inspection of the inverter 102 is completed in step S14, the determination device 12 stops the switching command to the IGBTs 116 to 126 of the inverter 102 and stops the operation of the inverter 102 (step S16). Control device 10 commands drive circuit 28 to stop its operation regardless of whether inverter 102 is stopped or in an abnormally energized state (step S18). Since the output chopper circuit 30 stops energization, the DC voltage supplied to the inverter 102 gradually decreases. The control device 10 monitors the value of the DC voltage supplied to the connection circuit 6 with a voltmeter 34 provided in the DC power supply device 4. If the monitored output voltage falls below the allowable switching voltage of the electromagnetic contactor pair 36, 38, the answer to step S20 becomes yes, and the control device 10 turns off the electromagnetic contactor pair 36, 38 and supplies the voltage to the inverter 102. Stop (step S22). In order for the control device 10 to execute steps S20 and S22, the magnetic contactor pair 36, 38 is not opened while the voltage of the connection circuit 6 is higher than the allowable switching voltage of the magnetic contactor pair 36, 38. . In order for the control device 10 to execute steps S20 and S22, the control circuit 10 is opened when the voltage of the connection circuit 6 falls below the allowable switching voltage of the electromagnetic contactor pairs 36 and 38. The control device 10 constitutes an opening timing regulating means that allows the electromagnetic contactor pair 36, 38 to be opened only when the voltage of the connection circuit 6 is lower than the allowable switching voltage of the electromagnetic contactor pair 36, 38. doing.

A mechanical lock type is adopted for the electromagnetic contactor pairs 36 and 38 of the inspection apparatus 2 of the present embodiment. For this reason, even when a power failure occurs during the inspection, the electromagnetic contactor pairs 36 and 38 are not opened. In FIG. 3, a processing flow that assumes the occurrence of a power failure is defined, and the control device 10 and the determination device 12 perform control according to this flow, whereby the electromagnetic contactor pairs 36 and 38 are damaged when the power failure occurs. To prevent that. Hereinafter, description common to FIG. 2 is omitted, and only different processing will be described.
If a power failure occurs while measuring the characteristics of the inverter 102 in step S12 (step S44), the control signal from the determination device 12 to the IGBTs 116 to 126 is stopped (step S46). Further, the operation of the drive circuit 28 is also stopped (step S48). At this time, the electromagnetic contactor pairs 36 and 38 are mechanically latched, so that the contacts are not opened even if a power failure occurs. In that state, wait for the power failure to recover. When the power failure is restored (step S50), the control device 10 monitors whether or not the DC voltage output from the DC power supply device 4 is equal to or lower than the allowable switching voltage of the electromagnetic contactor pairs 36 and 38 (step S20). When the voltage becomes equal to or lower than the allowable switching voltage, a message indicating that the electromagnetic contactor pairs 36 and 38 are to be turned off is displayed to instruct the operator (step S52). After the display is made, the electromagnetic contactor pair 36, 38 is manually opened by the operator (step S54). When the operator manually opens the electromagnetic contactor pair 36, 38, the voltage between the connecting wires 6a, 6b is lower than the allowable switching voltage of the electromagnetic contactor pair 36, 38, and the operator manually opens the contactor pair 36, 38. The electromagnetic contactor pair 36, 38 will not be damaged.
In the above description, the case where a power failure occurs while measuring the characteristics of the inverter 102 has been described, but the same processing is executed when the emergency stop switch is operated while measuring the characteristics of the inverter 102. . After the emergency stop switch is pushed, step S20 is affirmed to be yes, and step S52 and step S54 are executed.

  In the inverter inspection device 2 of this embodiment, the control device 10 and the determination device 12 control the drive circuit 28 that controls the output voltage of the DC power supply device in combination with the opening and closing of the electromagnetic contactor pairs 36 and 38, and the electromagnetic contact The electromagnetic contactor pair 36, 38 is allowed to open only when the voltage applied to the contactor pair 36, 38 is equal to or lower than the allowable switching voltage of the electromagnetic contactor pair 36, 38. Thereby, the electromagnetic contactor pairs 36 and 38 having a lower allowable switching voltage than the DC voltage applied to the connection circuit 6 can be used, and when an abnormal energization state occurs in the inverter 102 or when a power failure occurs However, it is possible to prevent the inspection apparatus 2 from being damaged.

