JP6042047B1 - DC circuit breaker test apparatus and test method - Google Patents

Abstract

The DC circuit breaker test device (100) generates an AC power source (1) that generates a first test current that flows through the DC circuit breaker (5) to be tested, and a second test current that flows through the DC circuit breaker. The voltage source circuit (10) is provided between the voltage source circuit and the DC circuit breaker, and is open when the first test current starts to flow from the AC power source to the DC circuit breaker. And a closing switch (9) for connecting the voltage source circuit to the DC circuit breaker, which is closed at a specified timing after the test current is cut off, and the voltage source circuit is turned off when the closing switch is closed. The capacitor (13) charged to a voltage higher than the limit voltage of the energy absorption unit (8) provided in the container is discharged to generate a second test current.

Description

  The present invention relates to a test apparatus and a test method for a DC circuit breaker.

  In recent years, development of high voltage direct current circuit breakers (DCCB) has been accelerated in various countries in order to realize multi-terminal high voltage direct current (HVDC) transmission. However, there are currently no industry standards for high voltage DCCB. In addition, a verification test method and a formal test method for the cutoff performance of the high voltage DCCB have not been established. For standardization of the test method, it is important to apply stress equivalent to or included in the actual HVDC system to the UUT, that is, the high voltage DCCB under test. However, if a test using an ideal test circuit that reproduces the HVDC system as it is (hereinafter referred to as “ideal DC power supply method”) is required, a large-scale test facility corresponding to the actual system is required. Therefore, this method is virtually impossible to realize in any high power laboratory.

  On the other hand, as a conventional test method, the rising portion of the sine wave short-circuit current waveform by the AC short-circuit generator is regarded as the rising portion of the DC fault current, and a zero point is formed by the test high voltage DCCB in the rising process to cut off ( Hereinafter, it is referred to as “AC short-circuit generator method”. Non-Patent Documents 1 and 2 include methods for performing a DCCB test using an alternating current.

  Non-Patent Document 1 describes a method of performing a DCCB test using a direct current discharge of a reactor, and Non-Patent Document 2 describes a DCCB using a low-frequency current due to low-speed operation of an AC short-circuit generator. The method of performing the test is described.

S. Tokoyoda, M. Sato, K. Kamei, D. Yoshida, M. Miyashita, K. Kikuchi, H. Ito, “High Frequency Interruption Characteristics of VCB and its Application to High Voltage DC Circuit Breaker”, ICEPE-ST 2015 , pp117-121 (2015) R.P.P.Smeets, A.Yanushkevich, N.A.Belda, R.Scharrenberg, “Design of Test-Circuits for HVDC Circuit Breakers”, ICEPE-ST 2015, pp229-234 (2015)

  In the conventional test method using an alternating current, the “breaking current waveform” is a waveform that is substantially equivalent to that of the actual HVDC system. However, stresses such as “Transient Recovery Voltage (TRV) waveform and recovery voltage waveform generated between DCCB poles after current interruption” and “Processing energy of a lightning arrester” installed in parallel with DCCB are not suitable for HDVC. There was a problem that it was smaller than expected in the system, and stress equivalent to that in the actual system could not be applied to the DC breaker to be tested.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a DC circuit breaker test apparatus capable of applying a stress close to a DC circuit breaker to be tested during operation in an actual system. To do.

  In order to solve the above-described problems and achieve the object, a test apparatus for a DC circuit breaker according to the present invention generates an AC current that generates a first test current that flows through a test DC circuit breaker that is a DC circuit breaker to be tested. A power source, and a voltage source circuit that generates a second test current that flows through the test DC circuit breaker. The DC circuit breaker test device is provided between the voltage source circuit and the test DC circuit breaker, and is open when the first test current starts flowing from the AC power source to the test DC circuit breaker. The test DC breaker is closed at a specified timing after the first test current is cut off, and includes a switch for connecting the voltage source circuit to the test DC breaker. The second test current is generated by discharging the capacitor charged to a voltage higher than the limit voltage of the energy absorption unit included in the test DC circuit breaker.

