Wind power plant multi-scale voltage coordination control method, device, equipment and medium

Abstract

The invention discloses a wind power plant multi-scale voltage coordination control method, device and equipment and a medium, and the method adopts a multi-time-scale architecture of global optimization, wind speed control and rapid control. The global optimization layer establishes a wind field optimization model with wind power plant outlet active power maximization and SVG reactive power margin maximization as targets based on a second-order cone relaxation technology, fully considers each constraint condition, and ensures that the terminal voltage of each unit runs within a safe range through rapid solving by a solver; the wind speed control layer can realize second-level system state updating and terminal voltage protection through wind speed real-time monitoring and MPPT control; and the rapid control layer realizes millisecond-level tracking compensation on the voltage of the grid-connected point through constant voltage control of the SVG, and voltage fluctuation caused by wind speed fluctuation is effectively inhibited. On the premise that the voltage safety of the unit is ensured, the active output capability and the reactive standby margin of the wind power plant outlet are remarkably improved.

Description

Technical Field

[0001] This application belongs to the field of wind power grid-connected operation control technology, specifically relating to a multi-scale voltage coordination control method, device, equipment and medium for wind farms, which is particularly applicable to the voltage control of wind farms containing doubly fed induction generators (DFIG). Background Technology

[0002] As wind power accounts for an increasingly larger share of the energy mix, the impact of wind farm grid-connected operation on grid voltage stability is becoming increasingly significant. Traditional reactive power optimization typically operates on a minute-level or longer cycle, making it difficult to handle second-level wind speed changes. These wind speed variations cause output fluctuations in wind turbines controlled by MPPT (Maximum Power Point Tracking), leading to grid connection voltage fluctuations. Furthermore, in pursuing maximum wind farm output and stable grid connection voltage, the local over-limit issues of individual turbine terminal voltages are often overlooked, thus reducing turbine lifespan. Additionally, wind farm control often fails to fully utilize the reactive power regulation capabilities of the wind turbines themselves, relying excessively on centralized reactive power compensation devices, which can also result in insufficient reactive power margin when adjusting grid connection voltage. Summary of the Invention

[0003] To address the shortcomings of existing wind farm voltage control technologies, this application proposes a multi-scale voltage coordination control method, device, equipment, and medium for wind farms. The aim is to solve the voltage fluctuation problem caused by wind speed fluctuations, while maximizing the active power output of the wind farm and the reactive power reserve margin of the SVG (Static Var Generator), and ensuring that the terminal voltage of all wind turbine units operates within a safe range.

[0004] This application is achieved through the following technical solution:

[0005] A multi-scale voltage coordination control method for wind farms includes:

[0006] Perform system initialization, including: setting the global optimization cycle, wind speed control cycle, and fast control cycle;

[0007] Multi-scale coordinated control is performed according to the preset global optimization cycle, wherein the multi-scale coordinated control process within one of the global optimization cycles includes:

[0008] Solve the pre-established wind farm optimization model to obtain the optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; wherein the wind farm optimization model takes the maximization of active power output and maximization of reactive power margin of wind farm outlet as objective functions, and comprehensively considers various constraints.

[0009] The optimized active and reactive power output reference values ​​for each wind turbine are distributed to each wind turbine, and the SVG output reference values ​​are allocated and distributed to each static var generator. The wind speed across the entire field is updated according to the preset wind speed control cycle, and the maximum power point tracking reference value for each wind turbine is calculated. It is determined whether each wind turbine is a derating unit; if so, the optimized active power output reference value is used as the upper limit of the active power output of the wind turbine, and the reactive power output of the wind turbine remains at the optimized reactive power output reference value; otherwise, the active power output of the wind turbine tracks the maximum power point tracking reference value. Real-time power flow calculations are performed on the power flow within the field to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage of the wind turbine exceeds the limit; if so, the active power output of the wind turbine is reduced, and the optimized reactive power output reference value is set as the maximum reactive power output under the active power output of the wind turbine; otherwise, the original active and reactive power outputs of the wind turbine remain unchanged.

[0010] According to the preset fast control cycle, the SVG connected at the grid connection point performs constant voltage PI control, and the time rapidly tracks the grid connection point voltage to compensate for voltage fluctuations in the global optimization cycle.

[0011] In some implementations, the process of establishing the wind field optimization model includes:

[0012] Based on the optimal power flow calculation method of second-order cone relaxation, an objective function is established to maximize the active power at the wind farm outlet and the reactive power margin of the SVG.

[0013] Establish constraints, including: branch power flow constraints, branch current constraints, branch start and end voltage constraints, branch power constraints considering losses and current shunting, node power constraints, maximum rotor current constraints of doubly-fed wind turbines, upper and lower limits of active and reactive power output constraints, node voltage safety domain constraints, and grid connection point voltage constraints.