(Embodiment 2) Instead of determining the timing for opening the electromagnetic contactor pair 36, 38 by directly measuring the voltage supplied to the connection circuit 6 by the DC power supply device 4 with the voltmeter 34, the output of the DC power supply device 4 The timing for opening the electromagnetic contactor pairs 36 and 38 can be determined based on the elapsed time since the stop.
In the DC power supply device 4 of this embodiment, two seconds after the output chopper circuit 28 stops energization, the DC voltage output to the connection circuit 6 falls below the allowable switching voltage of the electromagnetic contactor pairs 36 and 38. Therefore, in the control program of this embodiment, as shown in the flowchart of FIG. 4, it waits for 2 seconds to elapse after the operation of the DC power supply device 4 is stopped in step S18 (step S80). When two seconds have elapsed, step S80 becomes YES, and the control device 10 opens the electromagnetic contactor pair 36 and 38, and reliably stops the supply of voltage to the inverter 102.

Further, when a power failure occurs during the inspection of the inverter 102, processing according to the flowchart of FIG. 5 is performed. That is, when a power failure occurs (step S44), the control signal from the determination device 12 to the IGBTs 116 to 126 stops (step S46). Further, the operation of the drive circuit 28 is also stopped (step S48). At this time, the electromagnetic contactor pairs 36 and 38 are mechanically latched, so that the contacts are not opened even if a power failure occurs. In that state, wait for the power failure to recover. When the power failure is restored (step S50), the control device 10 waits for two seconds after the restoration of the power failure (step S80), and displays an instruction to open the magnetic contactor pairs 36 and 38 and instructs the operator. (Step S52). After the display is made, the electromagnetic contactor pair 36, 38 is manually opened by the operator (step S54). It waits for the power failure to be restored in a state where the supply of voltage to the inverter 102 is reliably stopped.
The same applies when an emergency stop is taken in place of a power failure. The electromagnetic contactor pair 36, 38 is opened after the voltage of the connection circuit falls below the allowable switching voltage of the electromagnetic contactor pair 36, 38. A message to the effect is displayed and the worker is instructed (step S52).

  The inspection device for the inverter 102 according to the present embodiment is output from the DC power supply device 4 to allow the electromagnetic contactor pairs 36 and 38 to be opened based on the elapsed time since the operation of the DC power supply device is stopped. There is no need to provide a voltmeter 34 for measuring the voltage. The inspection device 2 is configured more simply. Nevertheless, the DC voltage supplied to the inverter 102 can be cut off while preventing damage to the electromagnetic contactor pairs 36 and 38. Even when a power failure occurs or an emergency stop measure is taken, damage to the magnetic contactor pairs 36 and 38 is similarly prevented by measuring the time since restoration.

(Embodiment 3) FIG. 6 shows the configuration of an inspection apparatus 62 of this embodiment. The inspection device 62 includes a voltmeter 66 in the connection circuit 64. The voltmeter 66 measures a potential difference between the input terminal 104 and the input terminal 106 of the inverter 102. Based on the measurement result of the voltmeter 66, the control device 68 can confirm whether or not the magnetic contactor pair 36, 38 is normal.

FIG. 7 shows a processing procedure performed by the inspection apparatus 62 of this embodiment. The control device 68 turns on the electromagnetic contactor pairs 36 and 38 of the connection circuit 64 so that they can be energized (step S2), and waits for the electromagnetic contactor pairs 36 and 38 to be closed at intervals of 2 seconds. After opening (step S4), the drive circuit 28 is instructed to start operation (step S6). The drive circuit 28 starts the control of the output chopper circuit 30 and starts to output a DC voltage from the DC power supply device 4 (step S8). At this time, the control device 68 measures the potential difference with the voltmeter 66 and determines whether or not the potential difference has reached a predetermined value (step S130). If the measured value of the voltmeter 66 does not reach the predetermined value, step S130 is no, and the control device 68 warns that one or both of the electromagnetic contactor pairs 36, 38 is defective, and notifies the abnormality. Is displayed (step S134), the characteristic inspection of the inverter 102 is not performed, the voltage supply stop processing after step S18 is performed, and the inspection is terminated. If the measured value of the voltmeter 66 has reached the predetermined value, the answer to step S130 is yes, and the control device 66 causes the determination device 12 to inspect the inverter 102.
As described above, the inspection device 62 of this embodiment is provided with the voltmeter 66 that can confirm the normality / abnormality of the electromagnetic contactor pairs 36 and 38, and the control device 68 connects the electromagnetic contactor pairs 36 and 38. Is confirmed to be normal, the characteristics of the inverter 102 are inspected. On the other hand, when the control device 68 confirms that the connection of the magnetic contactor pairs 36 and 38 is abnormal, the control inspection of the inverter 102 is stopped and the drive circuit 28 is instructed to stop the operation. The output of the DC voltage of the device 4 is stopped. This prevents the voltage applied to the electromagnetic contactor pair 36, 38 from exceeding the allowable switching voltage of the electromagnetic contactor pair 36, 38 when the connection of the electromagnetic contactor pair 36, 38 is abnormal. Can be prevented from being damaged.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, the inspection apparatus according to the embodiment includes an inspection load connected to the output terminal of the inverter, but the inspection can also be performed using an actual load. By attaching a terminal for measuring the voltage and current output from the inverter to an actual load, it is possible to collect data necessary for the inspection of the inverter. In addition, a determination program can be installed in a computer of a measuring instrument that measures voltage and current values. In that case, data can be transmitted and received between the computer executing the control program and the computer of the measuring instrument.
In this embodiment, the case where the DC power supply 4 can adjust the output voltage is described. However, if the DC power supply 4 can adjust the output voltage to zero, it is abbreviated as the present embodiment. Similarly, an inspection apparatus can be configured. For example, if the AC power input by the DC power supply device 4 is rectified and boosted to output DC power, a relay such as an electromagnetic contactor is inserted upstream of the boosting circuit, and the relay is By opening, the output of the DC power supply can be made zero. At this time, the relay only needs to correspond to the voltage before boosting, the conditions of the allowable switching voltage are relaxed, and a small relay or the like can be employed.
In the present embodiment, a DC power supply device that converts a three-phase AC current into a DC voltage is illustrated, but a DC power supply device that converts single-phase AC power into DC power may be used.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

