Nuclear power plant interference signal absorption circuit and device, and electric head power supply system

Abstract

The utility model relates to an interference signal absorption circuit and device for a nuclear power plant, and an electric head power supply system, and the circuit comprises an interphase filtering unit which is used for filtering a differential mode interference signal at a low-voltage side of a transformer; the earth filtering unit is used for filtering common-mode interference signals on the low-voltage side of the transformer; the prompting unit is connected with the interphase filtering unit and the to-ground filtering unit and is used for outputting a fault prompting signal when the interphase filtering unit or the to-ground filtering unit has a fault; the switch unit is connected with the interphase filtering unit and the to-ground filtering unit and is used for being connected with the low-voltage side of the transformer so as to switch on or switch off the interphase filtering unit and the to-ground filtering unit; and the output filtering unit is used for being connected between the low-voltage side of the transformer and the electric head so as to suppress interference signals input to the electric head. According to the utility model, interference signals superposed on the low-voltage side of the transformer can be effectively filtered, false alarm of the open-phase protection device is avoided, and the operation stability of a nuclear power plant is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power plant equipment, in particular to a nuclear power plant interference signal absorption circuit and device, and an electric head power supply system. Background Art

[0002] In nuclear power plants, the electric motor is a crucial power source for driving valves and other components. To ensure stable operation, nuclear power plants typically equip the electric motor's power supply system with a phase-loss protection device. This device generates an alarm signal when a phase loss occurs in the output power of the electric motor's power supply system, preventing the electric motor from operating in a phase-loss state and potentially impacting plant safety. However, due to the large amount of high-frequency interference signals superimposed on the power supply during the operation of the electric motor, there is a risk of the electric motor triggering a phase-loss fault alarm. This has resulted in numerous false alarms at one nuclear power plant, causing the electric motor to fail unintentionally and impacting normal operation. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a nuclear power plant interference signal absorption circuit and device, and an electric head power supply system.

[0004] The technical solution adopted by the utility model to solve the technical problem is: constructing a nuclear power plant interference signal absorption circuit for an electric head power supply system, the electric head power supply system including a transformer, the nuclear power plant interference signal absorption circuit including:

[0005] An interphase filtering unit, used for filtering out differential-mode interference signals on the low-voltage side of the transformer;

[0006] A ground filtering unit, used for filtering out common-mode interference signals on the low-voltage side of the transformer;

[0007] a prompt unit connected to the interphase filtering unit and the ground filtering unit, and configured to output a fault prompt signal when the interphase filtering unit or the ground filtering unit fails;

[0008] a switch unit, connected to the interphase filter unit and the ground filter unit, and used to connect the low-voltage side of the transformer to activate or deactivate the interphase filter unit and the ground filter unit;

[0009] The output filter unit is used to be connected between the low-voltage side of the transformer and the electric head to suppress interference signals input to the electric head.

[0010] Preferably, the interphase filtering unit includes a first capacitor, a second capacitor and a third capacitor;

[0011] The first capacitor is connected between the first output terminal and the second output terminal of the switch unit, the second capacitor is connected between the first output terminal and the third output terminal of the switch unit, and the third capacitor is connected between the second output terminal and the third output terminal of the switch unit.

[0012] Preferably, the ground filtering unit includes a fourth capacitor, a fifth capacitor and a sixth capacitor;

[0013] The fourth capacitor is connected between the first output terminal of the switch unit and the ground, the fifth capacitor is connected between the second output terminal of the switch unit and the ground, and the sixth capacitor is connected between the sixth output terminal of the switch unit and the ground.

[0014] Preferably, the prompt unit includes six indicator lights; the six indicator lights are connected in parallel with the first to sixth capacitors one-to-one, and the indicator lights are used to go out when the switch unit is disconnected or the capacitor connected thereto has a short circuit fault.

[0015] Preferably, the switch unit includes a circuit breaker and a contactor;

[0016] The first input end, the second input end and the third input end of the circuit breaker are connected one-to-one to the A phase, the B phase and the C phase on the low-voltage side of the transformer; the first output end, the second output end and the third output end of the circuit breaker are connected one-to-one to the first input end, the second input end and the third input end of the contactor; the first output end, the second output end and the third output end of the contactor are connected to the interphase filter unit and the ground filter unit; the excitation coil of the contactor is used to receive the input control instruction.

