A fire protection device and system for stator and rotor junction box of a double-fed wind turbine generator

Abstract

The invention relates to a fire prevention device and system for a stator and rotor junction box of a double-fed wind turbine generator. The device comprises a temperature control switch component, a temperature sensor component and a PLC. A temperature measuring probe of the temperature control switch component is arranged in the stator and rotor junction box of the generator. One end of a normally closed switch of the temperature control switch component is connected to a signal output end of the temperature sensor component, and the other end of the normally closed switch of the temperature control switch component is connected to a PLC. The PLC is connected to a control end of the generator. When the temperature of the stator and rotor junction box of the generator measured by the temperature control switch component is greater than a temperature threshold, the temperature control switch component is turned off, the normally closed switch loses power and is disconnected, the PLC cannot obtain a measurement signal of the temperature sensor component, the PLC outputs a generator shutdown instruction, controls the generator to stop running, and the current of the cable in the stator and rotor junction box of the generator is reduced to 0, thereby interrupting the continued increase of the temperature in the stator and rotor junction box of the generator, and effectively preventing the occurrence of a fire caused by a partial fire of a stator and rotor outlet cable of the generator.

Description

Technical Field

[0001] The invention relates to the field of wind power generation, and in particular to a fire prevention device and system for a stator and rotor junction box of a double-fed wind turbine generator. Background Art

[0002] In recent years, cable fire accidents in the stator and rotor junction boxes of doubly-fed wind turbines have occurred frequently. There are 3-5 cables per phase in the junction box. If one phase cable is only partially burned, the unburned cables can continue to supply power, and the wind turbine can continue to generate electricity, which will cause the fault point to continue to expand. In severe cases, it can cause a fire in the cabin, bringing a devastating blow to the safe operation of the unit.

[0003] In response to the above problems, wind turbine manufacturers and equipment operation and maintenance units have tried their best to avoid fire accidents by optimizing design concepts and strengthening equipment management. However, looking at wind turbine accident cases in recent years, fire accidents still occur, especially in early installed units.

[0004] In the prior art, it is impossible to know the real-time temperature of the stator and rotor junction box of the double-fed wind turbine generator, and thus it is impossible to prevent a wind turbine fire caused by burning of cables in the junction box. Summary of the invention

[0005] The object of the present invention is to provide a fire prevention device and system for a stator and rotor terminal box of a doubly-fed wind turbine generator, so as to effectively prevent the occurrence of fires caused by partial fire of the stator and rotor outgoing cables of the generator.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A fire protection device for a stator and rotor junction box of a double-fed wind turbine generator, the device comprising: a temperature control switch component, a temperature sensor component and a PLC;

[0008] The temperature probe of the temperature control switch assembly is arranged in the stator and rotor junction box of the generator; the temperature sensor assembly is arranged on the generator winding;

[0009] One end of the normally closed switch of the temperature control switch assembly is connected to the signal output end of the temperature sensor assembly, and the other end of the normally closed switch of the temperature control switch assembly is connected to the PLC; the temperature control switch assembly is used to measure the temperature of the stator and rotor junction box of the generator, and is turned off when the temperature of the stator and rotor junction box of the generator is greater than the temperature threshold, and the normally closed switch of the temperature control switch assembly loses power and disconnects;

[0010] The PLC is connected to the control end of the generator, and is used to obtain the temperature of the generator winding measured by the temperature sensor assembly, and when the normally closed switch of the temperature control switch assembly loses power and is disconnected, outputs a generator shutdown command to control the generator to stop running.

[0011] Optionally, the temperature-controlled switch assembly includes a first temperature-controlled switch and a second temperature-controlled switch;

[0012] The temperature measuring probe of the first temperature control switch is arranged in the stator terminal box of the generator, and the temperature measuring probe of the second temperature control switch is arranged in the rotor terminal box of the generator;

[0013] The normally closed switch of the first temperature-controlled switch and the normally closed switch of the second temperature-controlled switch are both connected to the PLC;

[0014] The first temperature-controlled switch is used to measure the temperature of the generator stator terminal box, and is turned off when the temperature of the generator stator terminal box is greater than a temperature threshold, and the normally closed switch of the first temperature-controlled switch loses power and disconnects;

[0015] The second temperature-controlled switch is used to measure the temperature of the generator rotor terminal box. When the temperature of the generator rotor terminal box is greater than a temperature threshold, the second temperature-controlled switch is turned off, and the normally closed switch of the second temperature-controlled switch loses power and opens.