[0014] The nonlinear and non-convex power flow constraints are relaxed by second-order cone relaxation; the maximum rotor current constraint of the doubly-fed wind turbine is transformed into a circular constraint of active and reactive power output, and then relaxed by second-order cone relaxation to transform it into a convex second-order cone constraint.

[0015] In some implementations, the objective function is expressed as:

[0016] ;

[0017] in, Indicates the active power output of the wind farm. This indicates that the SVG has no active power output. and These represent the weighting coefficients;

[0018] The constraint condition is expressed as follows:

[0019] ;

[0020] ;

[0021] ;

[0022] ;

[0023] ;

[0024] in, Representing nodes respectively and nodes voltage, and Represents a node and nodes The resistance and reactance of the branches between them. , and Represents a node and nodes The current flowing through the branches, active power, and reactive power. and Representing nodes respectively Injected active and reactive power, , , These represent the active power reference value, reactive power reference value, and reactive power reference value of the SVG (Glass Var Generator) to be optimized, respectively. Indicates wind turbine Maximum power point tracking reference value, and These represent the upper and lower limits of reactive power under the current active power output. and These represent the upper and lower safety limits of the grid connection point voltage, respectively. This indicates the reactive power capacity of the SVG. This indicates the stator voltage of the wind turbine. , These represent the stator reactance and magnetizing reactance of the wind turbine, respectively. This indicates the maximum rotor current limit of the fan. and These represent the upper and lower safety limits of the node voltage, respectively. Indicates the branch current limit. and Representing the nodes respectively The active and reactive power on the connected branches.

[0025] In some implementations, the allocation principle of the SVG output reference value is as follows:

[0026] Multiple SVG units will be put into use sequentially according to the SVG output reference value.

[0027] In some implementations, the maximum power point tracking reference value of the wind turbine is calculated as follows:

[0028] ;

[0029] in, This is the maximum power point tracking reference value for the unit. Indicates air density, Indicates the maximum wind energy utilization factor. Indicates wind speed.

[0030] In some implementations, the method for determining the derating unit is as follows:

[0031] If the active power output reference value of the wind turbine meets the requirements... If so, the wind turbine is determined to be a derating unit, wherein, For the first Maximum power point tracking reference value for each unit This is the reduction factor.

[0032] In some embodiments, the constant voltage PI control of the SVG connected at the grid connection point according to the preset fast control cycle includes:

[0033] Each of the aforementioned fast control cycles is executed once, directly performing constant voltage PI control on the SVG connected at the grid connection point based on the grid connection point voltage. The constant voltage PI control is expressed as follows:

[0034] ;

[0035] in, This refers to the reactive power control command for the SVG after PI control. This is the reactive power reference value for SVG. This indicates the deviation between the grid connection point voltage and the reference value. and These represent the proportional coefficient and the integral coefficient, respectively.

[0036] Secondly, this application proposes a multi-scale voltage coordination control device for wind farms, comprising:

[0037] The initialization unit is used to perform system initialization, including setting the global optimization cycle, wind speed control cycle, and fast control cycle.

[0038] In addition, a multi-scale control unit is used to execute a multi-scale coordinated control process in each global optimization cycle: solving a pre-established wind farm optimization model to obtain optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; wherein the wind farm optimization model takes maximizing the active power output and maximizing the reactive power margin of the wind farm outlet as the objective function, and comprehensively considers various constraints.

[0039] The optimized active and reactive power output reference values ​​for each wind turbine are distributed to each wind turbine, and the SVG output reference values ​​are allocated and distributed to each static var generator. The wind speed across the entire field is updated according to the preset wind speed control cycle, and the maximum power point tracking reference value for each wind turbine is calculated. It is determined whether each wind turbine is a derating unit; if so, the optimized active power output reference value is used as the upper limit of the active power output of the wind turbine, and the reactive power output of the wind turbine remains at the optimized reactive power output reference value; otherwise, the active power output of the wind turbine tracks the maximum power point tracking reference value. Real-time power flow calculations are performed on the power flow within the field to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage of the wind turbine exceeds the limit; if so, the active power output of the wind turbine is reduced, and the optimized reactive power output reference value is set as the maximum reactive power output under the active power output of the wind turbine; otherwise, the original active and reactive power outputs of the wind turbine remain unchanged.

[0040] According to the preset fast control cycle, the SVG connected at the grid connection point performs constant voltage PI control, and the time rapidly tracks the grid connection point voltage to compensate for voltage fluctuations in the global optimization cycle.

[0041] Thirdly, this application proposes an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement any of the above-described embodiments of the multi-scale voltage coordination control method for wind farms.

[0042] Fourthly, this application proposes a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements any of the above-described embodiments of the multi-scale voltage coordination control method for wind farms.

