Insulation resistance monitoring system and method for wind turbine generator sets and wind turbine generator sets

Abstract

This invention provides an insulation resistance monitoring system, method, and wind turbine generator set, belonging to the field of wind turbine generator set control technology. It includes: an insulation resistance meter, installed inside the nacelle of the wind turbine generator set and connected to a target component of the wind turbine generator set, for continuously measuring the resistance value of the target component and sending the resistance value to the main control system; a heating and dehumidifying device, installed inside the nacelle of the wind turbine generator set, for reducing the humidity inside the nacelle; and a main control system, connected to the insulation resistance meter and the heating and dehumidifying device, for outputting a start command to the insulation resistance meter after receiving a shutdown command from the generator set, and outputting a start command to the heating and dehumidifying device when it is determined that the resistance value of any target component is less than a first preset threshold and greater than a second preset threshold. This invention automatically controls the heating and dehumidifying device based on the acquired resistance value, promptly changing the humidity inside the nacelle, improving operation and maintenance efficiency, and ensuring generator set operating time.

Description

Technical Field

[0001] This invention relates to the field of wind turbine generator control technology, specifically to an insulation resistance monitoring system for wind turbine generators, an online monitoring method for insulation resistance of wind turbine generators, and a wind turbine generator. Background Technology

[0002] Insulation resistance is the most basic insulation indicator for electrical equipment and circuits. If the insulation resistance is too low, it can easily cause inter-turn short circuits or phase-to-phase and phase-to-ground short circuits during operation, leading to fires and serious consequences. This is especially true in offshore wind power environments, where the high humidity, high salt spray, and long hours of sunlight create a highly corrosive environment, placing extremely high demands on equipment stability. However, maintenance personnel cannot always be on-site to measure the insulation resistance of electrical equipment, making it impossible to accurately and promptly obtain the current insulation status of the equipment, resulting in blind spots in monitoring unit operation. Furthermore, wind turbines may experience prolonged shutdowns. The usual practice is to heat and dehumidify the turbine for several hours before operation to address moisture issues. Then, maintenance personnel climb the tower and use a megohmmeter to measure the insulation resistance. Only if the resistance value meets the requirements can the turbine be started; if it is not qualified, heating and dehumidification are continued, and the measurement is repeated until the insulation resistance value meets the requirements. However, during this process, the repeated up-and-down measurement of insulation resistance by maintenance personnel poses certain difficulties to the maintenance work, resulting in a waste of personnel and time. Furthermore, it makes it impossible to accurately grasp and monitor the timing of when the insulation resistance is qualified. There may be situations where the insulation resistance is qualified, but heating and dehumidification continue, resulting in the inability to start the unit in time, causing a loss of power generation and affecting the unit's operating efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide an insulation resistance monitoring system for wind turbine generator sets, which solves the problem that the repeated up-and-down measurement of insulation resistance by maintenance personnel causes certain difficulties in maintenance work, wastes personnel and time, and makes it impossible to accurately grasp and monitor the timing of qualified insulation resistance. In some cases, the insulation resistance may be qualified, but the unit continues to be heated and dehumidified, resulting in the inability to start the unit in time, causing a loss of power generation and affecting the unit's operating efficiency.

[0004] To achieve the above objectives, embodiments of the present invention provide an insulation resistance monitoring system for wind turbine generator sets, the system comprising:

[0005] An insulation resistance measuring instrument is installed inside the nacelle of a wind turbine generator set and connected to the target component of the wind turbine generator set. It is used to continuously measure the resistance value of the target component and send the resistance value to the main control system.

[0006] Heating and dehumidifying equipment is installed inside the nacelle of the wind turbine generator set to reduce the humidity inside the nacelle;

[0007] The main control system is connected to the insulation resistance measuring instrument and the heating and dehumidifying equipment. It is used to output a start command to the insulation resistance measuring instrument after receiving the shutdown command of the wind turbine generator set, and to output a start command to the heating and dehumidifying equipment when it is determined that the resistance value of any target component is less than a first preset threshold and greater than a second preset threshold.

[0008] Optionally, the heating and dehumidification device includes:

[0009] A heater and a dehumidifier are provided, wherein the heater is used to increase the temperature of the nacelle and the dehumidifier is used to dehumidify.

