A wind power base phase modifier voltage and reactive power coordinated control system

Abstract

The application discloses a wind power base phase modifier voltage reactive power coordination control system, relates to the technical field of power system operation and control, and comprises a data acquisition and processing unit, a data analysis unit and an intelligent adjustment unit. Under a steady state condition, the application creatively adopts the strategy of preferentially scheduling wind turbine generators and SVG and controlling a synchronous phase modifier to be in a low output state, ensures that the synchronous phase modifier is not occupied in a normal state, thereby maximally plays the instantaneous overload capacity of the synchronous phase modifier in the moment when a power grid fault occurs, effectively overcomes the control instability risk caused by impedance fluctuation of a weak receiving end power grid based on dynamic sensitivity matrix control, simultaneously constructs a multi-time scale and multi-device coordinated transient overvoltage defense system, greatly improves the fault ride-through capacity of the wind power base, can realize real-time sensing of actual working conditions of each reactive power source, and precalculates the steady state adjustment capacity and transient overload capacity margin before generating an instruction.

Description

Technical Field

[0001] This invention relates to the field of power system operation and control technology, and in particular to a voltage and reactive power coordination control system for synchronous condensers in wind power bases. Background Technology

[0002] With the rapid growth of global demand for clean energy, the development model of wind power has shifted from distributed grid connection to large-scale, intensive, and base-based development. Due to the distribution characteristics of wind energy resources, large-scale wind power bases are usually far from load centers and need to be transmitted to other areas via long-distance high-voltage AC or high-voltage DC transmission systems. This structural feature of strong power sources and weak grids significantly reduces the short-circuit ratio at the wind power grid connection point, making it a typical scenario with a weak grid.

[0003] In weak grid environments, the grid impedance is high, and the voltage is extremely sensitive to reactive power fluctuations. Existing wind farms mainly consist of doubly-fed induction generators or full-power converter wind turbines. These power electronic converter-based devices face significant challenges in grids with low short-circuit ratios. First, the risk of phase-locked loop instability: Insufficient grid strength makes it difficult for voltage phase to follow, which can easily lead to subsynchronous oscillations or low-frequency oscillations, and in severe cases, it can cause system instability and grid disconnection. Second, transient voltage exceeding the limit: At the moment of DC blocking or AC fault clearing, due to the change from active power being sent out to surplus, coupled with the lag response of the line charging capacitor and reactive power compensation device, the system is very prone to severe transient overvoltage, which can lead to the high voltage of the wind turbine disconnecting from the grid.

