A wind farm reactive voltage regulation control method and system

Abstract

This invention discloses a reactive power voltage regulation control method and system for wind farms. The method first collects relevant information from the PCC (Power Conversion Control Center), wind turbines, SVG (Static Var Generator), and dispatching information to complete the initial reactive power allocation for each wind turbine. Then, considering the voltage balance of the wind turbine units, a reactive power optimization model is established with the objective of minimizing the voltage deviation at the turbine terminals after reactive power allocation. The Particle Swarm Optimization (PSO) algorithm is used to solve the reactive power optimization model to obtain the optimized reactive power. Finally, the optimized reactive power is distributed to the wind turbines and SVG, thereby achieving reactive power voltage regulation control for the wind farm. This invention can significantly reduce the investment cost of wind farms and, by utilizing power flow constraints and the PSO algorithm, controls the grid connection point and turbine terminal voltage within a safe and reasonable range, reducing the risk of wind farm voltage exceeding limits.

Description

Technical Field

[0001] This invention relates to the technical field of reactive voltage control in grid-connected wind farms, and in particular to a reactive voltage regulation control method and system for wind farms. Background Technology

[0002] Voltage plays a crucial role as an important indicator of power quality in the power grid. Reactive power is the factor that directly affects voltage changes. Therefore, the goal of reactive power control is to influence voltage changes by adjusting the reactive power output of wind farms, thereby meeting the voltage target instructions issued by the dispatching agency.

[0003] Generally, there are two types of reactive power sources in wind farms: one is reactive power compensation equipment, including capacitors, reactors, and dynamic reactive power compensation devices; the other is the wind turbine units. Reactive power compensation equipment is a device specifically designed to generate reactive power. It has multiple operating modes, such as reactive power tracking and voltage tracking, and it responds quickly, making it the first choice for reactive power regulation. However, because its compensation capacity decreases quadratically with voltage reduction, and its high price increases the construction cost of wind farms, its operating losses cannot be ignored.

[0004] Currently, most wind farms employ a control method that primarily uses SVG (Static Var Generator) reactive power compensation, supplemented by the reactive power source provided by the wind turbine. This reactive power regulation typically prioritizes adjusting the SVG and other reactive power compensation devices, only considering utilizing the reactive power capacity of the wind turbine when the SVG capacity is insufficient, thus neglecting the strong reactive power regulation capabilities of the wind turbine. Furthermore, this approach often requires a large reactive power compensation capacity for the wind farm, typically 30% of its total capacity, and its power consumption is considerable, significantly increasing the investment cost of the wind farm. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a reactive power voltage regulation control method and system for wind farms that uses wind turbine reactive power sources as the main source and SVG reactive power compensation as a supplement. This method can greatly save the investment cost of wind farms. Based on the initial reactive power allocation, and considering the voltage balance of wind turbine units, a reactive power optimization model is established with the goal of minimizing the voltage deviation at the turbine terminals after reactive power allocation. The reactive power optimization model is solved using a particle swarm optimization algorithm, which controls the grid connection point and turbine terminal voltage within a safe and reasonable range, reducing the risk of wind farm voltage exceeding limits.

[0006] The first objective of this invention is to provide a method for reactive power voltage regulation control in wind farms.

[0007] The second objective of this invention is to provide a reactive power regulation and control system for wind farms.

[0008] The first objective of this invention can be achieved by adopting the following technical solution:

[0009] A reactive power voltage regulation control method for wind farms is proposed. This method first collects relevant information on the PCC grid connection point, wind turbines, SVG, and dispatching to complete the initial reactive power allocation for each wind turbine. Then, considering the voltage balance of the wind turbine units, a reactive power optimization model is established with the goal of minimizing the voltage deviation at the turbine terminals after reactive power allocation. The reactive power optimization model is solved using a particle swarm optimization algorithm to obtain the reactive power after optimization. Finally, the reactive power after optimization is distributed to the wind turbines and SVG, thereby realizing reactive power voltage regulation control of the wind farm.