[0010] Optionally, the main control system is also used for:

[0011] If it is determined that the resistance value of any target component is less than or equal to the second preset threshold, a first fault alarm signal is generated.

[0012] Optionally, the main control system is also used for:

[0013] If, after a first preset time elapses from the moment the start command is output to the heating and dehumidifying device, it is determined that the resistance value of any target component is still less than the first preset threshold and greater than the second preset threshold, a second fault alarm signal is generated.

[0014] Optionally, the main control system is also used for:

[0015] After the heating and dehumidifying equipment is started, it continuously receives the resistance value of the target components. If the resistance value of each target component is greater than or equal to the first preset threshold for a second preset time, it outputs a shutdown command to the insulation resistance measuring instrument and the heating and dehumidifying equipment.

[0016] Optionally, the system further includes:

[0017] The display device, located in the central control room and connected to the main control system, is used to display the resistance value, the first fault alarm signal, and the second fault alarm signal.

[0018] Optionally, the target components include: the generator, transformer, and cable of the wind turbine generator set.

[0019] This invention also provides an online monitoring method for the insulation resistance of a wind turbine generator set, applied to the aforementioned insulation resistance monitoring system for wind turbine generator sets. The method includes:

[0020] Confirm that the wind turbine generator is in a shutdown state;

[0021] Continuously receive the resistance value of the target component measured by the insulation resistance meter;

[0022] If it is determined that the resistance value of any target component is less than the first preset threshold and greater than the second preset threshold, a start command is output to the heating and dehumidifying device.

[0023] From the moment the start command is output to the heating and dehumidifying device, after a first preset time, if it is determined that the resistance value of any target component is still less than the first preset threshold and greater than the second preset threshold, a second fault alarm signal is generated.

[0024] After the heating and dehumidifying equipment is started, it continuously receives the resistance value of the target components. If it is determined that the resistance value of each target component is greater than or equal to the first preset threshold for a second preset time, a shutdown command is output to the insulation resistance measuring instrument and the heating and dehumidifying equipment.

[0025] Optionally, the method further includes:

[0026] If it is determined that there is a target component with a resistance value less than or equal to the second preset threshold, a first fault alarm signal is generated.

[0027] The present invention also provides a wind turbine generator set, including the above-described insulation resistance monitoring system for the wind turbine generator set.

[0028] This technical solution collects the resistance values ​​of the target components of the wind turbine generator set in real time and realizes automatic control of the heating and dehumidification equipment based on the resistance values ​​of the target components. It can change the humidity inside the wind turbine generator set nacelle in a timely manner, and start the wind turbine generator set as soon as the resistance value is qualified, so that the wind turbine generator set can quickly enter the power generation state, ensure the operating time of the wind turbine generator set, and further improve the operation and maintenance efficiency and the unit operating efficiency.

[0029] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of the first insulation resistance monitoring system for wind turbine generator sets provided by the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of the second type of insulation resistance monitoring system for wind turbine generators provided by the present invention;

[0033] Figure 3 This is a flowchart of the online monitoring method for insulation resistance of wind turbine generator sets provided by the present invention;

[0034] Figure 4 This is a schematic diagram of the control logic for the online monitoring method of insulation resistance of wind turbine generator sets provided by the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 1-Insulation resistance measuring instrument; 2-Heating and dehumidifying equipment; 3-Main control system;

[0037] 4-Display device; 21-Heater; 22-Dehumidifier;

[0038] 101 - Target Component. Detailed Implementation

[0039] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0040] In the embodiments of the present invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use.

[0041] The terms “first,” “second,” “third,” etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0042] The terms "parallel" and "perpendicular" do not mean that the components must be absolutely parallel or perpendicular, but rather that they can be slightly tilted. For example, "parallel" simply means that its direction is more parallel than "perpendicular," not that the structure must be completely parallel, but that it can be slightly tilted.

[0043] The terms "horizontal," "vertical," and "sag" do not imply that a component must be absolutely horizontal, vertical, or sagging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0044] Furthermore, terms like "roughly" and "basically" are used to indicate that the content does not require absolute precision, but rather allows for a certain degree of deviation. For example, "roughly equal" does not simply mean absolute equality; in actual production and operation, achieving absolute "equality" is difficult, and a certain degree of deviation is generally present. Therefore, besides absolute equality, "roughly equal to" also includes the aforementioned situation where a certain degree of deviation exists. Using this as an example, in other cases, unless otherwise specified, terms like "roughly" and "basically" have similar meanings.

