Testing circuit and device for switching device of nuclear power plant
By designing a test circuit for switching devices in nuclear power plants, the problem of verifying the protection performance of switching devices in DC systems was solved, and short-circuit tests on circuit breakers or fuses were realized, thereby improving the stability and safety of nuclear power plant equipment.
Patent Information
- Application Number
- CN202423108675.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2034-12-16
AI Technical Summary
The inability to effectively verify the protection performance of switching devices in the DC system of nuclear power plants during faults makes it impossible to ensure that the fault range is limited to a minimum, thus affecting the stable operation of nuclear power plants.
A test circuit for switching devices in nuclear power plants was designed, including a power supply unit, a filtering unit, an adjustable power supply, a testing unit, a sampling unit, and a processing unit. By controlling the output power of the test power supply, the current and voltage data of the switching devices are tested to realize short-circuit tests on circuit breakers or fuses.
It enables performance testing of circuit breakers or fuses under short-circuit faults, improves testing efficiency, and ensures the stability and safety of nuclear power plant equipment in offline conditions.
Smart Images
Figure CN223637670U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to nuclear power plant equipment overhauling technical field especially relates to nuclear power plant switch device test circuit and device. BACKGROUND
[0002] The direct current system in the nuclear power plant is important power supply equipment of the load such as accident oil pump, UPS inverter, protection and safety automatic device, control and monitoring device and analog quantity control device. A large number of switch devices (such as fuse and circuit breaker) are arranged in the direct current system to ensure that the fault load can be disconnected in time when part of the load short-circuits, so that the fault wave and other normal load are avoided, and therefore the short-circuit performance of the direct current system is particularly important. Since the upstream and downstream configuration of the direct current system is complex and the nuclear power plant has strict requirements on the upstream and downstream level difference cooperation of the direct current system, if the test is carried out on the running direct current system, the service life of the equipment itself will be adversely affected, and the maintenance personnel do not have the corresponding test means and tools, so the direct current system cannot be checked whether it can execute protection fault in time when each load fails, which leads to the failure to guarantee that the fault range is limited to the minimum range when short-circuit occurs, and is not conducive to the stable operation of the nuclear power plant. UTILITY MODEL CONTENTS
[0003] The utility model solves the technical problem in providing a nuclear power plant switch device test circuit and device.
[0004] The utility model adopts the technical scheme in the technical problem that it solves: a nuclear power plant switch device test circuit is constructed, which comprises:
[0005] A power supply unit for outputting direct current power supply;
[0006] A first filter unit connected with the power supply unit;
[0007] An adjustable power supply connected with the first filter unit and used for connecting the filtered direct current power supply and outputting test power supply;
[0008] A test unit connected with the adjustable power supply and used for connecting at least one measured switch device;
[0009] A sampling unit connected with the test unit and used for collecting current and voltage data input to each measured switch device;
[0010] A processing unit connected with the adjustable power supply, the test unit and the sampling unit, used for controlling the output power of the test power supply, controlling the connection of the adjustable power supply and at least one measured switch device through the control of the test unit and acquiring the current and voltage data.
[0011] Preferably, the test unit comprises a first test switch for closing during testing, a first test interface for accessing a first switch device under test, a second test switch for closing during testing of the first switch device under test, and a second test interface for accessing a second switch device under test.
[0012] The first test switch comprises a first control terminal and two first switch loops, the first ends of the two first switch loops are connected to the adjustable power supply respectively, and the first control terminal is connected to the processing unit.
[0013] The first test interface comprises two first test loops, the first ends of the two first test loops are connected to the second ends of the two first switch loops respectively, and one of the first test loops is further connected to the sampling unit.
[0014] The first end and the second end of the second test switch are connected to the second ends of the two first test loops respectively, and the control terminal of the second test switch is connected to the sampling unit.
[0015] The second test interface comprises two second test loops, the first ends of the two second test loops are connected to the first end and the second end of the second test switch respectively, and the second ends of the two second test loops are shorted, and one of the second test loops is further connected to the sampling unit.
[0016] Preferably, the first test switch is a double-pole contactor, and the second test switch is a contactor.
[0017] Preferably, the sampling unit comprises a first current sampling unit for testing the current flowing through the first switch device under test, a second current sampling unit for testing the current flowing through the second switch device under test, a first voltage sampling unit for testing the voltage across the first switch device under test, and a second voltage sampling unit for testing the voltage across the second switch device under test.
