Primary frequency modulation control method and system for wind power plant

Abstract

The invention discloses a primary frequency modulation control method and system for a wind power plant. The control method comprises the following steps: in response to a signal for triggering a primary frequency modulation action, determining a current output gear of the capacitor battery energy storage system according to a frequency modulation demand of primary frequency modulation of a power grid, and executing a first energy storage action; if the triggering of the primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and the wind generating set is controlled to output the active power to the power grid in the second stage of the primary frequency modulation of the power grid, the frequency modulation requirement of primary frequency modulation of the power grid is met; and if the time for triggering the primary frequency modulation action signal exceeds the second preset time, controlling the capacitor battery energy storage system to quit the energy storage action. According to the invention, the problem that the active power regulation effect of the existing new energy station is poor is solved, the primary frequency modulation assessment requirement of the new energy station is met, and the maximum benefit is obtained.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of wind farm frequency regulation, and in particular to a primary frequency regulation control method and system for a wind farm. Background Art

[0002] In recent years, the installed capacity of my country's new energy stations has been climbing year by year, and the annual power generation has also been steadily increasing. Wind power has become one of the main power sources for the power grid, and has brought new challenges to the dynamic balance of active power and frequency stability and safety control of the power grid.

[0003] Primary frequency regulation is a key project in auxiliary services involving the dynamic balance of active power and frequency safety of the power grid. The performance of primary frequency regulation of wind farms directly affects the grid connection assessment and operating income of wind farms. At present, energy storage technology is developing rapidly, and there are also a variety of technologies available. Supercapacitor batteries and electrochemical energy storage batteries have the characteristics of fast charging and discharging speed and square bidirectional regulation. The difference is that supercapacitor batteries have many charging and discharging times and large charging and discharging ratios in their entire life cycle, but have the disadvantage of low energy capacity, while electrochemical energy storage batteries have high energy capacity but have the disadvantage of few charging and discharging times in their entire life cycle. At present, power grids in various places generally have a more stringent assessment of the integral power contribution rate of primary frequency regulation, that is, the integral power contribution rate in the effective process of a single primary frequency regulation is lower than the minimum standard value and higher than the maximum standard value, which is considered unqualified. Therefore, the active power regulation effect of existing new energy stations is not good, and it is impossible to meet the primary frequency regulation assessment requirements of new energy stations and obtain maximum benefits. Summary of the invention

[0004] The present invention provides a primary frequency regulation control method and system for a wind farm, which can solve the problem of poor active power regulation effect of existing new energy stations, realize the function of energy storage batteries participating in the primary frequency regulation control of wind farms, meet the primary frequency regulation assessment requirements of new energy stations and obtain maximum benefits.

[0005] In a first aspect, an embodiment of the present invention provides a primary frequency modulation control method for a wind farm, which is applied to a composite energy storage system, wherein the composite energy storage system includes a capacitor battery energy storage system and an electrochemical energy storage system, and the wind farm, the capacitor battery energy storage system and the electrochemical energy storage system are all connected to a power grid, and the control method includes:

[0006] Determining whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit;

[0007] In response to triggering a primary frequency modulation action signal, entering the first stage of the primary frequency modulation of the power grid, determining the current output gear of the capacitor battery energy storage system according to the frequency modulation demand of the primary frequency modulation of the power grid, and executing a first energy storage action;

[0008] If the triggering of the primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, the second stage of the primary frequency modulation of the power grid is entered, the wind turbine generator set in the wind farm responds according to the primary frequency modulation action signal, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbine generator set to output active power to the power grid in the second stage of the primary frequency modulation of the power grid until the frequency modulation demand of the primary frequency modulation of the power grid is met;

[0009] If the triggering signal of the primary frequency modulation action exceeds the second preset time, the third stage of the primary frequency modulation of the power grid is entered, and the capacitor battery energy storage system is controlled to exit the energy storage action.

[0010] In a second aspect, an embodiment of the present invention further provides a primary frequency regulation control system for a wind farm, wherein the primary frequency regulation control system for a wind farm is used to execute a primary frequency regulation control method for a wind farm described in any embodiment of the present invention, and the control system comprises:

[0011] A signal trigger module, used to determine whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit;

[0012] A first frequency modulation control module is used for responding to a triggering primary frequency modulation action signal, determining a current output gear of the capacitor battery energy storage system according to a frequency modulation demand of the primary frequency modulation of the power grid in a first stage of the primary frequency modulation of the power grid, and executing a first energy storage action;

[0013] A second frequency modulation control module is used for, if the triggering of the primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, entering the second stage of the primary frequency modulation of the power grid, the wind turbine generator set in the wind farm performs an action response according to the primary frequency modulation action signal, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbine generator set to output active power to the power grid in the second stage of the primary frequency modulation of the power grid until the frequency modulation demand of the primary frequency modulation of the power grid is met;

[0014] The third frequency modulation control module is used to control the capacitor battery energy storage system to exit the energy storage action if the triggering signal of the primary frequency modulation action exceeds the second preset time and enters the third stage of the primary frequency modulation of the power grid.

[0015] The present invention provides a primary frequency regulation control method and system for a wind farm. The control method comprises: judging whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit; in response to the triggering of the primary frequency regulation action signal, entering the first stage of the primary frequency regulation of the power grid, determining the current output gear of the capacitor battery energy storage system according to the frequency regulation demand of the primary frequency regulation of the power grid, and executing the first energy storage action, so that the capacitor battery energy storage system preferentially intervenes in the primary frequency regulation action process; if the triggering of the primary frequency regulation action signal exceeds the first preset time and does not exceed the second preset time, entering the second stage of the primary frequency regulation of the power grid, the wind turbine generator set in the wind farm performs an action response according to the primary frequency regulation action signal, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency regulation of the power grid, and controls the wind turbine generator set in the primary frequency regulation of the power grid. Active power is output to the power grid in the second stage of frequency modulation, so that the wind turbine generator set outputs active power to replace the capacitor battery energy storage system until the frequency modulation demand of the primary frequency modulation of the power grid is met, so that the capacitor battery energy storage system is efficiently utilized; if the triggering signal of the primary frequency modulation exceeds the second preset time, the third stage of the primary frequency modulation of the power grid is entered, and the capacitor battery energy storage system is controlled to exit the execution of the energy storage action, and the composite energy storage system is controlled to participate in the primary frequency modulation of the wind farm by stages, gears and continuous tracking and adjustment. It can effectively solve the problem of increased control system operation pressure caused by the principle of real-time tracking of primary frequency modulation demand by energy storage, and increased control difficulty of the battery body caused by changes in energy storage output with demand, and realizes the use of capacitor battery energy storage system to improve the primary frequency modulation control effect of the wind farm, thereby improving the work efficiency and operation and maintenance safety of the wind farm. The present invention solves the problem of poor active power regulation effect of existing new energy stations, realizes the function of energy storage batteries participating in the primary frequency modulation control of wind farms, and meets the primary frequency modulation assessment requirements of new energy stations and obtains maximum benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flow chart of a primary frequency regulation control method for a wind farm provided by an embodiment of the present invention;