[0043] This application proposes a multi-scale voltage coordination control method for wind farms, employing a multi-time-scale architecture of global optimization, wind speed control, and fast control. The global optimization layer establishes a wind farm optimization model based on second-order cone relaxation technology, aiming to maximize the active power output and reactive power reserve margin of the wind farm outlet. It fully considers various constraints and solves the model quickly using a solver, ensuring that the terminal voltage of each unit operates within a safe range. The wind speed control layer achieves second-level system status updates and terminal voltage protection through real-time wind speed monitoring and MPPT control. The fast control layer achieves millisecond-level tracking compensation of the grid connection point voltage through constant voltage control of the SVG, effectively suppressing voltage fluctuations caused by wind speed fluctuations. This application's embodiment combines global optimization with wind speed control and fast local compensation, significantly improving the active power output capacity and reactive power reserve margin of the wind farm outlet while ensuring unit voltage safety, thus resolving the contradiction between MPPT pursuit and voltage stability in traditional control methods.

[0044] Accordingly, the wind farm multi-scale voltage coordination control device, electronic device, and computer-readable storage medium proposed in this application also possess the same technical effects as described above. Attached Figure Description

[0045] The accompanying drawings, which are included to provide a further understanding of the embodiments of this application and form part of this application, do not constitute a limitation on the embodiments of this application. In the drawings:

[0046] Figure 1 This is a flowchart of the coordination control method proposed in the embodiments of this application;

[0047] Figure 2 This is a block diagram illustrating the principle of the coordination control device proposed in the embodiments of this application;

[0048] Figure 3 This is a schematic diagram of the coordination and control system architecture proposed in the embodiments of this application;

[0049] Figure 4 This is a schematic diagram of the electronic device proposed in the embodiments of this application;

[0050] Figure 5 This is a schematic diagram of a computer-readable storage medium proposed in an embodiment of this application;

[0051] Figure 6 A schematic diagram illustrating the upper and lower limits of active and reactive power output constraints.

[0052] Figure reference numerals and corresponding component names:

[0053] 200-Coordination control device, 201-Initialization unit, 202-Multi-scale control unit, 300-Coordination control system, 301-Input device, 302-Output device, 303-Processor A, 304-Memory A, 400-Electronic device, 410-Memory B, 420-Processor B, 411-Computer program A, 500-Computer-readable storage medium, 511-Computer program B. Detailed Implementation

[0054] In the following, the terms “comprising” or “may include” as used in the various embodiments of this application indicate the presence of a function, operation, or element of the invention and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in the various embodiments of this application, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0055] In various embodiments of this application, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0056] The terms used in the various embodiments of this application (such as "first," "second," etc.) may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above terms do not limit the order and / or importance of the elements. The above terms are only used for the purpose of distinguishing one element from other elements. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, without departing from the scope of the various embodiments of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0057] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0058] The terminology used in the various embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0059] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this application are only for explaining this application and are not intended to limit this application.

[0060] like Figure 1 As shown in the figure, this application proposes a multi-scale voltage coordination control method for wind farms, which includes the following steps:

[0061] Perform system initialization: Set the number of wind turbines in the wind farm, SVG configuration parameters, control cycle parameters, farm topology and feeder parameters; initialize the active power output, reactive power output, SVG reactive power output, grid connection point voltage, and turbine terminal voltage for each wind turbine; set the safe range for turbine terminal voltage. The global optimization cycle (e.g., 5 seconds), wind speed control cycle (e.g., 1 second), and fast control cycle (e.g., 0.01 seconds) are set. The global optimization cycle depends on the wind farm size and computing power, and should be set as small as possible while still meeting the optimization solution cycle requirements to ensure accurate power output allocation tracking of wind speed changes. The wind speed control cycle depends on the wind speed sensor sampling period, typically less than or equal to 1 second. The fast control cycle depends on the grid connection point voltage sampling period, communication, and control delays. The global optimization cycle is longer than the wind speed control cycle, and the wind speed control cycle is longer than the fast control cycle. When a control cycle arrives, global optimization is performed first, based on the current wind speed and the corresponding MPPT active power output calculation value. The output of wind turbines and reactive power compensation equipment in the wind farm will be initially set based on the optimization results during the future global control cycle.

[0062] To improve computational accuracy and speed and prevent getting trapped in local optima, the global layer field output optimization adopts an optimal power flow calculation method based on second-order cone relaxation. After convex relaxation of the model, the Gurobi solver is used to achieve fast solution of the model.

[0063] Multi-scale coordinated control is performed according to a preset global optimization cycle. The coordinated control process within one of the global optimization cycles is as follows:

[0064] Global optimization is performed to solve the pre-established wind farm optimization model, obtaining optimized reference values ​​for active and reactive power output and SVG output of each wind turbine. The wind farm optimization model includes an objective function and its constraints. Specifically, based on the optimal power flow calculation method using second-order cone relaxation, an objective function is established with the goal of maximizing active power output at the wind farm outlet and maximizing the reactive power margin of the SVG, which can be expressed as: .

