Control method of wind power generator, converter, control system, and storage medium

Abstract

The embodiment of the application provides a kind of wind-driven generator control method, converter, control system and storage medium, the output end of wind-driven generator is connected with the output end of converter, the direct current end of converter is connected with power grid, and converter is used to control the operation of wind-driven generator, the method comprises: obtaining the first direct current voltage output by converter;Judge whether the first direct current voltage is greater than the preset voltage threshold;If the first direct current voltage is greater than the voltage threshold, the second direct current voltage is used as the target output voltage of converter, and the operation of wind-driven generator is controlled;If the first direct current voltage is less than or equal to the voltage threshold, the third direct current voltage is used as the target output voltage of converter, and the operation of wind-driven generator is controlled.The scheme can solve the problem of low-speed start of wind-driven generator, can be normally connected with power grid, and can guarantee that the upper limit of the output of converter is not reduced.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of energy, in particular to a control method of a wind driven generator, a converter, a control system and a storage medium. BACKGROUND

[0002] Currently, wind driven generators mostly use permanent magnet synchronous generators, and use converters to drive the generators to rectify alternating current with changing amplitude and frequency into stable direct current. Specifically, the wind paddle drives the generator to rotate, and when the rotational speed reaches a predetermined value, the converter starts to work and forms a direct current voltage closed loop control mode, converts the power generated by the generator into stable direct current, and then outputs the direct current through an adjustable power supply module to be connected to an alternating current grid.

[0003] The converter has a certain voltage working interval. When the wind paddle drives the generator at a low speed, the output voltage of the generator is low, and the converter cannot start. The converter cannot start to perform closed loop control on the generator, resulting in that the wind driven generator cannot start or needs a long time to start.

[0004] Currently, in order to enable the wind driven generator to start at a low speed, the starting voltage of the converter is reduced, so that the converter can start when the generator rotates at a low speed to perform closed loop control on the generator.

[0005] However, reducing the starting voltage of the converter will reduce the upper limit of the output voltage of the converter, which will cause the converter to fail to work normally when the generator rotates at a high speed, and further cause the utilization rate of the wind driven generator to be low. SUMMARY

[0006] To solve the above technical problems, embodiments of the present application provide a control method of a wind driven generator, a converter, a control system and a storage medium to at least solve or alleviate the above problems.

[0007] According to a first aspect of embodiments of the present application, a control method of a wind driven generator is provided. The output end of the wind driven generator is connected to the output end of a converter, the direct current end of the converter is connected to a power grid, and the converter is used to control the operation of the wind driven generator. The method comprises: acquiring a first direct current voltage output by the converter; determining whether the first direct current voltage is greater than a preset voltage threshold; if the first direct current voltage is greater than the voltage threshold, using a second direct current voltage as a target output voltage of the converter to control the operation of the wind driven generator; and if the first direct current voltage is less than or equal to the voltage threshold, using a third direct current voltage as the target output voltage of the converter to control the operation of the wind driven generator, wherein the second direct current voltage is greater than the third direct current voltage, and the third direct current voltage is greater than the voltage threshold.

[0008] In a first possible implementation, in combination with the first aspect, the voltage threshold is positively correlated with the mode switching voltage, wherein the converter controls the wind power generator to operate in a first mode when the driving voltage of the converter is greater than or equal to the mode switching voltage, and controls the wind power generator to operate in a second mode when the driving voltage of the converter is less than the mode switching voltage, the overvoltage threshold of the converter is a first overvoltage threshold in the first mode, and the overvoltage threshold of the converter is a second overvoltage threshold in the second mode, the second DC voltage is greater than the second overvoltage threshold and less than the first overvoltage threshold, and the third DC voltage is less than the second overvoltage threshold.

[0009] In a second possible implementation, in combination with the first possible implementation, the voltage threshold and the mode switching voltage satisfy the following formula:

[0010] V1 = 0.82 * V2

[0011] V1 is used to represent the voltage threshold, and V2 is used to represent the mode switching voltage.

[0012] In a third possible implementation, in combination with the first possible implementation, the controlling the wind power generator to operate with the second DC voltage as the target output voltage of the converter comprises: determining a first driving voltage corresponding to the second DC voltage according to the mode switching voltage, wherein the first driving voltage is greater than or equal to the mode switching voltage; and controlling the wind power generator to operate with the first driving voltage as the target driving voltage of the converter for driving the wind power generator and the second DC voltage as the target output voltage of the converter.

[0013] In a fourth possible implementation, in combination with the first aspect or any possible implementation of the first aspect, the method further comprises: when the wind power generator is controlled to operate with the third DC voltage as the target output voltage of the converter, if it is determined that the first DC voltage is greater than the voltage threshold, then after a duration in which the first DC voltage is greater than the voltage threshold is greater than a preset delay time, the wind power generator is controlled to operate with the second DC voltage as the target output voltage of the converter.

[0014] In a fifth possible implementation, in combination with the fourth possible implementation described above, the operation of the wind power generator is controlled with the second DC voltage as the target output voltage of the converter after the duration that the first DC voltage is greater than the voltage threshold is greater than the preset delay time, including: after determining that the duration that the first DC voltage is greater than the voltage threshold is greater than the preset delay time, the converter is controlled to be shut down, and the operating parameters of the converter are reset so that the wind power generator is controlled to operate with the second DC voltage as the target output voltage after the converter is restarted.

[0015] According to a second aspect of the embodiments of the present application, a converter is provided, an output end of the converter is connected to an output end of a wind power generator, a DC end of the converter is connected to a power grid, and the converter includes: an acquisition module configured to acquire a first DC voltage output by the converter; a judgment module configured to judge whether the first DC voltage is greater than a preset voltage threshold; and an execution module configured to control the wind power generator to operate with a second DC voltage as a target output voltage of the converter when the first DC voltage is greater than the voltage threshold, and control the wind power generator to operate with a third DC voltage as the target output voltage of the converter when the first DC voltage is less than or equal to the voltage threshold, wherein the second DC voltage is greater than the third DC voltage.