[0017] Preferably, the output filtering unit includes:

[0018] a first filtering unit, configured to be connected in series between the low-voltage side of the transformer and the electric head to suppress high-frequency interference signals input to the electric head;

[0019] The second filtering unit is connected between the first filtering unit and the ground, and is used to filter out interference signals input to the electric head.

[0020] Preferably, the first filtering unit includes a first inductor, a second inductor and a third inductor;

[0021] The first ends of the first inductor, the second inductor and the third inductor are connected one-to-one to the A phase, B phase and C phase of the low-voltage side of the transformer, and the second ends of the first inductor, the second inductor and the third inductor are connected one-to-one to the A phase power supply end, B phase power supply end and C phase power supply end of the electric head.

[0022] Preferably, the second filtering unit includes a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor and a twelfth capacitor;

[0023] The seventh capacitor and the eighth capacitor are respectively connected between the second end of the first inductor and the ground, the ninth capacitor and the tenth capacitor are respectively connected between the second end of the second inductor and the ground, and the eleventh capacitor and the twelfth capacitor are respectively connected between the second end of the third inductor and the ground.

[0024] The utility model also constructs a nuclear power plant interference signal absorbing device, which comprises the nuclear power plant interference signal absorbing circuit described above.

[0025] The utility model also constructs an electric head power supply system, which comprises a transformer and the above-mentioned nuclear power plant interference signal absorbing device.

[0026] The implementation of the utility model has the following beneficial effects: providing a nuclear power plant interference signal absorption circuit, which can effectively filter out the interference signal superimposed on the low-voltage side of the transformer through the cooperation of the interphase filter unit, the ground filter unit and the output filter unit, thereby avoiding false alarms of the phase loss protection device and improving the operational stability of the nuclear power plant. The working status of the interphase filter unit and the ground filter unit is also prompted by the prompt unit, and a fault prompt signal is output in the prompt unit. The interphase filter unit and the ground filter unit can be controlled to be put into or out of use by controlling the on and off of the switch unit, so that staff can inspect and repair the interphase filter unit and the ground filter unit while ensuring power failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0028] Figure 1 This is a circuit structure block diagram of a nuclear power plant interference signal absorption circuit in some embodiments of the present utility model;

[0029] Figure 2 It is a circuit principle diagram of a nuclear power plant interference signal absorption circuit in some embodiments of the present utility model. DETAILED DESCRIPTION

[0030] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings.

[0031] In the following description, it should be understood that the directions or positional relationships indicated by “front”, “back”, “up”, “down”, “left”, “right”, “longitudinal”, “horizontal”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “head”, and “tail” are based on the directions or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific direction. They are only for the convenience of describing the technical solution, and do not indicate that the device or element referred to must have a specific direction. Therefore, they cannot be understood as a limitation on the present utility model.

[0032] This utility model provides a nuclear power plant interference signal absorption circuit. This circuit is used in the electric head power supply system. It can absorb the interference signal input into the electric head power supply, avoid false alarms of the phase loss protection device, and improve the operational stability of the nuclear power plant. In addition, the electric head power supply system includes a transformer 20. The function of the transformer 20 is to convert the high voltage AC voltage (380VAC) into a low voltage AC voltage that can directly power the electric head. Figure 1 The nuclear power plant interference signal absorption circuit may include an interphase filtering unit 1, a ground filtering unit 2, a prompting unit 3, a switching unit 4 and an output filtering unit 5.

[0033] like Figure 1 As shown, the switch unit 4 connects the interphase filter unit 1 and the ground filter unit 2. The switch unit 4 is used to connect the low-voltage side of the transformer 20 and activate or deactivate the interphase filter unit 1 and the ground filter unit 2 according to the operation of the staff.