[0017] Figure 2 A flow chart of the first stage of a capacitor battery energy storage system participating in a frequency modulation according to an embodiment of the present invention;

[0018] Figure 3 A flow chart of another primary frequency regulation control method for a wind farm provided by an embodiment of the present invention;

[0019] Figure 4 A schematic diagram of a frequency-active power droop characteristic curve of a typical wind farm participating in primary frequency modulation provided by an embodiment of the present invention;

[0020] Figure 5A control logic diagram of primary frequency regulation of a wind farm provided by an embodiment of the present invention;

[0021] Figure 6 A control logic diagram of a wind farm primary frequency modulation action late stage provided by an embodiment of the present invention;

[0022] Figure 7 A schematic structural diagram of a primary frequency regulation control system for a wind farm provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0024] At present, energy storage technology is developing rapidly, and there are also a variety of technologies available. Supercapacitor batteries and electrochemical energy storage batteries both have the characteristics of fast charging and discharging speed and square bidirectional regulation. The difference is that supercapacitor batteries have many charging and discharging times in their entire life cycle and a large charging and discharging ratio, but have the disadvantage of low energy capacity, while electrochemical energy storage batteries have high energy capacity, but have the disadvantage of few charging and discharging times in their entire life cycle. At present, power grids in various places generally have a more stringent assessment of the integral power contribution rate of primary frequency regulation, that is, the integral power contribution rate during the effective process of a single primary frequency regulation is lower than the minimum standard value and higher than the maximum standard value. It is considered unqualified. Therefore, a reasonable configuration of the use strategy of composite energy storage can improve the active power regulation effect of the station, further meet the primary frequency regulation assessment requirements of the station and obtain maximum benefits.

[0025] The existing technology generally focuses on the scheme of real-time tracking of frequency regulation demand by energy storage output of new energy stations, while the primary frequency regulation action process of the power grid generally shows the characteristics of short duration of frequency difference exceeding the limit, high frequency deviation first and then low, and small frequency exceeding the limit accounting for the majority of conditions. The embodiment of the present invention focuses on the investment and withdrawal strategy of the composite energy storage system, takes the primary frequency regulation integral power contribution rate as a reference condition constraint, and implements the primary frequency regulation control strategy of the new energy station by using the composite energy storage calling technology in stages and batches. Therefore, the embodiment of the present invention is different from the existing technology in terms of innovation direction.

[0026] The embodiment of the present invention provides a primary frequency modulation control method for a wind farm to solve the related technical problems in the above-mentioned prior art. Figure 1 A flow chart of a primary frequency modulation control method for a wind farm provided in an embodiment of the present invention. This embodiment can be applied to a composite energy storage system, which includes a capacitor battery energy storage system and an electrochemical energy storage system. The wind farm, the capacitor battery energy storage system and the electrochemical energy storage system are all connected to the power grid, such as Figure 1 As shown, the control method includes:

[0027] S110. Determine whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit.

[0028] Among them, the composite energy storage system includes a capacitor battery energy storage system and an electrochemical energy storage system. The wind turbine group control system, capacitor battery energy storage system and electrochemical energy storage system of the wind farm jointly serve as the active power control system of the wind farm. Taking into account the charging and discharging life of various energy storage devices, the energy storage function is put into use in stages, and the integral power contribution rate is kept within a reasonable range, so as to achieve the purpose of efficient utilization of equipment of various systems and reduce the primary frequency regulation assessment. Primary frequency regulation is the process of adjusting the active output of the generator set immediately to reduce the system frequency deviation when the frequency deviation of the power system exceeds the safe area. As a key project in auxiliary services involving the dynamic balance of active power and frequency safety of the power grid, the performance of the primary frequency regulation of the wind farm has a direct impact on the grid connection assessment and operating income of the wind farm.

[0029] Specifically, first, whether to trigger the primary frequency regulation action signal is determined based on whether the grid frequency of the wind farm exceeds the primary frequency regulation dead zone of the unit. When the grid frequency exceeds the primary frequency regulation dead zone of the unit, it is determined that the wind farm needs to be frequency regulated once, and the primary frequency regulation action signal is triggered. At this time, the first stage of the primary frequency regulation of the grid will be entered.

[0030] S120, in response to triggering a primary frequency modulation action signal, entering the first stage of the primary frequency modulation of the power grid, determining the current output gear of the capacitor battery energy storage system according to the frequency modulation demand of the primary frequency modulation of the power grid, and executing the first energy storage action.

[0031] Among them, in order to solve the problem of frequent action of the active control system of the wind farm station caused by the short duration of the frequency difference exceeding the limit and the large proportion of small frequency difference exceeding the limit during the primary frequency modulation action, the following factors are taken into consideration: 1. The active power action adjustment process of the wind turbine generator set in the wind farm needs to involve mechanical transmission and electrical loss problems. High-frequency repeated actions will bring safety hazards to the wind turbine group itself; 2. The number of actions of the capacitor battery energy storage system in its entire life cycle is about dozens or even hundreds of times the number of energy storage actions of the electrochemical energy storage system; 3. The capacitor battery energy storage system has the advantages of high charge and discharge rate, fast adjustment speed, and stable adjustment control; 4. The energy storage capacity of the capacitor battery energy storage system is low, and the high-rate charge and discharge time is short. Therefore, the capacitor battery energy storage system is preferentially intervened in the primary frequency modulation action process, and the action time limit is short. Optionally, the capacitor battery energy storage system is a supercapacitor battery, and the electrochemical energy storage system is an electrochemical energy storage battery.

[0032] Specifically, in response to triggering a frequency modulation action signal, the first stage of the primary frequency modulation of the power grid is entered, and the first stage of the primary frequency modulation is the energy storage rapid response stage. According to the frequency modulation requirements of the primary frequency modulation of the power grid, the current output gear of the capacitor battery energy storage system is determined, and the first energy storage action is executed. Since the capacitor battery energy storage system has the advantages of high charge and discharge rate, fast adjustment speed, and stable adjustment control, the primary frequency modulation response action effect is fast and positive; and by determining the current output gear of the capacitor battery energy storage system according to the frequency modulation requirements of the primary frequency modulation of the power grid, and executing the first energy storage action, it is ensured that the primary frequency modulation adjustment process at this stage is reasonable and effective, and can meet the frequency modulation requirements of the primary frequency modulation.

[0033] S130. If the triggering of the primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, the second stage of the primary frequency modulation of the power grid is entered, and the wind turbines in the wind farm respond according to the primary frequency modulation action signal, and the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbines to output active power to the power grid in the second stage of the primary frequency modulation of the power grid until the frequency modulation demand of the primary frequency modulation of the power grid is met.