[0010] Furthermore, the following steps are included:

[0011] S1, Communication Data Acquisition

[0012] Collect the voltage at the PCC grid connection point Active power reactive power and power factor Collect the terminal voltage of the wind turbine. Collect the current reactive power of SVG Residual emotional inefficiency and residual capacitive reactive power The control mode flag bit issued by the acquisition and scheduling system. and target instructions ;

[0013] S2, Initial Reactive Power Allocation

[0014] S2.1 Determine if the PCC grid connection point voltage exceeds the limit. If the PCC grid connection point voltage exceeds the limit, perform reactive power blocking. The turbines and SVG maintain the reactive power command from the previous cycle until the voltage recovers and control is unlocked, then return to step S1. If the PCC grid connection point voltage does not exceed the limit, proceed according to the control mode flag bit issued by the dispatcher. Obtain the control mode and the corresponding target command. ;

[0015] S2.2, Based on the functional relationship between the wind turbine terminal voltage and the upper limit of reactive power. Functional relationship between wind turbine terminal voltage and reactive power lower limit Calculate the upper limit of reactive power for each individual wind turbine. and the lower limit of reactive power ,in The voltage at the wind turbine terminals, and then based on the upper limit of reactive power. and the lower limit of reactive power Calculate the residual capacitive reactive power of each individual wind turbine. and remaining sensual inaction ;

[0016] S2.3, Upper limit of capacitive reactive power of statistical clusters upper limit of inductive reactive power of the machine cluster Residual capacitive reactive power of the generator group Remaining inductive reactive power in the fleet ;

[0017] S2.4 Unify the control command reference values ​​under different modes to reactive power values, where, when In constant voltage control mode, according to the formula , set the voltage target value Convert to reactive power target value ,in The system impedance value is determined by the system.

[0018] when In constant power factor control mode, according to the formula Target power factor Convert to reactive power target value ;

[0019] when When in constant reactive power mode, the target reactive power value ;

[0020] S2.5, Based on the reactive power target value and reactive power Calculate reactive power deficit ;

[0021] S2.6, Based on reactive power deficit The magnitude of the reactive power deficit determines whether reactive power needs to be generated or absorbed. When reactive power needs to be generated, it is determined based on the reactive power deficit. Residual capacitive reactive power of the cluster Calculate the corresponding reactive power target command for the machine group. When reactive power needs to be absorbed, it is based on the reactive power deficit. Residual inductive reactive power of the fleet Calculate the corresponding reactive power target command for the machine group. ;

[0022] S2.7, Based on the calculated reactive power target command of the machine group Perform reactive power distribution for individual wind turbines;

[0023] S3. Construct a reactive power optimization model

[0024] Under the premise of satisfying the grid connection point voltage, a reactive power optimization model is constructed with the objective of minimizing the voltage deviation at the generator terminals after reactive power distribution. The particle swarm optimization algorithm is used to solve the reactive power optimization model to obtain the optimized reactive power. The optimization objective is:

[0025] ;

[0026] in, This is the generator terminal voltage after reactive power distribution; The target for terminal voltage control; To optimize the objective function;

[0027] S4, Reactive Power Optimization

[0028] The optimized reactive power is sent to the wind turbine and SVG, and the wind turbine and SVG controllers execute the reactive power commands.

[0029] Furthermore, in step S2.2, the reactive power upper limit... The calculation process is as follows:

[0030] When the terminal voltage or At that time, the upper limit of reactive power This indicates that the fan voltage is out of limit, and its reactive power limit is set to 0.

[0031] When the terminal voltage At that time, the upper limit of reactive power ,in This represents the maximum reactive power of the generator unit.

[0032] When the terminal voltage At that time, the voltage-reactive power relationship is linearized according to... Calculate the upper limit of reactive power, where This is a linearization parameter, and its value is set according to the actual operating conditions.

[0033] When the terminal voltage At that time, the upper limit of reactive power of a single wind turbine. ;

[0034] Lower limit of reactive power The calculation process is as follows:

[0035] When the terminal voltage or At that time, the lower limit of reactive power This indicates that the fan voltage is out of limit, and its reactive power lower limit is set to 0.

[0036] When the terminal voltage At that time, the lower limit of reactive power ,in This is a linearization parameter, and its value is set according to the actual operating conditions.

[0037] When the terminal voltage At that time, the voltage-reactive power relationship is linearized according to... Calculate the lower limit of reactive power, where This represents the minimum reactive power of the generator unit.

