System and method for preventing false trips of generator excitation system jumper faults

Abstract

The present application belongs to the technical field of generator detection, and relates to a system and method for preventing fault action of a generator excitation system jumper, which comprises a shunt, a direct current transmitter, a controller, a de-excitation circuit connected in parallel with an output end of a generator rotor, a Hall transmitter and a current transformer; the de-excitation circuit comprises a de-excitation resistor and an electronic jumper connected in series. According to the collected excitation voltage signal of the generator rotor circuit, the excitation current signal of the generator rotor circuit, the current signal of the jumper and the current signal of the de-excitation circuit, the present application can accurately determine whether the jumper of the generator excitation system is faulty; by introducing a rotor overvoltage action signal as an auxiliary criterion for the jumper fault of the generator excitation system, the present application effectively avoids the unit mis-stop caused by the drift or jump of the Hall transmitter current sampling value triggering the jumper fault alarm action condition.

Description

Technical Field

[0001] This invention relates to the field of generator testing technology, and more specifically, to a system and method for preventing malfunctions of jumpers in generator excitation systems. Background Technology

[0002] The main function of the generator excitation system is to maintain stable terminal voltage, rationally distribute reactive load among units, and complete voltage and reactive power regulation after grid connection. The excitation system jumper consists of a set of thyristors connected in parallel in both directions and a demagnetizing resistor in series. The jumper is connected in parallel across the rotor windings. Its main function is to trigger the thyristors in the electronic jumper to connect the demagnetizing resistor to the rotor circuit during rotor overvoltage and generator failure demagnetization, thereby rapidly dissipating rotor energy and quickly reducing rotor voltage and performing emergency demagnetization.

[0003] Currently, most domestic power plant excitation system electronic jumper faults are diagnosed solely based on jumper current, which is a rather simplistic approach. During normal operation, the excitation system operates with the de-energizing switch in the closed position, and both excitation voltage and current are at normal levels. However, if the Hall effect transmitter's performance is unstable, causing a drift in the sampled forward current value and triggering the jumper fault alarm, the excitation system will send a severe fault signal to the generator protection device. This will then shut down the generator. If a large hydropower unit operates at full load and experiences an accidental shutdown, it will severely impact the grid's frequency quality. Furthermore, the enormous residual energy will cause the unit's speed to rise rapidly, posing a significant threat to rotating components. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a system and method for preventing malfunctions of jumpers in generator excitation systems.

[0005] In a first aspect, this disclosure provides a system for preventing malfunction of the jumper in the generator excitation system, including a shunt, a DC transmitter, a controller, a demagnetizing circuit connected in parallel with the output terminal of the generator rotor, a Hall transmitter, and a current transformer; the demagnetizing circuit includes a demagnetizing resistor and an electronic jumper connected in series.

[0006] One end of the demagnetizing resistor is electrically connected to the first output terminal of the generator rotor; the other end of the demagnetizing resistor is electrically connected to the second output terminal of the generator rotor through the electronic jumper.

[0007] The first input terminal of the DC transmitter is used to acquire the excitation voltage signal of the generator rotor circuit as a first detection signal; the input terminal of the shunt is electrically connected to the generator rotor circuit, and the output terminal of the shunt is electrically connected to the second input terminal of the DC transmitter to acquire the excitation current signal of the generator rotor circuit as a second detection signal.

[0008] The output terminal of the DC transmitter is electrically connected to the input terminal of the controller;

[0009] The Hall transmitter is installed in the demagnetizing circuit to collect the current signal of the jumper as a third detection signal; the current transformer is installed in the demagnetizing circuit to collect the current signal of the demagnetizing circuit as a fourth detection signal; the Hall transmitter and the current transformer are respectively electrically connected to the controller.

[0010] The controller is used to determine whether the jumper is faulty based on whether the first detection signal, the second detection signal, the third detection signal, and the fourth detection signal are within a set range; if the first detection signal, the second detection signal, the third detection signal, and the fourth detection signal are within the set range, then the jumper is not faulty; otherwise, the jumper is faulty.

[0011] Secondly, the present invention discloses a method for preventing malfunction of the jumper in a generator excitation system, comprising:

[0012] The excitation voltage signal of the generator rotor circuit is collected as the first detection signal; the excitation current signal of the generator rotor circuit is collected as the second detection signal; the current signal of the jumper is collected as the third detection signal; and the current signal of the demagnetizing circuit is collected as the fourth detection signal.