[0034] Among them, the first preset time is the time of the first stage of the primary frequency modulation, and also the time when the capacitor battery energy storage system takes priority in the primary frequency modulation action process. The first preset time can be adjusted according to the actual situation, and the recommended value is 3-5s. The second preset time is generally selected from the minimum duration of a single effective primary frequency modulation action specified by the local power grid, and the typical value is 15s.

[0035] Specifically, the capacitor battery energy storage system preferentially intervenes in the primary frequency modulation action process until it reaches the first preset time, that is, if the triggering primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, the second stage of the primary frequency modulation of the power grid is entered, and the wind turbine generator set starts to act in the second stage, and the wind turbine generator set in the wind farm responds according to the primary frequency modulation action signal. The capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbine generator set to output active power to the power grid in the second stage of the primary frequency modulation of the power grid. The active power regulation of the wind turbine generator set replaces the energy storage regulation process of the capacitor battery energy storage system until the frequency modulation demand of the primary frequency modulation of the power grid is met. During this period, the energy storage of the capacitor battery energy storage system is gradually withdrawn, and this process is maintained until the second preset time.

[0036] S140: If the primary frequency modulation action signal is triggered for more than the second preset time, the third stage of the primary frequency modulation of the power grid is entered, and the capacitor battery energy storage system is controlled to exit the energy storage action.

[0037] Specifically, if the triggering signal of the primary frequency modulation action exceeds the second preset time, the third stage of the primary frequency modulation of the power grid is entered, and the capacitor battery energy storage system is controlled to exit the energy storage action, and the capacitor battery energy storage system is unconditionally exited from energy storage. Optionally, in the third stage, the electrochemical energy storage system can also be conditionally selected to gradually correct the problem of inaccurate active power regulation of the entire wind turbine cluster according to the integral contribution power demand of the primary frequency modulation. After the primary frequency modulation action is completed, each system automatically returns to its original state before the start of the frequency modulation. By controlling the composite energy storage system to participate in the primary frequency modulation of the wind farm in a staged, geared and continuous tracking and adjustment manner, it can effectively solve the problem of increased control system operation pressure caused by the principle of real-time tracking of primary frequency modulation requirements by energy storage, and the problem of increased control difficulty of the battery body caused by changes in energy storage output with demand, and realize the use of capacitor battery energy storage system to improve the primary frequency modulation control effect of the wind farm, thereby improving the work efficiency and operation and maintenance safety of the wind farm.

[0038] The embodiment of the present invention provides a primary frequency regulation control method for a wind farm, and the control method includes: judging whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit; in response to the triggering of the primary frequency regulation action signal, entering the first stage of the primary frequency regulation of the power grid, determining the current output gear of the capacitor battery energy storage system according to the frequency regulation demand of the primary frequency regulation of the power grid, and executing the first energy storage action, so that the capacitor battery energy storage system preferentially intervenes in the primary frequency regulation action process; if the triggering of the primary frequency regulation action signal exceeds the first preset time and does not exceed the second preset time, entering the second stage of the primary frequency regulation of the power grid, the wind turbine generator set in the wind farm responds according to the primary frequency regulation action signal, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency regulation of the power grid, and controls the wind turbine generator set in the primary frequency regulation of the power grid. Active power is output to the power grid in the second stage of frequency modulation, so that the wind turbine generator set outputs active power to replace the capacitor battery energy storage system until the frequency modulation demand of the primary frequency modulation of the power grid is met, so that the capacitor battery energy storage system is efficiently utilized; if the triggering signal of the primary frequency modulation exceeds the second preset time, the third stage of the primary frequency modulation of the power grid is entered, and the capacitor battery energy storage system is controlled to exit the execution of the energy storage action, and the composite energy storage system is controlled to participate in the primary frequency modulation of the wind farm by stages, gears and continuous tracking and adjustment. It can effectively solve the problem of increased control system operation pressure caused by the principle of real-time tracking of primary frequency modulation demand by energy storage, and increased control difficulty of the battery body caused by changes in energy storage output with demand, and realizes the use of capacitor battery energy storage system to improve the primary frequency modulation control effect of the wind farm, thereby improving the work efficiency and operation and maintenance safety of the wind farm. The present invention solves the problem of poor active power regulation effect of existing new energy stations, realizes the function of energy storage batteries participating in the primary frequency modulation control of wind farms, and meets the primary frequency modulation assessment requirements of new energy stations and obtains maximum benefits.

[0039] In order to ensure that the capacitor battery energy storage system is reasonable and effective in the primary frequency regulation process, the embodiment of the present invention also provides another primary frequency regulation control method for a wind farm. Figure 2 The flow chart of the first stage of the capacitor battery energy storage system participating in a frequency modulation provided by the embodiment of the present invention is as follows: Figure 2 As shown, according to the frequency regulation demand of the primary frequency regulation of the power grid, the current output gear of the capacitor battery energy storage system is determined, and the first energy storage action is performed, including:

[0040] S210, dividing the output power of the capacitor battery energy storage system into a plurality of output gears with different output powers.

[0041] Optionally, the output gears of the capacitor battery energy storage system are divided into zero gear, a first output gear, a second output gear, a third output gear and a fourth output gear.

[0042] Zero gear satisfaction: P cr0 =0; first output gear P cr1 Satisfaction: P cr1 =2.5%P n ; Second output gear P cr1 Satisfaction: P cr2 =5%P n ; The third output gear P cr3 Satisfaction: P cr1 =7.5%P n ; The fourth output gear P cr4 Satisfaction: P cr1 =10%P n ; Among them, P n is the rated active power of the wind farm.

[0043] Specifically, the capacitor battery energy storage system participates in the first stage of primary frequency regulation, and the capacitor battery energy storage system gear adjustment method is selected to achieve it. Considering the problem that the capacitor battery energy storage system participates in the action time for a short time and contributes a small amount of electricity in this strategy, no fine adjustment is designed in this stage, and the capacitor battery energy storage system can be configured in equal and graded forms. The output gear of the capacitor battery energy storage system is divided into zero gear, the first output gear, the second output gear, the third output gear and the fourth output gear. The rated active power of the wind farm is P n , the maximum effective discharge power of the capacitor battery energy storage system is P cr and duration is configured as 10%P n / 5min, the power generation gear of the capacitor battery energy storage system is divided into 4 gears in the forward direction (the reverse direction is also the same), namely the first output gear, the second output gear, the third output gear and the fourth output gear, and the supercapacitor battery gear is zero gear P cr0=0, first output gear P cr1 (2.5%P n ), the second output gear P cr2 (5%P n ), the third output gear P cr3 (7.5%P n ), the fourth output gear P cr4 (10%P n ), the above output gears can meet the frequency regulation requirements of the first stage.