[0004] Currently, wind power bases are typically equipped with static var generators or capacitor banks, but these have inherent drawbacks: Although it has a fast response speed, it lacks physical inertia and its reactive power output is limited by the terminal voltage. During low voltage ride-through, its current output capability is limited. During high voltage, it is limited by the DC side capacitor voltage, and its ability to absorb reactive power is also limited, and it cannot provide short-circuit capacity support. The Revival and Coordination Challenges of Synchronous Condensers: As a type of rotating motor, synchronous condensers can provide physical inertia and short-circuit current, significantly improving the system's SCR (Stable Voltage Regulator). They can not only stabilize voltage but also suppress the oscillation risks of power electronic equipment. However, the excitation control response time of a synchronous condenser is much slower than that of an SVG (Static Var Generator) and a wind turbine converter. Without coordination, control conflicts can easily arise between the fast and slow devices, or the SVG may saturate prematurely due to the lag in the synchronous condenser's response, thus losing its transient regulation capability. To address the aforementioned technical deficiencies, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to creatively adopt a strategy of prioritizing the scheduling of wind turbines and SVG, and controlling synchronous condensers to be in a low-output state. This ensures that the synchronous condensers are not occupied under normal conditions, thereby maximizing their instantaneous overload capacity in the event of a grid fault. Based on dynamic sensitivity matrix control, it effectively overcomes the risk of control instability caused by impedance fluctuations in the weak receiving end of the grid. At the same time, it constructs a multi-timescale, multi-device collaborative transient overvoltage defense system, which significantly improves the fault ride-through capability of wind power bases. It can perceive the actual operating conditions of each reactive power source in real time, and pre-calculate the steady-state regulation capability and transient overload capacity margin before generating instructions, ensuring that the issued regulation instructions are always within the safe operating boundary of the equipment, thereby improving the reliability and predictability of the entire reactive power and voltage control system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a voltage and reactive power coordination control system for a wind power base synchronous condenser, comprising a data acquisition and processing unit, a data analysis unit, and an intelligent adjustment unit, wherein: The data acquisition and processing unit is used to collect the high-voltage side bus voltage of the wind power collection station, the real-time operating status of the synchronous condenser, the active and reactive power status of each wind turbine, the operating status of the SVG, and the stator current and excitation current of the synchronous condenser in real time. After removing invalid data, it is integrated into a real-time dataset and sent to the intelligent regulation unit. The data analysis unit includes a data correction module and a margin assessment module. The data correction module is used to acquire real-time datasets and dynamically calculate the sensitivity matrix of wind turbines, SVG and synchronous condensers to PCC point voltage based on the real-time operating status of the synchronous condenser. The margin assessment module is used to acquire real-time datasets, parse the actual operating conditions of each reactive power source, and calculate the steady-state regulation capability and transient overload capability margin of each reactive power source. The intelligent regulation unit is deployed at the wind power collection station to receive regulation instructions issued by the grid dispatch. Under steady-state conditions, with the goal of minimizing voltage deviation and grid loss, it prioritizes the scheduling of reactive power capacity of wind turbines and SVG, and controls synchronous condensers to be in a low-output state to reserve transient margin. When the voltage at the PCC point exceeds the set transient overvoltage threshold, the system switches to transient suppression mode, controls the synchronous condenser to enter a strong demagnetization state, controls the SVG to output maximum inductive reactive power, and instructs the wind turbine to absorb reactive power using the remaining capacity of the converter. Based on the preset regulation strategy, the system generates control commands and sends them to the execution unit.

[0007] Furthermore, it also includes an execution unit, which comprises a wind turbine generator set, a distributed compensation device, a centralized synchronous condenser, and a central coordination controller, wherein: The wind turbine generator set specifically consists of several doubly-fed induction generators (DFIGs), connected by a 35kV collector line. Each DFIG has reactive power regulation capability, constrained by its PQ operating limit curve. Distributed compensation devices are installed in a decentralized manner on the 35kV bus side of each wind farm to quickly smooth out local voltage fluctuations. Centralized synchronous condensers are used to be installed on the high-voltage side busbar of 330kV / 750kV step-up substations. They are connected through a step-up transformer, equipped with an excitation system and a starting device, and have instantaneous overload capacity. The central coordination controller is deployed within the integrated automation system of the booster station and communicates with each substation and synchronous condenser control panel via a fiber optic ring network.

[0008] Furthermore, the control strategy of the master station coordination controller includes: Steady-state voltage control mode: When grid voltage fluctuations are within the normal dead zone range, the main station prioritizes using the remaining capacity of the SVG and wind turbine inverters on the wind farm side for regulation. The control objective is to maintain the reactive power output of the synchronous condenser at a low level of inductive state, thereby reserving the maximum dynamic reactive power reserve to cope with sudden failures. Transient / Fault Emergency Support Mode: When the system voltage exceeds the set threshold, the system automatically locks out the slow logic. The strong excitation characteristics of the synchronous condenser are used to provide instantaneous short-circuit current and strong reactive power support. At the same time, the master station commands the SVG to issue maximum capacitive reactive power to jointly suppress voltage fluctuations. Damping control and anti-oscillation logic: During the voltage recovery phase, the response slope of the SVG is dynamically adjusted according to the response characteristics of the synchronous condenser to prevent voltage overshoot caused by excessively fast response of power electronic equipment and reactive power oscillation with the synchronous condenser.