  According to the present invention, there is an effect that it is possible to apply a stress close to the DC breaker to be tested during operation in the actual system.

The figure which shows an example of schematic structure of the testing apparatus of the DC circuit breaker concerning Embodiment 1. The figure which shows the circuit structural example of the testing apparatus of the DC circuit breaker concerning Embodiment 1. The figure which shows the specific structural example of the DC circuit breaker which the testing apparatus of the DC circuit breaker concerning Embodiment 1 tests. The figure which shows the operation example of the testing apparatus of the DC circuit breaker concerning Embodiment 1. Diagram showing a test circuit for realizing the AC short-circuit generator method Diagram showing the operation of the test circuit to realize the AC short circuit generator method The figure which shows the test circuit for realizing the ideal DC power supply method The figure which shows operation | movement of the test circuit for implement | achieving an ideal DC power supply method The figure which shows the circuit structural example of the testing apparatus of the DC circuit breaker concerning Embodiment 2.

  Hereinafter, a test apparatus and a test method for a DC circuit breaker according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
1 is a diagram illustrating an example of a schematic configuration of a test apparatus for a DC circuit breaker according to a first exemplary embodiment of the present invention.

  The DC circuit breaker test apparatus 100 includes a first test current generation unit 101 that generates a first test current to flow through a DC circuit breaker (DCCB) of a device under test, which is not shown in FIG. A second test current generator 102 for generating a second test current for flowing through the DC breaker of the device under test and terminals 103A, 103B, 103C and 103D for connecting the DC breaker of the device under test The device under test connecting part 103, the charging circuit 104 for charging the capacitor not shown in FIG. 1 of the second test current generating part 102, the first test current generating part 101, 2, a control circuit 105 that controls the charging circuit 104, and a DC circuit breaker connected to the device under test connection unit 103.

  The charging circuit 104 includes, for example, a circuit that generates DC power for charging by boosting AC power supplied from an AC power source to a desired voltage with a transformer, and then performing rectification and smoothing, and a capacitor to be charged. This switch is realized by a switch for starting and stopping the supply of charging power to the, and this switch is controlled by the control device 105.

  The control device 105 is realized by, for example, a processor, a memory, and a peripheral circuit. That is, the memory stores a program for controlling the first test current generation unit 101, the second test current generation unit 102, the DC circuit breaker connected to the device under test connection unit 103, and the charging circuit 104. In addition, the control device 105 can be realized by the processor executing the program held in the memory.

  In the test apparatus 100, the control device 105 controls the operation of the first test current generation unit 101 and the second test current generation unit 102, so that the DC circuit breaker of the device under test, that is, the device under test connection unit 103 is connected. The timing at which the first test current and the second test current are supplied to the connected DC circuit breaker is controlled, and stress close to that during operation in the actual system is applied.

  FIG. 2 is a diagram illustrating a circuit configuration example of the test apparatus 100 for the DC interrupter according to the first embodiment. In FIG. 2, the description of the charging circuit 104 shown in FIG. 1 is omitted. FIG. 2 also shows a test DC circuit breaker, that is, a DC circuit breaker 5 as a device under test.

  The first test current generation unit 101 of the test apparatus 100 includes an AC power source 1 that is a short-circuit generator and the like, and an auxiliary circuit breaker 4. In FIG. 2, the resistance component and the inductance component included in the test circuit constituting the first test current generation unit 101 are shown as a resistor 2 and an inductor 3.

  The first test current generator 101 may be configured to transform the output voltage of the AC power supply 1 with a transformer according to the test state. That is, a transformer that transforms a DC voltage applied to the DC circuit breaker 5 through the auxiliary circuit breaker 4 may be provided in the first test current generation unit 101. Further, in order to increase the power capacity, a plurality of AC power supplies connected in parallel may constitute the AC power supply 1. The operating frequency of the AC power supply 1 is not particularly specified. The DC breaker testing apparatus according to the present embodiment can be applied regardless of the operating frequency of the AC power supply.