[0044] S220. Determine the current output gear of the capacitor battery energy storage system according to the frequency regulation demand of the primary frequency regulation of the power grid, so that the capacitor battery energy storage system outputs electric energy to the power grid at the current output gear.

[0045] Specifically, the output gear of the capacitor battery energy storage system meets the following requirements:

[0046] When P i <P demand ≤P i+1 , take P i As the output gear of the capacitor battery energy storage system.

[0047] Among them, P i is one of the zero gear, the first output gear, the second output gear and the third output gear, P i+1 P i The output power is one gear higher than the output gear, P demand It is the frequency regulation power required for the primary frequency regulation of the power grid.

[0048] The first energy storage action is to take P i As the output gear of the capacitor battery energy storage system, the output gear of the capacitor battery energy storage system is matched with the frequency modulation demand power of the primary frequency modulation of the power grid. By determining the current output gear of the capacitor battery energy storage system according to the frequency modulation demand power of the primary frequency modulation of the power grid, and executing the first energy storage action, it is ensured that the primary frequency modulation adjustment process at this stage is reasonable and effective, and can meet the frequency modulation demand of the primary frequency modulation. In addition, since the capacitor battery energy storage system has the advantages of high charge and discharge rate, fast adjustment speed, and stable adjustment control, the primary frequency modulation response action effect is fast and positive.

[0049] In another primary frequency regulation control method for a wind farm provided by an embodiment of the present invention, the wind turbine generator sets gradually put into primary frequency regulation action response, the wind turbine generator sets in the wind farm respond according to the primary frequency regulation action signal, and the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency regulation of the power grid, including:

[0050] The wind turbines in the wind farm output dynamic active power according to the frequency regulation requirements of the primary frequency regulation of the power grid; the dynamic active power ΔP wind satisfy:

[0051] ΔP wind =P demand ; (1)

[0052] The capacitor battery energy storage system reduces the current output gear according to the dynamic active power to reduce the output power; when ΔP wind +P i+1 ≥P demand >ΔP wind +P i , take P i As the output gear of the capacitor battery energy storage system.

[0053] Specifically, the active power regulation of the wind turbine replaces the energy storage regulation process of the capacitor battery energy storage system until the frequency regulation demand of the primary frequency regulation of the power grid is met. The dynamic active power ΔP of the wind turbine wind Satisfy: ΔP wind =P demand ; In view of the possible problems of slow action and unsatisfactory adjustment accuracy during the adjustment of wind turbines, the capacitor battery energy storage system reduces the current output gear according to the dynamic active power. The exit mechanism of the capacitor battery energy storage system follows the following principles:

[0054] ΔP wind +P i+1 ≥P demand >ΔP wind +P i , take P i As the output gear of the capacitor battery energy storage system; the capacitor battery energy storage system gradually downshifts until it returns to 0, and no longer adjusts in the opposite direction, or the duration of a frequency modulation signal trigger exceeds the second preset time, the capacitor battery energy storage system directly exits the frequency modulation process.

[0055] In addition, in the third stage of the primary frequency regulation, the electrochemical energy storage system can be conditionally selected to gradually correct the inaccurate active power regulation of the entire wind turbine cluster based on the integral contribution power demand of the primary frequency regulation. The wind turbine group selects the mechanism mode that needs to be adjusted according to the actual working conditions, so as to achieve the following: 1. The integral power contribution rate of a single primary frequency regulation meets the requirements; 2. Battery energy storage is called upon as little as possible; 3. The wind turbines are "fully powered" and other principles. Figure 3 A flow chart of another wind farm primary frequency regulation control method provided by an embodiment of the present invention, such as Figure 3 As shown, the control method also includes:

[0056] S310. In the third stage of the primary frequency modulation of the power grid, the integral power contribution rate of the wind farm in the primary frequency modulation process of the power grid is obtained, and it is determined whether the integral power contribution rate is within a preset range; wherein the preset range is a range between a first contribution rate threshold and a second contribution rate threshold.

[0057] Specifically, the recommended value range of the integral electricity contribution rate K in the local "two detailed rules" assessment policy (the first contribution rate threshold K min , the second contribution rate threshold K max ), where K min <1<K max , the typical value is: K min =0.6, K max =1.8. The wind turbine group’s adjusted output is recorded as the dynamic active power ΔP of the wind farm. wind , the actual output power of the capacitor battery energy storage system is P cr_real , the actual output power of the electrochemical energy storage system is P dhx_real Therefore, in obtaining the integral power contribution rate of the wind farm in the primary frequency regulation process of the power grid, the integral power contribution rate satisfies:

[0058]

[0059] Among them, K is the integral power contribution rate, P demand is the power demand for primary frequency regulation of the power grid, ΔP wind is the dynamic active power of the wind farm, P crreal is the actual output power of the capacitor battery energy storage system, P dhxreal is the actual output power of the electrochemical energy storage system, t is the time to trigger a frequency modulation action signal, P tj_real is the total power of primary frequency modulation, W 实际 is the actual work in the primary frequency regulation process of the power grid, W 需求 It is the power demanded in the primary frequency regulation process of the power grid.

[0060] S320: If the integral electricity contribution rate is within a preset range, the electrochemical energy storage system is not put into use.

[0061] Specifically, if the active output regulation of the wind turbine group in the wind farm is relatively accurate, that is, the actual action amount ΔP of the wind turbine group wind Tracking the primary frequency regulation demand P demand , then its performance characteristics are as follows:

[0062] K min <K<K max ;

[0063] That is, if the integral power contribution rate is within the preset range, the electrochemical energy storage system will not be put into operation, and the electrochemical energy storage system will remain in a non-input state, and the regulation principle of the wind turbine group will be maintained as shown in formula (2).

[0064] S330: If the integrated electricity contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system is put into operation, and the electrochemical energy storage system is controlled to output electric energy to the grid in a second energy storage action.

[0065] Optionally, if the integral power contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system is put into operation; and the electrochemical energy storage system is controlled to output electric energy to the grid in a second energy storage action until the following conditions are met:

[0066] K>(1+K min ) / 2, control the electrochemical energy storage system to exit; where K min is the first contribution rate threshold.