[0009] Furthermore, the specific process for dynamically calculating the sensitivity matrix of the wind turbine, SVG, and synchronous condenser to the PCC point voltage is as follows: S101. By collecting the voltage change ΔU at point PCC within the continuous sliding time window Tω. PCC The system impedance is estimated in real time using a recursive least squares method with a forgetting factor, taking into account the total reactive power change ΔQtotal injected into the grid. The estimation model for the equivalent reactance X_system(t) on the system side is as follows: , where ΔQ 去吧 This includes the total reactive power injected by synchronous condensers, SVG, and all wind turbine units; S102. Based on the topology of the collector network inside the wind farm, construct the impedance model of each node: The synchronous condenser and SVG are connected via a short connecting cable, with a very short electrical distance. The equivalent impedance of their branch is set to the transformer impedance X. T_SC and X T_SVG ; Wind turbine units are located at the end of the collector line. Considering the impedance X of the collector line... line_i That is, the equivalent impedance of the i-th collector line and the transformer impedance X. BoX ; S103, Define the electrical coupling coefficient λ 我 This characterizes the effectiveness of the reactive power injected by the i-th reactive power source being transferred to the PCC point: X 在l-i中 Let λ be the internal impedance of the device to the PCC point. For a synchronous condenser directly connected to the PCC point, λ = 1. For a remote wind turbine, λ < 1. S104, X based on the above real-time identification 系统 Using (t) and topological parameters, construct the sensitivity matrix and sensitivity coefficient K. 我 Defined as the change in voltage at the PCC point caused by a unit change in reactive power, the calculation formula is derived as follows based on the longitudinal component formula of voltage drop and combined with incremental analysis: U N The rated voltage at point PCC, α 我 As a correction factor; S105. The generated real-time sensitivity matrix is ​​a 1×n row vector, represented as follows: , S106. The specific matrix representation elements are: Synchronous adjustment of camera sensitivity S11: ,β SC The transfer hysteresis coefficient of the synchronous condenser's excitation response is taken as 1 for steady-state calculation; SVG sensitivity S12: ; Sensitivity S1 of the k-th group of wind turbines (2+k) : .

[0010] Furthermore, the specific process of controlling the synchronous condenser to be in a low-output state to reserve transient margin is as follows: S201, Based on the target voltage U at PCC point 关于 With the measured voltage U 我 The deviation is used to calculate the total reactive power demand Q required to maintain the current voltage using the voltage outer loop PI controller. Total_reqThe data received from the margin assessment module is used to calculate the available adjustment capacity of priority-level devices in real time, and then integrated to obtain: Upper limit of emotional regulation: ; Capacity adjustment upper limit: ; S202, the intelligent adjustment unit will adjust the total demand Q Total_req Compare the capacity with the priority level devices and execute the following branching logic: Sufficient priority capacity: The power grid is in a normal, low-disturbance state, and the intelligent regulation unit determines that there is no need to use the synchronous condenser. Instruction generation: Issue adjustment instructions to SVG and wind turbine units to handle the entire total demand; A zero-maintenance command is issued to the synchronous condenser excitation system, setting the target reactive power of the synchronous condenser to 0.

[0011] Priority capacity exhausted: SVG and wind turbines alone cannot meet the voltage support requirements; Command generation: Command the SVG and wind turbines to operate at full capacity, output their maximum capacity, calculate the shortfall, and allocate the shortfall to the synchronous condenser; S203. When it is detected that the voltage at the PCC point has stabilized within the dead zone and the output of the synchronous condenser is greater than the preset threshold, the replacement logic is initiated. Margin testing: Check whether the SVG and wind turbine have any remaining adjustment margin; Slow migration: If the SVG has space, the intelligent adjustment unit generates a reverse micro-increment command, which instructs the SVG to increase reactive power output while the synchronous condenser reduces reactive power output; S204. Repeat the above process until the output of the camera returns to zero.

