Isomeric permanent magnet wind field self-starting networking control method and device

Abstract

This invention provides a method and apparatus for self-starting grid-connected control of heterogeneous permanent magnet wind farms. The method is applied to heterogeneous wind farms with multiple control modes, including grid-type permanent magnet wind turbines and farm-level grid-connected permanent magnet wind turbines. The method includes: using a grid-type controller in the grid-type permanent magnet wind turbine as the power outer loop, and utilizing at least the DC capacitor voltage of the turbine-side converter in the permanent magnet wind turbine to perform droop control of active power between the grid-type permanent magnet wind turbine and the farm-level grid-connected permanent magnet wind turbine; determining the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine; and combining the output phase angle to perform synchronization coordination and load distribution of the grid-connected permanent magnet wind turbines, thereby realizing the self-starting grid-connected heterogeneous permanent magnet wind farm.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a method and device for self-starting grid control of heterogeneous permanent magnet wind farms. Background Technology

[0002] Over the past decade, the penetration rate of new energy units such as wind power in the power system has increased rapidly. As the proportion of traditional thermal power generating units connected to the grid continues to decrease, the power system is showing characteristics of low inertia and weak support. When a large-scale power outage occurs, how to utilize large-scale wind farms and other new energy power generation equipment as self-starting power sources for islanded grid self-starting and self-recovery has become a key issue that the new power system urgently needs to solve.

[0003] Currently, traditional wind turbines mostly employ grid-following (GFL) control, heavily relying on the external power grid for voltage and frequency support, and are unable to independently establish voltage in isolated environments without grid support. In recent years, the introduction of grid-forming (GFM) control has enabled wind turbines to autonomously establish voltage and frequency. However, a large-scale renewable energy power plant often contains wind turbines with various control modes. If the entire plant adopts grid-forming control, the retrofit cost is high, and the control loop is highly susceptible to multi-machine coupling oscillations. If grid-forming and grid-following turbines operate in combination, during the self-starting phase, the lack of coordination and synchronization mechanisms between turbines with different control architectures can easily lead to huge frequency and voltage surges at the moment the grid-following turbines connect to the grid, causing the plant's self-starting to fail. Currently, scholars both domestically and internationally have conducted related research, such as proposing schemes to assist wind farm black starts through energy storage or large-capacity diesel generators. However, such schemes are highly dependent on external backup power sources, increasing system costs and maintenance complexity. Furthermore, some literature has conducted in-depth research on low-frequency AC transmission systems based on diode rectifier units and designed black-start strategies for grid-connected wind turbines based on self-synchronization control. However, it has not proposed effective control methods for multi-machine coordinated start-up timing and suppression of grid-connection transient impacts for heterogeneous permanent magnet wind farms that include both grid-connected and grid-connected systems. Therefore, there is an urgent need to propose a self-starting grid-connected control strategy for heterogeneous permanent magnet wind farms that does not rely on external backup power. Summary of the Invention

[0004] To address the aforementioned technical problems, embodiments of the present invention provide a self-starting grid control method for heterogeneous permanent magnet wind farms, applicable to heterogeneous wind farms with multiple control modes, including grid-connected permanent magnet wind turbine generators and farm-level grid-connected permanent magnet wind turbine generators. The method includes: The grid-type controller in the grid-type permanent magnet wind turbine is used as the power outer loop, and the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine is used at least to perform droop control of the active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine. The output phase angle is determined based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. By combining the output phase angle, the synchronous coordination and load distribution of the grid-connected permanent magnet wind turbine are achieved, realizing the self-starting grid connection of the heterogeneous permanent magnet wind farm.

[0005] In one embodiment, droop control is performed using at least the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine, including: The DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage and three-phase current signals of the AC grid side of the grid-type permanent magnet wind turbine are detected. The DC capacitor voltage of the generator-side converter, the DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage signal and three-phase current signal of the AC grid side of the grid-type permanent magnet wind turbine are input to the grid-type controller to realize the droop control.

[0006] In one embodiment, the method further includes: The active power output of the grid-side converter of the grid-type permanent magnet wind turbine is detected, as well as the three-phase voltage signal and three-phase current signal on the AC grid side. The active power output from the grid-side converter of the grid-connected permanent magnet wind turbine, as well as the three-phase voltage signal and three-phase current signal from the AC grid side, are input to the grid-connected controller in the station-level grid-connected permanent magnet wind turbine to cooperate with the grid-connected controller in performing the droop control.

[0007] In one embodiment, determining the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine includes: The angular frequency output value is determined based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. The output phase angle is generated by integrating the angular frequency output value.