[0038] When the terminal voltage At that time, the lower limit of reactive power of a single wind turbine ;

[0039] The residual capacitive reactive power of a single wind turbine is equal to the upper limit of reactive power of a single wind turbine. With the current actual reactive power of the wind turbine The difference, i.e. ;

[0040] The residual inductive reactive power of a single wind turbine is equal to the lower limit of reactive power of a single wind turbine. With the current actual reactive power of the wind turbine The difference, i.e. .

[0041] Furthermore, in step S2.6, the reactive power target instruction for the machine group... The calculation process is as follows:

[0042] If there is no functional deficit This indicates a need for reactive power:

[0043] If the cluster has remaining capacitive reactive power If the remaining capacitive reactive power of the generator group is sufficient, then all the target reactive power will be allocated to the generator group. In this case, the generator group reactive power target instruction... ;

[0044] If the cluster has remaining capacitive reactive power This indicates that the residual capacitive reactive power of the generator group is insufficient, and the SVG compensation capacity needs to be adjusted. At this time, the generator group reactive power target command is... SVG reactive power compensation capacity , This represents the actual reactive power value of the SVG.

[0045] If there is no functional deficit This indicates that reactive power needs to be absorbed.

[0046] If the cluster has remaining inductive reactive power If the remaining inductive reactive power of the generator group is sufficient, then all the target reactive power will be allocated to the generator group. In this case, the generator group reactive power target instruction... ;

[0047] If the cluster has remaining inductive reactive power This indicates that the remaining inductive reactive power of the generator group is insufficient, and the SVG compensation capacity needs to be adjusted. At this time, the generator group reactive power target command is... The capacity of SVG reactive power compensation is .

[0048] Furthermore, in step S2.7, reactive power is allocated according to the principle of similarity margin, and the allocation method is as follows:

[0049] ;

[0050] in, This is a reactive power command for a single wind turbine unit. This is the reactive power target instruction for the machine group.

[0051] Furthermore, in step S3, the power flow constraints of the reactive power optimization model are as follows:

[0052] ;

[0053] in, The active power injected into each node, Reactive power injected into each node For each branch road Node voltage amplitude, For the branch road Current voltage amplitude at the node and For the branch road Nodes and Mutual admittance of nodes Nodes in the branch and nodes The voltage phase angle difference;

[0054] Its variable constraints are:

[0055] ;

[0056] in, This represents the minimum node voltage. This represents the maximum value of the node voltage. This is the lower limit of reactive power for wind turbines. The upper limit of reactive power for wind turbines, To allow for the maximum reactive power adjustment step size each time, This represents the current actual reactive power of the wind turbine. This refers to the terminal voltage after reactive power distribution. This is a reactive power command for a single wind turbine unit.

[0057] Furthermore, in step S3, the steps for solving the reactive power optimization model using the particle swarm optimization algorithm are as follows:

[0058] S3.1 Based on the initial allocation results, randomly initialize the population to generate N feasible solutions;

[0059] S3.2 Substitute each particle into the objective function, calculate the power flow constraint equations again, obtain the initialization particle fitness value, and select the current particle position as the individual optimal solution. , This is the optimal solution for the current population.

[0060] S3.3, according to and Update the velocity and position of each particle, check if the stopping condition is met, stop if it is met, otherwise return to step S3.2.

[0061] The second objective of this invention can be achieved by adopting the following technical solution:

[0062] A wind farm reactive power voltage regulation control system, employing the aforementioned wind farm reactive power voltage regulation control method, the system comprising:

[0063] The data acquisition module is used to collect relevant information about PCC grid connection points, wind turbines, SVG, and scheduling.

[0064] The initial reactive power allocation module is used to allocate reactive power to individual wind turbines based on the reactive power target command of the computer group, which is related to the PCC grid connection point, wind turbines, SVG and scheduling.

[0065] The reactive power optimization calculation module is used to establish a reactive power optimization model based on the voltage balance of the wind turbine, with the goal of minimizing the voltage deviation at the turbine terminals after reactive power distribution, and to solve the reactive power optimization model using the particle swarm intelligence algorithm to obtain the reactive power after reactive power optimization.

