A fault detection circuit for a generator set

Abstract

The invention discloses a fault detection circuit of a generator set, and relates to the field of detection. The fault detection circuit of the generator set comprises: a signal acquisition module, which is used for acquiring voltage signals on Crowbar circuits in a plurality of double-fed wind generator sets, and outputting the maximum voltage signal to a power supply acquisition module and a fault judgment module; and a power supply acquisition module, which is used for outputting a constant voltage as a power supply for a fault judgment module and a fault indication module. Compared with the prior art, the invention has the following beneficial effects: the invention detects voltage signals on Crowbar circuits in a plurality of double-fed wind generator sets, and gives an alarm when the Crowbar circuit is abnormal, and through the cooperation of the signal acquisition module, a single-chip control module and a fault indication module, it can be determined which Crowbar circuit is currently faulty according to the number of lighted indicator lights, so as to handle the fault in time and avoid the spread of the fault.

Description

Technical Field

[0001] The invention relates to the field of detection, in particular to a fault detection circuit for a generator set. Background Art

[0002] In doubly-fed wind turbine generator sets, grid voltage drop is a common phenomenon. When the grid voltage drops, overcurrent will be generated on the rotor side, which may damage the excitation device and power electronic converter equipment on the rotor side. Therefore, a Crowbar circuit (also known as a crowbar circuit) is provided in the doubly-fed wind turbine generator set. The Crowbar circuit provides a bypass for the rotor side circuit, limits the rotor side overcurrent and the overvoltage on the DC side during a fault, thereby protecting the operation safety of the entire wind power generation system.

[0003] If the Crowbar circuit fails, the doubly-fed wind turbine generator set will not be protected. Grid voltage drops are common in doubly-fed wind turbine generator sets. Therefore, it is necessary to detect the Crowbar circuit failure in time to avoid damage to the doubly-fed wind turbine generator set equipment. Summary of the invention

[0004] The object of the present invention is to provide a fault detection circuit for a generator set to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A fault detection circuit for a generator set, comprising:

[0007] A signal acquisition module is used to collect voltage signals on the Crowbar circuits of multiple double-fed wind turbine generator sets and output the maximum voltage signal to the power supply acquisition module and the fault judgment module;

[0008] A power supply acquisition module is used to output a constant voltage as the power supply for the fault judgment module and the fault indication module;

[0009] The fault judgment module is used to judge whether the maximum voltage signal exceeds the set voltage. If it exceeds the set voltage, it is determined that there is a Crowbar circuit fault and provides a trigger signal for the fault alarm module and the single-chip microcomputer control module;

[0010] Fault alarm module, used to sound an alarm after a trigger signal is input;

[0011] The single-chip control module is used to control the disconnection of the voltage signals on the Crowbar circuits of multiple double-fed wind turbine generator sets collected in sequence according to the passage of time after the trigger signal is input, and there is a delay between the disconnection of two adjacent voltage signals;

[0012] Fault indication module, used for lighting the corresponding indicator light after a voltage signal is disconnected, until the maximum voltage signal is disconnected, and then no more indicator lights are lit (based on the lighting status of the indicator light, determine which doubly-fed wind turbine generator set has a Crowbar circuit failure);

[0013] The output end of the signal acquisition module is connected to the input end of the power supply acquisition module and the first input end of the fault judgment module, the output end of the power supply acquisition module is connected to the second input end of the fault judgment module and the first input end of the fault indication module, the output end of the fault judgment module is connected to the input end of the fault alarm module and the input end of the single-chip control module, and the output end of the single-chip control module is connected to the input end of the signal acquisition module and the second input end of the fault indication module.

[0014] As a further solution of the present invention: the signal acquisition module includes multiple signal acquisition units, and the number of the signal acquisition units is the same as the number of Crowbar circuits in multiple doubly-fed wind turbine generator sets; the signal acquisition unit includes a first diode and a first MOS tube, the positive electrode of the first diode is connected to the voltage on the corresponding Crowbar circuit, the negative electrode of the first diode is connected to the D electrode of the first MOS tube, the G electrode of the first MOS tube is connected to the output end of the single-chip control module, and the S electrode of the first MOS tube is connected to the input end of the power supply acquisition module and the first input end of the fault judgment module.