[0008] In one embodiment, droop control of active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine includes: DC voltage synchronous control is performed on the grid-side converter of the grid-type permanent magnet wind turbine to achieve angular velocity control of the grid-side converter of the grid-type permanent magnet wind turbine. The generator-side converters of the grid-type permanent magnet wind turbine and the station-level grid-connected permanent magnet wind turbine adopt DC voltage droop control to achieve active power distribution.

[0009] In one embodiment, the DC voltage synchronization control of the grid-side converter of the grid-type permanent magnet wind turbine includes: The DC voltage synchronous control of the grid-side converter of the grid-type permanent magnet wind turbine is achieved according to the following formula:

[0010] K dc For DC voltage synchronization gain, This is the reference value for the DC voltage of a grid-type permanent magnet wind turbine. ω 0 is the rated angular velocity. ω GFM ω represents the angular velocity of the grid-side converter.

[0011] In one embodiment, active power allocation includes: Active power allocation is based on the following formula:

[0012] Active power allocated to the generator-side converter of a grid-type permanent magnet wind turbine. The active power allocated to the generator-side converter of the station-level and grid-type permanent magnet wind turbine units. K F_GFM The sag coefficient of the grid-type permanent magnet wind turbine generator. K F_GFL To match the sag coefficient of the grid-type permanent magnet wind turbine generator. u dc This refers to the per-unit value of the DC voltage for grid-type permanent magnet wind turbine generators.

[0013] In one embodiment, the synchronization coordination and load distribution of the grid-connected permanent magnet wind turbine unit in conjunction with the output phase angle includes: Unlock the first trigger pulse of the generator-side converter of the grid-type permanent magnet wind turbine, and control the DC voltage of the generator-side converter to the rated value based on the first trigger pulse; Unlock the second trigger pulse of the grid-side converter of the grid-type permanent magnet wind turbine, and generate AC bus voltage in combination with the second trigger pulse; After the grid-type permanent magnet wind turbine is fully powered on, the AC voltage on the turbine side is determined and the pitch control is started based on the output phase angle. Control the circuit breaker of the station-level and grid-connected permanent magnet wind turbine to charge the DC capacitor using the AC bus voltage of the station-level and grid-connected permanent magnet wind turbine. Unlock the third trigger pulse of the grid-side converter of the station-level grid-connected permanent magnet wind turbine, and control the DC voltage of the grid-side converter to the rated value based on the third trigger pulse, while setting the reactive power reference value of the grid-side converter to 0. Unlock the fourth trigger pulse of the generator-side converter of the station-level grid-connected permanent magnet wind turbine, and configure the active power reference value of the generator-side converter to 0 based on the fourth trigger pulse; The control unit receives power distribution commands from the grid-type permanent magnet wind turbine, enabling the station-level grid-type permanent magnet wind turbine to output electrical energy together with the grid-type permanent magnet wind turbine.

[0014] In one embodiment, the grid-type permanent magnet wind turbine uses a phase-locked loop to control its turbine-side converter; the station-level grid-connected permanent magnet wind turbine uses a phase-locked loop to control its grid-side converter. The method further includes: When using phase-locked loop (PLL) based control, frequency compensation is performed using the following formula:

[0015] k p_PLL and k i_PLL These are the proportional and integral coefficients used in the phase-locked loop, respectively. U tq Three-phase voltage signal on the AC grid side U abc q-axis component, U dc0 This is the rated DC voltage. k p and k i These are the proportional coefficient and integral coefficient for frequency compensation, respectively. S 1 is the compensation status flag. θ PLL This is the output angle of the phase-locked loop.

[0016] Another embodiment of the present invention also provides a self-starting grid control device for heterogeneous permanent magnet wind farms, applied in heterogeneous wind farms with multiple control modes, including grid-connected permanent magnet wind turbine generators and farm-level grid-connected permanent magnet wind turbine generators. The device includes: The control module is used to perform droop control of active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine, based on the grid-type controller in the grid-type permanent magnet wind turbine as the power outer loop and at least using the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine. The determination module is used to determine the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. The networking module is used to coordinate the synchronization and load distribution of the grid-connected permanent magnet wind turbine in conjunction with the output phase angle, so as to realize the self-starting networking of the heterogeneous permanent magnet wind farm.

[0017] Other features and advantages of this application will be set forth in the following description. The objectives and other advantages of this application can be realized and obtained through the structures particularly pointed out in the written description and drawings.

[0018] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the self-starting network control method for heterogeneous permanent magnet wind farms in an embodiment of the present invention.