[0066] The reactive power distribution module is used to distribute the optimized reactive power to the wind turbine and SVG, and then the wind turbine and SVG controllers execute the reactive power commands.

[0067] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0068] This invention employs a control method that prioritizes reactive power generation from wind turbines, reducing the capacity of reactive power compensation equipment and SVG power consumption in wind farms, thereby lowering investment costs. It calculates the reactive power capacity of a single turbine based on its terminal voltage, allowing turbines with lower terminal voltages to generate more capacitive reactive power, thus increasing their terminal voltage; similarly, turbines with higher terminal voltages generate more inductive reactive power, thus decreasing their terminal voltage. This method also sets the reactive power capacity of all turbines to... In comparison, it can more easily control the terminal voltage within the normal operating range, reduce the risk of wind turbine disconnection, and make reactive power adjustments based on the initial reactive power distribution to further control the terminal voltage of all units within the safe range. Attached Figure Description

[0069] Figure 1 This is a flowchart illustrating the control method of the present invention.

[0070] Figure 2 This is a schematic diagram of the initial reactive power allocation process in this invention.

[0071] Figure 3 This is a schematic diagram illustrating the functional relationship between the wind turbine terminal voltage and the upper limit of reactive power in this invention.

[0072] Figure 4 This is a schematic diagram illustrating the relationship between the wind turbine terminal voltage and the lower limit function of reactive power in this invention. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0074] like Figures 1 to 4 As shown in the figure, this embodiment provides a reactive power voltage regulation control method for wind farms. The method first collects relevant information such as the PCC grid connection point, wind turbines, SVG, and dispatching to complete the initial reactive power allocation for a single wind turbine. Then, considering the voltage balance of the wind turbine units, a reactive power optimization model is established with the goal of minimizing the voltage deviation at the turbine terminals after reactive power allocation. The reactive power optimization model is solved using a particle swarm optimization algorithm to obtain the reactive power after optimization. The reactive power after optimization is then distributed to the wind turbines and SVG, thereby realizing reactive power voltage regulation control of the wind farm.

[0075] Specifically, the following steps are included:

[0076] S1, Communication Data Acquisition

[0077] Collect the voltage at the PCC grid connection point Active power reactive power and power factor Collect the terminal voltage of the wind turbine. Collect the current reactive power of SVG Residual emotional inefficiency and residual capacitive reactive power The control mode flag bit issued by the acquisition and scheduling system. and target instructions ;

[0078] S2, Initial Reactive Power Allocation

[0079] S2.1 Determine if the PCC grid connection point voltage exceeds the limit. If the PCC grid connection point voltage exceeds the limit, perform reactive power blocking. The turbines and SVG maintain the reactive power command from the previous cycle until the voltage recovers and control is unlocked, then return to step S1. If the PCC grid connection point voltage does not exceed the limit, proceed according to the control mode flag bit issued by the dispatcher. Obtain the control mode and the corresponding target command. ;

[0080] S2.2, Based on the functional relationship between the wind turbine terminal voltage and the upper limit of reactive power. Functional relationship between wind turbine terminal voltage and reactive power lower limit Calculate the upper limit of reactive power for each individual wind turbine. and the lower limit of reactive power ,in The voltage at the wind turbine terminals, and then based on the upper limit of reactive power. and the lower limit of reactive power Calculate the residual capacitive reactive power of each individual wind turbine. and remaining sensual inaction ;

[0081] S2.3, Upper limit of capacitive reactive power of statistical clusters upper limit of inductive reactive power of the machine cluster Residual capacitive reactive power of the generator group Remaining inductive reactive power in the fleet ;

[0082] S2.4 Unify the control command reference values ​​under different modes to reactive power values, where, when In constant voltage control mode, according to the formula , set the voltage target value Convert to reactive power target value ,in The system impedance value is determined by the system.