[0034] In some embodiments, as Figure 2 As shown, the switch unit 4 may include a circuit breaker 41 and a contactor 42. The circuit breaker 41 may be an existing three-pole circuit breaker, and the contactor 42 may be an existing three-pole contactor. The first input terminal, the second input terminal, and the third input terminal of the circuit breaker 41 are connected one-to-one to the A phase, the B phase, and the C phase of the low-voltage side of the transformer 20. The first output terminal, the second output terminal, and the third output terminal of the circuit breaker 41 are connected one-to-one to the first input terminal, the second input terminal, and the third input terminal of the contactor 42. The first output terminal, the second output terminal, and the third output terminal of the contactor 42 are connected to the interphase filter unit 1 and the ground filter unit 2. The excitation coil (not shown) of the contactor 42 is used to receive the input control instruction. It should be noted that the input control instructions can be provided by the nuclear power plant DCS system (i.e., nuclear power digital instrumentation and control system), so that the staff can remotely control the input or output of the interphase filter unit 1 and the ground filter unit 2; the function of the circuit breaker 41 is that when it is determined that any electronic component in the interphase filter unit 1 or the ground filter unit 2 is faulty and needs to be repaired or replaced, the staff can manually disconnect the circuit breaker 41, thereby ensuring that the staff can carry out maintenance work in a safe condition.

[0035] like Figure 1 As shown, the phase-to-phase filter unit 1 is connected with the switch unit 4, and the phase-to-phase filter unit 1 is used to filter the differential mode interference signals on the low voltage side of the transformer 20.

[0036] In some embodiments, the phase-to-phase filter unit 1 can include a first capacitor C1, a second capacitor C2 and a third capacitor C3 as shown. Figure 2 The first capacitor C1 is connected between the first output end and the second output end of the switch unit 4, so as to filter the differential mode interference signals between the A phase and the B phase on the low voltage side of the transformer 20. The second capacitor C2 is connected between the first output end and the third output end of the switch unit 4, so as to filter the differential mode interference signals between the A phase and the C phase on the low voltage side of the transformer 20. The third capacitor C3 is connected between the second output end and the third output end of the switch unit 4, so as to filter the differential mode interference signals between the B phase and the C phase on the low voltage side of the transformer 20.

[0037] As shown, the ground filter unit 2 is connected with the switch unit 4, and the ground filter unit 2 is used to filter the common mode interference signals on the low voltage side of the transformer 20. Figure 1

[0038] In some embodiments, the ground filter unit 2 can include a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6 as shown. Figure 2 The fourth capacitor C4 is connected between the first output end of the switch unit 4 and the ground, so as to filter the common mode interference signals in the A phase on the low voltage side of the transformer 20. The fifth capacitor C5 is connected between the second output end of the switch unit 4 and the ground, so as to filter the common mode interference signals in the B phase on the low voltage side of the transformer 20. The sixth capacitor C6 is connected between the third output end of the switch unit 4 and the ground, so as to filter the common mode interference signals in the C phase on the low voltage side of the transformer 20.

[0039] As shown, the prompt unit 3 is connected with the phase-to-phase filter unit 1 and the ground filter unit 2, and the prompt unit 3 is used to output a fault prompt signal when any capacitor in the phase-to-phase filter unit 1 or the ground filter unit 2 has a short circuit fault. Figure 1 In some embodiments, the prompt unit 3 can include a first resistor R1, a second resistor R2 and a third resistor R3 as shown.

[0040] Figure 2 ​​The six indicator lights D1 are shown. The six indicator lights D1 are connected in parallel with the first to sixth capacitors C6 one by one, and the indicator lights D1 are used to go out when the switch unit 4 is disconnected or the capacitor connected thereto has a short circuit fault. It can be understood that when the switch unit 4 is closed (i.e., the circuit breaker 41 and / or the contactor 42 is disconnected), the interphase filter unit 1 and the ground filter unit 2 are disconnected from the transformer 20, thereby losing power and the indicator lights D1 go out; taking the first capacitor C1 as an example, when the first capacitor C1 has a short circuit fault, the voltage drop across the first capacitor C1 is reduced, which is not enough to drive the indicator light D1 connected in parallel with the first capacitor C1, so that the indicator light D1 goes out, thereby reminding the staff that the first capacitor C1 has a short circuit fault.

[0041] like Figure 1 As shown, the output filter unit 5 is used to be connected between the low-voltage side of the transformer 20 and the electric head to suppress interference signals input to the electric head.

[0042] In some embodiments, the output filter unit 5 may include: Figure 2 The first filtering unit 51 and the second filtering unit 52 are shown.