[0016] Optionally, the temperature sensor assembly includes: a first temperature sensor and a second temperature sensor;

[0017] The first temperature sensor is arranged on the stator winding of the generator, and the second temperature sensor is arranged on the rotor winding of the generator;

[0018] The signal output end of the first temperature sensor is connected to the normally closed switch of the first temperature control switch, and the first temperature sensor is used to measure the temperature of the stator winding of the generator;

[0019] The signal output end of the second temperature sensor is connected to the normally closed switch of the second temperature-controlled switch, and the second temperature sensor is used to measure the temperature of the generator rotor winding.

[0020] Optionally, there are multiple first temperature sensors and multiple normally closed switches of the first temperature control switch;

[0021] The signal output ends of the plurality of first temperature sensors are connected to the plurality of normally closed switches of the first temperature controlled switch in a one-to-one correspondence.

[0022] Optionally, there are multiple second temperature sensors and multiple normally closed switches of the second temperature control switch;

[0023] The signal output ends of the plurality of second temperature sensors are connected to the plurality of normally closed switches of the second temperature controlled switch in a one-to-one correspondence.

[0024] Optionally, the first temperature control switch and the second temperature control switch are both BW9700 temperature control switches.

[0025] A fire protection device for a stator and rotor junction box of a double-fed wind turbine generator, the device comprising: a temperature control switch assembly and a PLC;

[0026] The temperature measuring probe of the temperature control switch assembly is arranged in the stator and rotor junction box of the generator;

[0027] One end of the normally closed switch of the temperature control switch assembly is connected to the power output interface of the PLC through a wire, and the other end of the normally closed switch of the temperature control switch assembly is connected to the signal input interface of the PLC through a wire;

[0028] The temperature control switch assembly is used to measure the temperature of the generator stator and rotor junction box, and is turned off when the temperature of the generator stator and rotor junction box is greater than the temperature threshold, and the normally closed switch of the temperature control switch assembly loses power and disconnects;

[0029] The PLC is connected to the control end of the generator, and is used to obtain the temperature of the generator winding measured by the temperature sensor assembly, and when the normally closed switch of the temperature control switch assembly loses power and is disconnected, outputs a generator shutdown command to control the generator to stop running.

[0030] A fire prevention system for a stator and rotor junction box of a doubly-fed wind turbine generator, the system comprising: a monitoring background and a fire prevention device for a stator and rotor junction box of a doubly-fed wind turbine generator;

[0031] The PLC of the fire protection device of the stator and rotor junction box of the doubly fed wind turbine generator is connected to the monitoring background. The PLC is used to obtain an alarm signal when the normally closed switch of the temperature control switch assembly of the fire protection device of the stator and rotor junction box of the doubly fed wind turbine generator loses power and is disconnected, and transmit the alarm signal to the monitoring background.

[0032] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0033] The present invention provides a fire prevention device and system for a stator and rotor junction box of a doubly-fed wind turbine generator set. The temperature measuring probe of a temperature control switch assembly is arranged in the stator and rotor junction box of the generator. One end of the normally closed switch of the temperature control switch assembly is connected to the signal output end of the temperature sensor assembly, and the other end of the normally closed switch of the temperature control switch assembly is connected to the PLC. The PLC is connected to the control end of the generator. When the temperature of the stator and rotor junction box of the generator measured by the temperature control switch assembly is greater than the temperature threshold, the temperature control switch assembly is shut down, the normally closed switch loses power and is disconnected, the PLC cannot obtain the measurement signal of the temperature sensor assembly, the PLC outputs a generator shutdown command, controls the generator to stop running, and the current of the cable in the stator and rotor junction box of the generator is reduced to 0, thereby interrupting the continued increase of the temperature in the stator and rotor junction box of the generator, and effectively preventing the occurrence of a fire caused by a partial fire in the stator and rotor outlet cable of the generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 This is the structural diagram of a traditional generator;

[0036] Figure 2 A structural diagram of a fire protection device for a stator and rotor junction box of a doubly-fed wind turbine generator provided in Embodiment 1 of the present invention;

[0037] Figure 3 A simplified structural diagram of a fire protection device for a stator and rotor junction box of a doubly-fed wind turbine generator provided in the second embodiment of the present invention;

[0038] Figure 4 A schematic diagram of a fire protection system for a stator and rotor junction box of a doubly-fed wind turbine generator provided by the present invention.