[0016] According to a third aspect of the embodiments of the present application, a control system of a wind power generator is provided, including: the converter of the second aspect described above, a first switch, a second switch, an adjustable power supply module, an adjustable interface module, and a transformer; one end of the first switch is connected to an output end of the wind power generator, the other end of the first switch is connected to an output end of the converter, a DC end of the converter is connected to an input end of the adjustable power supply module, an output end of the adjustable power supply module is connected to an input end of the adjustable interface module, an output end of the adjustable interface module is connected to an input end of the transformer, an output end of the transformer is connected to one end of the second switch, and the other end of the second switch is connected to a power grid; the first switch is configured to control the opening and closing of a circuit in which the wind power generator and the converter are connected; the second switch is configured to control the opening and closing of a circuit in which the transformer and the power grid are connected; the adjustable power supply module is configured to convert the second DC voltage output by the converter into an alternating voltage; the adjustable interface module is configured to filter the alternating voltage to obtain a stable alternating voltage; and the transformer is configured to step up the stable alternating voltage.

[0017] According to a fourth aspect of the embodiments of the present application, an electronic device is provided, including: a processor, a memory, a communication interface, and a communication bus, the processor, the memory, and the communication interface complete communication with each other through the communication bus.

[0018] The memory is configured to store at least one executable instruction, and the executable instruction causes the processor to execute operations corresponding to the control method of the wind driven generator according to the first aspect.

[0019] According to a fifth aspect of the embodiments of the present application, a computer storage medium is provided, and the computer storage medium stores a computer program. The computer program is executed by a processor to implement the control method of the wind driven generator according to the first aspect.

[0020] According to a sixth aspect of the embodiments of the present application, a computer program product is provided, and the computer program product includes computer instructions. The computer instructions instruct a computing device to execute operations corresponding to the control method of the wind driven generator according to the first aspect.

[0021] According to the above technical solution, when the speed of the wind driven generator is low, the first DC voltage output by the converter is low. At this time, the wind driven generator is controlled to operate by taking the third DC voltage as the target output voltage of the converter. The first DC voltage output by the converter can be gradually increased. When the first voltage threshold of the converter is greater than the voltage threshold, the wind driven generator is controlled to operate by taking the second DC voltage as the target output voltage of the converter. The output voltage of the converter is gradually increased to the second output voltage, so as to meet the grid-connected condition. During the starting process of the wind driven generator, the wind driven generator is controlled to operate by taking the third DC voltage as the target output voltage of the converter first, and then the wind driven generator is controlled to operate by taking the second DC voltage as the target output voltage of the converter. The time required for starting the wind driven generator can be shortened, and the upper limit of the output voltage of the converter does not need to be reduced. Therefore, the problem of low-speed starting of the wind driven generator can be solved, and the wind driven generator has a high energy utilization rate. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the embodiments of the present application. Those skilled in the art can also obtain other drawings from these drawings

[0023] Figure 1 is a schematic diagram of a control system of a wind driven generator according to an embodiment of the present application;

[0024] Figure 2 is a schematic diagram of a control system of a wind driven generator according to another embodiment of the present application;

[0025] Figure 3 is a schematic diagram of a converter according to an embodiment of the present application;

[0026] Figure 4Flow chart of a control method of a wind driven generator, which is an embodiment of the present application;

[0027] Figure 5 Flow chart of a control method of a wind driven generator, which is another embodiment of the present application;

[0028] Figure 6 Schematic diagram of an electronic device, which is an embodiment of the present application.

[0029] List of reference signs:

[0030] 100: control system of a wind driven generator 10: converter

[0031] 11: acquisition module 12: judgment module 13: execution module

[0032] 20: grid-connected module Q1: first switch Q2: second switch

[0033] 21: regulated power supply module 22: regulated interface module 23: transformer

[0034] 400: control method of a wind driven generator 40: power grid 30: wind driven generator

[0035] 500: control method of a wind driven generator 50: electronic device 51: processor

[0036] 52: communication interface 53: memory 54: communication bus

[0037] 55: program

[0038] 401: acquire a first direct current voltage output by the converter

[0039] 402: judge whether the first direct current voltage is greater than a preset voltage threshold

[0040] 403: control the wind driven generator to operate with a second direct current voltage as a target output voltage of the converter

[0041] 404: control the wind driven generator to operate with a third direct current voltage as a target output voltage of the converter

[0042] 501: acquire a first direct current voltage output by the converter

[0043] 502: judge whether the first direct current voltage is greater than a preset voltage threshold

[0044] 503: set a first driving voltage and a second direct current voltage

[0045] 504: set a second driving voltage and a third direct current voltage

[0046] 505: controlling the wind power generator to operate with the second DC voltage as a target output voltage of the converter

[0047] 506: controlling the wind power generator to operate with the third DC voltage as a target output voltage of the converter

[0048] 507: judging whether a duration that the first DC voltage is greater than the voltage threshold is greater than a preset delay time

[0049] 508: controlling the converter to shut down, resetting an operating parameter of the converter, and restarting the converter DETAILED DESCRIPTION

[0050] In order to make personnel in the art better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art should belong to the scope of protection of the embodiments of the present application.

[0051] Control system of a wind turbine

[0052] Figure 1 is a schematic diagram of a control system 100 of a wind power generator according to an embodiment of the present application. As shown in Figure 1 the control system 100 of the wind power generator includes a converter 10 and a grid-connected module 20. An output end of the converter 10 is connected to an output end of a wind power generator 30, a DC end of the converter 10 is connected to an input end of the grid-connected module 20, and an output end of the grid-connected module 20 is connected to a power grid 40.

[0053] The converter 10 is used to control the operation of the wind power generator 30 and convert an AC voltage output by the wind power generator 30 into a DC voltage, and then transmit the converted DC voltage to the grid-connected module 20. The grid-connected module 20 is used to convert the input DC voltage into an AC voltage that can be connected to the power grid 40, and then connect the converted AC voltage to the power grid 40.