[0065] in, Indicates the active power output of the wind farm. This indicates that the SVG has no active power output. and These represent the weighting coefficients.

[0066] Constraints include branch power flow constraints, branch current constraints, branch start-end voltage constraints, branch power constraints considering losses and current shunting, node power constraints, maximum rotor current constraints for doubly-fed induction generators, and upper and lower limits constraints for active and reactive power output (e.g., Figure 6 As shown in the figure, the horizontal axis represents active power output, and the vertical axis represents reactive power output. The curve represents the maximum reactive power output limit under the active power output obtained from the maximum rotor current constraint (i.e., the upper and lower limits of reactive power output), node voltage safety domain constraint, and grid connection point voltage constraint, which can be expressed as:

[0067]

[0068]

[0069]

[0070] in, Representing nodes respectively and nodes voltage, and Represents a node and nodes The resistance and reactance of the branches between them. , and Represents a node and nodes The current flowing through the branches, active power, and reactive power. and Representing nodes respectively Injected active and reactive power, , , These represent the active power reference value, reactive power reference value, and reactive power reference value of the SVG (Glass Var Generator) to be optimized, respectively. Indicates wind turbine Maximum power point tracking reference value, and These represent the upper and lower limits of reactive power under the current active power output. and These represent the upper and lower safety limits of the grid connection point voltage, respectively. This indicates the reactive power capacity of the SVG. This indicates the stator voltage of the wind turbine. , These represent the stator reactance and magnetizing reactance of the wind turbine, respectively. This indicates the maximum rotor current limit of the fan. and These represent the upper and lower safety limits of the node voltage, respectively. Indicates the branch current limit. and Representing the nodes respectively The active and reactive power on the connected branches.

[0071] The nonlinear and non-convex power flow constraints are relaxed using a second-order cone. The maximum rotor current constraint of the doubly-fed induction generator (DFIG) is transformed into a circular constraint of active and reactive power output, and then relaxed using a second-order cone to convert it into a convex second-order cone constraint, which is then incorporated into the wind farm optimization model. This can be expressed as:

[0072]

[0073]

[0074] In this embodiment, the Gurobi solver can be used to solve the above wind field optimization model to obtain the optimized active and reactive power output reference values ​​and SVG output reference values ​​for each unit, as well as the grid connection point voltage reference value at this time.

[0075] Perform wind speed layer control: Optimize the obtained active power control commands for the wind turbines. (i.e., active power output reference value) and reactive power control commands (Reactive power output reference value) is issued to each wind turbine unit; SVG reactive power control commands are then sent. After the (SVG output reference value) is allocated, it is sent to each Static Var Generator (SVG). The principle of allocation is that multiple SVGs are put into use in sequence according to the reactive power command, so as to prevent the communication delay when multiple SVGs are put into use at the same time from affecting the control effect.

[0076] The wind speed across the entire field is updated according to a preset wind speed control cycle, and the maximum power point tracking (MPPT) reference value for each turbine is calculated. This serves as the upper limit for the active power output of the turbines in global optimization and the actual active power output during operation. Specifically, the wind speed layer updates the wind speed information at the hub height of each wind turbine every second, using a turbulence model to simulate wind speed fluctuations and wind speeds at different locations within the wind farm. The MPPT reference value for each wind turbine is calculated based on the real-time wind speed.

[0077]

[0078] in, This is the maximum power point tracking reference value for the unit. Indicates air density, Indicates the maximum wind energy utilization factor. Indicates wind speed.

[0079] This value will serve as the upper limit of the unit's active power output in the global optimization and the actual active power output during operation. It is worth noting that due to the existence of terminal voltage safety constraints and grid connection voltage constraints in the global optimization, a control strategy of reducing active power output and utilizing reactive power output to a greater extent is adopted for some units. Specifically, it determines whether a unit is a derating unit. The specific determination method is: if the unit's active power output command meets... If so, it is determined to be a unit with reduced rating, among which, For the first MPPT reference values ​​for individual units The reduction factor is generally chosen as an empirical value of 0.9.

[0080] For derating units, which are required to maintain reactive power output under real-time fluctuating wind speeds, the active power control commands obtained through global optimization are used. As the upper limit of active power output, the reactive power control command maintains global optimization of the unit's reactive power output. This fully utilizes the reactive power potential of the wind turbine to balance the power flow within the site. If it is not a derating unit, the active power output of the unit tracks the MPPT reference value.