[0039] Explanation of symbols: 1-first temperature control switch, 2-second temperature control switch, 3-PLC, 4-temperature sensor assembly, 5-generator winding, 6-generator stator terminal box, 7-generator rotor terminal box. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The object of the present invention is to provide a fire prevention device and system for a stator and rotor terminal box of a doubly-fed wind turbine generator, so as to effectively prevent the occurrence of fires caused by partial fire of the stator and rotor outgoing cables of the generator.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] In order to effectively prevent fires caused by partial ignition of the stator and rotor outgoing cables of the generator, the present invention provides a method for preventing fires caused by partial ignition of the stator and rotor outgoing cables of the generator. Figure 1 The circuit topology is improved on the traditional generator structure shown, and two structures of a fire protection device for the stator and rotor terminal box of a doubly-fed wind turbine generator are provided.

[0044] Embodiment 1

[0045] like Figure 2 As shown, the device includes: a temperature control switch component, a temperature sensor component 4 and a PLC 3.

[0046] The temperature probe of the temperature control switch assembly is arranged in the stator and rotor junction box of the generator. The temperature sensor assembly 4 is arranged on the generator winding 5.

[0047] One end of the normally closed switch of the temperature control switch assembly is connected to the signal output end of the temperature sensor assembly 4, and the other end of the normally closed switch of the temperature control switch assembly is connected to the PLC3. The temperature control switch assembly is used to measure the temperature of the stator and rotor terminal box of the generator. When the temperature of the stator and rotor terminal box of the generator is greater than the temperature threshold, it is turned off, and the normally closed switch of the temperature control switch assembly loses power and disconnects. Preferably, the temperature threshold is 80°C.

[0048] PLC3 is connected to the control end of the generator. PLC3 is used to obtain the temperature of the generator winding 5 measured by the temperature sensor component 4. When the normally closed switch of the temperature control switch component loses power and is disconnected, PLC3 outputs a generator shutdown command to control the generator to stop running.

[0049] The temperature control switch assembly comprises a first temperature control switch 1 and a second temperature control switch 2 .

[0050] The temperature measuring probe of the first temperature-controlled switch 1 is arranged in the generator stator terminal box 6 , and the temperature measuring probe of the second temperature-controlled switch 2 is arranged in the generator rotor terminal box 7 .

[0051] The normally closed switch of the first temperature-controlled switch 1 and the normally closed switch of the second temperature-controlled switch 2 are both connected to the PLC 3 .

[0052] The first temperature control switch 1 is used to measure the temperature of the generator stator terminal box 6. When the temperature of the generator stator terminal box 6 is greater than the temperature threshold, the first temperature control switch 1 is turned off, and the normally closed switch of the first temperature control switch 1 loses power and opens.

[0053] The second temperature control switch 2 is used to measure the temperature of the generator rotor terminal box 7. When the temperature of the generator rotor terminal box 7 is greater than the temperature threshold, the second temperature control switch 2 is turned off, and the normally closed switch of the second temperature control switch 2 loses power and opens.

[0054] The temperature sensor assembly 4 includes: a first temperature sensor and a second temperature sensor.

[0055] The first temperature sensor is arranged on the stator winding of the generator, and the second temperature sensor is arranged on the rotor winding of the generator.

[0056] The signal output end of the first temperature sensor is connected to the normally closed switch of the first temperature-controlled switch 1 , and the first temperature sensor is used to measure the temperature of the stator winding of the generator.

[0057] The signal output end of the second temperature sensor is connected to the normally closed switch of the second temperature control switch 2. The second temperature sensor is used to measure the temperature of the generator rotor winding.

[0058] There are multiple first temperature sensors and multiple normally closed switches of the first temperature-controlled switch 1 .

[0059] The signal output ends of the plurality of first temperature sensors are connected to the plurality of normally closed switches of the first temperature controlled switch 1 in a one-to-one correspondence.

[0060] There are multiple second temperature sensors and multiple normally closed switches of the second temperature-controlled switch 2 .

[0061] The signal output ends of the plurality of second temperature sensors are connected to the plurality of normally closed switches of the second temperature-controlled switch 2 in a one-to-one correspondence.

[0062] Preferably, the first temperature control switch 1 and the second temperature control switch 2 are both BW9700 temperature control switches.

[0063] Figure 1 and Figure 2 In the figure, 306U6 represents the generator winding, 372B1, 372B2, 372B5 and 372B6 represent the temperature measuring points of the generator winding respectively, 406AI3.1, KL3204, 406AI4 and KL3204 represent the PLC analog interface respectively, PT100 is the temperature sensor, 1, 2, 5 and 6 represent the PLC analog interface respectively, W, V and U represent the W phase, V phase and U phase of the generator stator output line respectively, and M, L and K represent the W phase, V phase and U phase of the generator rotor output line respectively.