[0018] The first current sampling unit is coupled to one of the first test loops, the second current sampling unit is coupled to one of the second test loops, the first voltage sampling unit is connected across one of the first test loops, the second voltage sampling unit is connected across one of the second test loops, and the first current sampling unit, the second current sampling unit, the first voltage sampling unit, and the second voltage sampling unit are further connected to the processing unit.
[0019] Preferably, the first filter unit comprises an inductor L1 and a first capacitor C1; a first end of the inductor L1 is connected to a positive pole of the power supply unit, a second end of the inductor L1 is connected to the adjustable power supply and connected to a negative pole of the power supply unit through the first capacitor C1.
[0020] Preferably, the power supply unit comprises a transformer T1 and a rectifier bridge; a primary winding of the transformer T1 is used for connecting to an alternating current power supply, a secondary winding of the transformer T1 is connected to an alternating current input end of the rectifier bridge, and a direct current output end of the rectifier bridge is connected to the first filter unit to input the direct current power supply to the first filter unit.
[0021] Preferably, the rectifier bridge comprises a first diode V1, a second diode V2, a third diode V3 and a fourth diode V4.
[0022] An anode of the first diode V1 is connected to one end of the secondary winding of the transformer T1 and a cathode of the third diode V3, a cathode of the first diode V1 is connected to a cathode of the second diode V2 and serves as a positive pole of the power supply unit, an anode of the second diode V2 is connected to the other end of the secondary winding of the transformer T1 and a cathode of the fourth diode V4, and an anode of the fourth diode V4 is connected to an anode of the third diode V3 and serves as a negative pole of the power supply unit.
[0023] Preferably, the nuclear power plant switch device test circuit further comprises a second filter unit connected to the adjustable power supply; the second filter unit comprises a second capacitor C2.
[0024] Preferably, the processing unit comprises a host computer and a display for displaying the short circuit test result; the host computer is connected to the adjustable power supply, the test unit, the sampling unit and the display.
[0025] The utility model further constructs a kind of nuclear power plant switch device test device, including the nuclear power plant switch device test circuit as described above.
[0026] The utility model has the following beneficial effects: a kind of nuclear power plant switch device test circuit is improved, short circuit test is realized to circuit breaker or fuse in direct current system, help staff to test whether the performance of circuit breaker or fuse meets use requirement under offline condition when short circuit fault, test efficiency is high, and it plays a positive role in improving nuclear power plant stability. BRIEF DESCRIPTION OF DRAWINGS
[0027] The utility model will be further described below by combining with drawings and examples, and drawings are as follows:
[0028] Figure 1is a circuit structure block diagram of the switch device test circuit of the nuclear power plant in some embodiments of the utility model.
[0029] Figure 2 is a circuit principle diagram of the power supply unit, the first filter unit, the adjustable power supply and the test unit in some embodiments of the utility model.
[0030] Figure 3 is a circuit structure block diagram of the sampling unit and the processing unit in some embodiments of the utility model. DETAILED DESCRIPTION
[0031] In order to have a clearer understanding of the technical features, objects and effects of the utility model, the specific embodiments of the utility model will be described in detail with reference to the drawings.
[0032] In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "upper", "lower", "left", "right", "vertical", "horizontal", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail" and the like are based on the directions or positional relationships shown in the drawings, constructed and operated in a particular direction, and are only for the convenience of describing the technical scheme, and cannot be understood as indicating that the devices or elements referred to must have a particular direction, therefore, it cannot be understood as a limitation on the utility model.
[0033] As shown in Figure 1 The utility model provides a kind of switch device test circuit of nuclear power plant, the switch device test circuit of nuclear power plant can carry out short circuit test to circuit breaker or fuse in direct current system, help staff to test whether the performance of circuit breaker or fuse meets use requirement when short circuit fault under offline condition.The switch device test circuit of nuclear power plant can include power supply unit 1, first filter unit 2, adjustable power supply 3, test unit 4, sampling unit 5 and processing unit 6.
[0034] Power supply unit 1 is used to output direct current power supply.Specifically, the role of power supply unit 1 is to convert input alternating current power supply into direct current power supply.