[0013] The first detection signal is converted into the actual value of the excitation voltage, the second detection signal is converted into the actual value of the excitation current, the third detection signal is converted into the actual value of the jumper current, and the fourth detection signal is set as the rotor overvoltage action signal value.

[0014] Set reference threshold values ​​for excitation voltage, excitation current, and jumper current respectively;

[0015] The fault state of the jumper is determined based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and each of the reference thresholds.

[0016] The beneficial effects of this invention are: based on the collected excitation voltage signal of the generator rotor circuit, the excitation current signal of the generator rotor circuit, the current signal of the jumper, and the current signal of the demagnetizing circuit, this invention can accurately determine whether the jumper of the generator excitation system has a fault; by introducing the rotor overvoltage action signal value as an auxiliary criterion for fault judgment of the jumper of the generator excitation system, it can effectively avoid the unit from being shut down erroneously due to the drift or jump of the Hall transmitter current sampling value triggering the jumper fault alarm action condition.

[0017] Based on the above technical solution, the present invention can be further improved as follows.

[0018] Furthermore, the rotor circuit is equipped with a demagnetizing switch; the controller is connected to a step-down converter; the positive input terminal of the step-down converter is electrically connected to the positive input terminal of the rotor circuit, and the negative input terminal of the step-down converter is electrically connected to the negative input terminal of the rotor circuit; the output terminal of the step-down converter is electrically connected to the input terminal of the controller; the controller determines the operating state of the demagnetizing switch based on the voltage signal collected by the step-down converter.

[0019] Furthermore, the demagnetizing switch is connected to a relay auxiliary contact; the controller is connected to a relay; and the controller is electrically connected to the demagnetizing switch through the relay.

[0020] Furthermore, the excitation voltage signal of the generator rotor circuit is acquired using a DC transmitter as the first detection signal; the excitation current signal of the generator rotor circuit is acquired using the DC transmitter through a shunt as the second detection signal; the current signal of the jumper is acquired using a Hall transmitter as the third detection signal; and the current signal of the demagnetizing circuit is acquired using a current transformer as the fourth detection signal.

[0021] Furthermore, the fault state of the jumper is determined based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal, and each of the reference thresholds, including: setting the reference threshold of the jumper current value as a current setting threshold.

[0022] When the excitation voltage and excitation current are within the reference threshold range, if the rotor overvoltage action signal value is not 0 for no more than a first set time, and the jumper current value is greater than the current set threshold and continues for a second set time, then the jumper is faulty; otherwise, if the rotor overvoltage action signal value is 0 or the rotor overvoltage action signal value is not 0 for more than the first set time, then the jumper is not faulty.

[0023] If the excitation voltage is less than the first set voltage value, the excitation current is less than the first set current value, and the jumper current is greater than the second set current value, then the jumper will have a detection fault.

[0024] Furthermore, determining the jumper fault state based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and each of the reference thresholds also includes:

[0025] When both the excitation voltage and the excitation current are within the reference threshold range, it is determined whether the current value of the jumper is greater than the third set current and continues for a fourth set time within a third set time from the moment the rotor overvoltage occurs. If the current value of the jumper is greater than the third set current and continues for a fourth set time, the jumper is faulty and the unit trips. Otherwise, the jumper is not faulty and the unit operates normally.

[0026] Furthermore, determining the jumper fault state based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and each of the reference thresholds also includes:

[0027] If the excitation voltage value or either the excitation voltage value is outside the reference threshold range, determine whether the jumper current value is greater than the fourth set current value and the duration is greater than the fifth set time. If so, the jumper detection is incorrect and it cannot be determined whether the jumper has malfunctioned; otherwise, the jumper has not malfunctioned. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the system for preventing malfunction of the jumper in the generator excitation system provided in Embodiment 1 of the present invention;

[0029] Figure 2 This is a flowchart of a method for preventing malfunction of a jumper in a generator excitation system, provided in Embodiment 2 of the present invention.

[0030] Figure 3 This is a table showing the measured results of the generator phase advance test provided in Embodiment 2 of the present invention;

[0031] Figure 4 This is a flowchart for determining the fault state of a jumper provided in Embodiment 2 of the present invention.