[0012] Furthermore, the intelligent adjustment unit acquires the effective value of the PCC point voltage at high frequency sampling. When it detects that the effective value of the PCC point voltage is greater than the preset standard threshold for N consecutive cycles, it immediately triggers the transient suppression mode. In order to prevent the integral saturation effect of the conventional PI regulator, the intelligent adjustment unit immediately freezes the integral term of the steady-state control loop and cuts off the steady-state adjustment command output, completely transferring the control to the transient emergency control mode.

[0013] Furthermore, it also includes an adaptive parameter adjustment module, which adjusts the PI parameters of the voltage control loop in real time based on the real-time number of grid-connected wind turbines at the wind power base and the short-circuit capacity of the power grid.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The synchronous condenser voltage and reactive power coordination control system of this wind power base creatively adopts a strategy of prioritizing the scheduling of wind turbines and SVG under steady-state conditions and controlling the synchronous condenser to be in a low-output state. This ensures that the synchronous condenser is not occupied under normal conditions, thereby maximizing its instantaneous overload capacity at the moment of grid fault. Based on dynamic sensitivity matrix control, it effectively overcomes the risk of control instability caused by the impedance fluctuation of the weak receiving end of the grid. At the same time, it constructs a multi-timescale, multi-device collaborative transient overvoltage defense system, which greatly improves the fault ride-through capability of the wind power base. It can perceive the actual operating conditions of each reactive power source in real time and pre-calculate the steady-state regulation capability and transient overload capability margin before generating commands, ensuring that the issued regulation commands are always within the safe operating boundary of the equipment, thereby improving the reliability and predictability of the entire reactive power and voltage control system. Attached Figure Description

[0015] Figure 1 A schematic diagram of the overall structure of the present invention is shown. Detailed Implementation

[0016] 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 only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1: As Figure 1 As shown, a voltage and reactive power coordination control system for a wind power base synchronous condenser includes a data acquisition and processing unit, a data analysis unit, and an intelligent adjustment unit, wherein: The data acquisition and processing unit is used to collect the high-voltage side bus voltage of the wind power collection station, the real-time operating status of the synchronous condenser, the active and reactive power status of each wind turbine, the operating status of the SVG, and the stator current and excitation current of the synchronous condenser in real time. After removing invalid data, it is integrated into a real-time dataset and sent to the intelligent regulation unit. The data analysis unit includes a data correction module and a margin assessment module. The data correction module is used to acquire real-time datasets and dynamically calculate the sensitivity matrix of wind turbines, SVG and synchronous condensers to PCC point voltage based on the real-time operating status of the synchronous condenser. The specific process for dynamically calculating the sensitivity matrix of the wind turbine, SVG, and synchronous condenser to the PCC point voltage is as follows: S101. By collecting the voltage change ΔU at point PCC within the continuous sliding time window Tω. PCCThe system impedance is estimated in real time using a recursive least squares method with a forgetting factor, taking into account the total reactive power change ΔQtotal injected into the grid. The estimation model for the equivalent reactance X_system(t) on the system side is as follows: , where ΔQ 去吧 This includes the total reactive power injected by synchronous condensers, SVG, and all wind turbine units; S102. Based on the topology of the collector network inside the wind farm, construct the impedance model of each node: The synchronous condenser and SVG are connected via a short connecting cable, with a very short electrical distance. The equivalent impedance of their branch is set to the transformer impedance X. T_SC and X T_SVG ; Wind turbine units are located at the end of the collector line. Considering the impedance X of the collector line... line_i That is, the equivalent impedance of the i-th collector line and the transformer impedance X. BoX ; S103, Define the electrical coupling coefficient λ 我 This characterizes the effectiveness of the reactive power injected by the i-th reactive power source being transferred to the PCC point: X 在l-i中 Let λ be the internal impedance of the device to the PCC point. For a synchronous condenser directly connected to the PCC point, λ = 1. For a remote wind turbine, λ < 1. S104, X based on the above real-time identification 系统 Using (t) and topological parameters, construct the sensitivity matrix and sensitivity coefficient K. 我 Defined as the change in voltage at the PCC point caused by a unit change in reactive power, the calculation formula is derived as follows based on the longitudinal component formula of voltage drop and combined with incremental analysis: U N The rated voltage at point PCC, α 我 As a correction factor; S105. The generated real-time sensitivity matrix is ​​a 1×n row vector, represented as follows: , S106. The specific matrix representation elements are: Synchronous adjustment of camera sensitivity S11: ,β SC The transfer hysteresis coefficient of the synchronous condenser's excitation response is taken as 1 for steady-state calculation; SVG sensitivity S12: ; Sensitivity S1 of the k-th group of wind turbines (2+k) : .