[0021] Figure 2 This is a frequency compensation control diagram in an embodiment of the present invention.

[0022] Figure 3 The above is a simulation waveform diagram of the self-starting network control method for heterogeneous permanent magnet wind farms in the embodiments of the present invention during the self-starting network process.

[0023] Figure 4 The simulation waveform diagram shows the traditional direct grid connection strategy used in the self-starting grid connection process of a heterogeneous permanent magnet wind power system.

[0024] Figure 5 This is a structural block diagram of the heterogeneous permanent magnet wind farm self-starting network control device in an embodiment of the present invention. Detailed Implementation

[0025] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but these are not intended to limit the scope of the invention.

[0026] It should be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the following description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope of this disclosure will be apparent to those skilled in the art.

[0027] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present disclosure and, together with the general description of the disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.

[0028] These and other features of the invention will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0029] It should also be understood that although the invention has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of the invention, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0030] The above and other aspects, features and advantages of this disclosure will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0031] Specific embodiments of the present disclosure are described thereafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure and can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the present disclosure. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely to serve as the basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of substantially any suitable detailed structures.

[0032] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in still another embodiment,” all of which may refer to one or more of the same or different embodiments according to this disclosure.

[0033] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] like Figure 1 As shown, this embodiment of the invention provides a self-starting grid control method for heterogeneous permanent magnet wind farms, applicable to heterogeneous wind farms with multiple control modes, including grid-connected permanent magnet wind turbines and farm-level grid-connected permanent magnet wind turbines. The method includes: S1: Based on the grid-type controller in the grid-type permanent magnet wind turbine as the power outer loop, and at least using the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine, the droop control of the active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine is performed. S2: Determine the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator; S3: Combine the output phase angle to perform synchronous coordination and load distribution of the grid-connected permanent magnet wind turbine, so as to realize the self-starting grid connection of the heterogeneous permanent magnet wind farm.

[0035] The method in this embodiment is applied to heterogeneous wind farms with multiple control modes. The overall system adopts a hierarchical hybrid control mode, specifically including: grid-forming control (GFM) permanent magnet wind turbines, which serve as the outer power loop and support power for the isolated grid, using DC voltage synchronous control; a farm-level grid-following control (GFL) permanent magnet wind turbine, which receives power commands from the grid-forming control turbines and acts as an internal power follower; and a grid-following control framework (system) to execute the above method. For example, it includes using the grid-forming controller as the outer power loop, establishing inter-unit droop control using the DC capacitor voltage information of the turbine-side converter, and realizing active power distribution among the units. Simultaneously, the output phase angle of the grid-side converter of the grid-forming control turbine is determined using the DC capacitor voltage, and then this output phase angle is combined with other grid-following control turbines to achieve coordinated synchronization and load distribution. The networking method in this embodiment does not rely on external power sources such as energy storage. It achieves self-starting and networking of wind farms by coordinating grid-connected and grid-connected permanent magnet wind turbines, which has high reliability.

[0036] In one embodiment, droop control is performed using at least the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine, including: S101: Detects the DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage signal and three-phase current signal of the AC grid side of the grid-type permanent magnet wind turbine. S102: The DC capacitor voltage of the generator-side converter, the DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage signal and three-phase current signal of the AC grid side of the grid-type permanent magnet wind turbine are input to the grid-type controller to realize the droop control.

[0037] Furthermore, the method also includes: S103: Detects the active power output of the grid-side converter of the grid-connected permanent magnet wind turbine, as well as the three-phase voltage signal and three-phase current signal on the AC grid side; S104: The active power output from the grid-side converter of the grid-connected permanent magnet wind turbine, as well as the three-phase voltage signal and three-phase current signal from the AC grid side, are input to the grid-connected controller in the station-level grid-connected permanent magnet wind turbine to cooperate with the grid-connected controller in performing the droop control.

[0038] Based on the above, this embodiment takes the lead in establishing the islanded grid frequency and voltage of the permanent magnet wind turbine, while the station-level grid-following permanent magnet wind turbine serves as an internal power unit and is controlled accordingly. By utilizing the linkage mechanism between DC capacitor voltage and grid frequency, automatic droop distribution of active power among multiple units is achieved, enhancing the system's stable operation capability.

[0039] Specifically, the active power droop control between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine includes: S105: Perform DC voltage synchronous control on the grid-side converter of the grid-type permanent magnet wind turbine to achieve angular velocity control of the grid-side converter of the grid-type permanent magnet wind turbine. S106: The generator-side converters of the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine are controlled by DC voltage droop to achieve active power distribution.