[0015] As a further solution of the present invention: the power supply acquisition module includes a third resistor, a first capacitor, a fourth resistor, a fourth diode, and a second capacitor, one end of the third resistor is connected to the output end of the signal acquisition module, the other end of the third resistor is connected to one end of the first capacitor and one end of the fourth resistor, the other end of the first capacitor is grounded, the other end of the fourth resistor is connected to the cathode of the fourth diode, one end of the second capacitor, the second input end of the fault judgment module, and the first input end of the fault indication module, the anode of the fourth diode is grounded, and the other end of the second capacitor is grounded.

[0016] As a further solution of the present invention: the fault judgment module includes a first resistor, a second resistor, a third capacitor, a first amplifier, a fifth resistor, a sixth resistor, and a seventh resistor. One end of the first resistor is connected to the output end of the signal acquisition module, the other end of the first resistor is connected to one end of the second resistor, one end of the third capacitor, and the in-phase end of the first amplifier, the other end of the third capacitor is grounded, the other end of the second resistor is grounded, the inverting end of the first amplifier is connected to one end of the fifth resistor and one end of the sixth resistor, the other end of the fifth resistor is grounded, the other end of the sixth resistor is connected to the output end of the power supply acquisition module, the output end of the first amplifier is connected to one end of the seventh resistor and the input end of the fault alarm module, and the other end of the seventh resistor is connected to the input end of the single-chip control module.

[0017] As a further solution of the present invention: the fault alarm module includes an eighth resistor and a speaker, one end of the eighth resistor is connected to the output end of the fault judgment module, the other end of the eighth resistor is connected to one end of the speaker, and the other end of the speaker is grounded.

[0018] As a further solution of the present invention: the single-chip microcomputer control module includes a single-chip microcomputer, a signal input IO port of the single-chip microcomputer is connected to the output end of the fault judgment module, multiple signal output IO ports of the single-chip microcomputer are connected to the input end of the signal acquisition module and the second input end of the fault indication module, and the number of the signal output IO ports of the single-chip microcomputer is the same as the number of Crowbar circuits in multiple double-fed wind turbine generator sets.

[0019] As a further solution of the present invention: the fault indication module includes multiple fault indication units, and the number of the fault indication units is the same as the number of signal output IO ports of the single-chip computer; the fault indication unit includes a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth MOS tube, a sixth MOS tube, and a fifth diode. One end of the ninth resistor is connected to the signal output IO port of the single-chip computer corresponding to the fault indication unit (the output end of the single-chip computer control module), the other end of the ninth resistor is connected to one end of the tenth resistor, the D pole of the sixth MOS tube, and the G pole of the fifth MOS tube, the other end of the tenth resistor is grounded, the S pole of the fifth MOS tube is connected to the output end of the power supply acquisition module through the eleventh resistor, the D pole of the fifth MOS tube is connected to one end of the twelfth resistor, the other end of the twelfth resistor is connected to the G pole of the sixth MOS tube and the positive pole of the fifth diode, the negative pole of the fifth diode is grounded, and the S pole of the sixth MOS tube is grounded.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention detects the voltage signal on the Crowbar circuit in multiple doubly-fed wind turbine generator sets, issues an alarm when the Crowbar circuit is abnormal, and cooperates with the signal acquisition module, the single-chip control module, and the fault indication module to determine which Crowbar circuit is currently faulty according to the number of illuminated indicator lights, so as to handle it in time and avoid the spread of the fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure is a schematic diagram of a fault detection circuit for a generator set.

[0022] Figure 2 It is the circuit diagram of the signal acquisition module, power supply acquisition module, fault judgment module and fault alarm module.

[0023] Figure 3 This is a schematic diagram of the microcontroller control module.

[0024] Figure 4 This is the circuit diagram of the fault indication module. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 , a fault detection circuit of a generator set, comprising:

[0027] The signal acquisition module 1 is used to collect the voltage signals on the Crowbar circuits in multiple double-fed wind turbine generator sets, and output the maximum voltage signal to the power supply acquisition module 2 and the fault judgment module 3;

[0028] The power supply acquisition module 2 is used to output a constant voltage as the power supply VCC of the fault judgment module 3 and the fault indication module 6;

[0029] The fault judgment module 3 is used to judge whether the maximum voltage signal exceeds the set voltage. If it exceeds the set voltage, it is determined that there is a Crowbar circuit fault, and a trigger signal is provided to the fault alarm module 4 and the single-chip control module 5;

[0030] Fault alarm module 4, used to sound an alarm after a trigger signal is input;

[0031] The single-chip control module 5 is used to control the voltage signals on the Crowbar circuits of the multiple double-fed wind turbine generators to be disconnected in sequence according to the passage of time after the trigger signal is input, and there is a delay between the disconnection of two adjacent voltage signals;