[0032] Icons: K - demagnetizing switch; Rz - demagnetizing resistor; FL - shunt; J - jumper; H - Hall effect transmitter; CT - current transformer; F - fuse; JK - DC transmitter; CNTLR - controller; U+ - positive input terminal of generator rotor circuit; U- - negative input terminal of generator rotor circuit; G - generator rotor. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Example 1

[0035] As an example, see the attached document. Figure 1 As shown, to solve the above-mentioned technical problems, this embodiment provides a system to prevent malfunction of the jumper in the generator excitation system, including a shunt FL, a DC transmitter JK, a controller CNTLR, a demagnetizing circuit connected in parallel with the output terminal of the generator rotor G, a Hall transmitter H and a current transformer CT; the demagnetizing circuit includes a demagnetizing resistor Rz and an electronic jumper J connected in series.

[0036] One end of the demagnetizing resistor Rz is electrically connected to the first output terminal of the generator rotor G; the other end of the demagnetizing resistor Rz is electrically connected to the second output terminal of the generator rotor G through an electronic jumper J.

[0037] The first input terminal of the DC transmitter JK is used to acquire the excitation voltage signal of the generator rotor circuit as the first detection signal; the input terminal of the shunt FL is electrically connected to the generator rotor circuit, and the output terminal of the shunt FL is electrically connected to the second input terminal of the DC transmitter JK to acquire the excitation current signal of the generator rotor circuit as the second detection signal.

[0038] The output terminal of the DC transmitter JK is electrically connected to the input terminal of the controller CNTLR;

[0039] Hall transmitter H is set across the jumper J to collect the voltage signal of jumper J as the third detection signal; current transformer CT is set in the demagnetizing circuit to collect the current signal of the demagnetizing circuit as the fourth detection signal; Hall transmitter H and current transformer CT are respectively connected to the controller CNTLR electrical signal.

[0040] The controller CNTLR is used to determine whether the jumper J is faulty based on whether the first detection signal, the second detection signal, the third detection signal, and the fourth detection signal are within the set range. If the first detection signal, the second detection signal, the third detection signal, and the fourth detection signal are within the set range, then the jumper J is not faulty; otherwise, the jumper J is faulty.

[0041] Specifically, the demagnetizing circuit consists of a demagnetizing resistor Rz, an electronic jumper J, a Hall transmitter H, and a current transformer CT, all connected in parallel with the rotor, as shown in the attached diagram. Figure 3 As shown, the excitation voltage is input to the DC transmitter JK as the first detection signal, and the excitation current is input to the DC transmitter JK after passing through the shunt FL as the second detection signal. The first and second detection signals are processed and transmitted to the controller CNTLR. The current value of the jumper J collected by the Hall transmitter H is used as the third detection signal, and the current value collected by the current transformer CT is used as the fourth detection signal. The third and fourth detection signals are transmitted to the controller CNTLR.

[0042] In practical applications, Figure 1 In the generator rotor circuit, where the demagnetizing switch K is located, fuses F are installed between the positive input terminal U+ of the generator rotor circuit and the DC transmitter JK, and between the negative input terminal U- of the generator rotor circuit and the DC transmitter JK. The generator rotor G is connected in the generator rotor circuit.

[0043] Specifically, the controller CNTLR converts the received first detection signal into the actual value of the excitation voltage, the second detection signal into the actual value of the excitation current, the third detection signal into the current value of the jumper J, and the fourth detection signal into the rotor overvoltage action signal value.

[0044] The controller CNTLR collects the open / closed status of the demagnetizing switch K. When the demagnetizing switch K is closed, it combines the actual value of the excitation voltage, the actual value of the excitation current, the current value of the jumper J, and the rotor voltage to determine whether the jumper J has malfunctioned.

[0045] Optionally, the rotor circuit is equipped with a demagnetizing switch K; the controller CNTLR is connected to a step-down converter; the positive input terminal of the step-down converter is electrically connected to the positive input terminal of the rotor circuit, and the negative input terminal of the step-down converter is electrically connected to the negative input terminal of the rotor circuit; the output terminal of the step-down converter is electrically connected to the input terminal of the controller CNTLR; the controller CNTLR determines the operating state of the demagnetizing switch K based on the voltage signal collected by the step-down converter.