[0081] Based on this, real-time power flow calculations are performed on the power flow within the field to obtain the real-time grid connection point voltage. And monitor the terminal voltage of each wind turbine. It then determines whether the generator terminal voltage exceeds the limit. If the voltage exceeds the limit, the active power output of the unit is reduced (i.e., active power is reduced) to [a certain value]. and the reactive power control command The active power output of this unit is set as follows. Maximum reactive power output This allows for greater reactive power output (i.e., increased reactive power generation) to limit the generator terminal voltage from exceeding the limit. If the voltage does not exceed the limit, the active power control command and reactive power control command remain unchanged (i.e., the original active power output and reactive power output remain unchanged).

[0082] Fast-layer control is implemented: The SVG connected at the grid connection point undergoes constant-voltage PI control according to a preset fast-layer control cycle, achieving rapid tracking of the grid connection point (PCC) voltage and compensating for voltage fluctuations within the global optimization cycle. Specifically, the fast-layer control is executed every 0.01 seconds, directly performing constant-voltage PI control on the SVG connected at the grid connection point based on the grid connection point voltage. Since most wind turbines still use MPPT control... Changes in active power output will also affect the voltage at the grid connection point. Due to voltage fluctuations, voltage PI control is implemented on the SVG connected at the grid connection point to achieve rapid tracking of the grid connection point voltage, compensate for voltage fluctuations within the global optimization cycle, or receive grid connection point voltage commands from the upper-level AVC system. The SVG reactive power command value is:

[0083] ;

[0084] in, This refers to the reactive power control command for the SVG after PI control. This indicates the deviation between the grid connection point voltage and the reference value. and These represent the proportional coefficient and the integral coefficient, respectively.

[0085] After calculating the SVG reactive power command value, it is distributed to each static var compensator through a reactive power command allocation algorithm. Based on this, real-time power flow calculation is performed on the power flow within the field to obtain the real-time grid connection point voltage. Feedback control is implemented to ensure that the grid connection point voltage tracks the control commands in real time when the wind speed changes.

[0086] After a complete control cycle (5 seconds) ends, the wind farm will enter the next control cycle and continue with the next multi-scale coordinated control.

[0087] The coordinated control method proposed in this application adopts a multi-timescale architecture of global optimization, wind speed control, and fast control. The global optimization layer establishes a wind farm optimization model based on second-order cone relaxation technology, aiming to maximize the active power output and reactive power reserve margin of the wind farm outlet. It fully considers conditions such as DC power flow constraints, node voltage safety domain constraints, and maximum rotor current constraints of doubly-fed induction generators, and solves the problem quickly through a solver to ensure that the terminal voltage of each unit operates within a safe range. The wind speed control layer achieves second-level system status updates and terminal voltage protection through real-time wind speed monitoring and MPPT control. The fast control layer achieves millisecond-level tracking compensation of the grid connection point voltage through constant voltage control of the SVG, effectively suppressing voltage fluctuations caused by wind speed fluctuations. This application combines global optimization with wind speed control and fast local compensation, significantly improving the active power output capacity and reactive power reserve margin of the wind farm outlet while ensuring the safety of the unit voltage, and solving the contradiction between MPPT pursuit and voltage stability in traditional control methods.

[0088] Based on the same technical concept described above, this application also proposes a multi-scale voltage coordination control device for wind farms, such as... Figure 2 As shown, the coordination control device 200 includes:

[0089] Initialization unit 201 is used to set the number of wind turbines in the wind farm, SVG configuration parameters, control cycle parameters, farm topology and feeder parameters; initialize the active power output, reactive power output, SVG reactive power output, grid connection point voltage, and turbine terminal voltage of each wind turbine; set the global optimization cycle, wind speed control cycle, and fast control cycle; and set the safe range for turbine terminal voltage. The specific initialization method is as described in the coordinated control method above and will not be repeated here.

[0090] The multi-scale control unit 202 is used to execute the following multi-scale coordinated control process in each global optimization cycle: solve the pre-established wind farm optimization model to obtain optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; distribute the optimized active and reactive power output reference values ​​to each wind turbine, and distribute the SVG output reference values ​​to each static var generator after allocation; update the wind speed across the entire field according to the preset wind speed control cycle and calculate the maximum power point tracking reference value for each wind turbine; determine whether each wind turbine is a derating unit; if so, use the active power output reference value obtained from global optimization as the upper limit of the active power output of that wind turbine, and set the reactive power output reference value of that wind turbine as the upper limit of the active power output. The reactive power output is maintained at the reference value obtained from global optimization; otherwise, the active power output of the wind turbine tracks the maximum power point tracking reference value. Real-time power flow calculations are performed on the wind turbine's power flow within the site to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. If the terminal voltage exceeds the limit, the active power output of the wind turbine is reduced, and the reactive power output reference value obtained from global optimization is set as the maximum reactive power output under the active power output of the wind turbine. Otherwise, the active power control command and reactive power control command of the wind turbine remain unchanged. Constant voltage PI control is performed on the SVG connected at the grid connection point according to a preset fast control cycle to achieve rapid tracking of the grid connection point voltage and compensate for voltage fluctuations within the global optimization cycle. The specific multi-scale coordinated control process is as described in the coordinated control method above and will not be elaborated further here.