[0045] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] Figure 1 This is a schematic diagram of the structure of the first insulation resistance monitoring system for wind turbine generator sets provided by the present invention; Figure 2 This is a schematic diagram of the structure of the second type of insulation resistance monitoring system for wind turbine generators provided by the present invention; Figure 3 This is a flowchart of the online monitoring method for insulation resistance of wind turbine generator sets provided by the present invention;

[0047] Figure 4 This is a schematic diagram of the control logic for the online monitoring method of insulation resistance of wind turbine generator sets provided by the present invention.

[0048] Example 1

[0049] like Figure 1 As shown in the figure, this embodiment provides an insulation resistance monitoring system for wind turbine generator sets, the system comprising:

[0050] Insulation resistance measuring instrument 1 is installed in the nacelle of the wind turbine generator set and connected to the target component 101 of the wind turbine generator set. It is used to continuously measure the resistance value of the target component 101 after receiving the start command and send the resistance value to the main control system 3.

[0051] Heating and dehumidifying equipment 2 is installed in the nacelle of the wind turbine generator set. It is used to reduce the humidity in the nacelle by heating and dehumidifying after receiving the start command.

[0052] The main control system 3 is connected to the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2. It is used to output a start command to the insulation resistance measuring instrument 1 after receiving the shutdown command of the wind turbine generator set, and to output a start command to the heating and dehumidifying device 2 when it is determined that the resistance value of any target component 101 is less than the first preset threshold and greater than the second preset threshold.

[0053] The second preset threshold is less than the first preset threshold.

[0054] Specifically, in this embodiment, the nacelle of the wind turbine generator set is equipped with electrical equipment such as generators, transformers, and cables. As the target component 101, the insulation resistance value of this type of electrical equipment will change accordingly with the humidity value in the nacelle. If the insulation resistance value of the equipment is lower, it means that the humidity value of the environment is higher, and if the insulation resistance value is higher, it means that the humidity value of the environment is lower.

[0055] The insulation resistance meter 1 has multiple input interfaces. Taking connection with a generator as an example: the input interfaces of the insulation resistance meter 1 are connected to the three-phase stator winding copper busbar, the three-phase rotor winding copper busbar, and the grounding copper busbar of the generator, respectively. After receiving a command, the insulation resistance meter 1 sends out a DC voltage signal, forms a circuit with the generator, and measures the insulation resistance of the circuit. After the insulation resistance value stabilizes, it records the insulation resistance value and feeds it back to the control system 3. After the measurement is completed, it discharges according to the pre-set program.

[0056] The connection method of the insulation resistance meter 1 with other equipment is similar to that of the generator, and will not be elaborated here. Depending on the equipment connection, the insulation resistance of each connection circuit is measured sequentially and transmitted to the control system 3. Insulation resistance detection can be performed every time interval t. Upon receiving a command from the control system 3, it can automatically measure the insulation resistance of all input circuits sequentially and complete the discharge after measurement. The insulation resistance meter 1 is connected to the control system 3 via communication and hardwiring, allowing the insulation resistance value of each circuit to be transmitted to the main control system 3. The insulation resistance meter 1 can manually or automatically adjust the circuits and number of circuits measured. For example, if the stator winding insulation resistance to ground is qualified, the insulation resistance of this circuit can be stopped before the insulation resistance meter is de-energized, and only the unqualified circuits can be measured, thus speeding up the measurement time and improving measurement efficiency. The insulation resistance meter 1 can also select different output voltages according to the settings.

[0057] The main control system 3 can directly utilize the main control system of the wind turbine generator set, or it can set up a separate controller and connect the controller to the main control system 3 to realize data transmission.

[0058] Furthermore, such as Figure 2 As shown, the heating and dehumidifying device 2 includes:

[0059] A heater 21 and a dehumidifier 22 are installed inside the nacelle of the wind turbine generator set. The heater 21 is used to increase the temperature of the nacelle, and the dehumidifier 22 is used to dehumidify.

[0060] Specifically, in this embodiment, the heating of the chamber by the heater 21 and the dehumidification by the dehumidifier 22 are combined to improve the dehumidification efficiency and ensure rapid dehumidification.