[0018] The margin assessment module is used to acquire real-time datasets, parse the actual operating conditions of each reactive power source, and calculate the steady-state regulation capability and transient overload capability margin of each reactive power source. The specific process of controlling the synchronous condenser to be in a low-output state to reserve transient margin is as follows: S201, Based on the target voltage U at PCC point 关于 With the measured voltage U 我 The deviation is used to calculate the total reactive power demand Q required to maintain the current voltage using the voltage outer loop PI controller. Total_req The data received from the margin assessment module is used to calculate the available adjustment capacity of priority-level devices in real time, and then integrated to obtain: Upper limit of emotional regulation: ; Capacity adjustment upper limit: ; S202, the intelligent adjustment unit will adjust the total demand Q Total_req Compare the capacity with the priority level devices and execute the following branching logic: Sufficient priority capacity: The power grid is in a normal, low-disturbance state, and the intelligent regulation unit determines that there is no need to use the synchronous condenser. Instruction generation: Issue adjustment instructions to SVG and wind turbine units to handle the entire total demand; A zero-maintenance command is issued to the synchronous condenser excitation system, setting the target reactive power of the synchronous condenser to 0.

[0019] Priority capacity exhausted: SVG and wind turbines alone cannot meet the voltage support requirements; Command generation: Command the SVG and wind turbines to operate at full capacity, output their maximum capacity, calculate the shortfall, and allocate the shortfall to the synchronous condenser; S203. When it is detected that the voltage at the PCC point has stabilized within the dead zone and the output of the synchronous condenser is greater than the preset threshold, the replacement logic is initiated. Margin testing: Check whether the SVG and wind turbine have any remaining adjustment margin; Slow migration: If the SVG has space, the intelligent adjustment unit generates a reverse micro-increment command, which instructs the SVG to increase reactive power output while the synchronous condenser reduces reactive power output; S204. Repeat the above process until the output of the camera returns to zero.

[0020] The intelligent regulation unit is deployed at the wind power collection station to receive regulation instructions issued by the grid dispatch. Under steady-state conditions, with the goal of minimizing voltage deviation and grid loss, it prioritizes the scheduling of reactive power capacity of wind turbines and SVG, and controls synchronous condensers to be in a low-output state to reserve transient margin. When the voltage at the PCC point exceeds the set transient overvoltage threshold, the system switches to transient suppression mode, controls the synchronous condenser to enter a strong demagnetization state, controls the SVG to output maximum inductive reactive power, and instructs the wind turbine to absorb reactive power using the remaining capacity of the converter. Based on the preset regulation strategy, the system generates control commands and sends them to the execution unit.

[0021] It also includes execution units, which consist of wind turbine generators, distributed compensation devices, centralized synchronous condensers, and a central coordination controller, wherein: The wind turbine generator set consists of several doubly-fed induction generators (DFIGs), which are connected by a 35kV collection line. Each DFIG has reactive power regulation capability and is constrained by its PQ operating limit curve. Distributed compensation devices are installed in a decentralized manner on the 35kV bus side of each wind farm to quickly smooth out local voltage fluctuations. Centralized synchronous condensers are used to be installed on the high-voltage side busbar of 330kV / 750kV step-up substations. They are connected through a step-up transformer, equipped with an excitation system and a starting device, and have instantaneous overload capacity. The central coordination controller is deployed within the integrated automation system of the booster station and communicates with each substation and synchronous condenser control panel via a fiber optic ring network.