[0083] when In constant power factor control mode, according to the formula Target power factor Convert to reactive power target value ;

[0084] when When in constant reactive power mode, the target reactive power value ;

[0085] S2.5, Based on the reactive power target value and reactive power Calculate reactive power deficit ;

[0086] S2.6, Based on reactive power deficit The magnitude of the reactive power deficit determines whether reactive power needs to be generated or absorbed. When reactive power needs to be generated, it is determined based on the reactive power deficit. Residual capacitive reactive power of the cluster Calculate the corresponding reactive power target command for the machine group. When reactive power needs to be absorbed, it is based on the reactive power deficit. Residual inductive reactive power of the fleet Calculate the corresponding reactive power target command for the machine group. ;

[0087] S2.7, Based on the calculated reactive power target command of the machine group Perform reactive power distribution for individual wind turbines;

[0088] S3. Construct a reactive power optimization model

[0089] Under the premise of satisfying the grid connection point voltage, a reactive power optimization model is constructed with the objective of minimizing the voltage deviation at the generator terminals after reactive power distribution. The particle swarm optimization algorithm is used to solve the reactive power optimization model to obtain the optimized reactive power. The optimization objective is:

[0090] ;

[0091] in, This is the generator terminal voltage after reactive power distribution; The target for terminal voltage control; To optimize the objective function;

[0092] S4, Reactive Power Optimization

[0093] The optimized reactive power is sent to the wind turbine and SVG, and the wind turbine and SVG controllers execute the reactive power commands.

[0094] Specifically, in step S2.2, the reactive power upper limit... The calculation process is as follows:

[0095] When the terminal voltage or At that time, the upper limit of reactive power This indicates that the fan voltage has exceeded the limit, and its reactive power limit is set to 0, considering the normal operating voltage range of the generator terminal. In this embodiment The value is set to , The value is set to , The specific value is changed according to the actual operating conditions of the unit;

[0096] When the terminal voltage At that time, the upper limit of reactive power ,in This represents the maximum reactive power of the generator unit. The generator terminal voltage range is considered to be within the normal operating range of the unit. Its range of nonfunctionality is In this embodiment The value is set to It can also be modified according to the actual operating conditions of the unit. The value is determined by the performance of the unit;

[0097] When the terminal voltage At that time, the voltage-reactive power relationship is linearized according to... Calculate the upper limit of reactive power, where This is a linearization parameter, and its value is set according to the actual operating conditions. The value is determined by the performance of the unit;

[0098] When the terminal voltage At that time, the upper limit of reactive power of a single wind turbine. ;

[0099] Lower limit of reactive power The calculation process is as follows:

[0100] When the terminal voltage or At that time, the lower limit of reactive power This indicates that the wind turbine voltage is out of limit, and its reactive power lower limit is set to 0. This takes into account the normal operating voltage range of the turbine terminals. In this embodiment The value is set to , The value is set to , The specific value is changed according to the actual operating conditions of the unit;

[0101] When the terminal voltage At that time, the lower limit of reactive power ,in This is a linearization parameter, and its value is set according to the actual operating conditions. The value is determined by the performance of the unit;

[0102] When the terminal voltage At that time, the voltage-reactive power relationship is linearized according to... Calculate the lower limit of reactive power, where This is the minimum reactive power of the generator unit, taking into account the range of the generator terminal voltage during normal operation. Its range of nonfunctionality is In this embodiment The value is set to It can also be modified according to the actual operating conditions of the unit. The value is determined by the performance of the unit;

[0103] When the terminal voltage At that time, the lower limit of reactive power of a single wind turbine ;

[0104] The residual capacitive reactive power of a single wind turbine is equal to the upper limit of reactive power of a single wind turbine. With the current actual reactive power of the wind turbine The difference, i.e. ;

[0105] The residual inductive reactive power of a single wind turbine is equal to the lower limit of reactive power of a single wind turbine. With the current actual reactive power of the wind turbine The difference, i.e. .

[0106] Specifically, in step S2.6, the reactive power target instruction for the machine group... The calculation process is as follows:

[0107] If there is no functional deficit This indicates a need for reactive power:

[0108] If the cluster has remaining capacitive reactive power If the remaining capacitive reactive power of the generator group is sufficient, then all the target reactive power will be allocated to the generator group. In this case, the generator group reactive power target instruction... ;

[0109] If the cluster has remaining capacitive reactive power This indicates that the residual capacitive reactive power of the generator group is insufficient, and the SVG compensation capacity needs to be adjusted. At this time, the generator group reactive power target command is... SVG reactive power compensation capacity , This represents the actual reactive power value of the SVG.