[0091] Based on the same technical concept described above, this application also proposes a multi-scale voltage coordination control system for wind farms, such as... Figure 3 As shown, the coordination control system 300 proposed in this application embodiment includes:

[0092] The system comprises an input device 301, an output device 302, a processor A303, and a memory A304; wherein the number of processors A303 and memory A304 can be one or more. Figure 3 The following description uses a processor A303 and a memory A304 as an example. The input device 301, output device 302, processor A303, and memory A304 can be connected via a bus or other means. Figure 3 Taking the example of a connection between China and Israel via a bus.

[0093] Specifically, by calling the operation instructions stored in memory A304, processor A303 executes the following steps:

[0094] Set the number of wind turbines in the wind farm, SVG configuration parameters, control cycle parameters, farm topology and feeder parameters; initialize the active power output, reactive power output, SVG reactive power output, grid connection point voltage and turbine terminal voltage of each wind turbine; set the global optimization cycle, wind speed control cycle and fast control cycle; set the safe range of turbine terminal voltage.

[0095] Within each global optimization cycle, the following multi-scale coordinated control process is executed: Solve the pre-established wind farm optimization model to obtain optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; distribute the optimized active and reactive power output reference values ​​to each wind turbine, and distribute the SVG output reference values ​​to each static var generator (SVR); update the wind speed across the entire field according to the preset wind speed control cycle and calculate the maximum power point tracking (MPPT) reference value for each wind turbine; determine whether each wind turbine is a derating unit; if so, use the globally optimized active power output reference value as the upper limit of the active power output of that wind turbine, and maintain the global reactive power output of that wind turbine. The optimized reactive power output reference value is used; otherwise, the active power output of the wind turbine is tracked to the maximum power point tracking reference value. Real-time power flow calculation is performed on the power flow within the site to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage exceeds the limit. If so, the active power output of the wind turbine is reduced, and the reactive power output reference value obtained from global optimization is set as the maximum reactive power output under the active power output of the wind turbine. Otherwise, the active power control command and reactive power control command of the wind turbine remain unchanged. Constant voltage PI control is performed on the SVG connected at the grid connection point according to the preset fast control cycle to achieve fast tracking of the grid connection point voltage and compensate for voltage fluctuations within the global optimization cycle.

[0096] Optionally, by calling the operation instructions stored in memory A304, processor A303 is also used to execute any of the embodiments in the corresponding examples of the above-described coordination control method.

[0097] Based on the same technical concept described above, this application also proposes an electronic device, such as... Figure 4 As shown, the electronic device 400 includes: a memory B410, a processor B420, and a computer program A411 stored in the memory B410 and executable on the processor B420. When the processor B420 executes the computer program A411, it performs the following steps:

[0098] Set the number of wind turbines in the wind farm, SVG configuration parameters, control cycle parameters, farm topology and feeder parameters; initialize the active power output, reactive power output, SVG reactive power output, grid connection point voltage and turbine terminal voltage of each wind turbine; set the global optimization cycle, wind speed control cycle and fast control cycle; set the safe range of turbine terminal voltage.

[0099] Within each global optimization cycle, the following multi-scale coordinated control process is executed: Solve the pre-established wind farm optimization model to obtain optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; distribute the optimized active and reactive power output reference values ​​to each wind turbine, and distribute the SVG output reference values ​​to each static var generator (SVR); update the wind speed across the entire field according to the preset wind speed control cycle and calculate the maximum power point tracking (MPPT) reference value for each wind turbine; determine whether each wind turbine is a derating unit; if so, use the globally optimized active power output reference value as the upper limit of the active power output of that wind turbine, and maintain the global reactive power output of that wind turbine. The optimized reactive power output reference value is used; otherwise, the active power output of the wind turbine is tracked to the maximum power point tracking reference value. Real-time power flow calculation is performed on the power flow within the site to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage exceeds the limit. If so, the active power output of the wind turbine is reduced, and the reactive power output reference value obtained from global optimization is set as the maximum reactive power output under the active power output of the wind turbine. Otherwise, the active power control command and reactive power control command of the wind turbine remain unchanged. Constant voltage PI control is performed on the SVG connected at the grid connection point according to the preset fast control cycle to achieve fast tracking of the grid connection point voltage and compensate for voltage fluctuations within the global optimization cycle.

[0100] Optionally, when processor B420 executes computer program A411, it can implement any of the embodiments in the corresponding examples of the above-described coordination control method.