  The auxiliary circuit breaker 4 is provided between the AC power source 1 and the DC circuit breaker 5, and disconnects the AC power source 1 from the DC circuit breaker 5 in the duration of the transient recovery voltage of the DC circuit breaker 5 (TRV duration). The influence of the AC power supply 1 on the transient recovery voltage and the recovery voltage is reduced. In addition, the auxiliary circuit breaker 4 is configured such that when the DC circuit breaker 5 fails to break, the AC power supply 1, the DC circuit breaker 5, and the current zero point of the first test current that is the test current supplied from the AC power supply 1. Cut off the current flowing between. The auxiliary circuit breaker 4 is controlled by the control device 105. As the auxiliary circuit breaker 4, it is desirable to use a vacuum circuit breaker (VCB) with high frequency arc extinguishing performance.

  The second test current generator 102 includes a closing switch 9 for allowing the second test current to flow through the DC circuit breaker 5 and a voltage source circuit 10 for generating a second test current. The voltage source circuit 10 is a circuit in which a waveform adjusting reactor 11, a waveform adjusting resistor 12 and a capacitor 13 are connected in series, and generates a second test current which is a direct current.

  The closing switch 9 is a switch for connecting the voltage source circuit 10 and the DC circuit breaker 5 at an appropriate timing, and is realized by, for example, a discharge gap device. The closing switch 9 is controlled by the control device 105. That is, the closing switch 9 opens and closes the electric circuit according to instructions from the control device 105.

  The second test current generated by the voltage source circuit 10 is energy to be injected into the DC circuit breaker 5 during the transient recovery voltage period after the DC circuit breaker 5 performs the circuit breaking operation. In the state before starting the test of the DC circuit breaker 5, specifically, in the transient recovery voltage period after the capacitor 13 is charged in the state where the closing switch 9 is opened and the test of the DC circuit breaker 5 is started. When the control device 105 turns on the making switch 9, the energy accumulated in the capacitor 13 is injected into the DC circuit breaker 5. The reactor 11 and the resistor 12 for adjusting the waveform adjust the discharge current waveform and the voltage waveform when the capacitor 13 is discharged when the closing switch 9 is turned on. The energy injected into the DC circuit breaker 5 from the second test current generator 102 is mainly injected into the energy absorption unit 8 described later.

  The DC circuit breaker 5 is connected to the first test current generator 101 via the terminals 103A and 103B of the device under test connection 103, and to the second test current generator 102 via the terminals 103C and 103D. Connected. The DC circuit breaker 5 shown in FIG. 2 includes general components included in the DC circuit breaker, specifically, a circuit breaker unit 6, a commutation unit 7, and an energy absorption unit 8. The energy absorption unit 8 is generally a lightning arrester.

  FIG. 3 is a diagram illustrating a specific configuration example of the DC circuit breaker 5. The breaker unit 6 of the DC breaker 5 is constituted by a main breaker 61. The main breaker 61 cuts off the accident current when an accident occurs on the DC line in which the DC breaker 5 is inserted. The commutation unit 7 of the DC breaker 5 includes a closing switch 71, an inductance 72, and a capacitor 73. The commutation unit 7 generates a resonance current for forming a current zero point by superimposing it on the accident current when an accident occurs on the DC line in which the DC circuit breaker 5 is inserted. The energy absorption unit 8 is a lightning arrester as described above. The configuration shown in FIG. 3 is an example, and a DC circuit breaker having another configuration can be used as a test DC circuit breaker. That is, the DC circuit breaker that can be a test target of the DC circuit breaker test apparatus according to the present invention is not limited to the one shown in FIG.