[0040] The step of performing DC voltage synchronous control on the grid-side converter of the grid-type permanent magnet wind turbine includes: S107: DC voltage synchronous control of the grid-side converter of the grid-type permanent magnet wind turbine is achieved according to the following formula:

[0041] K dc For DC voltage synchronization gain, This is the reference value for the DC voltage of a grid-type permanent magnet wind turbine. ω 0 is the rated angular velocity. ω GFM ω represents the angular velocity of the grid-side converter.

[0042] To achieve active power allocation, the following steps are included: S108: Active power allocation based on the following formula:

[0043] Active power allocated to the generator-side converter of a grid-type permanent magnet wind turbine. The active power allocated to the generator-side converter of the station-level and grid-type permanent magnet wind turbine units. K F_GFM The sag coefficient of the grid-type permanent magnet wind turbine generator. K F_GFL To match the sag coefficient of the grid-type permanent magnet wind turbine generator. u dc This refers to the per-unit value of the DC voltage for grid-type permanent magnet wind turbine generators. By adjusting... K F—GFMIt can automatically distribute load capacity among multiple grid-type units according to the ratio of droop coefficients.

[0044] In one embodiment, determining the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine includes: S201: Determine the angular frequency output value based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator; S202: Integrate the angular frequency output value to generate the output phase angle.

[0045] Based on this output phase angle, the magnetic pole position angle of the rotor in the wind turbine can be determined. This characterizes the core working mechanism of the grid-connected converter in this embodiment as a "voltage source." It does not rely on the external power grid but autonomously determines the frequency and phase of the output voltage based on its own energy state (DC voltage), thus establishing a stable AC voltage like a true synchronous generator, laying the foundation for subsequent grid connection. For example, the output phase angle is directly used to generate the modulation wave of the grid-connected unit's grid-side converter, thereby establishing the amplitude and frequency of the AC bus voltage from zero. This is equivalent to "creating" a voltage reference in the isolated grid for other units to follow. The grid-connected unit obtains its output phase angle through an enhanced phase-locked loop (PLL), which is used to modulate the grid-connected unit's grid-side converter, ensuring that the voltage phase of the grid-connected unit's output is consistent with the bus voltage, avoiding inrush current at the moment of grid connection. Therefore, the output phase angle of the grid-connected unit determines the frequency and phase reference of the entire isolated grid. The output phase angle of the grid-connected unit follows this reference, achieving multi-unit synchronous grid connection. Ultimately, the output phase angles of all units remain consistent, jointly supplying power to the load.

[0046] Furthermore, the synchronization coordination and load distribution of the grid-connected permanent magnet wind turbine unit in conjunction with the output phase angle includes: S301: Unlock the first trigger pulse of the generator-side converter of the grid-type permanent magnet wind turbine, and control the DC voltage of the generator-side converter to the rated value based on the first trigger pulse; S302: Unlock the second trigger pulse of the grid-side converter of the grid-type permanent magnet wind turbine, and generate AC bus voltage in combination with the second trigger pulse; S303: After the grid-type permanent magnet wind turbine is fully powered on, determine the AC voltage on the turbine side and start the pitch control based on the output phase angle; S304: Control the circuit breaker of the station-level and grid-connected permanent magnet wind turbine to charge the DC capacitor using the AC bus voltage of the station-level and grid-connected permanent magnet wind turbine. S305: Unlock the third trigger pulse of the grid-side converter of the station-level grid-connected permanent magnet wind turbine, and control the DC voltage of the grid-side converter to the rated value based on the third trigger pulse, while setting the reactive power reference value of the grid-side converter to 0. S306: Unlock the fourth trigger pulse of the generator-side converter of the station-level grid-connected permanent magnet wind turbine, and configure the active power reference value of the generator-side converter to 0 based on the fourth trigger pulse; S307: Control the station-level grid-connected permanent magnet wind turbine to receive the power distribution command issued by the grid-connected permanent magnet wind turbine, so that the station-level grid-connected permanent magnet wind turbine and the grid-connected permanent magnet wind turbine output electrical energy together.

[0047] Specifically, the AC bus voltage is generated using a zero-start boost method in conjunction with the second trigger pulse. After setting the reactive power reference value of the grid-side converter to 0, control from the grid-connected permanent magnet wind turbine is temporarily suspended. After configuring the active power reference value of the turbine-side converter to 0 based on the fourth trigger pulse, the wind turbine unlocks and reaches a zero-power high-speed state.