[0035] In some embodiments, as Figure 2As shown, the power supply unit 1 can include a transformer T1 and a rectifier bridge 11. The primary winding of the transformer T1 is used to access an alternating current power source (such as a mains power supply). Since the internal resistance of the circuit breaker and the fuse is small, the required test voltage value is low in actual test, generally below 10V. The transformer T1 is used to convert the voltage of the alternating current power source into an alternating current voltage with a lower voltage value. According to the law of conservation of power, although the voltage output by the secondary winding is reduced, the output current is increased. Therefore, the alternating current power source with a lower voltage but higher current can be output through the secondary winding to meet the high current demand in the test. The secondary winding of the transformer T1 is connected to the alternating current input end of the rectifier bridge 11. The direct current output end of the rectifier bridge 11 is connected to the first filter unit 2 to input a direct current power source to the first filter unit 2. The rectifier bridge 11 is used to convert the alternating current power source output by the secondary winding of the transformer T1 into a direct current power source.
[0036] Further, as shown in Figure 2 , the rectifier bridge 11 can include a first diode V1, a second diode V2, a third diode V3 and a fourth diode V4. The anode of the first diode V1 is connected to one end of the secondary winding of the transformer T1 and the cathode of the third diode V3. The cathode of the first diode V1 is connected to the cathode of the second diode V2 and serves as the positive electrode of the power supply unit 1. The anode of the second diode V2 is connected to the other end of the secondary winding of the transformer T1 and the cathode of the fourth diode V4. The anode of the fourth diode V4 is connected to the anode of the third diode V3 and serves as the negative electrode of the power supply unit 1.
[0037] As shown in Figure 1 , the first filter unit 2 is connected to the power supply unit 1. The first filter unit 2 is used to filter the direct current power source output by the power supply unit 1 to eliminate the ripple content in the direct current power source, so that the direct current power source is closer to the field condition of the direct current system, which helps to improve the test accuracy.
[0038] In some embodiments, as shown in Figure 2 , the first filter unit 2 can include an inductor L1 and a first capacitor C1. The first end of the inductor L1 is connected to the positive electrode of the power supply unit 1. The second end of the inductor L1 is connected to the adjustable power supply 3 and connected to the negative electrode of the power supply unit 1 through the first capacitor C1. In this embodiment, the inductor L1 and the first capacitor C1 form an LC filter. The circuit structure is simple and the cost is low. The LC filter can effectively filter out the ripple in the direct current power source.
[0039] As shown in Figure 1The adjustable power supply 3 is connected with the first filter unit 2, and the adjustable power supply 3 is used to access the direct current power supply filtered by the first filter unit 2 and output adjustable test power according to the processing unit 6. Specifically, since the fuse or circuit breaker triggers its protection function generally because of overcurrent, and the internal resistance of the fuse and circuit breaker in the nuclear power plant is small (generally in the order of milliohm), but the protection current threshold is high (1A to 1000A), so the required test voltage is low, but the test current is high, so the processing unit 6 generally only controls the output current of the adjustable power supply 3, so the adjustable power supply 3 can be an adjustable current source that can output 1A to 1000A direct current power supply.
[0040] Please refer to Figure 1 The test unit 4 is connected with the adjustable power supply 3, and the test unit 4 is used to access at least one measured switching device. Among them, the measured switching device can be a fuse or a circuit breaker, and the number of measured switching devices that the test unit 4 can access can be 2, which are respectively the first measured switching device and the second measured switching device.
[0041] In some embodiments, as shown in Figure 2 The test unit 4 can include a first test switch 41, a first test interface 42, a second test switch 43, and a second test interface 44.
[0042] Please refer to Figure 2 The first test switch 41 is used to close during the test, and the first test switch 41 includes a first control end (not shown) and two first switch loops, the first ends of the two first switch loops are connected with the positive and negative poles of the adjustable power supply 3 one by one, and the first control end is connected with the processing unit 6. Optionally, the first test switch 41 is a double-pole contactor, the first control end corresponds to the excitation coil of the double-pole contactor, and the two first switch loops correspond to the two normally open contact loop of the double-pole contactor. When the processing unit 6 controls the excitation of the excitation coil of the double-pole contactor, the two first switch loops are closed, so that the test work can be performed. Of course, the first test switch 41 can also use a relay or other low on-resistance switching device to replace.