[0022] The control strategies of the master station coordination controller include: Steady-state voltage control mode: When grid voltage fluctuations are within the normal dead zone range, the main station prioritizes using the remaining capacity of the SVG and wind turbine inverters on the wind farm side for regulation. The control objective is to maintain the reactive power output of the synchronous condenser at a low level of inductive state, thereby reserving the maximum dynamic reactive power reserve to cope with sudden failures. Transient / Fault Emergency Support Mode: When the system voltage exceeds the set threshold, the system automatically locks out the slow logic. The strong excitation characteristics of the synchronous condenser are used to provide instantaneous short-circuit current and strong reactive power support. At the same time, the master station commands the SVG to issue maximum capacitive reactive power to jointly suppress voltage fluctuations. Damping control and anti-oscillation logic: During the voltage recovery phase, the response slope of the SVG is dynamically adjusted according to the response characteristics of the synchronous condenser to prevent voltage overshoot caused by excessively fast response of power electronic equipment and reactive power oscillation with the synchronous condenser.

[0023] The intelligent control unit acquires the effective value of the PCC point voltage at high frequency sampling. When it detects that the effective value of the PCC point voltage is greater than the preset standard threshold for N consecutive cycles, it immediately triggers the transient suppression mode. In order to prevent the integral saturation effect of the conventional PI regulator, the intelligent control unit immediately freezes the integral term of the steady-state control loop and cuts off the steady-state control command output, completely transferring the control to the transient emergency control mode.

[0024] It also includes an adaptive parameter adjustment module, which adjusts the PI parameters of the voltage control loop in real time based on the real-time number of grid-connected wind turbines at the wind power base and the short-circuit capacity of the power grid.

[0025] This invention creatively employs a strategy of prioritizing the scheduling of wind turbines and SVG (Static Var Generator) and controlling synchronous condensers to operate at low output under steady-state conditions. This ensures that the synchronous condensers are not occupied under normal conditions, thereby maximizing their instantaneous overload capacity in the event of a grid fault. Based on dynamic sensitivity matrix control, it effectively overcomes the risk of control instability caused by impedance fluctuations in the weak receiving end of the grid. At the same time, it constructs a multi-timescale, multi-device collaborative transient overvoltage defense system, significantly improving the fault ride-through capability of wind power bases. It can perceive the actual operating conditions of each reactive power source in real time and pre-calculate the steady-state regulation capacity and transient overload capacity margin before generating commands, ensuring that the issued regulation commands are always within the safe operating boundaries of the equipment, thus improving the reliability and predictability of the entire reactive power and voltage control system.

[0026] The size of the interval and threshold is set to facilitate comparison. The size of the threshold depends on the amount of sample data and the number of bases set by those skilled in the art for each set of sample data; as long as it does not affect the ratio between the parameter and the quantized value.