[0046] Optionally, the demagnetizing switch K is connected to a relay auxiliary contact; the controller CNTLR is connected to a relay; the controller CNTLR is electrically connected to the demagnetizing switch K via the relay. The controller CNTLR controls the opening and closing state of the demagnetizing switch K via the relay.

[0047] Based on the collected excitation voltage signal of the generator rotor circuit, the excitation current signal of the generator rotor circuit, the current signal of the jumper, and the current signal of the demagnetizing circuit, this invention can accurately determine whether there is a fault in the jumper of the generator excitation system. By introducing the rotor overvoltage action signal as an auxiliary criterion for fault judgment of the jumper of the generator excitation system, it can effectively avoid the unit from being shut down erroneously due to the drift or jump of the current sampling value of the Hall transmitter triggering the jumper fault alarm action condition.

[0048] Example 2

[0049] Based on the same principle as the method shown in Embodiment 1 of the present invention, as illustrated in the appendix. Figure 2 As shown, embodiments of the present invention also provide a method for preventing malfunction of the jumper in the generator excitation system, comprising:

[0050] The excitation voltage signal of the generator rotor circuit is collected as the first detection signal; the excitation current signal of the generator rotor circuit is collected as the second detection signal; the current signal of the jumper is collected as the third detection signal; and the current signal of the demagnetizing circuit is collected as the fourth detection signal.

[0051] The first detection signal is converted into the actual value of the excitation voltage, the second detection signal is converted into the actual value of the excitation current, the third detection signal is converted into the actual value of the jumper current, and the fourth detection signal is set as the rotor overvoltage action signal value.

[0052] Set reference threshold values ​​for excitation voltage, excitation current, and jumper current respectively;

[0053] The fault status of the jumper is determined based on the actual values ​​of the excitation voltage, excitation current, jumper current, rotor overvoltage action signal, and various reference thresholds.

[0054] Optionally, a DC transmitter is used to acquire the excitation voltage signal of the generator rotor circuit as the first detection signal; a DC transmitter is used to acquire the excitation current signal of the generator rotor circuit through a shunt as the second detection signal; a Hall transmitter is used to acquire the current signal of the jumper as the third detection signal; and a current transformer is used to acquire the current signal of the demagnetizing circuit as the fourth detection signal.

[0055] Optionally, the fault status of the jumper can be determined based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal, and various reference thresholds, including: setting the reference threshold for the jumper current value as the current setting threshold.

[0056] When the excitation voltage and excitation current are within the reference threshold range, if the rotor overvoltage action signal value is not 0 for no more than the first set time, and the jumper current value is greater than the current set threshold and continues for a second set time, then the jumper is faulty; otherwise, if the rotor overvoltage action signal value is 0 or the rotor overvoltage action signal value is not 0 for more than the first set time, then the jumper is not faulty.

[0057] If the excitation voltage is less than the first set voltage value and the excitation current is less than the first set current value, and the jumper current is greater than the second set current value, then the jumper will have a detection fault.

[0058] Specifically, the reference threshold for the excitation voltage during normal operation of the excitation system is set to 50V, and the reference threshold for the excitation current during normal operation is set to 100A. The excitation system is considered to be operating normally if either of these conditions is met. (See attached...) Figure 3 The data shows that when the unit is operating under the leading phase condition, the excitation voltage is greater than 50V and the excitation current is greater than 100A. Therefore, under the normal operating condition, the excitation voltage is also greater than 50V and the excitation current is greater than 100A.

[0059] The first set time is set to 10 seconds, the second set time is set to 3 seconds, and the judgment threshold for the positive current of the jumper is set to 200A. When the excitation system is running normally, no current flows through the jumper, and the Hall transmitter sampling current and the current transformer should be 0A. If there is a false connection of the jumper at this time, the excitation current will partially flow through the demagnetization circuit, causing the Hall transmitter and the current transformer to detect the positive current flowing through. When the current transformer sampling current is not 0, the controller outputs a rotor overvoltage signal. If the rotor overvoltage signal is output within 10 seconds and the positive current of the jumper is greater than 200A and lasts for more than 3 seconds, it is judged that the jumper is faulty.