[0064] Embodiment 2

[0065] like Figure 3 As shown, a fire protection device for a stator and rotor junction box of a double-fed wind turbine generator comprises: a temperature control switch component and a PLC.

[0066] The temperature measuring probe of the temperature control switch assembly is arranged in the stator and rotor junction box of the generator.

[0067] One end of the normally closed switch of the temperature control switch assembly is connected to the power output interface of the PLC through a wire, and the other end of the normally closed switch of the temperature control switch assembly is connected to the signal input interface of the PLC through a wire.

[0068] The temperature control switch assembly is used to measure the temperature of the generator stator and rotor junction box. When the temperature of the generator stator and rotor junction box is greater than the temperature threshold, it is shut down and the normally closed switch of the temperature control switch assembly loses power and disconnects.

[0069] The PLC is connected to the control end of the generator. The PLC is used to obtain the temperature of the generator winding measured by the temperature sensor component. When the normally closed switch of the temperature control switch component loses power and is disconnected, the PLC outputs a generator shutdown command to control the generator to stop running.

[0070] Reference Figure 3 The temperature control switch assembly includes two temperature control switches. One end of the normally closed switch of each temperature control switch is connected to the power output interface of the PLC through a wire, and the other end of the normally closed switch of each temperature control switch is connected to the signal input interface of the PLC through a wire.

[0071] A temperature probe of a temperature control switch is set in the generator stator terminal box to measure the temperature of the generator stator terminal box. When the temperature of the generator stator terminal box is greater than the temperature threshold, the temperature control switch is turned off, the normally closed switch of the temperature control switch loses power and disconnects, the input level of the PLC is low, and the PLC outputs a generator shutdown command to control the generator to stop running.

[0072] The temperature probe of another temperature control switch is set in the generator rotor junction box to measure the temperature of the generator rotor junction box. When the temperature of the generator rotor junction box is greater than the temperature threshold, the temperature control switch is turned off, the normally closed switch of the temperature control switch loses power and disconnects, the input level of the PLC is low, and the PLC outputs a generator shutdown command to control the generator to stop running.

[0073] Figure 3 In the figure, I / 24V and O / 24V represent the I / O interfaces of PLC respectively.

[0074] The present invention utilizes the temperature measurement function of the fan main control system (PLC3) for the generator winding 5 and other positions, installs a sensor of a mechanical temperature control switch in the stator and rotor junction box, and connects the normally closed contacts of the temperature control switch to the measurement circuit of the main control system for the generator winding 5 and other positions. If the generator junction box is over-temperature, the corresponding monitoring circuit is disconnected. After PLC3 issues a shutdown command, the blades are retracted, the speed is reduced, the switches on the stator and rotor sides of the generator are disconnected, the generator stops running, and no electricity is generated after shutdown. The current flowing through the cable is reduced to 0, thereby reducing the risk of further expansion of the fire and achieving the purpose of early intervention and prevention of fire.

[0075] It is also possible to separately install a temperature monitoring circuit for the stator and rotor junction boxes based on the reserved measuring points of the main control system (PLC3), and name the reserved measuring points according to the opening of the main control program, such as "temperature exceeding the limit in the stator / rotor junction box".

[0076] The present invention can effectively prevent the stator and rotor terminal boxes from catching fire, greatly improve the ability of safe and reliable operation, and further ensure the safe operation of the fan without changing the fan control program.

[0077] The present invention also provides a fire protection system for the stator and rotor junction box of a double-fed wind turbine generator, such as Figure 4 As shown, the system includes: a monitoring background and a fire protection device for the stator and rotor junction box of the double-fed wind turbine generator.

[0078] The PLC3 of the fire protection device of the stator and rotor junction box of the doubly-fed wind turbine generator is connected to the monitoring background. The PLC3 is used to obtain an alarm signal when the normally closed switch of the temperature control switch component of the fire protection device of the stator and rotor junction box of the doubly-fed wind turbine generator loses power and is disconnected, and transmit the alarm signal to the monitoring background.