  The main breaker 61 of the breaker unit 6 is in a closed state at normal times, that is, in a state where the DC breaker 5 is put into the actual system and no accident has occurred. Further, the closing switch 71 of the commutation unit 7 is normally open. The capacitor 73 is quickly charged by the charging circuit, which is not shown in FIG. 3, after the DC circuit breaker 5 is put into the actual system. When the closing switch 71 is closed in a state where charges are accumulated in the capacitor 73, the capacitor 73 is discharged and a resonant current flows from the commutation unit 7 toward the cutoff unit 6.

  The main breaker 61 of the breaker unit 6 and the closing switch 71 of the commutation unit 7 are controlled by a controller in the DC breaker 5 that is not shown in FIG. When the control device that controls the main breaker 61 and the closing switch 71 detects that an accident has occurred in the DC line in which the DC breaker 5 is inserted, it instructs the main breaker 61 to open the circuit. The closing switch 71 is instructed to close. When the closing switch 71 is closed, a resonant current flows from the commutation unit 7 to the main cutoff unit 61 to form a current zero point, and the cutoff of the accident current by the main cutoff unit 61 is completed. In FIG. 3, a change in the connection state of the main breaker 61 and the terminals of the closing switch 71 when an accident occurs in the DC line where the DC breaker 5 is turned on is indicated by an arrow.

  The details of the operation when the test apparatus 100 for the DC circuit breaker according to the first embodiment tests the DC circuit breaker 5 shown in FIG. 3 are as shown in FIG. When the test of the DC circuit breaker 5 is performed, for example, the control device 105 of the test apparatus 100 instructs the control device in the DC circuit breaker 5 to start the breaking operation, and the DC circuit breaker 5 that has received this instruction. The internal control device opens the main blocking unit 61 and turns on the closing switch 71.

  Here, before explaining the detailed operation of the test apparatus 100 according to the first embodiment, as a comparative example, the test circuit and operation for realizing the above-described AC short-circuit generator method and the ideal DC power supply method are realized. A test circuit will be described.

  FIG. 5 is a diagram showing a test circuit for realizing the AC short-circuit generator method. A DC circuit breaker 5 as a device under test is also shown. The configuration and operation of the DC circuit breaker 5 are the same as those of the DC circuit breaker 5 shown in FIGS.

  The test circuit shown in FIG. 5 includes an AC power supply 21 and a cutoff unit 24. The resistor 22 shown in FIG. 5 is a resistance component that the test circuit has, and the inductor 23 is an inductance component that the test circuit has. The AC power source 21 can be an AC short-circuit generator.

FIG. 6 is a diagram illustrating an operation of the test circuit of the AC short-circuit generator method illustrated in FIG. FIG. 6 shows the waveforms of the current (i _cb , i _ar ) and voltage (V _t ) of each part when the interruption test of the DC breaker 5 is carried out with the test circuit shown in FIG. The waveform of the energy (E _ar ) and the operation sequence of each device of the test circuit and the DC circuit breaker 5 are shown. In addition, about the energy absorption unit 8 described in the lowest stage, the change of the impedance is shown.

  FIG. 7 is a diagram showing a test circuit for realizing the ideal DC power supply method. A DC circuit breaker 5 as a device under test is also shown. The configuration and operation of the DC circuit breaker 5 are the same as those of the DC circuit breaker 5 shown in FIGS.

  The test circuit shown in FIG. 7 includes a DC power supply 31 and a blocking unit 34. The resistor 32 shown in FIG. 7 is a resistance component that the test circuit has, and the inductor 33 is an inductance component that the test circuit has.

FIG. 8 is a diagram showing the operation of the ideal DC power supply method test circuit shown in FIG. FIG. 8 shows the waveforms of the current (i _cb , i _ar ) and voltage (V _t ) of each part when the interruption test of the DC circuit breaker 5 is performed by the test circuit shown in FIG. The waveform of the energy (E _ar ) and the operation sequence of each device of the test circuit and the DC circuit breaker 5 are shown. Similar to FIG. 6, the energy absorption unit 8 described in the lowermost stage shows a change in impedance. As already explained, the ideal DC power supply method is virtually impossible to configure with the equipment of a high power laboratory, but it reproduces the basic phenomenon of an actual HVDC system as it is. The current, voltage, and energy waveform of each part obtained by the power supply method is an ideal reference waveform.