[0067] Specifically, in the third stage of the primary frequency regulation of the power grid, if the regulation accuracy of the wind turbine group is insufficient, the electrochemical energy storage system can be used to correct the active power of the entire field, that is, if the integral power contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system will be put into use. First, the electrochemical energy storage system is divided into grades. The main principle is to divide it according to the number of battery stacks actually configured on site, and to adjust the full-capacity charging in units of battery stacks. Each battery stack follows the principle of full-capacity output, and different battery stacks follow the principle of automatic forward configuration if the cumulative number of call rounds is small, to ensure that each battery stack participating in the frequency regulation can achieve a reasonable distribution of the number of actions. For example, a large-scale station is equipped with a total of 10 battery stacks for battery energy storage, namely D1, D2, ...D n ,…D 10 , whose capacities are P D1 , P D2 …P Dn …P D10 , the cumulative number of actions is N1, N2…N n …N 10 , then the electrochemical energy storage can be divided into 10 gears for adjustment. If the integral power contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system is put into operation, and the electrochemical energy storage system is controlled to output electric energy to the grid in the second energy storage action. The second energy storage action is: take the battery stacks of the electrochemical energy storage system with the least number of top rankings to participate in the action, and the actual power P of the electrochemical energy storage system dhx_real When the following conditions are met:

[0068]

[0069] At this time: 1. The wind turbine group is adjusted as shown in formula (2); 2. A battery stack or multiple battery stacks involved in the adjustment move forward to the maximum capacity, and the default time is T. L_lim After exiting, T L_lim Typical parameters are: 5s; 3. If the state of the next operation cycle does not satisfy formula (2), the battery stack screening is terminated. If it satisfies formula (2), the battery stack investment is continued to be added to ensure that the active power regulation of the wind farm is slightly greater than the actual demand, thereby ensuring that the integral power contribution rate K is less than K. min Quickly approach 1; 4. If the first batch of battery stacks are maintained for more than T L_lim After that, the integral power contribution rate K<K min , then the battery stack or multiple battery stacks that have been put into use continue to remain in the put-in-use state until the following conditions are met:

[0070] K>(1+K min ) / 2;

[0071] Subsequently, the battery stacks of the electrochemical energy storage system are withdrawn in sequence according to the order in which they were put into use.

[0072] S340: If the integrated electricity contribution rate is greater than the second contribution rate threshold, the electrochemical energy storage system is put into operation, and the electrochemical energy storage system is controlled to output electric energy to the grid in a third energy storage action.

[0073] Optionally, if the integral power contribution rate is greater than the second contribution rate threshold, the electrochemical energy storage system is put into operation; and the electrochemical energy storage system is controlled to output electric energy to the grid in a third energy storage action until the following conditions are met:

[0074] K<(1+K max ) / 2, control the electrochemical energy storage system to exit; where K max is the second contribution rate threshold.

[0075] Specifically, in the third stage of the primary frequency regulation of the power grid, if the regulation accuracy of the wind turbine group is insufficient, the electrochemical energy storage system can be used to correct the active power of the entire field, that is, if the integral power contribution rate is greater than the second contribution rate threshold, the electrochemical energy storage system is put into use, and the actual power P of the electrochemical energy storage system dhx_real The actual power P of the electrochemical energy storage system is reset to 0. The electrochemical energy storage system is controlled to output electric energy to the grid in the third energy storage action. The third energy storage action is: dhx_real The following conditions must be met:

[0076]

[0077] At this time: 1. The wind turbine group is adjusted as shown in formula (2); 2. A battery stack or multiple battery stacks involved in the adjustment move forward to the maximum capacity, and the default time is T. L_lim3. If the state of the next operation cycle does not satisfy formula (2), the battery stack screening is terminated. If it satisfies formula (2), the battery stack investment is continued to be added to ensure that the active power regulation of the wind farm is slightly less than the actual demand, thereby ensuring that the integral power contribution rate K exceeds K. max Quickly approach 1; 4. If the first batch of battery stacks lasts longer than T L_lim After that, the integral power contribution rate K>K max , then the battery stack or multiple battery stacks that have been put into use will remain in the put-in-use state until the following conditions are met:

[0078] K<(1+K max ) / 2;

[0079] Subsequently, the battery stacks of the electrochemical energy storage system are withdrawn in sequence according to the order in which they were put into use.

[0080] In addition, if the floating charge state of the battery stack does not meet the basic input conditions, the battery stack has participated in the adjustment action or other conditions that affect the battery stack body input are met, the battery stack automatically exits the action count ranking.

[0081] It should be noted that in the embodiment of the present invention, in combination with the normal changes in the grid frequency and possible abnormal conditions, the exit mechanisms of the three active power control objects of the wind turbine (wind turbine), capacitor battery energy storage system and electrochemical energy storage system in the wind farm are set as follows: 1. The exit conditions of the capacitor battery energy storage system include: 1. The action signal of the primary frequency modulation disappears; 2. Step by step exit, in ΔP wind +P i+1 ≥P demand >ΔP wind +P i When P i As the output gear of the capacitor battery energy storage system; 3. All forced exits, the duration t of the primary frequency modulation action signal exceeds the second preset time T2 as a sign signal. 2. The exit conditions of the electrochemical energy storage system include: 1. The primary frequency modulation action signal disappears; 2. The duration t of the primary frequency modulation action signal exceeds the maximum calculation time T3 of a single effective process; 3. Other situations that affect the safe operation of battery energy storage. 3. The exit conditions of fan adjustment include: 1. The primary frequency modulation action signal disappears; 2. The duration t of the primary frequency modulation action signal exceeds the maximum calculation time T3 of a single effective process and the adjustment direction of the fan output is to reduce the load at this time. In addition: When the primary frequency modulation process requires the fan to increase the load, for the special operating state of the power grid that exceeds the maximum calculation time T3 of a single effective process, the fan exits the power-limiting adjustment and changes to free power generation. Under the premise of ensuring the correct adjustment direction, the power grid is effectively supported, and the wind turbine group is objectively fully powered.

[0082] In the process of conventional grid frequency changes: 1. The capacitor battery energy storage system can cooperate with the first preset time T1 to filter out most of the invalid short-term frequency limit disturbances; 2. The time difference between the first preset time T1 and the second preset time T2 can ensure that the mechanical structure of the wind turbine group can be adjusted in place, and with the assistance of the exit mechanism of the capacitor battery energy storage system, it can ensure that before the second preset time T2, regardless of whether the capacitor battery energy storage system is completely at 0, the primary frequency regulation response effect of the wind farm is better (expressed as K≈1); 3. After the duration of a primary frequency regulation exceeds the second preset time T2, if the adjustment effect of the wind turbine group is better, the call of the electrochemical energy storage system can be completely avoided. If the adjustment of the wind turbine group deviates, the minimum battery stack unit in the electrochemical energy storage system can be called for adjustment and correction, and the default input time T can be maintained. L_lim The wind turbine group is given more time to adjust into place. If the wind turbine group continues to fail to adjust into place, the battery stack units that have been put into use can continue to be used for adjustment until this adjustment process meets the relevant conditions and then exits.

[0083] The key points of the above frequency modulation process are as follows:

[0084] Key point (I) Capacitor battery energy storage system capacity configuration and first preset time T1 configuration

[0085] The main purpose of this content is to filter out a large number of invalid short-term, low-frequency difference grid disturbances. Generally, combined with the frequency over-limit statistics of the local power grid, the first preset time T1 is configured to avoid the invalid frequency difference over-limit period with a relatively high proportion, so as to reduce the mechanical action of the wind turbine cluster. For example, in the frequency over-limit action times of a local power grid over a long period of time, the probability that the frequency modulation action does not last more than 5s is 50%, then the first preset time T1 can be configured to be 5s, or adjusted according to the actual situation, and the recommended value is 3-5s. By flexibly configuring the first preset time T1, the unnecessary and repeated actions of the wind turbine cluster can be reduced, thereby achieving the strategy and design method of protecting the main equipment of the wind turbine cluster.