[0048] In this embodiment, the grid-connected permanent magnet wind turbine unit uses a phase-locked loop (PLL) to control its turbine-side converter; the station-level grid-connected permanent magnet wind turbine unit uses a PLL to control its grid-side converter. The PLL is configured because the grid-connected unit needs to follow the phase and frequency of the established bus voltage. When it is unlocked, frequency compensation is performed. After the grid-connected unit is running stably, it runs normally and frequency compensation stops. Specifically, such as Figure 2 As shown, the method further includes: S4: When using phase-locked loop (PLL) based control, frequency compensation is performed using the following formula:

[0049] k p_PLL and k i_PLL These are the proportional and integral coefficients used in the phase-locked loop, respectively. U tq Three-phase voltage signal on the AC grid side U abc q-axis component, U dc0 This is the rated DC voltage. k p and k i These are the proportional coefficient and integral coefficient for frequency compensation, respectively. S 1 is the compensation status flag; it is set to 1 when compensation is started and set to 0 when compensation is finished. θPLL This is the output angle of the phase-locked loop.

[0050] This embodiment provides reliable support for the rapid self-recovery of new power systems in the event of large power outages by using grid-connected and grid-building coordinated control and frequency compensation strategies, while also utilizing grid-building units to effectively achieve self-starting of wind farms and using a grid-connected and grid-building coordinated control framework to achieve synchronous networking of units in heterogeneous wind farms.

[0051] Based on the solutions of the above embodiments, it can be seen that this application designs a clear step-by-step self-starting sequence for wind turbine units, following the logic of "first establishing grid voltage, then unlocking and controlling grid connection," effectively avoiding disorderly competition and islanded system collapse caused by simultaneous startup of heterogeneous multiple units. Simultaneously, a frequency compensation strategy is introduced in the phase-locked loop (PLL) stage of the grid-connected units. At the moment the grid-connected equipment is connected to the already voltage-established islanded bus, it can adaptively suppress system frequency drops and overvoltage surges caused by phase and frequency deviations, significantly improving the safety and stability upper limit of large-capacity grid-connected units when connected to the islanded grid, significantly reducing the impact and fluctuations during grid-connected unit access, and enhancing the stable operation capability of the wind power grid-connected system during islanded load periods.

[0052] The following section uses system simulation waveforms under different scenarios to illustrate the solution and effects of this application: Figure 3 Simulation waveforms are presented for the self-starting and recovery process of a heterogeneous permanent magnet wind farm, following the collaborative control method proposed in this application. First, the grid-type permanent magnet wind turbine successfully establishes bus voltage through self-starting. Second, the grid-type permanent magnet wind turbine is connected to the islanded bus network. The waveforms show that the grid-side converter of the grid-type permanent magnet wind turbine unlocks after 5 seconds, and the bus voltage control starts after 5.5 seconds. After establishing bus voltage, the grid-side converter of the grid-type permanent magnet wind turbine connects first at 9.05 seconds. At this time, the grid-type permanent magnet wind turbine generates active power to charge the DC capacitor, which returns to zero after a brief fluctuation. Reactive power fluctuates during the DC capacitor charging process. The grid-type permanent magnet wind turbine starts and connects at 12.5 seconds. At this time, the bus frequency and voltage fluctuate slightly but quickly recover. Afterward, the grid-type and the wind turbines successfully connect to the islanded bus network simultaneously.

[0053] Figure 4 Under the same operating conditions, when using the direct grid connection scheme, the instantaneous connection of the grid-connected permanent magnet wind turbine causes severe power quality degradation, a significant drop in the AC bus frequency, and a noticeable bus overvoltage surge. This results in a high risk of system instability and grid startup failure. This contrasts with the grid-connected and grid-structured coordinated control and frequency compensation scheme designed in this application. Figure 3Compared with the waveform results, the system's impact and fluctuations are significantly improved. Therefore, the simulation results show that the grid-type permanent magnet wind turbine can smoothly charge the DC capacitor of the grid-connected permanent magnet wind turbine by spontaneously adjusting the active power output; at the same time, the frequency compensation strategy in the phase-locked loop of the grid-connected permanent magnet wind turbine effectively suppresses the frequency drop and overvoltage impact generated at the moment of synchronous connection.

[0054] Therefore, the control method designed in this application can effectively adjust the synchronization state between grid-connected and grid-connected permanent magnet wind turbine units, solve the problem of impact and severe fluctuations in the self-starting process of isolated grid parallel connection of units in large-capacity heterogeneous wind farms, and improve the stable and reliable operation capability of the system under grid faults and self-starting recovery.