[0079] The temperature sensor of the temperature control switch detects that the temperature in the generator stator terminal box 6 rises to the temperature control switch action value ( Figure 2 When the temperature is 80 degrees Celsius (which can be adjusted according to the on-site operating temperature), the temperature control switch is activated, the normally closed contact is disconnected, and the PLC3 module detects that the PT circuit ( Figure 2 If the PT100 and PLC3 connection circuit in the middle are disconnected or the PLC loses power, the corresponding temperature fault will be reported (the measured value discontinuously reaches the temperature upper limit instantaneously). At this time, the unit will report a fault and shut down. The above information can be used to determine that the PT circuit is abnormal. The abnormal cause is likely to be caused by the terminal box temperature exceeding the limit. Similarly, if the rotor terminal box temperature exceeds the limit, the unit will also shut down. At the same time, PLC3 will report the corresponding fault (select a fixed circuit, for example: U-phase fault must not only check the U-phase itself, but also check the stator outlet box; W-phase fault must not only check the W-phase itself, but also check the rotor outlet box), shut down the fan and notify the monitoring background, inform the operation and maintenance personnel, and achieve the purpose of early intervention to prevent fire.

[0080] The present invention uses the simplest way to detect temperature and enables the unit to accurately respond to shutdown or alarm, and is applicable to all double-fed wind turbines. In particular, old units that have been in operation for a long time have greater fire hazards as they age. The present invention simplifies the complexities and solves such problems with a method that requires less investment and is simple in solution. It can not only be used for the technical transformation of wind turbines that have been put into operation, but can also be applied to the design of wind turbines in main engine factories, which will not only greatly improve the economic benefits, but also have great significance.

[0081] In addition, the present invention has been tested as a prototype on a United Power 1.5MW wind turbine. When the simulated temperature rises to a set value, the wind turbine can accurately shut down or issue an alarm, and no other faults caused by the modification occur. The wind turbine operates in good condition.

[0082] The present invention has the following technical effects:

[0083] 1. Safety: It can effectively prevent fire in the stator and rotor terminal boxes, greatly improving the ability of safe and reliable operation. The solution itself does not change the fan control program, further ensuring the safe operation of the fan.

[0084] 2. Environmental protection: No part that has a negative impact on the environment has been included, and the plan does not involve chemicals, pollutants, etc.

[0085] 3. Energy saving: The device has low power consumption, no high energy consumption equipment, and meets energy saving standards.

[0086] 4. Improved reliability: Through prototype testing, the solution can accurately detect over-temperature conditions and enable the wind turbine to respond accurately. The solution itself does not reduce reliability and greatly improves the ability of wind turbines to operate safely and reliably.

[0087] 5. Investment saving: The control loop design of the scheme is ingenious, which reduces the input of spare parts while ensuring reliability, greatly reduces the cost investment, and has a high input-output ratio. It meets the requirements of "zero cost, low cost" technical transformation and achieves the purpose of improving quality and efficiency. When the precursor of fire appears, the fan accurately shuts down or responds to the alarm, avoiding the occurrence of unsafe incidents.

[0088] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0089] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fire protection device for the stator and rotor junction box of a double-fed wind turbine generator, characterized in that: The device comprises: a temperature control switch component, a temperature sensor component and a PLC; The temperature probe of the temperature control switch assembly is arranged in the stator and rotor junction box of the generator; the temperature sensor assembly is arranged on the generator winding; One end of the normally closed switch of the temperature control switch assembly is connected to the signal output end of the temperature sensor assembly, and the other end of the normally closed switch of the temperature control switch assembly is connected to the PLC; the temperature control switch assembly is used to measure the temperature of the stator and rotor junction box of the generator, and is turned off when the temperature of the stator and rotor junction box of the generator is greater than the temperature threshold, and the normally closed switch of the temperature control switch assembly loses power and disconnects; The PLC is connected to the control end of the generator, and is used to obtain the temperature of the generator winding measured by the temperature sensor assembly, and output a generator shutdown instruction when the normally closed switch of the temperature control switch assembly loses power and is disconnected, so as to control the generator to stop running; The temperature control switch assembly includes a first temperature control switch and a second temperature control switch; The temperature measuring probe of the first temperature control switch is arranged in the stator terminal box of the generator, and the temperature measuring probe of the second temperature control switch is arranged in the rotor terminal box of the generator; The normally closed switch of the first temperature-controlled switch and the normally closed switch of the second temperature-controlled switch are both connected to the PLC; The first temperature-controlled switch is used to measure the temperature of the generator stator terminal box, and is turned off when the temperature of the generator stator terminal box is greater than a temperature threshold, and the normally closed switch of the first temperature-controlled switch loses power and disconnects; The second temperature-controlled switch is used to measure the temperature of the generator rotor terminal box, and is turned off when the temperature of the generator rotor terminal box is greater than a temperature threshold, and the normally closed switch of the second temperature-controlled switch loses power and disconnects; The first temperature control switch and the second temperature control switch are both BW9700 temperature control switches; The temperature sensor assembly comprises: a first temperature sensor and a second temperature sensor; The first temperature sensor is arranged on the stator winding of the generator, and the second temperature sensor is arranged on the rotor winding of the generator; The signal output end of the first temperature sensor is connected to the normally closed switch of the first temperature control switch, and the first temperature sensor is used to measure the temperature of the stator winding of the generator; The signal output end of the second temperature sensor is connected to the normally closed switch of the second temperature-controlled switch, and the second temperature sensor is used to measure the temperature of the generator rotor winding.