[0086] Key point (ii) In combination with the frequency over-limit action characteristics of the local power grid, the second preset time T2 can be optimized. In addition, it is necessary to refer to the specific conditions on site, and the battery type can be selected more flexibly. By flexibly configuring the second preset time T2, each energy storage system can be efficiently called and switched. Under the premise that the wind turbine group has poor regulation stability and control deviation capabilities, a strategy and design method for effectively supporting the integral power contribution rate of the entire primary frequency regulation process can be achieved.

[0087] On-site plan 1: Among the frequency over-limit actions of a local power grid over a long period of time, the probability that the frequency regulation action lasts no longer than 20s is low (lower than the typical value: 10%), so the second preset time T2 is configured to be close to T3, such as: T2=25s or T2=30s, and the maximum probability plan is to use the effective exit mechanism of the capacitor battery energy storage system to achieve stable regulation of the whole process, thereby reducing the action probability of the electrochemical energy storage system.

[0088] On-site plan 2: Among the frequency over-limit actions N of a local power grid over a relatively long period of time, the probability that the frequency regulation action lasts no longer than 20s is relatively high (higher than the typical value: 20%), so the second preset time T2 is configured to be close to the first preset time T1, such as: T2=15s or T2=20s, to maximize the probability of giving full play to the advantage that the energy storage capacity of the electrochemical energy storage system is far greater than that of the capacitor battery energy storage system. It is planned to use the effective exit mechanism of the two energy storage batteries to achieve stable regulation of the whole process, thereby reducing the total amount of energy charging and discharging of the capacitor battery energy storage system.

[0089] Key point (iii) Other key parameter configurations.

[0090] According to the characteristics of the local power grid, the capacity configuration of the capacitor battery energy storage system can be optimized, such as the maximum effective discharge power P of the capacitor battery energy storage system. cr It should not be too low below the maximum adjustment limit of a frequency modulation, and the minimum duration should not be less than 3 minutes. For example, the capacity of the capacitor battery energy storage system is 5%P n / 3min, thereby saving a lot of investment and increasing equipment utilization.

[0091] The electrochemical energy storage system is an electrochemical energy storage battery. According to the characteristics of the local power grid, the capacity division method of the electrochemical energy storage system can be optimized. In addition to sorting and calling according to the battery stack, it can also be configured in a flexible manner according to the number of energy storage inverters (generally corresponding to 2 battery stacks) and the number of battery units (regarding multiple energy storage inverters as one). In principle, the more callable units are divided, the more refined the response to the primary frequency modulation action needs, and the call rate of the electrochemical energy storage system is reduced, thereby minimizing the life reduction problem caused by equipment loss, and further achieving the purpose of increasing equipment utilization. By flexibly configuring the investment mechanism and exit mechanism of the electrochemical energy storage battery, an efficient utilization strategy and design method of the electrochemical energy storage battery equipment during the call process is realized.

[0092] In combination with the above, this solution has great advantages in frequency modulation applications in large wind farms or large clean energy bases. The larger the wind farm or large clean energy base, the smaller the configuration cost and use cost of the capacitor battery energy storage system and the electrochemical energy storage system will be, and the economic benefits will be obvious.

[0093] also, Figure 4 A schematic diagram of a frequency-active power droop characteristic curve of a typical wind farm participating in primary frequency modulation provided by an embodiment of the present invention, such as Figure 4 As shown, the frequency-active power droop characteristic curve function of a typical wind farm participating in primary frequency regulation is as follows:

[0094]

[0095] Where: f d is the primary frequency modulation dead zone, f n is the system rated frequency, in Hz, P0 is the system initial power, P n is the rated power of the whole site, in MW, and δ% is the primary frequency modulation rate. d 50±0.05Hz, δ% is 3%, and the load limit value of a frequency modulation action is ±10%P n ) as an example, the curve diagram is as follows Figure 3 As shown, the primary frequency modulation related parameters are: dead zone range is 50±0.05Hz; primary frequency modulation difference rate is 3%; primary frequency modulation load limit value is ±10%PN; the initial active minimum value of primary frequency modulation action is 20%PN.

[0096] In order to further illustrate the control process of the primary frequency modulation control method of a wind farm in the embodiment of the present invention, supercapacitor energy storage and electrochemical energy storage are used as the capacitor battery energy storage system and the electrochemical energy storage system respectively. Figure 5 A control logic diagram of primary frequency modulation of a wind farm provided by an embodiment of the present invention, Figure 6 A control logic diagram of a wind farm primary frequency modulation operation in the later stage provided by an embodiment of the present invention. Figure 5As shown, first, after the system is started, it will start to collect relevant parameters such as the grid frequency, and determine whether the grid frequency exceeds the primary frequency regulation dead zone of the unit. When it exceeds the primary frequency regulation dead zone of the unit, the primary frequency regulation action signal will be triggered. At this time, the energy storage output gear selection logic of the first stage of primary frequency regulation will be executed, and the energy storage action will be executed. At the same time, the time will start to be counted, and it will be continuously determined whether the grid frequency exceeds the primary frequency regulation dead zone of the unit. If the grid frequency recovers to within the dead zone, it means that the second stage of frequency regulation is not required. At this time, the primary frequency regulation action signal and related parameters will be reset, and the time timer will be reset to zero. If the grid frequency still exceeds the dead zone, and the accumulated time of the timer reaches time T1 (i.e., the first preset time T1), the second stage of primary frequency regulation will be entered. After entering the second stage, the wind turbine group frequency modulation logic is executed, and the wind turbines in the wind farm respond to the primary frequency modulation action signal. At the same time, the time counter accumulates and counts. After receiving the signal that the grid frequency returns to the dead zone, the time counter is reset to zero. When the accumulated time of the timer reaches time T2 (i.e., the second preset time T2), the third stage of primary frequency modulation is entered, and the S2 process is started. Figure 6 As shown, after the S2 process is started, the calculation begins to obtain the integral power contribution rate K of the wind farm in the primary frequency modulation process of the power grid, and judge whether the integral power contribution rate K is within (K min , K max ) range, if yes, the electrochemical energy storage battery is restored; if not, then the integral power contribution rate K<K min When the integrated power contribution rate K>K min When the output increase logic of the electrochemical energy storage system is executed, the frequency modulation logic of the fan is executed synchronously, and the time counter accumulates the count; when the trigger signal of a frequency modulation action exceeds T3, the reset logic of the fan group is executed, and the electrochemical energy storage battery is reset, completing the frequency modulation action process.