Circuit diagram of the inverter inspection apparatus of the first embodiment Flowchart of inverter inspection by the inspection apparatus of the first embodiment The flowchart which shows the control contents when a power failure occurs during the inspection of the first embodiment Flowchart of inverter inspection by inspection apparatus of second embodiment The flowchart which shows the control contents when a power failure occurs during the inspection of the second embodiment Circuit diagram of inspection apparatus for inverter of third embodiment Flowchart of inverter inspection by inspection apparatus of third embodiment

2, 62 .. Inspection device 4... DC power supply devices 6, 6 a, 6 b, 64, 64 a, 64 b .. Connection circuit 8 .. Inspection load 10, 68 .. Control device 12. 15, 15, 40, 42, 44, 104, 106... Input terminals 18, 20, 108, 110, 112, output terminal 28, drive circuit 30, output chopper circuit 32, rectifier circuits 34, 66 ..Voltmeters 36, 38..Electromagnetic contactor pairs 46, 48, 50..Coil 102..Inverters 116, 118, 120, 122, 124, 126..Transistors (IGBTs)

Claims (6)

An inverter inspection device that inputs DC power, switches a built-in semiconductor switch group, and adjusts drive power supplied to an electrical device,
A DC power supply device that converts AC power into DC power input to the inverter;
A connection circuit for connecting the DC power supply device and the inverter to be inspected;
An electromagnetic contactor provided in the connection circuit;
It has means to regulate the opening timing of the electromagnetic contactor,
The allowable switching voltage of the magnetic contactor is lower than the output voltage of the DC power supply device, the allowable energizing voltage and the allowable non-conducting maintenance voltage of the magnetic contactor are higher than the output voltage of the DC power supply device,
The timing regulating means permits the opening operation of the magnetic contactor only when the voltage of the connection circuit is lower than the allowable switching voltage of the magnetic contactor.   2. The inspection apparatus according to claim 1, wherein the timing regulating means comprises voltage measuring means for measuring the voltage of the connection circuit and means for comparing the measured voltage with an allowable switching voltage of the magnetic contactor.   2. The inspection according to claim 1, wherein the timing regulating means comprises a device for measuring an elapsed time since the output of the DC power supply device is stopped, and a means for comparing the measured elapsed time with a predetermined time. apparatus.   4. The inspection apparatus according to claim 1, wherein the electromagnetic contactor is a mechanical lock type electromagnetic contactor.   5. The inspection apparatus according to claim 1, further comprising voltage measuring means for measuring a voltage on an inverter side of the electromagnetic contactor of the connection circuit. A method of inspecting an inverter that inputs DC power, switches a built-in semiconductor switch group, and adjusts driving power supplied to an electrical device,
Converting AC power into DC power input to the inverter;
Inputting the DC power into an inverter to be inspected through an electromagnetic contactor;
It has a process to regulate the opening timing of the electromagnetic contactor,
The allowable switching voltage of the magnetic contactor is lower than the maximum voltage input to the inverter, the allowable energizing voltage and allowable non-conducting maintenance voltage of the magnetic contactor are higher than the maximum voltage input to the inverter,
In the timing regulating step, the inspection method is characterized in that the opening operation of the magnetic contactor is permitted only when the DC voltage input to the inverter is lower than the allowable switching voltage of the magnetic contactor.

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