[0101] It should be noted that the electronic device proposed in this application embodiment is a device used to implement the above-mentioned coordination control method. Therefore, based on the above-mentioned coordination control method proposed in this application embodiment, those skilled in the art can understand the specific implementation method and various variations of the electronic device in this application embodiment. Therefore, how the electronic device specifically implements the above-mentioned coordination control method will not be described in detail here. Any electronic device used by those skilled in the art to implement the above-mentioned coordination control method falls within the scope of protection of this application.

[0102] Based on the same technical concept described above, embodiments of this application also propose a computer-readable storage medium, such as... Figure 5 As shown, the computer-readable storage medium 500 stores a computer program B511, which, when executed by a processor, performs the following steps:

[0103] Set the number of wind turbines in the wind farm, SVG configuration parameters, control cycle parameters, farm topology and feeder parameters; initialize the active power output, reactive power output, SVG reactive power output, grid connection point voltage and turbine terminal voltage of each wind turbine; set the global optimization cycle, wind speed control cycle and fast control cycle; set the safe range of turbine terminal voltage.

[0104] Within each global optimization cycle, the following multi-scale coordinated control process is executed: Solve the pre-established wind farm optimization model to obtain optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; distribute the optimized active and reactive power output reference values ​​to each wind turbine, and distribute the SVG output reference values ​​to each static var generator (SVR); update the wind speed across the entire field according to the preset wind speed control cycle and calculate the maximum power point tracking (MPPT) reference value for each wind turbine; determine whether each wind turbine is a derating unit; if so, use the globally optimized active power output reference value as the upper limit of the active power output of that wind turbine, and maintain the global reactive power output of that wind turbine. The optimized reactive power output reference value is used; otherwise, the active power output of the wind turbine is tracked to the maximum power point tracking reference value. Real-time power flow calculation is performed on the power flow within the site to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage exceeds the limit. If so, the active power output of the wind turbine is reduced, and the reactive power output reference value obtained from global optimization is set as the maximum reactive power output under the active power output of the wind turbine. Otherwise, the active power control command and reactive power control command of the wind turbine remain unchanged. Constant voltage PI control is performed on the SVG connected at the grid connection point according to the preset fast control cycle to achieve fast tracking of the grid connection point voltage and compensate for voltage fluctuations within the global optimization cycle.

[0105] Optionally, when the computer program B511 is executed by the processor, it can implement any of the embodiments corresponding to the above-described coordination control method.

[0106] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0107] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0108] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0109] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0110] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0111] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A multi-scale voltage coordination control method for wind farms, characterized in that, include: Perform system initialization, including: setting the global optimization cycle, wind speed control cycle, and fast control cycle; Multi-scale coordinated control is performed according to the preset global optimization cycle, wherein the multi-scale coordinated control process within one of the global optimization cycles includes: Solve the pre-established wind farm optimization model to obtain the optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; wherein the wind farm optimization model takes the maximization of active power output and maximization of reactive power margin of wind farm outlet as objective functions, and comprehensively considers various constraints. The optimized active and reactive power output reference values ​​for each wind turbine are distributed to each wind turbine, and the SVG output reference values ​​are allocated and distributed to each static var generator. The wind speed across the entire field is updated according to the preset wind speed control cycle, and the maximum power point tracking reference value for each wind turbine is calculated. It is determined whether each wind turbine is a derating unit; if so, the optimized active power output reference value is used as the upper limit of the active power output of the wind turbine, and the reactive power output of the wind turbine remains at the optimized reactive power output reference value; otherwise, the active power output of the wind turbine tracks the maximum power point tracking reference value. Real-time power flow calculations are performed on the power flow within the field to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage of the wind turbine exceeds the limit; if so, the active power output of the wind turbine is reduced, and the optimized reactive power output reference value is set as the maximum reactive power output under the active power output of the wind turbine; otherwise, the original active and reactive power outputs of the wind turbine remain unchanged. According to the preset fast control cycle, the SVG connected at the grid connection point performs constant voltage PI control, and the time rapidly tracks the grid connection point voltage to compensate for voltage fluctuations in the global optimization cycle.

2. The multi-scale voltage coordination control method for wind farms according to claim 1, characterized in that, The process of establishing the wind field optimization model includes: Based on the optimal power flow calculation method of second-order cone relaxation, an objective function is established to maximize the active power at the wind farm outlet and the reactive power margin of the SVG. Establish constraints, including: branch power flow constraints, branch current constraints, branch start and end voltage constraints, branch power constraints considering losses and current shunting, node power constraints, maximum rotor current constraints of doubly-fed wind turbines, upper and lower limits of active and reactive power output constraints, node voltage safety domain constraints, and grid connection point voltage constraints. The nonlinear and non-convex power flow constraints are relaxed by second-order cone relaxation; the maximum rotor current constraint of the doubly-fed wind turbine is transformed into a circular constraint of active and reactive power output, and then relaxed by second-order cone relaxation to transform it into a convex second-order cone constraint.