[0097] The embodiment of the present invention uses a primary frequency regulation control method for a wind farm, and controls the composite energy storage system to participate in the primary frequency regulation of the wind farm by stages, gears and continuous tracking and adjustment. It can effectively solve the problem of increased control system operation pressure caused by the real-time tracking of the primary frequency regulation demand principle by energy storage, and increased control difficulty of the battery body caused by changes in energy storage output with demand, and realizes the use of capacitor battery energy storage system to improve the primary frequency regulation control effect of the wind farm, thereby improving the work efficiency and operation and maintenance safety of the wind farm. The present invention solves the problem of poor active power regulation effect of existing new energy stations, realizes the function of energy storage batteries participating in the primary frequency regulation control of wind farms, and meets the primary frequency regulation assessment requirements of new energy stations and obtains maximum benefits.

[0098] An embodiment of the present invention provides a primary frequency regulation control system for a wind farm, and the primary frequency regulation control system for a wind farm is used to execute a primary frequency regulation control method for a wind farm in any embodiment of the present invention. Figure 7 A schematic diagram of a primary frequency modulation control system for a wind farm provided by an embodiment of the present invention is shown in FIG. Figure 7 As shown, the control system includes:

[0099] The signal trigger module 110 is used to determine whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit.

[0100] The first frequency modulation control module 120 is used to respond to the triggering signal of the primary frequency modulation action, in the first stage of the primary frequency modulation of the power grid, determine the current output gear of the capacitor battery energy storage system according to the frequency modulation demand of the primary frequency modulation of the power grid, and perform the first energy storage action.

[0101] The second frequency modulation control module 130 is used for entering the second stage of the primary frequency modulation of the power grid if the triggering primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time. The wind turbine generator sets in the wind farm respond according to the primary frequency modulation action signal, and the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbine generator sets to output active power to the power grid in the second stage of the primary frequency modulation of the power grid until the frequency modulation demand of the primary frequency modulation of the power grid is met.

[0102] The third frequency modulation control module 140 is used to control the capacitor battery energy storage system to exit the energy storage action if the primary frequency modulation action signal is triggered for longer than the second preset time and the third stage of the primary frequency modulation of the power grid is entered.

[0103] Specifically, the signal trigger module 110 first determines whether to trigger a primary frequency regulation action signal according to whether the grid frequency of the wind farm exceeds the primary frequency regulation dead zone of the unit. When the grid frequency exceeds the primary frequency regulation dead zone of the unit, it is determined that the wind farm needs to be frequency regulated once, and the primary frequency regulation action signal is triggered. At this time, the first stage of the primary frequency regulation of the grid will be entered; after responding to the triggering of the primary frequency regulation action signal, the first stage of the primary frequency regulation of the grid will be entered, and the first stage of the primary frequency regulation is the energy storage rapid response stage. The first frequency modulation control module 120 determines the current output gear of the capacitor battery energy storage system according to the frequency modulation demand of the primary frequency modulation of the power grid, and executes the first energy storage action. Since the capacitor battery energy storage system has the advantages of high charge and discharge ratio, fast adjustment speed and stable adjustment control, the primary frequency modulation response action effect is fast and positive; the second frequency modulation control module 130 controls the wind turbine generator set to output active power to the power grid in the second stage of the primary frequency modulation of the power grid, and the active power regulation of the wind turbine generator set replaces the energy storage regulation process of the capacitor battery energy storage system until the frequency modulation demand of the primary frequency modulation of the power grid is met. During this period, the energy storage of the capacitor battery energy storage system is gradually withdrawn, and this process is maintained until the second preset time; the third frequency modulation control module 140 controls the capacitor battery energy storage system to exit the execution of the energy storage action when the triggering primary frequency modulation action signal exceeds the second preset time and enters the third stage of the primary frequency modulation of the power grid, and unconditionally exits the energy storage of the capacitor battery energy storage system, so as to realize the use of the capacitor battery energy storage system to improve the primary frequency modulation control effect of the wind farm, thereby improving the working efficiency and operation and maintenance safety of the wind farm.

[0104] It should be noted that the primary frequency regulation control system of a wind farm provided by the embodiment of the present invention is a hardware setting for executing a primary frequency regulation control method of a wind farm in any embodiment of the present invention, and can be configured with the hardware of the primary frequency regulation control system and related communication accessories, the communication of the data transmission channel between the primary frequency regulation control system and each active control system of the wind farm station, the control logic software program in the primary frequency regulation control system, the logic software program of the capacitor battery energy storage system, and the logic software program of the electrochemical energy storage system. The communication configuration is mainly to complete the information interaction between the primary frequency regulation control system and the energy storage system. The interactive measurement points include the adjustment instructions of each energy storage system given by the primary frequency regulation control system, the communication status of the primary frequency regulation control system, the communication status of each energy storage system, etc., so as to ensure the normal operation of the system. While realizing the real-time collection function of power and frequency at the grid connection point, the primary frequency modulation control system adds the operation logic configuration, including realizing the calculation of primary frequency modulation active output demand, primary frequency modulation integral power contribution rate, wind turbine energy storage output command calculation, capacitor battery energy storage system output command calculation, electrochemical energy storage system output command calculation and other functions within the primary frequency modulation, and transmits the calculation results to each active power control system. The logic configuration of each energy storage control system includes receiving the active output demand command parameters given by the primary frequency modulation control system, executing related commands, and feeding back the execution results to the primary frequency modulation system.

[0105] The embodiment of the present invention uses a primary frequency regulation control system for a wind farm, and controls the composite energy storage system to participate in the primary frequency regulation of the wind farm by means of phased, geared and continuous tracking and adjustment. It can effectively solve the problem of increased control system operation pressure caused by the real-time tracking of the primary frequency regulation demand principle by energy storage, and increased control difficulty of the battery body caused by changes in energy storage output with demand, and realizes the use of capacitor battery energy storage system to improve the primary frequency regulation control effect of the wind farm, thereby improving the work efficiency and operation and maintenance safety of the wind farm. The embodiment of the present invention solves the problem of poor active power regulation effect of existing new energy stations, realizes the function of energy storage batteries participating in the primary frequency regulation control of wind farms, and meets the primary frequency regulation assessment requirements of new energy stations and obtains maximum benefits.

[0106] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A primary frequency modulation control method for a wind farm, characterized in that: Applied to a composite energy storage system, the composite energy storage system includes a capacitor battery energy storage system and an electrochemical energy storage system, the wind farm, the capacitor battery energy storage system and the electrochemical energy storage system are all connected to a power grid, and the control method includes: Determining whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit; In response to triggering a primary frequency modulation action signal, entering the first stage of the primary frequency modulation of the power grid, determining the current output gear of the capacitor battery energy storage system according to the frequency modulation demand of the primary frequency modulation of the power grid, and executing a first energy storage action; If the triggering of the primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, the second stage of the primary frequency modulation of the power grid is entered, the wind turbine generator set in the wind farm responds according to the primary frequency modulation action signal, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbine generator set to output active power to the power grid in the second stage of the primary frequency modulation of the power grid until the frequency modulation demand of the primary frequency modulation of the power grid is met; If the triggering signal of the primary frequency modulation action exceeds the second preset time, the third stage of the primary frequency modulation of the power grid is entered, and the capacitor battery energy storage system is controlled to exit the energy storage action.