[0060] Optionally, determining the jumper fault state based on the actual excitation voltage, actual excitation current, jumper current, rotor overvoltage action signal value, and various reference thresholds also includes:

[0061] When both the excitation voltage and excitation current are within the reference threshold range, determine whether the jumper current is greater than the third set current and continues for a fourth set time within a third set time from the moment the rotor overvoltage occurs. If the jumper current is greater than the third set current and continues for a fourth set time, the jumper is faulty and the unit trips. Otherwise, the jumper is not faulty and the unit operates normally.

[0062] Specifically, the third set time is 10 seconds, the fourth set time is 3 seconds, and the third set current is 200A, as shown in the attached diagram. Figure 4As shown, determining the jumper fault state based on the actual excitation voltage, actual excitation current, jumper current, rotor overvoltage action signal value, and reference thresholds for each of the aforementioned parameters also includes:

[0063] S1: When the unit's FCB (Functional Load Shedding) is in the closed position, determine whether the excitation voltage and excitation current values ​​are within the reference threshold range. If the excitation voltage or excitation current values ​​meet the reference threshold range, the unit is in operation and proceeds to step S2. If neither the excitation voltage nor the excitation current values ​​meet the reference threshold range, proceed to step S3.

[0064] S2: Determine whether the forward current of the jumper is greater than 200A and lasts for more than 3 seconds within 10 seconds from the moment the rotor overvoltage action occurs. If so, report a jumper fault, the protection device trips GCB (generator outlet circuit breaker) and FCB, and the unit shuts down and disconnects. Otherwise, the jumper has not failed.

[0065] S3: Determine if the forward current of the jumper is greater than 50A and lasts for more than 2 seconds. If so, the jumper detection system is faulty, the Hall transmitter element is faulty, and it is impossible to determine whether the jumper is faulty. Otherwise, the jumper is not faulty.

[0066] Optionally, determining the jumper fault state based on the actual excitation voltage, actual excitation current, jumper current, rotor overvoltage action signal value, and various reference thresholds also includes:

[0067] When the excitation voltage or excitation current is not within the reference threshold range, it is determined whether the jumper current is greater than the fourth set current value and the duration is greater than the fifth set time. If so, the jumper detection is incorrect and it cannot be determined whether the jumper is faulty. The fourth set current value is set to 50A and the fifth set time is set to 2 seconds. That is, in the above S3, it is determined whether the jumper forward current is greater than 50A and lasts for more than 2 seconds. If so, the jumper detection system is faulty and the Hall transmitter element is faulty, and it cannot be determined whether the jumper is faulty; otherwise, the jumper is not faulty.

[0068] This invention can accurately determine whether the generator excitation system jumper is faulty based on the collected excitation voltage signal of the generator rotor circuit, the excitation current signal of the generator rotor circuit, the current signal of the jumper, and the current signal of the demagnetizing circuit. By introducing the rotor overvoltage action signal value as an auxiliary criterion for generator excitation system jumper faults, it can effectively avoid the unit from being mistakenly shut down due to the drift or jump of the Hall transmitter current sampling value triggering the jumper fault alarm action condition, thus ensuring the stability of the unit operation.

[0069] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A system for preventing malfunctions of jumpers in generator excitation systems, characterized in that, It includes a shunt, a DC transmitter, a controller, a demagnetizing circuit connected in parallel with the output terminal of the generator rotor, a Hall transmitter, and a current transformer; the demagnetizing circuit includes a demagnetizing resistor and a jumper connected in series. One end of the demagnetizing resistor is electrically connected to the first output terminal of the generator rotor; the other end of the demagnetizing resistor is electrically connected to the second output terminal of the generator rotor through the jumper. The first input terminal of the DC transmitter is used to acquire the excitation voltage signal of the generator rotor circuit as a first detection signal; the input terminal of the shunt is electrically connected to the generator rotor circuit, and the output terminal of the shunt is electrically connected to the second input terminal of the DC transmitter to acquire the excitation current signal of the generator rotor circuit as a second detection signal. The output terminal of the DC transmitter is electrically connected to the input terminal of the controller; The Hall transmitter is installed in the demagnetizing circuit to collect the current signal of the jumper as a third detection signal; the current transformer is installed in the demagnetizing circuit to collect the current signal of the demagnetizing circuit as a fourth detection signal; the Hall transmitter and the current transformer are respectively electrically connected to the controller. The controller is used to determine whether the jumper is faulty based on whether the first detection signal, the second detection signal, the third detection signal, and the fourth detection signal are within a set range; if the first detection signal, the second detection signal, the third detection signal, and the fourth detection signal are within the set range, then the jumper is not faulty; otherwise, the jumper is faulty.