When the test waveform assumed to be obtained by the test circuit of the AC short-circuit generator method shown in FIG. 6 is compared with the ideal reference waveform shown in FIG. 8, the test waveform shown in FIG. In the case of FIG. 6 (time t ₁ to time t ₂ , in the case of FIG. 8 time t ₁ to time t ₃ ) and in the subsequent recovery voltage period, the inter-electrode voltage (V _t ) of the DC breaker 5 is shown in FIG. Does not include the ideal reference waveform. Also, due to that, the absorbed energy (E _ar ) of the energy absorption unit of the DC circuit breaker 5 is also smaller than the ideal reference waveform. This indicates that the test using the AC short-circuit generator method cannot be performed under conditions close to the actual environment.

Non-Patent Document 2 described above describes the stress applied to the DC breaker to be tested when the fault current interruption phenomenon in the HVDC real system is reproduced by a high power test facility. According to the description of Non-Patent Document 2, the total stress imposed on the DC circuit breaker during the interruption process of the interruption test can be defined by the following items (a) to (c).
(A) Breaking current waveform flowing in the breaker unit of the DC breaker (A) Transient recovery voltage (TRV) waveform generated between the DC breaker poles after the breaking unit cuts off the current, and the subsequent recovery voltage waveform ( C) Processing energy of the energy absorption unit installed in parallel with the breaker unit and commutation unit of the DC breaker

When the test circuit of the AC short-circuit generator method shown in FIG. 5 is used, the above (a), that is, the waveform of _icb shown in FIG. By adjusting the content ratio and the like, a waveform equivalent to the actual system, that is, a waveform corresponding to the waveform of _icb shown in FIG. However, the (i), i.e., the waveform of V _t shown in FIG. 6, in particular the duration of the transient recovery voltage (TRV duration) is shorter than HVDC actual system behavior, the real system and equivalent stress Cannot be applied to the DC breaker under test.

Here, the duration of the transient recovery voltage is determined by the following elements (1) to (4).
(1) When DC current is interrupted, the energy determined by 0.5 × L × I ² remaining in the inductance of the test circuit (L is the inductance of the system, I is the instantaneous current value at the time of interruption)
(2) DC breaker power supply side voltage (3) Energy absorption unit characteristics (4) Capacitance between the DC breaker poles (between breaker poles)

  When (1), (3), and (4) are constant, the power supply side voltage waveform of (2) becomes larger as compared to the HVDC actual system (DC constant voltage), that is, AC short-circuit power generation. In terms of tests by the method, generally, the higher the operating frequency of the short-circuit generator that is the power source, the shorter the duration of the transient recovery voltage, and the lower the equivalence of (a) to the HVDC actual system.

  As for the above (c), the absorbed energy becomes smaller as the recovery voltage duration of (a), that is, the operation time of the energy absorption unit is shorter, and the equivalence to the HVDC actual system becomes lower.

  In the test method described in Non-Patent Document 2, the equivalence of the above (a) and (c) is improved by reducing the operating frequency of the AC short-circuit generator as much as possible to bring the power supply voltage closer to the DC voltage waveform. ing. In this case, the lower the operating frequency of the AC short-circuit generator, the lower the output voltage of the generator. Therefore, in order to perform a high voltage and large current test, a short-circuit transformer that sufficiently boosts the generator voltage and a power supply capacity that can supply a sufficiently large current even when boosted are required. There is a problem that it requires a lot of equipment. Also, even in a test using a low frequency power supply, the power supply side voltage vibrates at that frequency, so the voltage across the DC circuit breaker also oscillates in the recovery voltage region after the transient recovery voltage duration. It becomes. In the HVDC real system, the recovery voltage is a direct current and has a constant waveform, and therefore, a stress equivalent to that in the HVDC real system cannot be applied to the recovery voltage region.