[0054] Figure 2 is a schematic diagram of a control system 100 of a wind power generator according to another embodiment of the present application. As shown in Figure 2As shown, the control system 100 of the wind power generator further comprises a first switch Q1 and a second switch Q2, and the grid-connected module 20 comprises a regulated power module 21, a regulated interface module 22 and a transformer 23. An output end of the wind power generator 30 is connected to one end of the first switch Q1, the other end of the first switch Q1 is connected to an output end of the converter 10, a direct current end of the converter 10 is connected to an input end of the regulated power module 21, an output end of the regulated power module 21 is connected to an input end of the regulated interface module 22, an output end of the regulated interface module 22 is connected to an input end of the transformer 23, an output end of the transformer 23 is connected to one end of the second switch Q2, the other end of the second switch Q2 is connected to the power grid 40.

[0055] The first switch Q1 is used to control the on-off of the electrical connection between the wind power generator 30 and the converter 10, and when the output voltage of the wind power generator 30 reaches the starting voltage threshold of the converter 10, the first switch Q1 is closed to turn on the electrical connection between the wind power generator 30 and the converter 10.

[0056] The second switch Q2 is used to control the on-off of the electrical connection between the transformer 23 and the power grid 40, and when the direct current voltage output by the converter 10 reaches the operating voltage threshold of the transformer 23, the second switch Q2 is closed, the transformer 23 boosts the alternating current voltage output by the regulated interface module 22 to obtain an alternating current voltage that can be connected to the power grid 40, and the obtained alternating current voltage is connected to the power grid 40.

[0057] The regulated power module 21 is used to convert the direct current voltage output by the converter 10 into an alternating current voltage and transmit it to the regulated interface module 22. The regulated interface module 22 is used to rectify the input alternating current voltage, output a stable alternating current voltage, and transmit the obtained alternating current voltage to the transformer 23. The transformer 23 is used to boost the input alternating current voltage, convert the input lower alternating current voltage into a higher alternating current voltage, so that the output alternating current voltage meets the grid-connected requirement.

[0058] The converter 10 is used to control the wind power generator 30 to operate with a second direct current voltage as a target output voltage when a first direct current voltage output by the converter 10 is greater than a preset voltage threshold during the starting process of the wind power generator 30, and control the wind power generator 30 to operate with a third direct current voltage as a target output voltage when the first direct current voltage is less than or equal to the voltage threshold. The second direct current voltage is greater than the third direct current voltage, and the third direct current voltage is greater than the voltage threshold.

[0059] In the embodiment of the application, during the starting process of the wind driven generator 30, when the rotating speed of the wind driven generator 30 is low, the first DC voltage output by the converter 10 is low, at this time, the wind driven generator 30 is controlled to operate with the third DC voltage as the target output voltage of the converter 10, which can gradually increase the first DC voltage output by the converter 10, and after the first DC voltage output by the converter 10 is greater than the voltage threshold, the wind driven generator 30 is controlled to operate with the second DC voltage as the target output voltage of the converter 10, which can gradually increase the output voltage of the converter 10 to the second output voltage, so as to meet the grid-connected condition. During the starting process of the wind driven generator 30, the wind driven generator 30 is first controlled to operate with the third DC voltage as the target output voltage of the converter 10, and then the wind driven generator 30 is controlled to operate with the second DC voltage as the target output voltage of the converter 10, which can shorten the time required for the starting of the wind driven generator 30, and does not need to reduce the upper limit of the output voltage of the converter 10, thereby solving the problem of low-speed starting of the wind driven generator 30 and ensuring that the wind driven generator 30 has a high energy utilization rate.

[0060] The embodiment of the application focuses on the process of controlling the wind driven generator 30 to start at a low speed by the converter 10, and the process of controlling the wind driven generator 30 to start by the converter 10 will be described in detail hereinafter.

[0061] Converter

[0062] Based on the control system 100 of the wind driven generator in the above embodiment, the embodiment of the application provides a converter, Figure 3 is a schematic diagram of the converter according to an embodiment of the application. As shown in Figure 3 the converter 10 comprises:

[0063] The acquisition module 11 is configured to acquire the first DC voltage output by the converter 10.

[0064] The judgment module 12 is configured to judge whether the first DC voltage is greater than a preset voltage threshold.

[0065] The execution module 13 is configured to control the wind driven generator 30 to operate with the second DC voltage as the target output voltage of the converter 10 when the first DC voltage is greater than the voltage threshold, and control the wind driven generator 30 to operate with the third DC voltage as the target output voltage of the converter 10 when the first DC voltage is less than or equal to the voltage threshold, wherein the second DC voltage is greater than the third DC voltage, and the third DC voltage is greater than the voltage threshold.

[0066] In the embodiment of the present application, the acquisition module 11 acquires the first DC voltage output by the converter 10 during the starting of the wind driven generator 30, the judging module 12 judges whether the first DC voltage acquired by the acquisition module 11 is greater than the voltage threshold, and the execution module 13 controls the wind driven generator 30 to operate with the second DC voltage as the target output voltage of the converter 10 when the first DC voltage is greater than the voltage threshold and controls the wind driven generator 30 to operate with the third DC voltage as the target output voltage of the converter 10 when the first DC voltage is less than or equal to the voltage threshold according to the judgment result of the judging module 12. Based on the judgment result of the judging module 12, the wind driven generator 30 is controlled to operate with the smaller third DC voltage as the target output voltage of the converter 10 first during the starting of the wind driven generator 30, and then the wind driven generator 30 is controlled to operate with the increased second DC voltage as the target output voltage of the converter 10, which can shorten the time required for the starting of the wind driven generator 30 and does not need to reduce the upper limit of the output voltage of the converter 10, thereby solving the problem of the low-speed starting of the wind driven generator 30 and ensuring that the wind driven generator 30 has a high energy utilization rate.

[0067] In a possible implementation manner, the converter 10 is internally provided with a rectifying module, which can convert the AC voltage output by the power grid into the first DC voltage and provide the first DC voltage to the acquisition module 11. The execution module 13 is internally provided with a normal operation unit and a low-speed operation unit, and the normal operation unit or the low-speed operation unit is started according to the judgment signal provided by the judging module 12 after the judgment signal is provided. The normal operation unit and the low-speed operation unit are both provided with a current limiting program, which can limit the output current of the converter 10 to prevent the circuit from being overloaded and causing damage to the equipment. The converter 10 is further provided with an alarm device, and the effect of the current limiting program will be affected when the output current of the converter 10 is too large. At this time, the alarm device will send a warning signal.