[0032] Fault indication module 6, used for lighting the corresponding indicator light after a voltage signal is disconnected, until the maximum voltage signal is disconnected, and then no more indicator lights are lit (according to the lighting condition of the indicator light, it is determined which doubly-fed wind turbine generator set has a Crowbar circuit failure);

[0033] The output end of the signal acquisition module 1 is connected to the input end of the power supply acquisition module 2 and the first input end of the fault judgment module 3; the output end of the power supply acquisition module 2 is connected to the second input end of the fault judgment module 3 and the first input end of the fault indication module 6; the output end of the fault judgment module 3 is connected to the input end of the fault alarm module 4 and the input end of the single-chip control module 5; the output end of the single-chip control module 5 is connected to the input end of the signal acquisition module 1 and the second input end of the fault indication module 6.

[0034] In this example: See Figure 2 The signal acquisition module 1 includes multiple signal acquisition units, and the number of the signal acquisition units is the same as the number of Crowbar circuits in multiple doubly-fed wind turbine generator sets; the signal acquisition unit includes a first diode D1 and a first MOS tube V1, the positive electrode of the first diode D1 is connected to the voltage on the corresponding Crowbar circuit, the negative electrode of the first diode D1 is connected to the D electrode of the first MOS tube V1, the G electrode of the first MOS tube V1 is connected to the output end of the single-chip control module 5, and the S electrode of the first MOS tube V1 is connected to the input end of the power supply acquisition module 2 and the first input end of the fault judgment module 3.

[0035] like Figure 2 As shown, three signal acquisition units (the first diode D1 and the first MOS tube V1 are one, the second diode D2 and the second MOS tube V2 are one, and the third diode D3 and the third MOS tube V3 are one) are used as examples, that is, corresponding to the Crowbar circuits in the three doubly-fed wind turbine generator sets, the Crowbar circuit is provided with a capacitor, and the voltage on the capacitor is the voltage on the feedback Crowbar circuit. When the doubly-fed wind turbine generator set is working normally, the capacitor voltage is normal. When the grid voltage of the doubly-fed wind turbine generator set drops, an overcurrent will be generated on the rotor side, causing the capacitor voltage to rise. After the capacitor voltage rises, the Crowbar circuit will build a circuit break during normal operation to burn the fuse and disconnect the power supply circuit to avoid damage to the doubly-fed wind turbine generator set equipment. Therefore, the capacitor voltages on the three Crowbar circuits are collected and output through the three signal acquisition units respectively, and the output end of the signal acquisition module 1 outputs the maximum voltage signal.

[0036] In another embodiment: Here, the Crowbar circuit in three doubly-fed wind turbine generator sets is taken as an example. In actual use, there may be different numbers of doubly-fed wind turbine generator sets depending on the size of the power generation site, so there is no limit on the number of signal acquisition units.

[0037] In this example: See Figure 2 The power supply acquisition module 2 includes a third resistor R3, a first capacitor C1, a fourth resistor R4, a fourth diode D4, and a second capacitor C2. One end of the third resistor R3 is connected to the output end of the signal acquisition module 1, the other end of the third resistor R3 is connected to one end of the first capacitor C1 and one end of the fourth resistor R4, the other end of the first capacitor C1 is grounded, the other end of the fourth resistor R4 is connected to the cathode of the fourth diode D4, one end of the second capacitor C2, the second input end of the fault judgment module 3, and the first input end of the fault indication module 6, the anode of the fourth diode D4 is grounded, and the other end of the second capacitor C2 is grounded.

[0038] After the voltage signal is input, a constant voltage is formed on the fourth diode D4 (voltage regulator diode) as the power supply VCC to supply power to the fault judgment module 3 and the fault indication module 6 .

[0039] In another embodiment: the power supply VCC is finally formed by the output terminal voltage of the signal acquisition module 1, and the power supply VCC can also be obtained by a battery or a mains supply.

[0040] In this example: See Figure 2 The fault judgment module 3 includes a first resistor R1, a second resistor R2, a third capacitor C3, a first amplifier U1, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. One end of the first resistor R1 is connected to the output end of the signal acquisition module 1, and the other end of the first resistor R1 is connected to one end of the second resistor R2, one end of the third capacitor C3, and the in-phase end of the first amplifier U1. The other end of the third capacitor C3 is grounded, and the other end of the second resistor R2 is grounded. The inverting end of the first amplifier U1 is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6. The other end of the fifth resistor R5 is grounded, and the other end of the sixth resistor R6 is connected to the output end of the power supply acquisition module 2. The output end of the first amplifier U1 is connected to one end of the seventh resistor R7 and the input end of the fault alarm module 4, and the other end of the seventh resistor R7 is connected to the input end of the single-chip control module 5.