[0055] like Figure 5 As shown, this embodiment of the invention provides a self-starting grid control device for heterogeneous permanent magnet wind farms, applied in heterogeneous wind farms with multiple control modes, including grid-connected permanent magnet wind turbine generators and farm-level grid-connected permanent magnet wind turbine generators. The device includes: The control module is used to perform droop control of active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine, based on the grid-type controller in the grid-type permanent magnet wind turbine as the power outer loop and at least using the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine. The determination module is used to determine the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. The networking module is used to coordinate the synchronization and load distribution of the grid-connected permanent magnet wind turbine in conjunction with the output phase angle, so as to realize the self-starting networking of the heterogeneous permanent magnet wind farm.

[0056] In one embodiment, droop control is performed using at least the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine, including: The DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage and three-phase current signals of the AC grid side of the grid-type permanent magnet wind turbine are detected. The DC capacitor voltage of the generator-side converter, the DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage signal and three-phase current signal of the AC grid side of the grid-type permanent magnet wind turbine are input to the grid-type controller to realize the droop control.

[0057] In one embodiment, the device further includes: The detection module is used to detect the active power output of the grid-side converter of the grid-connected permanent magnet wind turbine, as well as the three-phase voltage signal and three-phase current signal on the AC grid side. The input module is used to input the active power output by the grid-side converter of the grid-connected permanent magnet wind turbine, as well as the three-phase voltage signal and three-phase current signal of the AC grid side, to the grid-connected controller in the station-level grid-connected permanent magnet wind turbine, so as to cooperate with the grid-connected controller to perform the droop control.

[0058] In one embodiment, determining the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine includes: The angular frequency output value is determined based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. The output phase angle is generated by integrating the angular frequency output value.

[0059] In one embodiment, droop control of active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine includes: DC voltage synchronous control is performed on the grid-side converter of the grid-type permanent magnet wind turbine to achieve angular velocity control of the grid-side converter of the grid-type permanent magnet wind turbine. The generator-side converters of the grid-type permanent magnet wind turbine and the station-level grid-connected permanent magnet wind turbine adopt DC voltage droop control to achieve active power distribution.

[0060] In one embodiment, the DC voltage synchronization control of the grid-side converter of the grid-type permanent magnet wind turbine includes: The DC voltage synchronous control of the grid-side converter of the grid-type permanent magnet wind turbine is achieved according to the following formula:

[0061] K dc For DC voltage synchronization gain, This is the reference value for the DC voltage of a grid-type permanent magnet wind turbine. ω 0 is the rated angular velocity. ω GFM ω represents the angular velocity of the grid-side converter.

[0062] In one embodiment, active power allocation includes: Active power allocation is based on the following formula:

[0063] Active power allocated to the generator-side converter of a grid-type permanent magnet wind turbine. The active power allocated to the generator-side converter of the station-level and grid-type permanent magnet wind turbine units. K F_GFM The sag coefficient of the grid-type permanent magnet wind turbine generator.K F_GFL To match the sag coefficient of the grid-type permanent magnet wind turbine generator. u dc This refers to the per-unit value of the DC voltage for grid-type permanent magnet wind turbine generators.

[0064] In one embodiment, the synchronization coordination and load distribution of the grid-connected permanent magnet wind turbine unit in conjunction with the output phase angle includes: Unlock the first trigger pulse of the generator-side converter of the grid-type permanent magnet wind turbine, and control the DC voltage of the generator-side converter to the rated value based on the first trigger pulse; Unlock the second trigger pulse of the grid-side converter of the grid-type permanent magnet wind turbine, and generate AC bus voltage in combination with the second trigger pulse; After the grid-type permanent magnet wind turbine is fully powered on, the AC voltage on the turbine side is determined and the pitch control is started based on the output phase angle. Control the circuit breaker of the station-level and grid-connected permanent magnet wind turbine to charge the DC capacitor using the AC bus voltage of the station-level and grid-connected permanent magnet wind turbine. Unlock the third trigger pulse of the grid-side converter of the station-level grid-connected permanent magnet wind turbine, and control the DC voltage of the grid-side converter to the rated value based on the third trigger pulse, while setting the reactive power reference value of the grid-side converter to 0. Unlock the fourth trigger pulse of the generator-side converter of the station-level grid-connected permanent magnet wind turbine, and configure the active power reference value of the generator-side converter to 0 based on the fourth trigger pulse; The control unit receives power distribution commands from the grid-type permanent magnet wind turbine, enabling the station-level grid-type permanent magnet wind turbine to output electrical energy together with the grid-type permanent magnet wind turbine.