[0068] It should be noted that the information interaction and execution process between the modules in the converter 10 can be referred to the description in the following embodiment of the control method of the wind driven generator.

[0069] Control method of a wind turbine

[0070] Based on the control system 100 of the wind driven generator in the above embodiment, the embodiment of the present application provides a control method of a wind driven generator. Figure 4 The control method 400 of the wind driven generator is an embodiment of the present application, and can be executed by the converter 10 in the foregoing embodiment. Unless otherwise specified, the converter in the following method embodiments can be the converter 10 in the foregoing embodiment, the wind driven generator in the following method embodiments can be the wind driven generator 30 in the foregoing embodiment, and the power grid in the following method embodiments can be the power grid 40 in the foregoing embodiment. For example, Figure 4As shown, the control method 400 of the wind power generator includes the following steps:

[0071] Step 401, obtaining a first direct current voltage output by a converter.

[0072] The output end of the wind power generator is connected to the output end of the converter, and the direct current end of the converter is connected to the power grid. The converter is used to control the operation of the wind power generator. The converter can include a rectifying unit, which can convert the alternating current voltage output by the wind power generator into a direct current voltage output. During the starting process of the wind power generator, a first direct current voltage output by the rectifying unit can be obtained.

[0073] Step 402, determining whether the first direct current voltage is greater than a preset voltage threshold. If yes Y, step 403 is performed, and if no N, step 404 is performed.

[0074] According to the voltage range output by the converter in different operating states, a voltage threshold is preset. When the output voltage of the converter is greater than the voltage threshold, the converter controls the operation of the wind power generator with a second direct current voltage as the target output voltage. When the output voltage of the converter is less than or equal to the voltage threshold, the converter controls the operation of the wind power generator with a third direct current voltage as the target output voltage, wherein the second direct current voltage is greater than the third direct current voltage.

[0075] During the starting process of the wind power generator, after obtaining the first direct current voltage output by the converter, the obtained first direct current voltage is compared with the voltage threshold. If the first direct current voltage is greater than the voltage threshold, the converter should control the operation of the wind power generator with the second direct current voltage as the target output voltage, and step 403 is performed accordingly. If the first direct current voltage is less than or equal to the voltage threshold, the converter should control the operation of the wind power generator with the third direct current voltage as the target output voltage, and step 404 is performed accordingly.

[0076] Step 403, controlling the operation of the wind power generator with the second direct current voltage as the target output voltage of the converter, and ending the current process.

[0077] The second direct current voltage is set according to the demand of grid connection. When the direct current voltage output by the converter reaches the second direct current voltage, the direct current voltage output by the converter can be connected to the power grid after being boosted by a transformer. In order to enable the voltage output by the converter to reach the second direct current voltage, the converter controls the wind power generator based on the direct current voltage output by the converter with the second direct current voltage as the target output voltage of the converter.

[0078] Step 404, controlling the operation of the wind power generator with the third direct current voltage as the target output voltage of the converter.

[0079] When the first DC voltage is small, the AC voltage output by the wind power generator is small, and if the target output voltage of the converter is too large, the deviation between the target output voltage and the actual output voltage of the converter is large, and the converter needs to consume a long time to make the output voltage reach the target output voltage in the DC voltage closed-loop control, resulting in low starting efficiency of the wind power generator. Since the third DC voltage is smaller than the second DC voltage, when the rotating speed of the wind power generator is low, the wind power generator is controlled to operate with the third DC voltage as the target output voltage of the converter, which can reduce the deviation between the target output voltage and the actual output voltage of the converter, so that the output voltage of the converter can reach the third DC voltage in a short time. Since the third DC voltage is larger than the voltage threshold, as the output voltage of the converter gradually increases, the output voltage of the converter will be greater than the voltage threshold. When the output voltage of the converter is greater than the voltage threshold, based on the judgment in step 402, step 403 is executed to control the wind power generator to operate with the second DC voltage as the target output voltage of the converter. When the output voltage of the converter reaches the second DC voltage, the wind power generator is connected to the grid, and the starting of the wind power generator is completed.

[0080] It should be understood that step 401 is a step that is executed in a cycle. When the wind power generator is controlled to operate with the third DC voltage as the target output voltage of the converter, the output voltage of the converter gradually increases. When the first DC voltage output by the converter is greater than the voltage threshold, the wind power generator is controlled to operate with the second DC voltage as the target output voltage of the converter, so as to complete the starting of the wind power generator.

[0081] In the embodiment of the present application, when the rotating speed of the wind power generator is low, the first DC voltage output by the converter is low. At this time, the wind power generator is controlled to operate with the small third DC voltage as the target output voltage of the converter, so as to gradually increase the first DC voltage output by the converter. When the first DC voltage output by the converter is greater than the voltage threshold, the wind power generator is controlled to operate with the second DC voltage as the target output voltage of the converter, so as to gradually increase the output voltage of the converter to the large second output voltage to meet the grid connection condition. In the process of starting the wind power generator, the wind power generator is first controlled to operate with the small third DC voltage as the target output voltage of the converter, and then the wind power generator is controlled to operate with the increased second DC voltage as the target output voltage of the converter. This can shorten the time required for starting the wind power generator, and does not need to reduce the upper limit of the output voltage of the converter, so as to solve the problem of low-speed starting of the wind power generator while ensuring that the wind power generator has high energy utilization rate.

[0082] In one possible implementation, the voltage threshold is positively correlated with the mode switching voltage of the converter, where the converter controls the wind generator to operate in the first mode when the driving voltage of the converter is greater than or equal to the mode switching voltage, and controls the wind generator to operate in the second mode when the driving voltage of the converter is less than the mode switching voltage, the overvoltage threshold of the converter is the first overvoltage threshold in the first mode, and is the second overvoltage threshold in the second mode, the second DC voltage is greater than the second overvoltage threshold and less than the first overvoltage threshold, and the third DC voltage is less than the second overvoltage threshold.