[0041] After the power supply VCC is divided by the fifth resistor R5 and the sixth resistor R6, the voltage on the fifth resistor R5 is the set voltage, and the voltage on the second resistor R2 is the sampling voltage of the maximum voltage signal. When the sampling voltage is greater than the set voltage, it is determined that the Crowbar circuit is damaged and cannot provide power-off protection. At this time, the voltage at the in-phase terminal of the first amplifier U1 is greater than the voltage at the inverting terminal, and a high level is output as a trigger signal. After the voltage of the Crowbar circuit triggering the short circuit is divided by the first resistor R1 and the second resistor R2, the voltage formed on the second resistor R2 will be slightly less than the set voltage. Therefore, when the Crowbar circuit triggers the short circuit, the voltage at the in-phase terminal of the first amplifier U1 is still less than the voltage at the inverting terminal. Only when the voltage on the Crowbar circuit continues to increase will the fault judgment module 3 be triggered to output a high level.

[0042] In another embodiment, the seventh resistor R7 can be omitted. The seventh resistor R7 is used for current limiting to prevent the single-chip microcomputer U2 from being damaged due to excessive current.

[0043] In this example: See Figure 2 The fault alarm module 4 includes an eighth resistor R8 and a speaker SPEAKER. One end of the eighth resistor R8 is connected to the output end of the fault judgment module 3, the other end of the eighth resistor R8 is connected to one end of the speaker SPEAKER, and the other end of the speaker SPEAKER is grounded.

[0044] After the trigger signal is input, the speaker SPEAKER is powered on and starts to work, sounding an alarm; after the single-chip microcomputer U2 controls the signal acquisition module 1 and the fault indication module 6 to find the fault area, the first amplifier U1 outputs a low level and the speaker SPEAKER stops working.

[0045] In another embodiment, the speaker SPEAKER may also be set to continue to alarm after being triggered until it is manually released.

[0046] In this example: See Figure 3 The single-chip microcomputer control module 5 includes a single-chip microcomputer U2, a signal input IO port of the single-chip microcomputer U2 is connected to the output end of the fault judgment module 3, and multiple signal output IO ports of the single-chip microcomputer U2 are connected to the input end of the signal acquisition module 1 and the second input end of the fault indication module 6. The number of the signal output IO ports of the single-chip microcomputer U2 is the same as the number of Crowbar circuits in multiple double-fed wind turbine generator sets.

[0047] Based on three doubly-fed wind turbines, the single-chip microcomputer U2 has three signal output IOs, namely IO2, IO3, and IO4. The signal input IO port of the single-chip microcomputer U2 is IO1. After a trigger signal is input to IO1, the single-chip microcomputer U2 controls IO2, IO3, and IO4 to output low levels in sequence according to the passage of time. There is a delay in the output of low levels between the two IO ports. If the signal acquisition unit corresponding to the maximum voltage signal is found, the trigger signal is disconnected, and the single-chip microcomputer U2 stops outputting low levels in sequence.

[0048] Take the failure of the Crowbar circuit of the second doubly-fed wind turbine generator set as an example. The failure of the Crowbar circuit causes the maximum voltage signal to be high. This maximum voltage signal is output by the Crowbar circuit of the second doubly-fed wind turbine generator set through the second diode D2 and the second MOS tube V2. At this time, the first amplifier U1 outputs a high level and outputs a trigger signal. The single-chip computer U2 triggers the operation. The IO2 port first outputs a low level, which makes the first MOS tube V1 cut off. At this time, the maximum voltage signal still exists. The first amplifier U1 still outputs a high level. The single-chip computer U2 continues to work. After a delay, the IO3 port is controlled to output a low level, and the second MOS tube V2 is cut off. At this time, the voltage signal output by the third diode D3 and the third MOS tube V3 is no longer sufficient to trigger the first amplifier U1 to output a high level, and IO4 maintains a high output level. Similarly, when the Crowbar circuit of the Nth doubly-fed wind turbine generator set fails, after the Nth signal acquisition unit is disconnected, the IO (N+2) port maintains a high output level.

[0049] In another embodiment: the corresponding signal acquisition unit can also be controlled to be disconnected or not by triggering a time relay. The disadvantage is that if too many doubly-fed wind turbines are involved, there will be too many time relays and a complicated structure, while a single microcontroller U2 has a large number of IO ports.