  As described above, with the conventional AC short-circuit generator method, testing cannot be performed under conditions close to the actual environment, or a vast amount of equipment is required for testing under conditions close to the actual environment. Is necessary and difficult to implement.

  On the other hand, in the test apparatus 100 for the DC circuit breaker according to the first embodiment, as shown in FIG. 1, the voltage source circuit 10 is connected in parallel to the DC circuit breaker 5 to be tested. Yes. As a result, the duration of the transient recovery voltage (b) obtained by the conventional AC short-circuit generator method test is extended to the equivalent of the ideal reference waveform, and the processing energy of the energy absorption unit (c) is changed to the ideal standard. It is possible to compensate to the waveform equivalent, and to improve the equivalence of the test.

As shown in FIG. 4, when the test apparatus 100 performs a current interruption test of the DC breaker 5, the test apparatus 100 operates at time t in the state where the auxiliary breaker 4 is ON or closed and the closing switch 9 is OFF or opened. _{At 0} , the operation of the AC power source 1 is started and the first test current starts to flow through the line in which the DC breaker 5 is inserted, and the test is started. At the start of the test, the main circuit breaker 61 of the DC circuit breaker 5 is closed and the closing switch 71 is opened.

When the first test current reaches a peak at time t ₁ after the test is started, an instruction is issued from the control device 105 to the DC circuit breaker 5. Judgment is made, the main shut-off portion 61 is opened, and the closing switch 71 is closed. As a result, the capacitor 73 of the commutation unit 7 starts discharging, and a resonant current starts to flow from the closing unit 7 to the cutoff unit 6. Thereafter, when the current zero point is formed by the action of the resonant current flowing through the interruption unit 6, the interruption of the current by the main interruption unit 61 is completed, and the injection of the first test current into the energy absorption unit 8 is started. Then, the test apparatus 100, at time t ₄ is a timing defined within the duration of the transient recovery voltage (TRV duration), the control device 105 closes the start switch 9. As a result, the voltage source circuit 10 of the second test current generator 102 is turned on, and the energy accumulated in the capacitor 13 of the voltage source circuit 10 is used as the current i _h that is the second test current. The energy absorption unit 8 is injected. Also, the test apparatus 100, the current i _s greet current zero point in time t _2, the by closing the auxiliary circuit breaker 4, in time t _2, the, or at its front and rear, disconnect the AC power supply 1 from the DC circuit breaker 5 . That is, the auxiliary circuit breaker 4 blocks the AC current that is the first test current flowing from the AC power source 1 to the DC circuit breaker 5. Thus, at time t ₄ within the TRV continuation period, the injection of the energy stored in the capacitor 13 into the energy absorption unit 8 is started, thereby extending the TRV continuation time and the current conduction time of the energy absorption unit 8. To do. Further, the energy absorbed by the energy absorption unit 8 increases due to the TRV duration and the extension of the current conduction time of the energy absorption unit 8. In Figure 4, shown in FIG. 6, the machining gap voltage of the DC circuit breaker 5 when tested with DC circuit breaker 5 through the test circuit of a conventional AC shorted generator method (DCCB inter-electrode voltage) V _t and energy absorption The waveform of the energy E _ar absorbed by the unit 8 is also described, and the voltage V _t when the DC circuit breaker 5 is tested by the ideal DC power method test circuit shown in FIG. 8 is also described. .