2. The fire protection device for the stator and rotor junction box of a doubly-fed wind turbine generator according to claim 1, characterized in that: There are multiple first temperature sensors and multiple normally closed switches of the first temperature control switch; The signal output ends of the plurality of first temperature sensors are connected to the plurality of normally closed switches of the first temperature controlled switch in a one-to-one correspondence.

3. The fire protection device for the stator and rotor junction box of a doubly-fed wind turbine generator according to claim 1, characterized in that: There are multiple second temperature sensors and multiple normally closed switches of the second temperature control switch; The signal output ends of the plurality of second temperature sensors are connected to the plurality of normally closed switches of the second temperature controlled switch in a one-to-one correspondence.

4. A fire protection device for the stator and rotor junction box of a double-fed wind turbine generator, characterized in that: The device comprises: a temperature control switch component and a PLC; The temperature measuring probe of the temperature control switch assembly is arranged in the stator and rotor junction box of the generator; One end of the normally closed switch of the temperature control switch assembly is connected to the power output interface of the PLC through a wire, and the other end of the normally closed switch of the temperature control switch assembly is connected to the signal input interface of the PLC through a wire; The temperature control switch assembly is used to measure the temperature of the generator stator and rotor junction box, and is turned off when the temperature of the generator stator and rotor junction box is greater than the temperature threshold, and the normally closed switch of the temperature control switch assembly loses power and disconnects; The PLC is connected to the control end of the generator, and is used to obtain the temperature of the generator winding measured by the temperature sensor assembly, and output a generator shutdown instruction when the normally closed switch of the temperature control switch assembly loses power and is disconnected, so as to control the generator to stop running; The temperature control switch assembly includes a first temperature control switch and a second temperature control switch; The temperature measuring probe of the first temperature control switch is arranged in the stator terminal box of the generator, and the temperature measuring probe of the second temperature control switch is arranged in the rotor terminal box of the generator; The normally closed switch of the first temperature-controlled switch and the normally closed switch of the second temperature-controlled switch are both connected to the PLC; The first temperature-controlled switch is used to measure the temperature of the generator stator terminal box, and is turned off when the temperature of the generator stator terminal box is greater than a temperature threshold, and the normally closed switch of the first temperature-controlled switch loses power and disconnects; The second temperature-controlled switch is used to measure the temperature of the generator rotor terminal box, and is turned off when the temperature of the generator rotor terminal box is greater than a temperature threshold, and the normally closed switch of the second temperature-controlled switch loses power and disconnects; The first temperature control switch and the second temperature control switch are both BW9700 temperature control switches; The temperature sensor assembly comprises: a first temperature sensor and a second temperature sensor; The first temperature sensor is arranged on the stator winding of the generator, and the second temperature sensor is arranged on the rotor winding of the generator; The signal output end of the first temperature sensor is connected to the normally closed switch of the first temperature control switch, and the first temperature sensor is used to measure the temperature of the stator winding of the generator; The signal output end of the second temperature sensor is connected to the normally closed switch of the second temperature-controlled switch, and the second temperature sensor is used to measure the temperature of the generator rotor winding.

5. A fire protection system for the stator and rotor junction box of a doubly-fed wind turbine generator, characterized in that: The system comprises: a monitoring background and a fire protection device for a stator and rotor junction box of a doubly-fed wind turbine generator according to any one of claims 1 to 3; The PLC of the fire protection device of the stator and rotor junction box of the doubly fed wind turbine generator is connected to the monitoring background. The PLC is used to obtain an alarm signal when the normally closed switch of the temperature control switch assembly of the fire protection device of the stator and rotor junction box of the doubly fed wind turbine generator loses power and is disconnected, and transmit the alarm signal to the monitoring background.

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