[0083] It should be understood that the driving voltage of the converter is used to generate a resistance torque acting on the rotor of the wind generator, and by adjusting the driving voltage of the converter, the speed of the wind generator can be controlled, and in turn the AC voltage output by the wind generator is adjusted, thereby realizing closed-loop control of the wind generator. The driving voltage is derived from the electrical energy generated by the wind generator.

[0084] The converter can control the wind generator in the first mode or the second mode, the overvoltage threshold of the converter is the first overvoltage threshold in the first mode, and is the second overvoltage threshold in the second mode, the first overvoltage threshold is greater than the second overvoltage threshold. When the output voltage of the converter is greater than the overvoltage threshold, the converter will not operate normally. The mode switching voltage is a critical voltage at which the converter controls the wind generator to operate in the first mode or the second mode, the converter controls the wind generator to operate in the first mode when the driving voltage of the converter is set to be greater than or equal to the mode switching voltage, and controls the wind generator to operate in the second mode when the driving voltage of the converter is set to be less than the mode switching voltage.

[0085] For example, the mode switching voltage is 362V, the first overvoltage threshold is 820V, the second overvoltage threshold is 420V, the second DC voltage is 600, and the third DC voltage is 400. When the driving voltage of the converter is set to be 380V, since the set driving voltage is greater than the mode switching voltage, the converter will control the wind generator to operate in the first mode at this time. When the driving voltage of the converter is set to be 100V, since the set driving voltage is less than the mode switching voltage, the converter will control the wind generator to operate in the second mode at this time. When the converter controls the wind generator to operate in the second mode, the maximum DC voltage output by the converter is less than 420V, while the condition for grid connection is that the DC voltage output by the converter is not less than 600V, so when the converter controls the wind generator to operate in the second mode, grid connection cannot be completed.

[0086] In the embodiment of the present application, in order to guarantee the grid utilization rate of the power generated by the wind driven generator, when the driving voltage of the converter increases, the output voltage of the converter should be increased accordingly, so the voltage threshold positively correlates with the mode switching voltage of the converter, after guaranteeing that the output voltage of the converter is greater than the voltage threshold, the wind driven generator can output the voltage meeting the grid demand through the first mode control, while the converter can be guaranteed to be normally started, and then the converter can control the wind driven generator in the first mode or the second mode according to the size relationship between the first direct current voltage and the voltage threshold.

[0087] In a possible implementation manner, the voltage threshold and the switching voltage are calculated according to the following formula:

[0088] V1 = 0.82 * V2

[0089] Wherein, V1 is used to represent the voltage threshold, and V2 is used to represent the mode switching voltage.

[0090] In the embodiment of the present application, in order to enable the converter to switch between the first mode and the second mode, the voltage threshold is determined according to the mode switching voltage, so that the converter can determine whether the wind driven generator is in the low-speed running state, and then the wind driven generator is controlled to run in the first mode or the second mode according to the determination result, so that the wind driven generator can have a high energy utilization rate while solving the low-speed starting problem of the wind driven generator.

[0091] In a possible implementation manner, when the wind driven generator has a high speed and a high output voltage, the converter controls the wind driven generator to run with the second direct current voltage as the target output voltage, at this time, the first driving voltage corresponding to the second direct current voltage needs to be determined according to the mode switching voltage, the converter takes the first driving voltage as the target driving voltage and takes the second direct current voltage as the target output voltage to control the wind driven generator to run. When the wind driven generator has a low speed and a low output voltage, the converter controls the wind driven generator to run with the third direct current voltage as the target output voltage, at this time, the second driving voltage corresponding to the third direct current voltage needs to be determined according to the mode switching voltage, the converter takes the second driving voltage as the target driving voltage and takes the third direct current voltage as the target output voltage to control the wind driven generator to run.

[0092] When the wind turbine runs at a low speed, the first DC voltage output by the converter is low. If the drive voltage is set as the first drive voltage, the wind turbine needs a long time to start up because the first drive voltage is high. By setting the second drive voltage as the target drive voltage, the wind turbine can be controlled to start up at a low speed in a short time. After the wind turbine starts up at a low speed, the wind turbine can be controlled by setting the first drive voltage as the target drive voltage, so that the output voltage of the converter gradually increases to the second output voltage, to meet the grid-connected condition.

[0093] In the embodiment of the application, during the starting of the wind turbine, the wind turbine is controlled to run at a low speed by setting the second drive voltage as the target drive voltage and the third DC voltage as the target output voltage, and then the wind turbine is controlled to run by setting the first drive voltage as the target drive voltage and the second DC voltage as the target output voltage. In this way, the time required for starting up the wind turbine can be shortened, and the upper limit of the output voltage of the converter does not need to be reduced, so that the problem of starting up the wind turbine at a low speed can be solved, and the wind turbine has a high energy utilization rate.

[0094] In a possible implementation, if the first DC voltage output by the converter is greater than the voltage threshold, and the wind turbine is controlled to run by setting the third DC voltage as the target output voltage, it can be determined whether the duration for which the first DC voltage is greater than the voltage threshold is greater than a preset delay time. If the duration for which the first DC voltage is greater than the voltage threshold is greater than the preset delay time, the converter is switched to control the wind turbine to run by setting the second DC voltage as the target output voltage.

[0095] When the wind turbine runs at a low speed, the first DC voltage output by the converter is less than or equal to the voltage threshold. In this case, the wind turbine is controlled to run by setting the third DC voltage as the target output voltage, and the first DC voltage output by the converter gradually increases to be greater than the voltage threshold. In this case, the converter is switched to control the wind turbine to run by setting the second DC voltage as the target output voltage. Because the voltage output by the wind turbine is not stable, the first DC voltage may fluctuate above and below the voltage threshold during the gradual increase. In order to avoid frequent switching of the converter between the two modes, a preset delay time can be set. When the duration for which the first DC voltage is greater than the voltage threshold is greater than the preset delay time, the first DC voltage is stabilized above the voltage threshold, and the converter is switched to control the wind turbine to run by setting the second DC voltage as the target output voltage. When the duration for which the first DC voltage is greater than the voltage threshold is less than or equal to the preset delay time, the running mode of the converter is not switched.