3. The multi-scale voltage coordination control method for wind farms according to claim 2, characterized in that, The objective function is expressed as: ； in, Indicates the active power output of the wind farm. This indicates that the SVG has no active power output. and These represent the weighting coefficients; The constraint condition is expressed as follows: ； ； ； ； ； in, Representing nodes respectively and nodes voltage, and Represents a node and nodes The resistance and reactance of the branches between them. , and Represents a node and nodes The current flowing through the branches, active power, and reactive power. and Representing nodes respectively Injected active and reactive power, , , These represent the active power reference value, reactive power reference value, and reactive power reference value of the SVG (Glass Var Generator) to be optimized, respectively. Indicates wind turbine Maximum power point tracking reference value, and These represent the upper and lower limits of reactive power under the current active power output. and These represent the upper and lower safety limits of the grid connection point voltage, respectively. This indicates the reactive power capacity of the SVG. This indicates the stator voltage of the wind turbine. , These represent the stator reactance and magnetizing reactance of the wind turbine, respectively. This indicates the maximum rotor current limit of the fan. and These represent the upper and lower safety limits of the node voltage, respectively. Indicates the branch current limit. and Representing the nodes respectively The active and reactive power on the connected branches.

4. A multi-scale voltage coordination control method for wind farms according to any one of claims 1-3, characterized in that, The allocation principle for the SVG output reference value is as follows: Multiple SVG units will be put into use sequentially according to the SVG output reference value.

5. A multi-scale voltage coordination control method for wind farms according to any one of claims 1-3, characterized in that, The calculation method for the maximum power point tracking reference value of the wind turbine is as follows: ； in, This is the maximum power point tracking reference value for the unit. Indicates air density, Indicates the maximum wind energy utilization factor. Indicates wind speed.

6. A multi-scale voltage coordination control method for wind farms according to any one of claims 1-3, characterized in that, The method for determining the reduced-rate generator unit is as follows: If the active power output reference value of the wind turbine meets the requirements... If so, the wind turbine is determined to be a derating unit, wherein... For the first Maximum power point tracking reference value for each unit This is the reduction factor.

7. A multi-scale voltage coordination control method for wind farms according to any one of claims 1-3, characterized in that, The constant voltage PI control of the SVG connected at the grid connection point according to the preset fast control cycle includes: Each of the aforementioned fast control cycles is executed once, directly performing constant voltage PI control on the SVG connected at the grid connection point based on the grid connection point voltage. The constant voltage PI control is expressed as follows: ； in, This refers to the reactive power control command for the SVG after PI control. This is the reactive power reference value for SVG. This indicates the deviation between the grid connection point voltage and the reference value. and These represent the proportional coefficient and the integral coefficient, respectively.

8. A multi-scale voltage coordination control device for wind farms, characterized in that, include: The initialization unit is used to perform system initialization, including setting the global optimization cycle, wind speed control cycle, and fast control cycle. In addition, a multi-scale control unit is used to execute a multi-scale coordinated control process in each global optimization cycle: solving a pre-established wind farm optimization model to obtain optimized active and reactive power output reference values ​​and SVG output reference values ​​for each wind turbine; wherein the wind farm optimization model takes maximizing the active power output and maximizing the reactive power margin of the wind farm outlet as the objective function, and comprehensively considers various constraints. The optimized active and reactive power output reference values ​​for each wind turbine are distributed to each wind turbine, and the SVG output reference values ​​are allocated and distributed to each static var generator. The wind speed across the entire field is updated according to the preset wind speed control cycle, and the maximum power point tracking reference value for each wind turbine is calculated. It is determined whether each wind turbine is a derating unit; if so, the optimized active power output reference value is used as the upper limit of the active power output of the wind turbine, and the reactive power output of the wind turbine remains at the optimized reactive power output reference value; otherwise, the active power output of the wind turbine tracks the maximum power point tracking reference value. Real-time power flow calculations are performed on the power flow within the field to obtain the real-time grid connection point voltage and monitor the terminal voltage of each wind turbine. It is determined whether the terminal voltage of the wind turbine exceeds the limit; if so, the active power output of the wind turbine is reduced, and the optimized reactive power output reference value is set as the maximum reactive power output under the active power output of the wind turbine; otherwise, the original active and reactive power outputs of the wind turbine remain unchanged. According to the preset fast control cycle, the SVG connected at the grid connection point performs constant voltage PI control, and the time rapidly tracks the grid connection point voltage to compensate for voltage fluctuations in the global optimization cycle.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the wind farm multi-scale voltage coordination control method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the wind farm multi-scale voltage coordination control method according to any one of claims 1-7.

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