2. The primary frequency modulation control method of a wind farm according to claim 1, characterized in that: The determining the current output gear of the capacitor battery energy storage system according to the frequency modulation demand of the primary frequency modulation of the power grid and executing the first energy storage action includes: Dividing the output power of the capacitor battery energy storage system into a plurality of output gears with different output powers; According to the frequency regulation demand of the primary frequency regulation of the power grid, the current output gear of the capacitor battery energy storage system is determined, so that the capacitor battery energy storage system outputs electric energy to the power grid at the current output gear.

3. The primary frequency modulation control method of a wind farm according to claim 2, characterized in that: The step of dividing the output power of the capacitor battery energy storage system into a plurality of output gears with different output powers includes: The output gear of the capacitor battery energy storage system is divided into a zero gear, a first output gear, a second output gear, a third output gear and a fourth output gear; The zero gear meets: P cr0 =0; the first output gear position P cr1 Satisfaction: P cr1 =2.5%P n The second output gear P cr1 Satisfaction: P cr2 =5%P n The third output gear P cr3 Satisfaction: P cr1 =7.5%P n The fourth output gear P cr4 Satisfaction: P cr1 =10%P n ; Among them, P n is the rated active power of the wind farm.

4. The primary frequency modulation control method of a wind farm according to claim 3, characterized in that: The step of determining the output gear of the capacitor battery energy storage system according to the frequency regulation demand of the primary frequency regulation of the power grid comprises: The output gear of the capacitor battery energy storage system meets the following requirements: When P i <P demand ≤P i+1 , take P i As the output gear of the capacitor battery energy storage system; Among them, P i is one of the zero gear, the first output gear, the second output gear and the third output gear, P i+1 P i The output power is one gear higher than the output gear, P deman d is the frequency regulation required power of the primary frequency regulation of the power grid.

5. The primary frequency modulation control method of a wind farm according to claim 1, characterized in that: The wind turbine generator set in the wind farm responds to the primary frequency modulation action signal, and the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, including: The wind turbine generator set in the wind farm outputs dynamic active power according to the frequency regulation demand of the primary frequency regulation of the power grid; the dynamic active power ΔP wind satisfy: ΔP wind =P demand ; The capacitor battery energy storage system reduces the current output gear according to the dynamic active power to reduce the output power; When ΔP wind +P i+1 ≥P demand >ΔP wind +P i , take P i As the output gear of the capacitor battery energy storage system.

6. The primary frequency modulation control method of a wind farm according to claim 1, characterized in that: The control method further comprises: In the third stage of the primary frequency regulation of the power grid, an integral power contribution rate of the wind farm in the primary frequency regulation process of the power grid is obtained, and it is determined whether the integral power contribution rate is within a preset range; wherein the preset range is a range between a first contribution rate threshold and a second contribution rate threshold; If the integral electricity contribution rate is within the preset range, the electrochemical energy storage system is not put into use; If the integral electric quantity contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system is put into operation, and the electrochemical energy storage system is controlled to output electric energy to the power grid in a second energy storage action; If the integrated electricity contribution rate is greater than the second contribution rate threshold, the electrochemical energy storage system is put into operation and controlled to output electrical energy to the power grid in a third energy storage action.

7. The primary frequency modulation control method of a wind farm according to claim 6, characterized in that: The obtaining of the integral power contribution rate of the wind farm in the primary frequency modulation process of the power grid includes: The integral power contribution rate satisfies: Wherein, K is the integral power contribution rate, P demand is the frequency regulation power required for the primary frequency regulation of the power grid, ΔP wind is the dynamic active power of the wind farm, P crreal is the actual output power of the capacitor battery energy storage system, P dhxreal is the actual output power of the electrochemical energy storage system, t is the time to trigger the primary frequency modulation action signal, P tj_real is the total power of primary frequency modulation, W 实际 is the actual work in the primary frequency regulation process of the power grid, W 需求 is the power required in the primary frequency regulation process of the power grid.

8. The primary frequency modulation control method of a wind farm according to claim 7, characterized in that: If the integral power contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system is put into operation, and the electrochemical energy storage system is controlled to output electric energy to the power grid in a second energy storage action, including: If the integral electricity contribution rate is less than the first contribution rate threshold, the electrochemical energy storage system is put into use; Control the electrochemical energy storage system to output electric energy to the power grid in a second energy storage action until: K>(1+K min ) / 2, controlling the electrochemical energy storage system to exit; Among them, K min is the first contribution rate threshold.

9. The primary frequency modulation control method of a wind farm according to claim 7, characterized in that: If the integral electric quantity contribution rate is greater than the second contribution rate threshold, the electrochemical energy storage system is put into operation, and the electrochemical energy storage system is controlled to output electric energy to the power grid in a third energy storage action, including: If the integral electricity contribution rate is greater than the second contribution rate threshold, the electrochemical energy storage system is put into use; Control the electrochemical energy storage system to output electric energy to the power grid in the third energy storage action until: K<(1+K max ) / 2, controlling the electrochemical energy storage system to exit; Among them, K max is the second contribution rate threshold.

10. A primary frequency modulation control system for a wind farm, characterized in that: The primary frequency regulation control system of a wind farm is used to execute a primary frequency regulation control method of a wind farm according to any one of claims 1 to 9, and the control system comprises: A signal trigger module, used to determine whether to trigger a primary frequency regulation action signal according to whether the frequency of the power grid exceeds the primary frequency regulation dead zone of the unit; A first frequency modulation control module is used for responding to a triggering primary frequency modulation action signal, in a first stage of the primary frequency modulation of the power grid, determining a current output gear of the capacitor battery energy storage system according to a frequency modulation demand of the primary frequency modulation of the power grid, and executing a first energy storage action; A second frequency modulation control module is used for, if the triggering of the primary frequency modulation action signal exceeds the first preset time and does not exceed the second preset time, entering the second stage of the primary frequency modulation of the power grid, the wind turbine generator set in the wind farm performs an action response according to the primary frequency modulation action signal, the capacitor battery energy storage system reduces the output power in the second stage of the primary frequency modulation of the power grid, and controls the wind turbine generator set to output active power to the power grid in the second stage of the primary frequency modulation of the power grid until the frequency modulation demand of the primary frequency modulation of the power grid is met; The third frequency modulation control module is used to control the capacitor battery energy storage system to exit the energy storage action if the triggering signal of the primary frequency modulation action exceeds the second preset time and enters the third stage of the primary frequency modulation of the power grid.

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