[0096] In the embodiment, the converter is switched to control the wind power generator to operate with the second DC voltage as the target output voltage after the duration that the first DC voltage is greater than the voltage threshold is greater than the preset delay time by the preset delay time, so that the converter can be prevented from frequently switching between the two modes during the low-speed starting process of the wind power generator, and the service life of the converter can be prolonged.

[0097] In a possible implementation manner, after it is determined that the duration that the first DC voltage is greater than the voltage threshold is greater than the preset delay time, the converter can be controlled to stop and the operating parameters of the converter can be reset so that the converter is restarted to control the wind power generator to operate with the second DC voltage as the target output voltage.

[0098] In the embodiment, after it is determined that the first output voltage has been stabilized above the voltage threshold, the converter is controlled to stop, the operating parameters of the converter are reset, the target output voltage of the converter is switched from the third DC voltage to the second DC voltage, and then the converter is restarted so that the second DC voltage takes effect as the target output voltage, and then the converter starts to control the wind power generator to operate with the second DC voltage as the target output voltage. After the converter stops, the operating parameters of the converter are reset, so that the wind power generator can be controlled to operate with the reconfigured target output voltage after the converter is restarted, and the correctness of the operating logic of the converter is ensured.

[0099] Figure 5 FIG. 5 is a flowchart of a control method of a wind power generator according to another embodiment of the present application. As shown in FIG. 5, the control method 500 of the wind power generator includes the following steps: Figure 5

[0100] Step 501: Obtain a first DC voltage output by a converter.

[0101] The converter can include a rectifying unit, and the rectifying unit can convert an alternating voltage output by the wind power generator into a DC voltage output. During the starting process of the wind power generator, the first DC voltage output by the rectifying unit can be obtained.

[0102] Step 502: Determine whether the first DC voltage is greater than a preset voltage threshold. If yes, Y, perform step 503; if no, N, perform step 504.

[0103] During the starting process of the wind power generator, after the first DC voltage output by the converter is obtained, the obtained first DC voltage is compared with the voltage threshold. If the first DC voltage is greater than the voltage threshold, the converter should control the wind power generator to operate with the second DC voltage as the target output voltage, and step 503 is performed accordingly. If the first DC voltage is less than or equal to the voltage threshold, the converter should control the wind power generator to operate with the third DC voltage as the target output voltage, and step 504 is performed accordingly.​

[0104] Step 503, set the first driving voltage and the second DC voltage, and execute step 505.

[0105] The second DC voltage is determined according to the AC voltage required by the grid and the conversion ratio of the transformer, and the first driving voltage is determined according to the second DC voltage. The first driving voltage is a threshold voltage for starting the normal operation state of the converter, and when the converter reaches the threshold voltage, the wind turbine can be controlled in a closed loop.

[0106] Step 504, set the second driving voltage and the third DC voltage, and execute step 506.

[0107] The working voltage range of the low-speed operation state of the converter is determined according to the working voltage range of the normal operation state of the converter, and the second driving voltage is set according to the working voltage range of the low-speed operation state of the converter. The second driving voltage is a threshold voltage for starting the low-speed operation state of the converter, and when the converter reaches the threshold voltage, the power generated by the wind turbine can be supplied to a closed loop circuit for controlling the wind turbine in a closed loop.

[0108] Step 505, set the first driving voltage as the target driving voltage of the converter, and set the second DC voltage as the target output voltage of the converter, control the wind turbine to run, and end the current process.

[0109] The second DC voltage is set according to the requirements of the grid, so that the voltage output by the converter can reach the second DC voltage. The second DC voltage is set as the target output voltage of the converter, and the converter controls the wind turbine in a closed loop based on the output DC voltage. When the output DC voltage of the converter reaches the second DC voltage, the output DC voltage of the converter can be boosted by the transformer and connected to the grid.

[0110] Step 506, set the second driving voltage as the target driving voltage of the converter, and set the third DC voltage as the target output voltage of the converter, control the wind turbine to run.

[0111] When the first DC voltage is small, the AC voltage output by the wind turbine is small, and the converter controls the wind turbine to run with the third DC voltage as the target output voltage. When the output voltage of the converter is greater than the voltage threshold, based on the judgment of step 502, step 503 will be executed, and then step 505 will be executed. The converter controls the wind turbine to run with the second DC voltage as the target output voltage.

[0112] Step 507, judging whether the duration of the first DC voltage being greater than the voltage threshold is greater than the preset delay time in the process of controlling the wind driven generator to operate with the third DC voltage as the target output voltage of the converter, if yes Y, executing step 508, if no N, executing step 506.

[0113] When the converter is in the low-speed operating state, if the rotating speed of the wind driven generator is increased, at this time the first DC voltage is increased and exceeds the working voltage range of the converter in the process of controlling the wind driven generator to operate with the third DC voltage as the target output voltage, at this time the duration of the first DC voltage being greater than the voltage threshold needs to be judged, if the duration is greater than the preset delay time, switching the converter to control the wind driven generator to operate with the second DC voltage as the target output voltage.

[0114] Step 508, controlling the converter to stop and resetting the operating parameters of the converter, restarting the converter and executing step 503.

[0115] After determining that the first output voltage has been stabilized above the voltage threshold, the converter is controlled to stop, the operating parameters of the converter are reset, the target output voltage of the converter is switched from the third DC voltage to the second DC voltage, and then the converter is restarted so that the second DC voltage takes effect as the target output voltage, and then the converter starts to control the wind driven generator to operate with the second DC voltage as the target output voltage. After the converter stops, the operating parameters of the converter are reset.

[0116] In the embodiment of the present application, when the rotating speed of the wind driven generator is low, the first DC voltage output by the converter is low, at this time the wind driven generator is controlled to operate with the third DC voltage as the target output voltage of the converter, which can make the first DC voltage output by the converter gradually increase, and after the first DC voltage threshold output by the converter is greater than the voltage threshold, the wind driven generator is controlled to operate with the second DC voltage as the target output voltage of the converter, so that the output voltage of the converter gradually increases to the second output voltage which is relatively large, to meet the grid-connected condition. In the process of starting the wind driven generator, the wind driven generator is first controlled to operate with the third DC voltage as the target output voltage of the converter, and then the wind driven generator is controlled to operate with the second DC voltage as the target output voltage of the converter, which can shorten the time required for starting the wind driven generator, and does not need to reduce the upper limit of the output voltage of the converter, so that the problem of low-speed starting of the wind driven generator can be solved while ensuring that the wind driven generator has a high energy utilization rate.