2. The system for preventing malfunction of the jumper in the generator excitation system according to claim 1, characterized in that, The rotor circuit is equipped with a demagnetizing switch; the controller is connected to a step-down converter; the positive input terminal of the step-down converter is electrically connected to the positive input terminal of the rotor circuit, and the negative input terminal of the step-down converter is electrically connected to the negative input terminal of the rotor circuit; the output terminal of the step-down converter is electrically connected to the input terminal of the controller; the controller determines the operating state of the demagnetizing switch based on the voltage signal collected by the step-down converter.

3. The system for preventing malfunction of the jumper in the generator excitation system according to claim 2, characterized in that, The demagnetizing switch is connected to a relay auxiliary contact; the controller is connected to a relay; the controller is electrically connected to the demagnetizing switch through the relay.

4. A method for preventing malfunction of the jumper in a generator excitation system, characterized in that, include: The excitation voltage signal of the generator rotor circuit is collected as the first detection signal; The excitation current signal of the generator rotor circuit is collected as the second detection signal; The current signal of the jumper is collected as the third detection signal, and the current signal of the demagnetizing circuit is collected as the fourth detection signal. The first detection signal is converted into the actual value of the excitation voltage, the second detection signal is converted into the actual value of the excitation current, the third detection signal is converted into the actual value of the jumper current, and the fourth detection signal is set as the rotor overvoltage action signal value. Set reference threshold values ​​for excitation voltage, excitation current, and jumper current respectively; The fault state of the jumper is determined based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and each of the reference thresholds.

5. The method for preventing malfunction of the jumper in the generator excitation system according to claim 4, characterized in that, The excitation voltage signal of the generator rotor circuit is acquired using a DC transmitter as the first detection signal; the excitation current signal of the generator rotor circuit is acquired using the DC transmitter through a shunt as the second detection signal. The current signal of the jumper is acquired using a Hall effect transmitter and used as the third detection signal; The current signal of the demagnetizing circuit is collected using a current transformer and used as the fourth detection signal.

6. The method for preventing malfunction of the jumper in the generator excitation system according to claim 4, characterized in that, The fault state of the jumper is determined based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and each of the reference thresholds, including: setting the reference threshold of the jumper current value as a current setting threshold; When the excitation voltage and excitation current are within the reference threshold range, if the rotor overvoltage action signal value is not 0 for no more than a first set time, and the jumper current value is greater than the current set threshold and continues for a second set time, then the jumper is faulty; otherwise, if the rotor overvoltage action signal value is 0 or the rotor overvoltage action signal value is not 0 for more than the first set time, then the jumper is not faulty. If the excitation voltage is less than the first set voltage value, the excitation current is less than the first set current value, and the jumper current is greater than the second set current value, then the jumper will have a detection fault.

7. The method for preventing malfunction of the jumper in the generator excitation system according to claim 6, characterized in that, The method for determining the jumper fault state based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and various reference thresholds further includes: When both the excitation voltage and the excitation current are within the reference threshold range, it is determined whether the current value of the jumper is greater than the third set current and continues for a fourth set time within a third set time from the moment the rotor overvoltage action occurs. If the current value of the jumper is greater than the third set current and continues for a fourth set time, the jumper is faulty and the unit trips. Otherwise, the jumper is not faulty and the unit operates normally.

8. The method for preventing malfunction of the jumper in the generator excitation system according to claim 6, characterized in that, The method for determining the jumper fault state based on the actual value of the excitation voltage, the actual value of the excitation current, the jumper current value, the rotor overvoltage action signal value, and various reference thresholds further includes: If either the excitation voltage or the excitation current is outside the reference threshold range, determine whether the jumper current is greater than the fourth set current value and the duration is greater than the fifth set time. If so, the jumper detection is incorrect and it cannot be determined whether the jumper has malfunctioned; otherwise, the jumper has not malfunctioned.

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