[0050] In this example: See Figure 4 The fault indication module 6 includes a plurality of fault indication units, and the number of the fault indication units is the same as the number of the signal output IO ports of the single-chip computer U2; the fault indication unit includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a fifth MOS transistor V5, a sixth MOS transistor V6, and a fifth diode D5. One end of the ninth resistor R9 is connected to the signal output IO port of the single-chip computer U2 corresponding to the fault indication unit (the output end of the single-chip computer control module 5), the other end of the ninth resistor R9 is connected to one end of the tenth resistor R10, the D pole of the sixth MOS transistor V6, and the G pole of the fifth MOS transistor V5, the other end of the tenth resistor R10 is grounded, the S pole of the fifth MOS transistor V5 is connected to the output end of the power supply acquisition module 2 through the eleventh resistor R11, the D pole of the fifth MOS transistor V5 is connected to one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is connected to the G pole of the sixth MOS transistor V6 and the positive pole of the fifth diode D5, the negative pole of the fifth diode D5 is grounded, and the S pole of the sixth MOS transistor V6 is grounded.

[0051] Similarly, using the fault description of the Crowbar circuit of the second doubly-fed wind turbine generator set, the output IO ports of the microcontroller U2 are IO2, IO3, and IO4, corresponding to three fault indication units ( Figure 4 The fifth diode D5 is an indicator light, the sixth diode D6 is an indicator light, and the seventh diode D7 is an indicator light). When IO2 outputs a low level (normally a high level), the fifth MOS tube V5 changes from being cut off to being turned on, and the fifth diode D5 emits light for indication, and at the same time triggers the sixth MOS tube V6 to be turned on, so that the G pole of the fifth MOS tube V5 becomes a low level, forming a self-locking circuit, and the fifth diode D5 continues to emit light; when IO3 outputs a low level, similarly, the sixth diode D6 continues to emit light. At this time, since the faulty Crowbar circuit is found, the IO4 port of the single-chip computer U2 no longer outputs a low level, and the seventh diode D7 does not emit light. The two indicator lights (the fifth diode D5 and the sixth diode D6) that are on indicate a fault in the Crowbar circuit of the second double-fed wind turbine generator set.

[0052] In another embodiment: the tenth resistor R10 is designed as a pull-down resistor to prevent the fifth MOS tube V5 from being triggered by mistake.

[0053] The working principle of the present invention is as follows: the signal acquisition module 1 is used to collect voltage signals on the Crowbar circuit in multiple double-fed wind turbine generator sets, and output the maximum voltage signal to the power supply acquisition module 2 and the fault judgment module 3; the power supply acquisition module 2 is used to output a constant voltage as the power supply VCC of the fault judgment module 3 and the fault indication module 6; the fault judgment module 3 is used to judge whether the maximum voltage signal exceeds the set voltage. When it exceeds the set voltage, it is determined that there is a Crowbar circuit fault, and a trigger signal is provided to the fault alarm module 4 and the single-chip control module 5; the fault alarm module 4 is used to sound an alarm after the trigger signal is input; the single-chip control module 5 is used to control the collected voltage signals on the Crowbar circuit in the multiple double-fed wind turbine generator sets to be disconnected in sequence according to the passage of time after the trigger signal is input, and there is a delay between the disconnection of two adjacent voltage signals; the fault indication module 6 is used to make the corresponding indicator light up after a voltage signal is disconnected, until the maximum voltage signal is disconnected, and no more indicator lights up after the corresponding indicator light up.

[0054] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered as exemplary and non-restrictive in all respects.

[0055] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A fault detection circuit for a generator set, characterized in that: The fault detection circuit of the generator set includes: A signal acquisition module is used to collect voltage signals on the Crowbar circuits of multiple double-fed wind turbine generator sets and output the maximum voltage signal to the power supply acquisition module and the fault judgment module; A power supply acquisition module, used to output a constant voltage as the power supply for the fault judgment module and the fault indication module; The fault judgment module is used to judge whether the maximum voltage signal exceeds the set voltage. If it exceeds the set voltage, it is determined that there is a Crowbar circuit fault and provides a trigger signal for the fault alarm module and the single-chip microcomputer control module; Fault alarm module, used to sound an alarm after a trigger signal is input; The single-chip control module is used to control the disconnection of the voltage signals on the Crowbar circuits of multiple double-fed wind turbine generator sets collected in sequence according to the passage of time after the trigger signal is input, and there is a delay between the disconnection of two adjacent voltage signals; A fault indication module is used for causing a corresponding indicator light to illuminate after a voltage signal is disconnected, until the maximum voltage signal is disconnected, and no more indicator lights are illuminated after the corresponding indicator light illuminates; The output end of the signal acquisition module is connected to the input end of the power supply acquisition module and the first input end of the fault judgment module, the output end of the power supply acquisition module is connected to the second input end of the fault judgment module and the first input end of the fault indication module, the output end of the fault judgment module is connected to the input end of the fault alarm module and the input end of the single-chip control module, and the output end of the single-chip control module is connected to the input end of the signal acquisition module and the second input end of the fault indication module.