[0117] Figure 6 is a schematic diagram of an electronic device according to an embodiment of the present application, and the specific implementation of the electronic device is not limited in the specific embodiments of the present application. For example, Figure 6As shown, the electronic device 50 can include a processor 51, a communications interface 52, a memory 53, and a communications bus 54. Among them:

[0118] The processor 51, the communications interface 52, and the memory 53 complete the communication with each other through the communications bus 54.

[0119] The communications interface 52 is configured to communicate with other electronic devices or servers.

[0120] The processor 51 is configured to execute the program 55, and specifically can execute the related steps in the foregoing embodiments of the control method of the wind power generator.

[0121] Specifically, the program 55 can include program code, and the program code includes computer operation instructions.

[0122] The processor 51 can be a CPU, or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application. The one or more processors included in the smart device can be processors of the same type, such as one or more CPUs; or can be processors of different types, such as one or more CPUs and one or more ASICs.

[0123] The memory 53 is configured to store the program 55. The memory 53 can include a high-speed RAM memory, and can also include a non-volatile memory, for example, at least one disk memory.

[0124] The program 55 can be specifically used for causing the processor 51 to execute the control method of the wind power generator in the foregoing embodiments.

[0125] The specific implementation of each step in the program 55 can refer to the corresponding description in the corresponding steps and units in the foregoing embodiments of the control method of the wind power generator, and will not be described here. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the device and the module described above can refer to the corresponding process description in the foregoing method embodiments, and will not be described here.

[0126] By the electronic device of the embodiment of the present application, when the rotating speed of the wind driven generator is low, the first DC voltage output by the converter is low, at this time, the wind driven generator is controlled to operate by taking the third DC voltage as the target output voltage of the converter, the first DC voltage output by the converter can be gradually increased, after the first voltage threshold of the output of the converter is greater than the voltage threshold, the wind driven generator is controlled to operate by taking the second DC voltage as the target output voltage of the converter, the output voltage of the converter is gradually increased to the second output voltage, so as to meet the grid-connected condition. In the process of starting the wind driven generator, the wind driven generator is controlled to operate by taking the third DC voltage as the target output voltage of the converter first, and then the wind driven generator is controlled to operate by taking the second DC voltage as the target output voltage of the converter, the time required for starting the wind driven generator can be shortened, and the upper limit of the output voltage of the converter does not need to be reduced, so that the problem of low-speed starting of the wind driven generator can be solved, and the wind driven generator has a high energy utilization rate.

[0127] The present application also provides a computer readable storage medium storing instructions for causing a machine to perform the control method of the wind driven generator as described herein. Specifically, a system or apparatus equipped with a storage medium can be provided, on which a software program code for realizing the functions of any one of the above embodiments is stored, and a computer (or CPU or MPU) of the system or apparatus reads out and executes the program code stored in the storage medium.

[0128] In this case, the program code read from the storage medium itself can realize the functions of any one of the above embodiments, and therefore the program code and the storage medium storing the program code constitute a part of the present application.

[0129] The storage medium for providing the program code includes a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer via a communication network.

[0130] The embodiment of the present application also provides a computer program product, including computer instructions, which instruct a computing device to perform any corresponding operation in the above method embodiments.

[0131] It should be noted that, according to the needs of implementation, each component / step described in the embodiments of the present application can be split into more components / steps, or two or more components / steps or part of the operations of the components / steps can be combined into a new component / step, to achieve the purpose of the embodiments of the present application.

[0132] The methods according to the embodiments of the present application described above can be implemented in hardware, firmware, or implemented as software or computer code that can be stored in a recording medium such as a CD ROM, a RAM, a floppy disk, a hard disk, or an optical disk, or be downloaded through a network originally stored in a remote recording medium or a non-transitory machine readable medium and stored in a local recording medium, so that the methods described herein can be processed by such software using a general purpose computer, a special purpose processor, or programmable or dedicated hardware such as an ASIC or an FPGA. It can be understood that the computer, the processor, the microprocessor controller, or the programmable hardware includes a storage component (for example, a RAM, a ROM, a flash memory, etc.) that can store or receive software or computer code, when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the methods described herein are implemented. In addition, when a general purpose computer accesses the code for implementing the methods shown herein, the execution of the code will convert the general purpose computer into a special purpose computer for executing the methods shown herein.

[0133] It should be noted that not all steps and modules in the above-mentioned flowcharts and system structure diagrams are necessary, and some steps or modules can be omitted according to actual needs. The execution order of each step is not fixed and can be adjusted as needed. The system structure described in each of the above embodiments can be a physical structure or a logical structure, that is, some modules can be implemented by the same physical entity, or some modules can be implemented by multiple physical entities, or can be implemented by some components in multiple independent devices together.

[0134] In the above embodiments, a hardware module can be implemented mechanically or with electrical means. For example, a hardware module can include a permanent, dedicated circuit or logic (such as a dedicated processor, FPGA, or ASIC) to perform the corresponding operation. A hardware module can also include programmable logic or circuitry (such as a general-purpose processor or other programmable processor) that can be temporarily configured by software to perform the corresponding operation. The specific implementation method (mechanical or dedicated permanent circuit, or temporarily configured circuit) can be determined based on cost and time considerations.

[0135] The above has been described and illustrated by the drawings and preferred embodiments, but the present application is not limited to these disclosed embodiments, and those skilled in the art can know that the code review means in the above different embodiments can be combined to obtain more embodiments of the present application, and these embodiments are also within the protection scope of the present application.