[0043] Please refer to Figure 2The first test interface 42 is used for connecting a first switch device (which can be a circuit breaker or a fuse) to be tested, and the first test interface 42 includes two first test loops, the first ends of the two first test loops are respectively connected to the second ends of the two first switch loops, and one of the two first test loops is further connected to the sampling unit 5. It should be noted that in a DC system, the fuse used is usually a bipolar fuse, and the circuit breaker is a bipolar circuit breaker, and the two first test loops are connected to the two fuses of the bipolar fuse or the two switches of the bipolar circuit breaker, so as to restore the on-site situation of the switch device to be tested as much as possible. Further, the first test interface 42 can include a fuse holder capable of being connected to the bipolar fuse and a circuit breaker holder capable of being connected to the bipolar circuit breaker, so that the worker can directly install the switch device to be tested on the corresponding holder, thereby realizing the connection between the first test interface 42 and the switch device to be tested.
[0044] Please refer to Figure 1 The second test switch 43 is used for closing when testing the first switch device, the first end and the second end of the second test switch 43 are respectively connected to the second ends of the two second test loops, and the control end of the second test switch 43 is connected to the sampling unit 5. Optionally, the second test switch 43 is a single-pole contactor, the control end of the second test switch 43 corresponds to the magnet coil of the single-pole contactor, and the first end and the second end of the second test switch 43 correspond to the first end and the second end of the normally open contact loop of the single-pole contactor. When the processing unit 6 controls the magnet coil of the single-pole contactor to be magnetized, the normally open contact loop of the single-pole contactor is closed. It should be noted that when only the first switch device to be tested (i.e. the switch device connected to the first test interface 42) is tested, the processing unit 6 controls the second test switch 43 to be closed, and when the first switch device to be tested and the second switch device to be tested (i.e. the switch device connected to the second test interface 44) are tested at the same time, the processing unit 6 controls the second test switch 43 to be opened.
[0045] Please refer to Figure 2 The second test interface 44 is used for connecting a second switch device (which can be a circuit breaker or a fuse) to be tested, and the second test interface 44 includes two second test loops, the first ends of the two second test loops are respectively connected to the first end and the second end of the second test switch 43, and the second ends of the two second test loops are short-circuited, and one of the two second test loops is further connected to the sampling unit 5. It should be noted that the specific structure of the second test interface 44 can refer to the first test interface 42, which will not be described here.
[0046] Please refer to Figure 1The sampling unit 5 is connected with the testing unit 4, and the sampling unit 5 is used to collect the current and voltage data input to each measured switching device. Specifically, the current and voltage data includes the current information flowing through each measured switching device and the voltage information across each measured switching device, i.e. the sampling unit 5 tests the input current of each measured switching device and tests the voltage across each measured switching device.
[0047] In some embodiments, as shown in Figure 3 The sampling unit 5 includes a first current sampling unit 51 for testing the current flowing through the first measured switching device, a second current sampling unit 52 for testing the current flowing through the second measured switching device, a first voltage sampling unit 53 for testing the voltage across the first measured switching device, and a second voltage sampling unit 54 for testing the voltage across the second measured switching device. The first current sampling unit 51 and the second current sampling unit 52 can each include a current detection sensor, which can be a current transformer, a Hall effect current sensor, etc. The first voltage sampling unit 53 and the second voltage sampling unit 54 can each include a voltage sensor, which can be a resistive voltage sensor and a voltage sensor, and the voltage sensor is preferably a resistive voltage sensor. The first current sampling unit 51 is coupled with one of the first test loops, the second current sampling unit 52 is coupled with one of the second test loops, the first voltage sampling unit 53 is connected across one of the first test loops, and the second voltage sampling unit 54 is connected across one of the second test loops. The first current sampling unit 51, the second current sampling unit 52, the first voltage sampling unit 53, and the second voltage sampling unit 54 are further connected to the processing unit 6 to send corresponding test signals to the processing unit 6, so that the processing unit 6 can obtain the current and voltage data.
[0048] Referring to Figure 1 The processing unit 6 is connected with the adjustable power supply 3, the testing unit 4, and the sampling unit 5, and the processing unit 6 is used to control the output power of the testing power supply, control the adjustable power supply 3 to be connected with at least one measured switching device by controlling the operation of the testing unit 4, obtain the current and voltage data, and output the short-circuit test result of the measured switching device.
[0049] In some embodiments, as shown in Figure 3As shown, the processing unit 6 can include a host computer 61 and a display 62 for displaying the short-circuit test results. The host computer 61 is connected to the adjustable power supply 3, the test unit 4, the sampling unit 5 and the display 62. The host computer 61 can be an existing PLC controller, which outputs high and low levels to control the first test switch 41 and the second test switch 43 in the test unit 4 to be closed or opened (i.e. to control whether the double-pole contactor and the single-pole contactor are excited), and which can also be connected to the adjustable power supply 3 to control the current of the test power supply, and which can also be connected to the test unit 4 to obtain the current and voltage data.