[0065] In one embodiment, the grid-type permanent magnet wind turbine uses a phase-locked loop to control its turbine-side converter; the station-level grid-connected permanent magnet wind turbine uses a phase-locked loop to control its grid-side converter. The device further includes: The compensation module is used to perform frequency compensation in phase-locked loop-based control by combining the following formula:

[0066] k p_PLL and k i_PLL These are the proportional and integral coefficients used in the phase-locked loop, respectively. U tq Three-phase voltage signal on the AC grid side Uabc q-axis component, U dc0 This is the rated DC voltage. k p and k i These are the proportional coefficient and integral coefficient for frequency compensation, respectively. S 1 is the compensation status flag. θ PLL This is the output angle of the phase-locked loop.

[0067] Another embodiment of the present invention also provides an electronic device, comprising: One or more processors; Memory, configured to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the heterogeneous permanent magnet wind farm self-starting network control method as described above.

[0068] Furthermore, one embodiment of the present invention also provides a storage medium storing a computer program, which, when executed by a processor, implements the self-starting network control method for heterogeneous permanent magnet wind farms as described above. It should be understood that the various solutions in this embodiment have the corresponding technical effects in the above-described method embodiments, and will not be repeated here.

[0069] Furthermore, embodiments of the present invention also provide a computer program product, which is tangibly stored on a computer-readable medium and includes computer-readable instructions, which, when executed, cause at least one processor to perform a heterogeneous permanent magnet wind farm self-starting network control method as described in the embodiments above.

[0070] It should be noted that the computer storage medium of the present invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access storage medium (RAM), a read-only storage medium (ROM), an erasable programmable read-only storage medium (EPROM or flash memory), an optical fiber, a portable compact disk read-only storage medium (CD-ROM), an optical storage medium, a magnetic storage medium, or any suitable combination thereof. In the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. In the present invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media can also be any computer-readable medium other than computer-readable storage media, which can send, propagate, or transmit a program configured for use by or in connection with an instruction execution system, system, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, antenna, optical fiber, RF, etc., or any suitable combination thereof.

[0071] Furthermore, those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0072] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1One or more processes and / or boxes Figure 1 A system that specifies functions in one or more boxes.

[0073] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction set implemented in a process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0074] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

Claims

1. A heterogeneous permanent magnet wind farm self-starting networking control method, characterized in that, The method, applicable to heterogeneous wind farms with multiple control modes, including grid-connected permanent magnet wind turbines and farm-level grid-connected permanent magnet wind turbines, includes: The grid-type controller in the grid-type permanent magnet wind turbine is used as the power outer loop, and the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine is used at least to perform droop control of the active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine. The output phase angle is determined based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. By combining the output phase angle, the synchronous coordination and load distribution of the grid-connected permanent magnet wind turbine are achieved, realizing the self-starting grid connection of the heterogeneous permanent magnet wind farm.

2. The heterogeneous permanent-magnet wind farm self-starting networking control method according to claim 1, characterized in that, At least the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine is used for droop control, including: The DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage and three-phase current signals of the AC grid side of the grid-type permanent magnet wind turbine are detected. The DC capacitor voltage of the generator-side converter, the DC voltage of the grid-type permanent magnet wind turbine, the active power output of the grid-side converter of the grid-type permanent magnet wind turbine, and the three-phase voltage signal and three-phase current signal of the AC grid side of the grid-type permanent magnet wind turbine are input to the grid-type controller to realize the droop control.

3. The heterogeneous permanent-magnet wind farm self-starting networking control method according to claim 1, characterized in that, The method further includes: The active power output of the grid-side converter of the grid-type permanent magnet wind turbine is detected, as well as the three-phase voltage signal and three-phase current signal on the AC grid side. The active power output from the grid-side converter of the grid-connected permanent magnet wind turbine, as well as the three-phase voltage signal and three-phase current signal from the AC grid side, are input to the grid-connected controller in the station-level grid-connected permanent magnet wind turbine to cooperate with the grid-connected controller in performing the droop control.

4. The self-starting network control method for heterogeneous permanent magnet wind farms according to claim 1, characterized in that, The determination of the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine includes: The angular frequency output value is determined based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. The output phase angle is generated by integrating the angular frequency output value.

5. The heterogeneous permanent-magnet wind farm self-starting networking control method according to claim 1, characterized in that, Performing droop control of active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine includes: DC voltage synchronous control is performed on the grid-side converter of the grid-type permanent magnet wind turbine to achieve angular velocity control of the grid-side converter of the grid-type permanent magnet wind turbine. The generator-side converters of the grid-type permanent magnet wind turbine and the station-level grid-connected permanent magnet wind turbine adopt DC voltage droop control to achieve active power distribution.