Claims

1. A method (400) for controlling a wind power generator (30), an output end of the wind power generator (30) being connected to an output end of a converter (10), a direct current end of the converter (10) being connected to a power grid (40) through a grid connection module (20), the converter (10) being configured to control operation of the wind power generator (30), the method comprising: obtaining a first direct current voltage output by the converter (10) ; determining whether the first direct current voltage is greater than a preset voltage threshold; if the first direct current voltage is greater than the voltage threshold, controlling the wind power generator (30) to operate with a second direct current voltage as a target output voltage of the converter (10) ; and if the first direct current voltage is less than or equal to the voltage threshold, controlling the wind power generator (30) to operate with a third direct current voltage as the target output voltage of the converter (10), wherein the second direct current voltage is greater than the third direct current voltage, and the third direct current voltage is greater than the voltage threshold. The voltage threshold is positively correlated with a mode switching voltage of the converter (10) ; wherein, when a driving voltage of the converter (10) is greater than or equal to the mode switching voltage, the converter (10) controls the wind power generator (30) to operate in a first mode, when the driving voltage of the converter (10) is less than the mode switching voltage, the converter (10) controls the wind power generator (30) to operate in a second mode, an overvoltage threshold of the converter (10) is a first overvoltage threshold in the first mode, and an overvoltage threshold of the converter (10) is a second overvoltage threshold in the second mode, the second direct current voltage is greater than the second overvoltage threshold and less than the first overvoltage threshold, and the third direct current voltage is less than the second overvoltage threshold. The voltage threshold and the mode switching voltage satisfy the following formula: V1=0.82×V2 V1 is used to represent the voltage threshold, and V2 is used to represent the mode switching voltage.

2. The method of claim 1, wherein, 4.The method of claim 2, wherein the controlling the wind power generator (30) to operate with the second direct current voltage as the target output voltage of the converter (10) comprises: determining a first driving voltage corresponding to the second direct current voltage according to the mode switching voltage, wherein the first driving voltage is greater than or equal to the mode switching voltage; taking the first driving voltage as a target driving voltage of the converter (10) for driving the wind power generator (30), and taking the second direct current voltage as the target output voltage of the converter (10) to control the wind power generator (30) to operate; and the controlling the wind power generator (30) to operate with the third direct current voltage as the target output voltage of the converter (10) comprises: determining a second driving voltage corresponding to the third direct current voltage according to the mode switching voltage, wherein the second driving voltage is less than the mode switching voltage; taking the second driving voltage as the target driving voltage of the converter (10) for driving the wind power generator (30), and taking the third direct current voltage as the target output voltage of the converter (10) to control the wind power generator (30) to operate. ​ 3. The method of claim 2, wherein, ​ ​ ​ ​ ​ ​ ​ According to the mode switching voltage, a second driving voltage corresponding to the third DC voltage is determined, wherein the second driving voltage is less than the mode switching voltage; the second driving voltage is taken as a target driving voltage of the wind driven generator (30) driven by the converter (10), and the third DC voltage is taken as a target output voltage of the converter (10), and the wind driven generator (30) is controlled to operate.

5. The method of any one of claims 1-4, wherein, The method further comprises: When the wind driven generator (30) is controlled to operate with the third DC voltage as the target output voltage of the converter (10), if it is determined that the first DC voltage is greater than the voltage threshold, the wind driven generator (30) is controlled to operate with the second DC voltage as the target output voltage of the converter (10) after the duration that the first DC voltage is greater than the voltage threshold is greater than a preset delay time.

6. The method of claim 5, wherein, The wind driven generator (30) is controlled to operate with the second DC voltage as the target output voltage of the converter (10) after the duration that the first DC voltage is greater than the voltage threshold is greater than a preset delay time, comprising: After it is determined that the duration that the first DC voltage is greater than the voltage threshold is greater than a preset delay time, the converter (10) is controlled to stop, and the operating parameters of the converter (10) are reset, so that the wind driven generator (30) is controlled to operate with the second DC voltage as the target output voltage after the converter (10) is restarted.

7. A converter (10), an output end of the converter (10) being connected with an output end of a wind driven generator (30), a DC end of the converter (10) being connected with a power grid (40) through a grid-connected module (20), the converter (10) comprising: an acquisition module (11) configured to acquire a first DC voltage output by the converter (10); a judgment module (12) configured to judge whether the first DC voltage is greater than a preset voltage threshold; an execution module (13) configured to control the wind driven generator (30) to operate with a second DC voltage as a target output voltage of the converter (10) when the first DC voltage is greater than the voltage threshold, and control the wind driven generator (30) to operate with a third DC voltage as the target output voltage of the converter (10) when the first DC voltage is less than or equal to the voltage threshold, wherein the second DC voltage is greater than the third DC voltage, and the third DC voltage is greater than the voltage threshold.

8. A control system (100) for a wind power generator, comprising: The converter (10), the first switch (Q1), the second switch (Q2), the regulated power supply module (21), the regulated interface module (22) and the transformer (23) according to claim 7; One end of the first switch (Q1) is connected to the output end of the wind turbine (30), the other end of the first switch (Q1) is connected to the output end of the converter (10), the direct current end of the converter (10) is connected to the input end of the regulated power module (21), the output end of the regulated power module (21) is connected to the input end of the regulated interface module (22), the output end of the regulated interface module (22) is connected to the input end of the transformer (23), the output end of the transformer (23) is connected to one end of the second switch (Q2), the other end of the second switch (Q2) is connected to the power grid (40); The first switch (Q1) is used for controlling the opening and closing of the circuit connected between the wind turbine (30) and the converter (10); The second switch (Q2) is used for controlling the opening and closing of the circuit connected between the transformer (23) and the power grid (40); The regulated power module (21) is used for converting the second direct current voltage output by the converter (10) into an alternating current voltage; The regulated interface module (22) is used for filtering the alternating current voltage to obtain a stable alternating current voltage; The transformer (23) is used for boosting the stable alternating current voltage.

9. An electronic device (50) comprising: The processor (51), the communication interface (52), the memory (53) and the communication bus (54), the processor (51), the memory (53) and the communication interface (52) complete the communication among each other through the communication bus (54); The memory (53) is used for storing at least one executable instruction, and the executable instruction makes the processor (51) execute the operation corresponding to the control method of the wind turbine in any one of claims 1-6. 10.A computer storage medium, having a computer program stored thereon, the program being executed by a processor to implement the control method of the wind turbine in any one of claims 1-6. 11.A computer program product, comprising computer instructions, the computer instructions instructing a computing device to execute the operation corresponding to the control method of the wind turbine in any one of claims 1-6.

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