2. The fault detection circuit of the generator set according to claim 1, characterized in that: The signal acquisition module includes multiple signal acquisition units, and the number of the signal acquisition units is the same as the number of Crowbar circuits in multiple double-fed wind turbine generator sets; the signal acquisition unit includes a first diode and a first MOS tube, the positive electrode of the first diode is connected to the voltage on the corresponding Crowbar circuit, the negative electrode of the first diode is connected to the D electrode of the first MOS tube, the G electrode of the first MOS tube is connected to the output end of the single-chip control module, and the S electrode of the first MOS tube is connected to the input end of the power supply acquisition module and the first input end of the fault judgment module.

3. The fault detection circuit of the generator set according to claim 1, characterized in that: The power supply acquisition module includes a third resistor, a first capacitor, a fourth resistor, a fourth diode and a second capacitor, one end of the third resistor is connected to the output end of the signal acquisition module, the other end of the third resistor is connected to one end of the first capacitor and one end of the fourth resistor, the other end of the first capacitor is grounded, the other end of the fourth resistor is connected to the cathode of the fourth diode, one end of the second capacitor, the second input end of the fault judgment module and the first input end of the fault indication module, the anode of the fourth diode is grounded, and the other end of the second capacitor is grounded.

4. The fault detection circuit of the generator set according to claim 1, characterized in that: The fault judgment module includes a first resistor, a second resistor, a third capacitor, a first amplifier, a fifth resistor, a sixth resistor and a seventh resistor. One end of the first resistor is connected to the output end of the signal acquisition module, the other end of the first resistor is connected to one end of the second resistor, one end of the third capacitor and the in-phase end of the first amplifier, the other end of the third capacitor is grounded, the other end of the second resistor is grounded, the inverting end of the first amplifier is connected to one end of the fifth resistor and one end of the sixth resistor, the other end of the fifth resistor is grounded, the other end of the sixth resistor is connected to the output end of the power supply acquisition module, the output end of the first amplifier is connected to one end of the seventh resistor and the input end of the fault alarm module, and the other end of the seventh resistor is connected to the input end of the single-chip control module.

5. The fault detection circuit of the generator set according to claim 1, characterized in that: The fault alarm module comprises an eighth resistor and a speaker, one end of the eighth resistor is connected to the output end of the fault judgment module, the other end of the eighth resistor is connected to one end of the speaker, and the other end of the speaker is grounded.

6. The fault detection circuit of the generator set according to claim 1 or 2, characterized in that: The single-chip microcomputer control module includes a single-chip microcomputer, a signal input IO port of the single-chip microcomputer is connected to the output end of the fault judgment module, multiple signal output IO ports of the single-chip microcomputer are connected to the input end of the signal acquisition module and the second input end of the fault indication module, and the number of the signal output IO ports of the single-chip microcomputer is the same as the number of Crowbar circuits in multiple double-fed wind turbine generator sets.

7. The fault detection circuit of the generator set according to claim 6, characterized in that: The fault indication module includes a plurality of fault indication units, and the number of the fault indication units is the same as the number of the signal output IO ports of the single-chip computer; the fault indication unit includes a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth MOS tube, a sixth MOS tube and a fifth diode, one end of the ninth resistor is connected to the signal output IO port of the single-chip computer corresponding to the fault indication unit, the other end of the ninth resistor is connected to one end of the tenth resistor, the D pole of the sixth MOS tube and the G pole of the fifth MOS tube, the other end of the tenth resistor is grounded, the S pole of the fifth MOS tube is connected to the output end of the power supply acquisition module through the eleventh resistor, the D pole of the fifth MOS tube is connected to one end of the twelfth resistor, the other end of the twelfth resistor is connected to the G pole of the sixth MOS tube and the positive pole of the fifth diode, the negative pole of the fifth diode is grounded, and the S pole of the sixth MOS tube is grounded.

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