The TRV duration and the amount of energy absorbed by the energy absorption unit 8 depend on the voltage of the capacitor 13 at the start of the test and the timing at which the closing switch 9 is turned on. Therefore, the time t _{4 at} which the closing switch 9 is turned on, and the voltage of the capacitor 13 at the time of starting the test, that is, the voltage at which the charging circuit 104 shown in FIG. 8 is equal to or longer than the TRV duration shown in FIG. 8, and the energy absorbed by the energy absorption unit 8 (absorbed energy E _ar ) is equal to or greater than the absorbed energy E _ar shown in FIG. Determined by simulation. However, the voltage of the capacitor 13 at the start of the test is set to a value larger than at least the limit voltage of the lightning arrester that is the energy absorption unit 8. By setting the voltage of the capacitor 13 at the start of the test to a value larger than the limit voltage of the lightning arrester, the energy discharged from the capacitor 13 is injected into the lightning arrester.

  As described above, the test apparatus 100 according to the present embodiment includes the first test current generation unit 101 and the second test current generation unit 102, and first performs the first test when the DC circuit breaker is tested. A first test current is supplied from the current generator 101 to the DC circuit breaker 5 of the device under test, and then a DC second test current is supplied from the second test current generator 102 at a specified timing to the device under test. It was decided to flow through the DC breaker 5. As a result, the waveform of the transient recovery voltage (TRV) obtained by the first test current that is the same test current as the test circuit that performs the test by the conventional AC short-circuit generator method is extended to the equivalent of the ideal reference waveform, The energy injected into the energy absorption unit 8 can be increased. Therefore, it is possible to apply a stress close to the DC circuit breaker of the device under test during operation in the actual system.

Embodiment 2. FIG.
FIG. 9 is a diagram illustrating a configuration example of a test apparatus for a DC circuit breaker according to the second embodiment. The test apparatus 100a according to the second embodiment illustrated in FIG. 9 is obtained by replacing the second test current generation unit 102 of the test apparatus 100 according to the first embodiment with a second test current generation unit 102a. Although not shown in FIG. 9, the test apparatus 100a includes a charging circuit for charging a capacitor inside the second test current generation unit 102a, similarly to the test apparatus 100 according to the first embodiment. I have. Since the second test current generation unit 102a is the same as that of the first embodiment except for the second test current generation unit 102a, the second test current generation unit 102a will be described in this embodiment, and the description of the other components will be omitted.

  The second test current generator 102a is obtained by adding a circuit composed of a switch 9a and a voltage source circuit 10a to the second test current generator 102. In the voltage source circuit 10 a, the closing switch 9 a is the same switch as the closing switch 9. The voltage source circuit 10 a is a circuit having a configuration in which a waveform adjusting reactor 11 a, a waveform adjusting resistor 12 a, and a capacitor 13 a are connected in series, and is the same circuit as the voltage source circuit 10. The constants of reactor 11a, resistor 12a and capacitor 13a are the same as reactor 11, resistor 12 and capacitor 13, but are not essential. Different constants may be used for the voltage source circuit 10 and the voltage source circuit 10a.

  In the second test current generator 102a, the circuit composed of the making switch 9a and the voltage source circuit 10a is the same circuit as the DC current producing circuit that is a circuit comprising the making switch 9 and the voltage source circuit 10. In addition, the direct current generating circuit including the closing switch 9 a and the voltage source circuit 10 a is connected in parallel with the direct current generating circuit including the closing switch 9 and the voltage source circuit 10. Therefore, the second test current generation unit 102a corresponds to the second test current generation unit 102 described in Embodiment 1 in two stages.

  In the test apparatus 100a according to the embodiment, the second test current is injected into the DC circuit breaker 5 of the device under test in two portions. In the test apparatus 100a, for example, after the injection of the first test current to the DC circuit breaker 5 is started, the closing switch 9 is closed at the first specified time within the TRV duration, and accumulated in the capacitor 13. Is injected into the energy absorption unit 8 of the DC circuit breaker 5 as a second test current. Thereafter, the closing switch 9a is closed at the second specified time within the TRV duration, and the energy stored in the capacitor 13a is injected into the energy absorption unit 8 of the DC circuit breaker 5 as the second test current. The order of closing the closing switches 9 and 9a may be reversed.