6. The self-starting network control method for heterogeneous permanent magnet wind farms according to claim 5, characterized in that, The DC voltage synchronization control of the grid-side converter of the grid-type permanent magnet wind turbine includes: The DC voltage synchronous control of the grid-side converter of the grid-type permanent magnet wind turbine is achieved according to the following formula: K dc For DC voltage synchronization gain, This is the reference value for the DC voltage of a grid-type permanent magnet wind turbine. ω 0 is the rated angular velocity. ω GFM ω represents the angular velocity of the grid-side converter.

7. The heterogeneous permanent-magnet wind farm self-starting networking control method according to claim 5, characterized in that, To achieve active power allocation, the following steps are included: Active power allocation is based on the following formula: Active power allocated to the generator-side converter of a grid-type permanent magnet wind turbine. The active power allocated to the generator-side converter of the station-level and grid-type permanent magnet wind turbine units. K F_GFM The sag coefficient of the grid-type permanent magnet wind turbine generator. K F_GFL To match the sag coefficient of the grid-type permanent magnet wind turbine generator. u dc This refers to the per-unit value of the DC voltage for grid-type permanent magnet wind turbine generators.

8. The self-starting network control method for heterogeneous permanent magnet wind farms according to claim 1, characterized in that, The synchronization coordination and load distribution of the grid-connected permanent magnet wind turbine unit based on the output phase angle includes: Unlock the first trigger pulse of the generator-side converter of the grid-type permanent magnet wind turbine, and control the DC voltage of the generator-side converter to the rated value based on the first trigger pulse; Unlock the second trigger pulse of the grid-side converter of the grid-type permanent magnet wind turbine, and generate AC bus voltage in combination with the second trigger pulse; After the grid-type permanent magnet wind turbine is fully powered on, the AC voltage on the turbine side is determined and the pitch control is started based on the output phase angle. Control the circuit breaker of the station-level and grid-connected permanent magnet wind turbine to charge the DC capacitor using the AC bus voltage of the station-level and grid-connected permanent magnet wind turbine. Unlock the third trigger pulse of the grid-side converter of the station-level grid-connected permanent magnet wind turbine, and control the DC voltage of the grid-side converter to the rated value based on the third trigger pulse, while setting the reactive power reference value of the grid-side converter to 0. Unlock the fourth trigger pulse of the generator-side converter of the station-level grid-connected permanent magnet wind turbine, and configure the active power reference value of the generator-side converter to 0 based on the fourth trigger pulse; The control unit receives power distribution commands from the grid-type permanent magnet wind turbine, enabling the station-level grid-type permanent magnet wind turbine to output electrical energy together with the grid-type permanent magnet wind turbine.

9. The self-starting network control method for heterogeneous permanent magnet wind farms according to claim 8, characterized in that, The grid-type permanent magnet wind turbine unit uses a phase-locked loop to control its turbine-side converter; the station-level grid-type permanent magnet wind turbine unit uses a phase-locked loop to control its grid-side converter. The method further includes: When using phase-locked loop (PLL) based control, frequency compensation is performed using the following formula: k p_PLL and k i_PLL These are the proportional and integral coefficients used in the phase-locked loop, respectively. U tq Three-phase voltage signal on the AC grid side U abc q-axis component, U dc0 This is the rated DC voltage. k p and k i These are the proportional coefficient and integral coefficient for frequency compensation, respectively. S 1 is the compensation status flag. θ PLL This is the output angle of the phase-locked loop.

10. A heterogeneous permanent magnet wind farm self-starting networking control device, characterized in that, Applied to heterogeneous wind farms with multiple control modes, including grid-connected permanent magnet wind turbines and farm-level grid-connected permanent magnet wind turbines, the device includes: The control module is used to perform droop control of active power between the grid-type permanent magnet wind turbine and the station-level grid-type permanent magnet wind turbine, based on the grid-type controller in the grid-type permanent magnet wind turbine as the power outer loop and at least using the DC capacitor voltage of the generator-side converter in the permanent magnet wind turbine. The determination module is used to determine the output phase angle based on the DC capacitor voltage of the grid-side converter in the grid-type permanent magnet wind turbine generator. The networking module is used to coordinate the synchronization and load distribution of the grid-connected permanent magnet wind turbine in conjunction with the output phase angle, so as to realize the self-starting networking of the heterogeneous permanent magnet wind farm.

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