[0050] When the PLC controller obtains the current and voltage data, it can determine whether each measured switching device triggers protection according to the relevant voltage information. Understandably, when the fuse or circuit breaker does not trigger protection, its two ends are closed, so the voltage difference between its two ends is small (generally below 1V), and when the fuse or circuit breaker triggers protection, its two ends are disconnected, which is equivalent to a rapid increase in its internal resistance, which will cause the voltage difference between its two ends to increase significantly in a short time (more than 2V). Therefore, the PLC controller can determine the disconnection time of the fuse or circuit breaker according to the voltage information. In addition, the PLC controller can gradually control the output current of the adjustable power supply 3, so as to gradually increase the input current of the fuse or circuit breaker. The PLC controller can monitor the input current change of the measured switching device through the test unit 4, so as to fit the current-time waveform, and can determine the input current corresponding to the disconnection time of the fuse or circuit breaker as the actual protection current threshold of the fuse or circuit breaker, so as to determine whether the actual protection current threshold meets the relevant requirements (e.g. whether it is less than the nominal protection current threshold). Furthermore, the PLC controller can also be connected to the display 62 to display the current-time waveform and the protection current threshold corresponding to each measured switching device through the display 62.
[0051] In order to filter out the ripple of the test power supply output by the adjustable power supply 3, in some embodiments, as shown in Figure 2 The nuclear power plant switching device test circuit can further include a second filter unit 7 connected to the adjustable power supply 3. Further, the second filter unit 7 can include a second capacitor C2 connected in parallel with the positive and negative electrodes of the adjustable power supply 3.
[0052] Please refer to Figure 1 , Figure 2 and Figure 3 , the test process of the utility model is as follows:
[0053] 1. Based on the nominal protection current threshold size, the two measured switch devices to be tested are connected to the first test interface 42 and the second test interface 44, wherein the second test interface 44 is connected to the measured switch device with a smaller nominal protection current threshold;
[0054] 2. The host computer 61 controls the first test switch 41 to be closed, at this time, the test power output by the adjustable power supply 3 will flow through the measured switch devices (i.e. the first measured switch device and the second measured switch device) in the first test interface 42 and the second test interface 44;
[0055] 3. The host computer 61 controls the test power output by the adjustable power supply 3 to gradually increase from small to large;
[0056] 4. The on-off state of the first measured switch device and the second measured switch device is detected: if the second measured switch device is disconnected first (the principle of how to determine the disconnection is described above, and will not be repeated here), after the second measured switch device is disconnected, the second test switch 43 is controlled to be closed, and then the test power is controlled to continue to gradually increase until the first measured switch device is also disconnected; if the first measured switch device is disconnected first than the second measured switch device, it is determined that the first measured switch device does not meet the use requirements;
[0057] 5. When the adjustable power supply 3 outputs the test power, the corresponding current-time waveform is fitted based on the input current of the first measured switch device and the second measured switch device, and when a certain measured switch device is disconnected, the input current at the disconnection time is recorded as the actual protection current threshold of the certain measured switch device.
[0058] It can be understood that the utility model realizes the short circuit test of the circuit breaker or the fuse in the direct current system, helps the staff to test whether the performance of the circuit breaker or the fuse in the short circuit fault meets the use requirements under the offline condition, the test efficiency is high, and the stability of the nuclear power plant is improved.
[0059] The utility model also provides a nuclear power plant switch device test device, including the nuclear power plant switch device test circuit provided by the utility model embodiment.
[0060] It can be understood that the above embodiment only expresses the preferred implementation of the utility model, which is described in detail, but it cannot be understood as the limitation of the patent range of the utility model; it should be pointed out that the above technical features can be freely combined without departing from the concept of the utility model, and some deformations and improvements can be made, which belong to the protection range of the utility model; therefore, all equivalent transformations and modifications within the scope of the utility model claims should belong to the coverage range of the utility model claims.
Claims
1. A nuclear power plant switch device test circuit, characterized by, The utility model relates to a test system for switch device, comprising: a power supply unit (1) for outputting direct current power supply; a first filter unit (2) connected with the power supply unit (1); an adjustable power supply (3) connected with the first filter unit (2) for accessing filtered direct current power supply and outputting test power supply; a test unit (4) connected with the adjustable power supply (3) for accessing at least one switch device under test; a sampling unit (5) connected with the test unit (4) for collecting current and voltage data input to each switch device under test; a processing unit (6) connected with the adjustable power supply (3), the test unit (4) and the sampling unit (5) for controlling output power of the test power supply, controlling the adjustable power supply (3) to be connected with at least one switch device under test by controlling the test unit (4) to work and acquiring the current and voltage data.