[0110] If there is no functional deficit This indicates that reactive power needs to be absorbed.

[0111] If the cluster has remaining inductive reactive power If the remaining inductive reactive power of the generator group is sufficient, then all the target reactive power will be allocated to the generator group. In this case, the generator group reactive power target instruction... ;

[0112] If the cluster has remaining inductive reactive power This indicates that the remaining inductive reactive power of the generator group is insufficient, and the SVG compensation capacity needs to be adjusted. At this time, the generator group reactive power target command is... The capacity of SVG reactive power compensation is .

[0113] Specifically, in step S2.7, reactive power is allocated according to the principle of similarity margin, and the allocation method is as follows:

[0114] ;

[0115] in, This is a reactive power command for a single wind turbine unit. This is the reactive power target instruction for the machine group.

[0116] Specifically, in step S3, the power flow constraints of the reactive power optimization model are as follows:

[0117] ;

[0118] in, The active power injected into each node, Reactive power injected into each node For each branch road Node voltage amplitude, For the branch road Current voltage amplitude at the node and For the branch road Nodes and Mutual admittance of nodes Nodes in the branch and nodes The voltage phase angle difference;

[0119] Its variable constraints are:

[0120] ;

[0121] in, This represents the minimum node voltage. This represents the maximum value of the node voltage. This is the lower limit of reactive power for wind turbines. The upper limit of reactive power for wind turbines, To allow for the maximum reactive power adjustment step size each time, This represents the current actual reactive power of the wind turbine.

[0122] Specifically, in step S3, the steps for solving the reactive power optimization model using the particle swarm optimization algorithm are as follows:

[0123] S3.1 Based on the initial allocation results, randomly initialize the population to generate N feasible solutions;

[0124] S3.2 Substitute each particle into the objective function, calculate the power flow constraint equations again, obtain the initialization particle fitness value, and select the current particle position as the individual optimal solution. , This is the optimal solution for the current population.

[0125] S3.3, according to and Update the velocity and position of each particle, check if the stopping condition is met, stop if it is met, otherwise return to step S3.2.

[0126] This embodiment also provides a wind farm reactive power voltage regulation control system. Employing the aforementioned wind farm reactive power voltage regulation control method, the system includes:

[0127] The data acquisition module is used to collect relevant information about PCC grid connection points, wind turbines, SVG, and scheduling.

[0128] The initial reactive power allocation module is used to allocate reactive power to individual wind turbines based on the reactive power target command of the computer group, which is related to the PCC grid connection point, wind turbines, SVG and scheduling.

[0129] The reactive power optimization calculation module is used to establish a reactive power optimization model based on the voltage balance of the wind turbine, with the goal of minimizing the voltage deviation at the turbine terminals after reactive power distribution, and to solve the reactive power optimization model using the particle swarm intelligence algorithm to obtain the reactive power after reactive power optimization.

[0130] The reactive power distribution module is used to distribute the optimized reactive power to the wind turbine and SVG, and then the wind turbine and SVG controllers execute the reactive power commands.

[0131] This invention adopts a wind farm reactive power voltage regulation control method that prioritizes wind turbine regulation and supplements it with SVG reactive power compensation. This allows wind farms to reduce the capacity of reactive power compensation equipment and SVG power consumption, thereby reducing wind farm investment costs and power losses. Furthermore, by utilizing power flow constraints and particle swarm intelligence algorithms, the grid connection point voltage and turbine terminal voltage are controlled within a reasonable range.