[0027] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation. The above description is only 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 of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A voltage and reactive power coordination control system for a wind power base synchronous condenser, characterized in that, It includes a data acquisition and processing unit, a data analysis unit, and an intelligent adjustment unit, wherein: The data acquisition and processing unit is used to collect the high-voltage side bus voltage of the wind power collection station, the real-time operating status of the synchronous condenser, the active and reactive power status of each wind turbine, the operating status of the SVG, and the stator current and excitation current of the synchronous condenser in real time. After removing invalid data, it is integrated into a real-time dataset and sent to the intelligent regulation unit. The data analysis unit includes a data correction module and a margin assessment module. The data correction module is used to acquire real-time datasets and dynamically calculate the sensitivity matrix of wind turbines, SVG and synchronous condensers to PCC point voltage based on the real-time operating status of the synchronous condenser. The margin assessment module is used to acquire real-time datasets, parse the actual operating conditions of each reactive power source, and calculate the steady-state regulation capability and transient overload capability margin of each reactive power source. The intelligent regulation unit is deployed at the wind power collection station to receive regulation instructions issued by the grid dispatch. Under steady-state conditions, with the goal of minimizing voltage deviation and grid loss, it prioritizes the scheduling of reactive power capacity of wind turbines and SVG, and controls synchronous condensers to be in a low-output state to reserve transient margin. When the voltage at the PCC point exceeds the set transient overvoltage threshold, the system switches to transient suppression mode, controls the synchronous condenser to enter a strong demagnetization state, controls the SVG to output maximum inductive reactive power, and instructs the wind turbine to absorb reactive power using the remaining capacity of the converter. Based on the preset regulation strategy, the system generates control commands and sends them to the execution unit.

2. The voltage and reactive power coordination control system for a wind power base synchronous condenser according to claim 1, characterized in that, It also includes an execution unit, which comprises a wind turbine generator, a distributed compensation device, a centralized synchronous condenser, and a central coordination controller, wherein: The wind turbine generator set specifically consists of several doubly-fed induction generators (DFIGs), connected by a 35kV collector line. Each DFIG has reactive power regulation capability, constrained by its PQ operating limit curve. Distributed compensation devices are installed in a decentralized manner on the 35kV bus side of each wind farm to quickly smooth out local voltage fluctuations. Centralized synchronous condensers are used to be installed on the high-voltage side busbar of 330kV / 750kV step-up substations. They are connected through a step-up transformer, equipped with an excitation system and a starting device, and have instantaneous overload capacity. The central coordination controller is deployed within the integrated automation system of the booster station and communicates with each substation and synchronous condenser control panel via a fiber optic ring network.

3. The voltage and reactive power coordination control system for a wind power base synchronous condenser according to claim 1, characterized in that, The control strategy of the master station coordination controller includes: Steady-state voltage control mode: When grid voltage fluctuations are within the normal dead zone range, the main station prioritizes using the remaining capacity of the SVG and wind turbine inverters on the wind farm side for regulation. The control objective is to maintain the reactive power output of the synchronous condenser at a low level of inductive state, thereby reserving the maximum dynamic reactive power reserve to cope with sudden failures. Transient / Fault Emergency Support Mode: When the system voltage exceeds the set threshold, the system automatically locks out the slow logic. The strong excitation characteristics of the synchronous condenser are used to provide instantaneous short-circuit current and strong reactive power support. At the same time, the master station commands the SVG to issue maximum capacitive reactive power to jointly suppress voltage fluctuations. Damping control and anti-oscillation logic: During the voltage recovery phase, the response slope of the SVG is dynamically adjusted according to the response characteristics of the synchronous condenser to prevent voltage overshoot caused by excessively fast response of power electronic equipment and reactive power oscillation with the synchronous condenser.