[0061] More specifically, multiple heaters 21 and dehumidifiers 22 can be configured, and multiple dehumidification zones are determined based on the location of the target components. One heater 21 and one dehumidifier 22 are installed in each dehumidification zone. Furthermore, for each target component 101, when the insulation resistance value of the target component 101 is less than a first preset threshold but greater than a second preset threshold, the heating and dehumidification device 2 in the dehumidification zone corresponding to the target component 101 is controlled to start working for dehumidification. Similarly, if it is determined that the insulation resistance measurement value of the target component 101 is greater than or equal to the first preset threshold multiple times consecutively, the insulation resistance of the circuit of this target component 101 will no longer be measured, and the heating and dehumidification device 2 in the dehumidification zone corresponding to the target component 101 will stop working.

[0062] Furthermore, the main control system 3 is also used for:

[0063] When it is determined that there is an insulation resistance with a resistance value less than or equal to the second preset threshold, a first fault alarm signal is generated.

[0064] Specifically, after receiving the resistance value of each target component 101, based on the received insulation resistance value of the target component 101, it is determined that there is an insulation resistance value less than or equal to the second preset threshold. This indicates that the insulation resistance of the target component 101 is too low, and there may be a short circuit in the equipment. This situation cannot be resolved by heating and dehumidification, and the control system will generate a first fault alarm signal, which is fed back to the central control room through the SCADA system to notify maintenance personnel to conduct on-site troubleshooting. Furthermore, based on the different interfaces between each target component 101 and the insulation resistance measuring instrument 1, the specific setting location of the target component 101 that generated the first fault alarm signal can be accurately determined. Thus, the first fault alarm signal contains the setting location information of the corresponding target component 101, thereby improving the efficiency of maintenance.

[0065] Furthermore, the main control system 3 is also used for:

[0066] From the moment the start command is output to the moment the heating and dehumidifying device 2 is activated, after a first preset time period, if it is determined that the resistance value of any target component 101 is still less than the first preset threshold and greater than the second preset threshold, a second fault alarm signal is generated.

[0067] Specifically, based on the received insulation resistance value of the target component, and after determining that there is a target component 101 with a resistance value less than the first preset threshold and greater than the second preset threshold, a start command is output to the heating and dehumidifying equipment 2 to control the operation of the heating and dehumidifying equipment 2 to reduce the humidity value in the cabin. After the heating and dehumidifying equipment 2 has been operating for a first preset time, the insulation resistance value of the target component 101 is obtained again through the insulation resistance measuring instrument 1. If there is still a target component 101 with a resistance value less than the first preset threshold and greater than the second preset threshold, it indicates that the dehumidification effect has not met expectations. It is believed that the heating and dehumidifying equipment 2 may be faulty, resulting in the inability to dehumidify the cabin in a timely manner. Then, a second fault alarm signal is generated and fed back to the central control room through the SCADA system to notify the operation and maintenance personnel to go to the site for troubleshooting.

[0068] Furthermore, the main control system 3 is also used for:

[0069] After the heating and dehumidifying device 2 is started, it continuously receives the resistance value of the target component 101. If the resistance value of each target component 101 is greater than or equal to the first preset threshold for a second preset time, a shutdown command is output to the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2.

[0070] Specifically, when all insulation resistance measurements are greater than or equal to a first preset threshold, it indicates that the insulation of the target component 101 is normal. In this embodiment, the resistance values ​​of the target component 101 are continuously received. Only when the duration for which the resistance values ​​are all greater than or equal to the first preset threshold reaches a second preset duration is the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2 controlled to shut down, and the generator start-up process begins. This avoids measurement errors that could lead to misjudgments and improves the accuracy of control. Alternatively, when each insulation resistance measurement obtained from a preset number of consecutive measurements is greater than or equal to the first preset threshold, a shutdown command is output to the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2. After receiving the shutdown command, the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2 shut down and then enter the generator start-up process.

[0071] More specifically, for each target component 101, if the duration for which all resistance values ​​are greater than or equal to the first preset threshold reaches a second preset duration (e.g., 15 minutes), a shutdown command is output to the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2. This can be replaced by: taking the insulation resistance measuring instrument 1 performing a resistance measurement every five minutes as an example, then three measurements are performed within 15 minutes. Therefore, if the insulation resistance measurement values ​​obtained for all target components 101 for a preset number of consecutive preset times (3 times) are all greater than or equal to the first preset threshold, a shutdown command is output to the insulation resistance measuring instrument 1 and the heating and dehumidifying device 2. This effectively reduces errors caused by data jumps during measurement that could lead to misjudgments.