[0132] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for reactive power voltage regulation control in a wind farm, characterized in that, This method first collects relevant information on the PCC grid connection point, wind turbine, SVG, and scheduling to complete the initial reactive power allocation for a single wind turbine. Then, considering the voltage balance of the wind turbine, a reactive power optimization model is established with the goal of minimizing the voltage deviation at the turbine terminals after reactive power allocation. The reactive power optimization model is solved using a particle swarm optimization algorithm to obtain the reactive power after optimization. Finally, the reactive power after optimization is distributed to the wind turbine and SVG, thereby realizing reactive power voltage regulation control of the wind farm. The method includes the following steps: S1, Communication Data Acquisition Collect the voltage at the PCC grid connection point Active power reactive power and power factor Collect the terminal voltage of the wind turbine. Collect the current reactive power of the SVG Residual emotional inefficiency and residual capacitive reactive power The control mode flag bit issued by the acquisition and scheduling system. and target instructions ; S2, Initial Reactive Power Allocation S2.1 Determine if the PCC grid connection point voltage exceeds the limit. If the PCC grid connection point voltage exceeds the limit, perform reactive power blocking. The turbines and SVG maintain the reactive power command from the previous cycle until the voltage recovers and control is unlocked, then return to step S1. If the PCC grid connection point voltage does not exceed the limit, proceed according to the control mode flag bit issued by the dispatcher. Obtain the control mode and the corresponding target command. ; S2.2, Based on the functional relationship between the wind turbine terminal voltage and the upper limit of reactive power. Functional relationship between wind turbine terminal voltage and reactive power lower limit Calculate the upper limit of reactive power for each individual wind turbine. and the lower limit of reactive power ,in The voltage at the wind turbine terminals, and then based on the upper limit of reactive power. and the lower limit of reactive power Calculate the residual capacitive reactive power of each individual wind turbine. and remaining sensual inaction ; S2.3, Upper limit of capacitive reactive power of statistical clusters upper limit of inductive reactive power of the machine cluster Residual capacitive reactive power of the generator group Remaining inductive reactive power in the fleet ; S2.4 Unify the control command reference values ​​under different modes to reactive power values, where, when In constant voltage control mode, according to the formula , set the voltage target value Convert to reactive power target value ,in The system impedance value is determined by the system. when In constant power factor control mode, according to the formula Target power factor Convert to reactive power target value ; when In constant reactive power mode, the target reactive power value ; S2.5, Based on the reactive power target value and reactive power Calculate reactive power deficit ; S2.6, Based on reactive power deficit The magnitude of the reactive power deficit determines whether reactive power needs to be generated or absorbed. When reactive power needs to be generated, it is determined based on the reactive power deficit. Residual capacitive reactive power of the cluster Calculate the corresponding reactive power target command for the machine group. When reactive power needs to be absorbed, it is based on the reactive power deficit. Residual inductive reactive power of the fleet Calculate the corresponding reactive power target command for the machine group. ; S2.7, Based on the calculated reactive power target command of the machine group Perform reactive power distribution for individual wind turbines; S3. Construct a reactive power optimization model Under the premise of satisfying the grid connection point voltage, a reactive power optimization model is constructed with the objective of minimizing the voltage deviation at the generator terminals after reactive power distribution. The particle swarm optimization algorithm is used to solve the reactive power optimization model to obtain the optimized reactive power. The optimization objective is: ； in, This refers to the terminal voltage after reactive power distribution. The target for terminal voltage control; To optimize the objective function; S4, Reactive Power Optimization The optimized reactive power is sent to the wind turbine and SVG, and the wind turbine and SVG controllers execute the reactive power commands.

2. The wind farm reactive power voltage regulation control method according to claim 1, characterized in that, In step S2.2, the upper limit of reactive power The calculation process is as follows: When the terminal voltage or At that time, the upper limit of reactive power This indicates that the fan voltage is out of limit, and its reactive power limit is set to 0. When the terminal voltage At that time, the upper limit of reactive power ,in This represents the maximum reactive power of the generator unit. When the terminal voltage At that time, the voltage-reactive power relationship is linearized according to... Calculate the upper limit of reactive power, where This is a linearization parameter, and its value is set according to the actual operating conditions. When the terminal voltage At that time, the upper limit of reactive power of a single wind turbine ; Lower limit of reactive power The calculation process is as follows: When the terminal voltage or At that time, the lower limit of reactive power This indicates that the fan voltage is out of limit, and its reactive power lower limit is set to 0. When the terminal voltage At that time, the lower limit of reactive power ,in This is a linearization parameter, and its value is set according to the actual operating conditions. When the terminal voltage At that time, the voltage-reactive power relationship is linearized according to... Calculate the lower limit of reactive power, where This represents the minimum reactive power of the generator unit. When the terminal voltage At that time, the lower limit of reactive power of a single wind turbine ; The residual capacitive reactive power of a single wind turbine is equal to the upper limit of reactive power of a single wind turbine. With the current actual reactive power of the wind turbine The difference, i.e. ; The residual inductive reactive power of a single wind turbine is equal to the lower limit of reactive power of a single wind turbine. With the current actual reactive power of the wind turbine The difference, i.e. .