  The first specified time, the second specified time, and the voltages of the capacitors 13 and 13a at the start of the test are determined by simulation, as in the first embodiment. The voltage of the capacitors 13 and 13a at the start of the test is set to a value that is at least larger than the limit voltage of the lightning arrester that is the energy absorption unit 8.

  Although FIG. 9 shows an example in which the circuit (the input switch and the voltage source circuit) for generating the second test current has a two-stage configuration, a three-stage or more configuration may be used.

  Thus, the test apparatus 100a according to the present embodiment includes a plurality of stages of voltage source circuits that generate the second test current, and injects the second test current in two or more times. As a result, it is possible to further extend the transient recovery voltage period as compared with the case where the voltage source circuit has one stage. Therefore, for example, the transient recovery voltage duration (TRV duration) is shorter than the ideal reference waveform simply by injecting the second test current from the first-stage voltage source circuit to the energy absorption unit 8 of the DC circuit breaker 5. In some cases, the TRV duration can be further extended. That is, the second test current is injected from the first-stage voltage source circuit to the energy absorption unit 8 of the DC circuit breaker 5, and the second-stage voltage source circuit is at a timing before the end of the TRV duration. By injecting the second test current into the energy absorption unit 8 of the DC circuit breaker 5, the TRV duration can be further extended to approach the ideal reference waveform.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  1,21 AC power supply, 2,12,12a, 22,32 resistance, 3,23,33 inductor, 11,11a reactor, 4,24,34 Auxiliary circuit breaker, 5 DC circuit breaker, 6 circuit breaker unit, 7 commutation Unit, 8 Energy absorption unit, 9, 9a Input switch, 10, 10a Voltage source circuit, 13, 13a, 73 Capacitor, 31 DC power source, 61 Main cutoff unit, 71 Input switch, 72 Inductance, 100, 100a Test device, 101 First test current generation unit, 102, 102a Second test current generation unit, 103 device under test connection unit, 103A to 103D terminals, 104 charging circuit, 105 control device.

Claims (6)

An AC power source that generates a first test current that flows through a test DC circuit breaker that is a DC circuit breaker to be tested;
A voltage source circuit for generating a second test current flowing through the DC breaker;
Provided between the voltage source circuit and the test DC circuit breaker, and open when the first test current starts to flow from the AC power source to the test DC circuit breaker, and the test DC circuit breaker A switch that enters a closed state at a specified timing after the circuit breaks the first test current and connects the voltage source circuit to the DC circuit breaker;
With
When the switch is closed, the voltage source circuit discharges a capacitor charged to a voltage higher than a limit voltage of an energy absorption unit included in the DC breaker to be used to generate the second test current. Generate,
DC breaker testing device characterized by the above.   2. The DC circuit breaker testing device according to claim 1, wherein the switch is a discharge gap. An auxiliary circuit breaker provided between the AC power source and the test DC circuit breaker, and configured to interrupt the first test current flowing from the AC power source to the test DC circuit breaker after the switch is closed;
The test apparatus for a DC circuit breaker according to claim 1, comprising:   4. The DC circuit breaker testing device according to claim 3, wherein the auxiliary circuit breaker is a vacuum circuit breaker. A plurality of DC current generation circuits comprising the voltage source circuit and the switch,
Each of the DC current generation circuits is configured to apply the second test to the test DC circuit breaker in turn at different specified timings after the test DC circuit breaker performs the first test current interrupt. Current flow,
5. The DC circuit breaker testing device according to claim 1, wherein the DC circuit breaker is tested. A test method for testing a DC circuit breaker,
A first step of flowing a first test current generated by an AC power source to a test DC circuit breaker that is a DC circuit breaker to be tested;
A second step in which the DC breaker under test interrupts the first test current;
A third step in which a second test current generated by the voltage source circuit is caused to flow through the test DC breaker at a specified timing after the second step is executed;
Including
The voltage source circuit generates the second test current by discharging a capacitor charged to a voltage higher than a limit voltage of an energy absorption unit included in the test DC breaker;
A test method characterized by the above.

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