2. The nuclear power plant switch device test circuit of claim 1, wherein, The test unit (4) comprises a first test switch (41) for closing during test, a first test interface (42) for accessing a first switch device under test, a second test switch (43) for closing during test of the first switch device under test and a second test interface (44) for accessing a second switch device under test; The first test switch (41) comprises a first control end and two first switch loops, the first ends of the two first switch loops are connected with the adjustable power supply (3) respectively, and the first control end is connected with the processing unit (6); The first test interface (42) comprises two first test loops, the first ends of the two first test loops are connected with the second ends of the two first switch loops respectively, and one of the first test loops is further connected with the sampling unit (5); The first end and the second end of the second test switch (43) are connected with the second ends of the two first test loops respectively, and the control end of the second test switch (43) is connected with the sampling unit (5); The second test interface (44) comprises two second test loops, the first ends of the two second test loops are connected with the first end and the second end of the second test switch (43) respectively, the second ends of the two second test loops are short-circuited, and one of the second test loops is further connected with the sampling unit (5).
3. The nuclear power plant switch device test circuit of claim 2, wherein, The first test switch (41) is a double-pole contactor, and the second test switch (43) is a contactor.
4. The nuclear power plant switch device test circuit of claim 2, wherein, The sampling unit (5) comprises a first current sampling unit (51) for testing current flowing through the first switch device under test, a second current sampling unit (52) for testing current flowing through the second switch device under test, a first voltage sampling unit (53) for testing voltage across the first switch device under test and a second voltage sampling unit (54) for testing voltage across the second switch device under test. The first current sampling unit (51) is coupled with one of the first test loops, the second current sampling unit (52) is coupled with one of the second test loops, the first voltage sampling unit (53) is connected to both ends of one of the first test loops, and the second voltage sampling unit (54) is connected to both ends of one of the second test loops; the first current sampling unit (51), the second current sampling unit (52), the first voltage sampling unit (53) and the second voltage sampling unit (54) are further connected to the processing unit (6).
5. The nuclear power plant switch device test circuit of claim 2, wherein, The first filter unit (2) comprises an inductor L1 and a first capacitor C1; a first end of the inductor L1 is connected to the positive pole of the power supply unit (1), a second end of the inductor L1 is connected to the adjustable power supply (3) and connected to the negative pole of the power supply unit (1) through the first capacitor C1.
6. The nuclear power plant switch device test circuit of claim 2, wherein, The power supply unit (1) comprises a transformer T1 and a rectifier bridge (11); a primary winding of the transformer T1 is used to connect to an AC power supply, a secondary winding of the transformer T1 is connected to an AC input end of the rectifier bridge (11), and a DC output end of the rectifier bridge (11) is connected to the first filter unit (2) to input the DC power supply thereto.
7. The nuclear power plant switch device test circuit of claim 6, wherein, The rectifier bridge (11) comprises a first diode V1, a second diode V2, a third diode V3 and a fourth diode V4. An anode of the first diode V1 is connected to one end of the secondary winding of the transformer T1 and a cathode of the third diode V3, a cathode of the first diode V1 is connected to a cathode of the second diode V2 and serves as a positive pole of the power supply unit (1), an anode of the second diode V2 is connected to the other end of the secondary winding of the transformer T1 and a cathode of the fourth diode V4, and an anode of the fourth diode V4 is connected to an anode of the third diode V3 and serves as a negative pole of the power supply unit (1).
8. The nuclear power plant switch device test circuit of claim 1, wherein, Further comprising a second filter unit (7) connected to the adjustable power supply (3); the second filter unit (7) comprises a second capacitor C2.
9. The nuclear power plant switch device test circuit of any one of claims 1 to 8, wherein, The processing unit (6) comprises an upper computer (61) and a display (62) for displaying short circuit test results; the upper computer (61) is connected to the adjustable power supply (3), the test unit (4), the sampling unit (5) and the display (62).
10. A nuclear power plant switch device testing apparatus characterized by comprising: The nuclear power plant switch device test circuit comprises the nuclear power plant switch device test circuit according to any one of claims 1 to 9.