3. The wind farm reactive power voltage regulation control method according to claim 1, characterized in that, In step S2.6, the reactive power target command for the machine group is... The calculation process is as follows: If there is no functional deficit This indicates a need for reactive power: If the cluster has remaining capacitive reactive power If the remaining capacitive reactive power of the generator group is sufficient, then all the target reactive power will be allocated to the generator group. In this case, the generator group reactive power target instruction... ; If the cluster has remaining capacitive reactive power This indicates that the residual capacitive reactive power of the generator group is insufficient, and the SVG compensation capacity needs to be adjusted. At this time, the generator group reactive power target command is... SVG reactive power compensation capacity , This represents the actual reactive power value of the SVG. If there is no functional deficit This indicates that reactive power needs to be absorbed. If the cluster has remaining inductive reactive power If the remaining inductive reactive power of the generator group is sufficient, then all the target reactive power will be allocated to the generator group. In this case, the generator group reactive power target instruction... ; If the cluster has remaining inductive reactive power This indicates that the remaining inductive reactive power of the generator group is insufficient, and the SVG compensation capacity needs to be adjusted. At this time, the generator group reactive power target command is... The capacity of SVG reactive power compensation is .

4. The wind farm reactive power voltage regulation control method according to claim 1, characterized in that, In step S2.7, reactive power is allocated according to the principle of similarity margin, and the allocation method is as follows: ； in, This is a reactive power command for a single wind turbine unit. This is the reactive power target instruction for the machine group.

5. The wind farm reactive power voltage regulation control method according to claim 1, characterized in that, In step S3, the power flow constraints of the reactive power optimization model are as follows: ； in, The active power injected into each node, Reactive power injected into each node For each branch road Node voltage amplitude, For the branch road Current voltage amplitude at the node and For the branch road Nodes and Mutual admittance of nodes Nodes in the branch and nodes The voltage phase angle difference; Its variable constraints are: ； in, This represents the minimum node voltage. This represents the maximum value of the node voltage. This is the lower limit of reactive power for the wind turbine. The upper limit of reactive power for wind turbines, To allow for the maximum reactive power adjustment step size each time, This represents the current actual reactive power of the wind turbine. This refers to the terminal voltage after reactive power distribution. This is a reactive power command for a single wind turbine unit.

6. The wind farm reactive power voltage regulation control method according to claim 1, characterized in that: In step S3, the steps for solving the reactive power optimization model using the particle swarm optimization algorithm are as follows: S3.1 Based on the initial allocation results, randomly initialize the population to generate N feasible solutions; S3.2 Substitute each particle into the objective function, calculate the power flow constraint equations again, obtain the initialization particle fitness value, and select the current particle position as the individual optimal solution. , This is the optimal solution for the current population. S3.3, according to and Update the velocity and position of each particle, check if the stopping condition is met, stop if it is met, otherwise return to step S3.

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7. A reactive power voltage regulation control system for wind farms, characterized in that, The wind farm reactive power voltage regulation control method according to any one of claims 1 to 6, the system comprising: The data acquisition module is used to collect relevant information about PCC grid connection points, wind turbines, SVG, and scheduling. The initial reactive power allocation module is used to allocate reactive power to individual wind turbines based on the reactive power target command of the computer group, which is related to the PCC grid connection point, wind turbines, SVG and scheduling. The reactive power optimization calculation module is used to establish a reactive power optimization model based on the voltage balance of the wind turbine, with the goal of minimizing the voltage deviation at the turbine terminals after reactive power distribution, and to solve the reactive power optimization model using the particle swarm intelligence algorithm to obtain the reactive power after reactive power optimization. The reactive power distribution module is used to distribute the optimized reactive power to the wind turbine and SVG, and then the wind turbine and SVG controllers execute the reactive power commands.

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