4. The voltage and reactive power coordination control system for a wind power base synchronous condenser according to claim 1, characterized in that, The specific process for dynamically calculating the sensitivity matrix of the wind turbine, SVG, and synchronous condenser to the PCC point voltage is as follows: S101. By collecting the voltage change ΔU at point PCC within the continuous sliding time window Tω. PCC The system impedance is estimated in real time using a recursive least squares method with a forgetting factor, taking into account the total reactive power change ΔQtotal injected into the grid. The estimation model for the equivalent reactance X_system(t) on the system side is as follows: , where ΔQ 去吧 This includes the total reactive power injected by synchronous condensers, SVG, and all wind turbine units; S102. Based on the topology of the collector network inside the wind farm, construct the impedance model of each node: The synchronous condenser and SVG are connected via a short connecting cable, with a very short electrical distance. The equivalent impedance of their branch is set to the transformer impedance X. T_SC and X T_SVG ; Wind turbine units are located at the end of the collector line. Considering the impedance X of the collector line... line_i That is, the equivalent impedance of the i-th collector line and the transformer impedance X. BoX ; S103, Define the electrical coupling coefficient λ 我 This characterizes the effectiveness of the reactive power injected by the i-th reactive power source being transferred to the PCC point: X 在l-i中 Let λ be the internal impedance of the device to the PCC point. For a synchronous condenser directly connected to the PCC point, λ = 1. For a remote wind turbine, λ < 1. S104, X based on the above real-time identification 系统 Using (t) and topological parameters, construct the sensitivity matrix and sensitivity coefficient K. 我 Defined as the change in voltage at the PCC point caused by a unit change in reactive power, the calculation formula is derived as follows based on the longitudinal component formula of voltage drop and combined with incremental analysis: U N The rated voltage at point PCC, α 我 As a correction factor; S105. The generated real-time sensitivity matrix is ​​a 1×n row vector, represented as follows: S106. The specific matrix representation elements are: Synchronous adjustment of camera sensitivity S11: ,β SC The transfer hysteresis coefficient of the synchronous condenser's excitation response is taken as 1 for steady-state calculation; SVG sensitivity S12: ； Sensitivity S1 of the k-th group of wind turbines (2+k) : 。 5. A voltage and reactive power coordination control system for a wind power base synchronous condenser according to claim 1, characterized in that, The specific process of controlling the synchronous condenser to be in a low-output state to reserve transient margin is as follows: S201, Based on the target voltage U at PCC point 关于 With the measured voltage U 我 The deviation is used to calculate the total reactive power demand Q required to maintain the current voltage using the voltage outer loop PI controller. Total_req The data received from the margin assessment module is used to calculate the available adjustment capacity of priority-level devices in real time, and then integrated to obtain: Upper limit of emotional regulation: ; Capacity adjustment upper limit: ; S202, the intelligent adjustment unit will adjust the total demand Q Total_req Compare the capacity with the priority level devices and execute the following branching logic: Sufficient priority capacity: The power grid is in a normal, low-disturbance state, and the intelligent regulation unit determines that there is no need to use the synchronous condenser. Instruction generation: Issue adjustment instructions to SVG and wind turbine units to handle the entire total demand; A zero-maintenance command is issued to the synchronous condenser excitation system, setting the target reactive power of the synchronous condenser to 0. Priority capacity exhausted: SVG and wind turbines alone cannot meet the voltage support requirements; Command generation: Command the SVG and wind turbines to operate at full capacity, output their maximum capacity, calculate the shortfall, and allocate the shortfall to the synchronous condenser; S203. When it is detected that the voltage at the PCC point has stabilized within the dead zone and the output of the synchronous condenser is greater than the preset threshold, the replacement logic is initiated. Margin testing: Check whether the SVG and wind turbine have any remaining adjustment margin; Slow migration: If the SVG has space, the intelligent adjustment unit generates a reverse micro-increment command, which instructs the SVG to increase reactive power output while the synchronous condenser reduces reactive power output; S204. Repeat the above process until the output of the camera returns to zero.

6. The voltage and reactive power coordination control system for a wind power base synchronous condenser according to claim 1, characterized in that, The intelligent adjustment unit acquires the effective value of the PCC point voltage at high frequency sampling. When it detects that the effective value of the PCC point voltage is greater than the preset standard threshold for N consecutive cycles, it immediately triggers the transient suppression mode. In order to prevent the integral saturation effect of the conventional PI regulator, the intelligent adjustment unit immediately freezes the integral term of the steady-state control loop and cuts off the steady-state adjustment command output, completely transferring the control to the transient emergency control mode.

7. A voltage and reactive power coordination control system for a wind power base synchronous condenser according to claim 1, characterized in that, It also includes an adaptive parameter adjustment module, which adjusts the PI parameters of the voltage control loop in real time based on the real-time number of grid-connected wind turbines at the wind power base and the short-circuit capacity of the power grid.

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