[0072] In another implementation, for each target component 101, if the duration for which all resistance values ​​are greater than or equal to the first preset threshold reaches a second preset duration (e.g., 15 minutes), then the insulation resistance of the circuit of this target component 101 will no longer be measured. Only the circuits of the remaining unqualified target components 101 will be measured to speed up the measurement time and improve the measurement efficiency. It can be understood that, taking the insulation resistance measuring instrument 1 performing a resistance measurement every five minutes as an example, a total of three measurements will be performed within 15 minutes. Therefore, if the insulation resistance measurement values ​​obtained for a certain target component 101 for a preset number of consecutive (3 times) tests are all greater than or equal to the first preset threshold, then the insulation resistance of the circuit of this target component 101 will no longer be measured. Only the circuits of the remaining unqualified target components 101 will be measured to speed up the measurement time and improve the measurement efficiency.

[0073] Furthermore, such as Figure 2 As shown, system 1 further includes:

[0074] Display device 4, located in the central control room, is communicatively connected to the main control system 3 and is used to display the resistance value, the first fault alarm signal, and the second fault alarm signal.

[0075] Specifically, the display device 4 is embedded with a SCADA system. The SCADA system is connected to the control system through communication methods such as optical fiber to realize data transmission, so as to transmit the resistance value, the first fault alarm signal and the second fault alarm signal to the display device 4 for real-time display, so that the operation and maintenance personnel can view it in real time.

[0076] Example 2

[0077] like Figure 3 As shown, this invention also provides an online monitoring method for the insulation resistance of a wind turbine generator set, applied to the aforementioned insulation resistance monitoring system for wind turbine generator sets. The method includes:

[0078] Step 101: Confirm that the wind turbine generator is in a shutdown state;

[0079] Step 102: Continuously receive the resistance value of the target component measured by the insulation resistance measuring instrument;

[0080] Step 103: If it is determined that the resistance value of any target component is less than the first preset threshold and greater than the second preset threshold, then a start command is output to the heating and dehumidifying device.

[0081] From the moment the start command is output to the heating and dehumidifying device, after a first preset time, if it is determined that the resistance value of any target component is still less than the first preset threshold and greater than the second preset threshold, a second fault alarm signal is generated.

[0082] After the heating and dehumidifying equipment is started, it continuously receives the resistance value of the target components. If it is determined that the resistance value of each target component is greater than or equal to the first preset threshold for a second preset time, a shutdown command is output to the insulation resistance measuring instrument and the heating and dehumidifying equipment.

[0083] Furthermore, the method also includes:

[0084] If it is determined that there is a target component with a resistance value less than or equal to the second preset threshold, a first fault alarm signal is generated.

[0085] Specifically, in this embodiment, as Figure 4 As shown, when the wind turbine generator is detected to be in a shutdown state, the control system sends an insulation resistance measurement command to the insulation resistance measuring instrument. After receiving the command, the insulation resistance measuring instrument measures the insulation resistance value R of each circuit in sequence and uploads it to the control system. After receiving the insulation resistance value, the control system determines whether the insulation resistance value R is greater than the second preset threshold R2. If it is less than or equal to the second preset threshold, it indicates that the insulation resistance value is too low, and a fault signal (first fault alarm signal) is sent to the SCDAD system, and the fault is displayed in the central control room. If the insulation resistance value R is greater than the second preset threshold R2, the control system continues to determine the insulation resistance value. If R is greater than or equal to the first preset threshold R1, and less than the first preset threshold R1, a start signal is sent to the heating and dehumidification equipment. After receiving the instruction, the heating and dehumidification equipment performs heating and dehumidification. After time t, the insulation resistance value R is retested. If the insulation resistance value R obtained from multiple consecutive tests is greater than or equal to the first preset threshold R1 and continues to reach the second preset time, it indicates that the insulation resistance value is normal and the unit starts up. If, after the first preset time, the insulation resistance value is still less than the first preset threshold R1, a fault signal (second fault alarm signal) is sent to the SCDAD system and the fault is displayed in the central control room.