[0043] like Figure 2 As shown, the first filtering unit 51 is used to be connected in series between the low-voltage side of the transformer 20 and the electric head to suppress high-frequency interference signals input to the electric head.

[0044] In some embodiments, as Figure 2 As shown, the first filtering unit 51 may include a first inductor L1, a second inductor L2, and a third inductor L3. The first ends of the first inductor L1, the second inductor L2, and the third inductor L3 are connected one-to-one to the A phase, B phase, and C phase of the low-voltage side of the transformer 20, and the second ends of the first inductor L1, the second inductor L2, and the third inductor L3 are connected one-to-one to the A phase power supply terminal, the B phase power supply terminal, and the C phase power supply terminal of the electric head. The operating frequency of the transformer 20 is generally 50 Hz. In this embodiment, the first inductor L1, the second inductor L2, and the third inductor L3 are connected in series as low-pass filters between the A, B, and C phases of the low-voltage side of the transformer 20 and the electric head, playing a low-pass filtering role, and can filter out high-frequency interference signals superimposed on each phase, that is, filter out interference signals with a frequency greater than 50 Hz, and the higher the frequency of the interference signal, the better the filtering effect.

[0045] like Figure 2 As shown, the second filtering unit 52 is connected between the first filtering unit 51 and the ground, and the second filtering unit 52 is used to filter out interference signals input to the electric head.

[0046] In some embodiments, as Figure 2As shown, the second filtering unit 52 may include a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, and a twelfth capacitor C12. The seventh capacitor C7 and the eighth capacitor C8 are respectively connected between the second end of the first inductor L1 and the ground. The seventh capacitor C7 and the eighth capacitor C8 can further filter out interference signals input to the electric head. It is understandable that the capacitance of the seventh capacitor C7 and the eighth capacitor C8 can be set according to actual needs. For example, the capacitance value of the seventh capacitor C7 is set to be smaller than the capacitance value of the eighth capacitor C8, so that the seventh capacitor C7 is specifically used to filter out interference signals with a frequency higher than 50 Hz, while the eighth capacitor C8 is specifically used to filter out interference signals with a frequency less than 50 Hz. It is understandable that the seventh capacitor C7 and the eighth capacitor C8 and the first inductor L1 can effectively retain signals with a frequency close to 50 Hz as much as possible, that is, interference signals with a larger frequency difference from 50 Hz are more easily filtered out. The ninth capacitor C9 and the tenth capacitor C10 are respectively connected between the second end of the second inductor L2 and the ground. The ninth capacitor C9 and the tenth capacitor C10 can further filter out the interference signal input to the electric head. It is understandable that the ninth capacitor C9 and the tenth capacitor C10 can set their capacitance according to actual needs. The eleventh capacitor C11 and the twelfth capacitor C12 are respectively connected between the second end of the third inductor L3 and the ground. The eleventh capacitor C11 and the twelfth capacitor C12 can further filter out the interference signal input to the electric head. It is understandable that the eleventh capacitor C11 and the twelfth capacitor C12 can set their capacitance according to actual needs. It should be noted that the functions of the ninth capacitor C9 and the tenth capacitor C10, the eleventh capacitor C11 and the twelfth capacitor C12 can refer to the functions of the seventh capacitor C7 and the eighth capacitor C8, and will not be repeated here.

[0047] It should be noted that the utility model can effectively filter out the interference signal superimposed on the low-voltage side of the transformer through the cooperation of the interphase filter unit, the ground filter unit and the output filter unit, thereby avoiding false alarms of the phase loss protection device and improving the operational stability of the nuclear power plant. The working status of the interphase filter unit and the ground filter unit can be prompted by the prompt unit, and a fault prompt signal can be output in the prompt unit. The interphase filter unit and the ground filter unit can be controlled to be put into or withdrawn by controlling the on and off of the switch unit, so that the staff can inspect and repair the interphase filter unit and the ground filter unit while ensuring power off.

[0048] The utility model also provides a nuclear power plant interference signal absorption device, which includes the nuclear power plant interference signal absorption circuit provided by the embodiment of the utility model.