[0086] This technical solution detects the insulation resistance of target components after the unit is shut down, and starts heating and dehumidifying equipment to improve the humid environment based on the measurement results, or sends a fault signal to notify maintenance personnel for repair. At the same time, the insulation status of the equipment can be monitored in the central control room, and the unit can be started as soon as the insulation is qualified, which improves the unit's operating time and efficiency. It also solves the problem of maintenance personnel having to repeatedly climb the tower to measure the insulation resistance, thus improving maintenance efficiency.

[0087] Example 3

[0088] The present invention also provides a wind turbine generator set, including the insulation resistance monitoring system for the wind turbine generator set described above.

[0089] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0090] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0091] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0092] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application.

[0093] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. An insulation resistance monitoring system for a wind turbine generator unit, characterized by, The system comprises: an insulation resistance measuring instrument (1) arranged in a nacelle of a wind turbine generator set, connected with target components (101) of the wind turbine generator set, used for continuously measuring resistance values of the target components (101) and sending the resistance values to a main control system (3); a heating and dehumidifying device (2) arranged in the nacelle of the wind turbine generator set, used for reducing humidity in the nacelle; the main control system (3) connected with the insulation resistance measuring instrument (1) and the heating and dehumidifying device (2), used for outputting a start instruction to the insulation resistance measuring instrument (1) after receiving a shutdown instruction of the wind turbine generator set, and outputting the start instruction to the heating and dehumidifying device (2) in a case that resistance values of any of the target components (101) are determined to be less than a first preset threshold value and greater than a second preset threshold value; the main control system (3) is further used for: generating a first fault alarm signal in a case that resistance values of any of the target components (101) are determined to be less than or equal to the second preset threshold value; generating a second fault alarm signal if it is determined that resistance values of any of the target components (101) are still less than the first preset threshold value and greater than the second preset threshold value after a first preset time period from the time when the start instruction is output to the heating and dehumidifying device (2); continuously receiving the resistance values of the target components (101) after the heating and dehumidifying device (2) is started, and outputting a shutdown instruction to the insulation resistance measuring instrument (1) and the heating and dehumidifying device (2) if the resistance values of each of the target components (101) are determined to be greater than or equal to the first preset threshold value for a second preset time period.

2. The insulation resistance monitoring system of a wind power generating unit according to claim 1, characterized in that, the heating and dehumidifying device (2) comprises: a heater (21) and a dehumidifier (22), the heater (21) and the dehumidifier (22) are arranged in the nacelle of the wind turbine generator set, the heater (21) is used for increasing the temperature of the nacelle, and the dehumidifier (22) is used for dehumidifying.

3. The insulation resistance monitoring system of a wind power generator set according to claim 1, characterized by, The system further comprises: a display device (4) arranged in a central control room, in communication connection with the main control system (3), used for displaying the resistance values, the first fault alarm signal and the second fault alarm signal.

4. The insulation resistance monitoring system of a wind power generating unit according to claim 1, characterized by, The target components (101) comprise: a generator, a transformer and a cable of the wind turbine generator set.

5. A method for on-line monitoring of insulation resistance of a wind turbine generator set, applied to the insulation resistance monitoring system of any one of claims 1-4, characterized in that, The method comprises: determining that the wind turbine generator set is in a shutdown state; continuously receiving resistance values of target components measured by an insulation resistance measuring instrument; outputting a start instruction to a heating and dehumidifying device if it is determined that resistance values of any of the target components are less than a first preset threshold value and greater than a second preset threshold value; generating a second fault alarm signal if it is determined that resistance values of any of the target components are still less than the first preset threshold value and greater than the second preset threshold value after a first preset time period from the time when the start instruction is output to the heating and dehumidifying device; continuously receiving the resistance values of the target components after the heating and dehumidifying device is started, and outputting a shutdown instruction to the insulation resistance measuring instrument and the heating and dehumidifying device if the resistance values of each of the target components are determined to be greater than or equal to the first preset threshold value for a second preset time period.

6. The wind turbine generator set insulation resistance on-line monitoring method according to claim 5, characterized by, The method further comprises: generating a first fault alarm signal if it is determined that there is a target component whose resistance value is less than or equal to the second preset threshold value.

7. A wind power unit, characterized in that An insulation resistance monitoring system for a wind turbine generator according to any one of claims 1-4.

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