[0049] The utility model also provides an electric head power supply system, comprising a transformer and a nuclear power plant interference signal absorbing device provided in an embodiment of the utility model.

[0050] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A nuclear power plant interference signal absorption circuit, used in an electric head power supply system, wherein the electric head power supply system includes a transformer, characterized in that: The nuclear power plant interference signal absorption circuit includes: An interphase filtering unit, used for filtering out differential-mode interference signals on the low-voltage side of the transformer; A ground filtering unit, used for filtering out common-mode interference signals on the low-voltage side of the transformer; a prompt unit connected to the interphase filtering unit and the ground filtering unit, and configured to output a fault prompt signal when the interphase filtering unit or the ground filtering unit fails; a switch unit, connected to the interphase filter unit and the ground filter unit, and used to connect the low-voltage side of the transformer to activate or deactivate the interphase filter unit and the ground filter unit; The output filter unit is used to be connected between the low-voltage side of the transformer and the electric head to suppress interference signals input to the electric head.

2. The nuclear power plant interference signal absorption circuit according to claim 1, characterized in that: The interphase filtering unit includes a first capacitor, a second capacitor and a third capacitor; The first capacitor is connected between the first output terminal and the second output terminal of the switch unit, the second capacitor is connected between the first output terminal and the third output terminal of the switch unit, and the third capacitor is connected between the second output terminal and the third output terminal of the switch unit.

3. The nuclear power plant interference signal absorption circuit according to claim 2, characterized in that: The ground filtering unit includes a fourth capacitor, a fifth capacitor and a sixth capacitor; The fourth capacitor is connected between the first output terminal of the switch unit and the ground, the fifth capacitor is connected between the second output terminal of the switch unit and the ground, and the sixth capacitor is connected between the sixth output terminal of the switch unit and the ground.

4. The nuclear power plant interference signal absorption circuit according to claim 3, characterized in that: The prompt unit includes six indicator lights; the six indicator lights are connected in parallel with the first to sixth capacitors one by one, and the indicator lights are used to go out when the switch unit is disconnected or the capacitor connected to it has a short circuit fault.

5. The nuclear power plant interference signal absorption circuit according to claim 1, characterized in that: The switch unit includes a circuit breaker and a contactor; The first input end, the second input end and the third input end of the circuit breaker are connected one-to-one to the A phase, the B phase and the C phase on the low-voltage side of the transformer; the first output end, the second output end and the third output end of the circuit breaker are connected one-to-one to the first input end, the second input end and the third input end of the contactor; the first output end, the second output end and the third output end of the contactor are connected to the interphase filter unit and the ground filter unit; the excitation coil of the contactor is used to receive the input control instruction.

6. The nuclear power plant interference signal absorbing circuit according to any one of claims 1 to 5, characterized in that: The output filtering unit comprises: a first filtering unit, configured to be connected in series between the low-voltage side of the transformer and the electric head to suppress high-frequency interference signals input to the electric head; The second filtering unit is connected between the first filtering unit and the ground, and is used to filter out interference signals input to the electric head.

7. The nuclear power plant interference signal absorption circuit according to claim 6, characterized in that: The first filtering unit includes a first inductor, a second inductor and a third inductor; The first ends of the first inductor, the second inductor and the third inductor are connected one-to-one to the A phase, B phase and C phase of the low-voltage side of the transformer, and the second ends of the first inductor, the second inductor and the third inductor are connected one-to-one to the A phase power supply end, B phase power supply end and C phase power supply end of the electric head.

8. The nuclear power plant interference signal absorption circuit according to claim 7, characterized in that: The second filtering unit includes a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, an eleventh capacitor and a twelfth capacitor; The seventh capacitor and the eighth capacitor are respectively connected between the second end of the first inductor and the ground, the ninth capacitor and the tenth capacitor are respectively connected between the second end of the second inductor and the ground, and the eleventh capacitor and the twelfth capacitor are respectively connected between the second end of the third inductor and the ground.

9. A nuclear power plant interference signal absorption device, characterized in that: The invention comprises the nuclear power plant interference signal absorbing circuit according to any one of claims 1 to 8.

10. A power supply system for an electric head, characterized in that: The device comprises a transformer and the nuclear power plant interference signal absorbing device as claimed in claim 9.

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