Offshore wind plant reactive power optimization method, device, equipment, medium and product
By optimizing reactive power regulation in offshore wind farms, and utilizing sensitivity analysis of wind turbines and reactive power compensation equipment, as well as particle swarm optimization, the problems of excessive reactive power, voltage exceeding limits, and increased active power loss in offshore wind farms have been solved, achieving the effects of voltage balance and reduced active power loss.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-13
AI Technical Summary
The use of high-voltage AC cables for power transmission in deep-sea offshore wind farms leads to problems such as excess reactive power, voltage exceeding limits, and increased active power loss. Existing technologies have not been able to effectively solve the problems of voltage exceeding limits and increased active power loss, and are particularly unsuitable for offshore wind farms.
By determining the offshore wind farms involved in regulation based on voltage-reactive power sensitivity and active power loss at the initial moment, and utilizing the regulation capabilities of wind turbines and reactive power compensation equipment, reactive power is optimized. The objective function aims to minimize voltage deviation and active power loss, and is solved using the particle swarm optimization algorithm to dynamically adjust the reactive power compensation strategy.
It effectively solved the problems of excessive reactive power, voltage exceeding limits, and increased active power loss. After optimization, the active power loss was reduced by 0.208% to 19.833%, and the voltage was controlled within a safe range, improving the safety and economy of the power grid.
Smart Images
Figure CN121663655A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of new energy power generation, and in particular to a method, apparatus, equipment, medium and product for optimizing reactive power in offshore wind farms. Background Technology
[0002] Deep-sea offshore wind farms use high-voltage AC cables for power transmission. The large capacitance of these cables to ground can lead to excessive reactive power injected into the system, causing problems such as excess reactive power, voltage exceeding limits, and increased active power losses. Therefore, a method for optimizing reactive power in offshore wind farms under voltage balance conditions is needed.
[0003] Reactive power optimization in wind farms refers to adjusting the reactive power compensation capacity of wind farms while ensuring power system voltage quality. This can reduce wasted reactive power capacity, lower active power losses, and improve the voltage level of wind farms. The optimization process is highly complex due to the presence of both discrete and continuous variables under control. To address these complex variables and improve reactive power utilization, some researchers have proposed reactive power output strategies for wind farms based solely on the reactive power regulation capabilities of doubly-fed induction generators (DFIGs) from the perspective of grid voltage control. However, these strategies neglect active power losses. While they address the issue of excess reactive power, they fail to resolve problems such as voltage exceeding limits and increased active power losses, potentially leading to increased grid losses despite voltage control after optimization.
[0004] Some scholars have analyzed the reactive power limit of doubly-fed wind turbine generators and considered the reactive power regulation capability of wind turbine generators in the reactive power optimization process. Although this method can solve the problems of excessive reactive power, voltage exceeding limits and increased active power loss, it is only applicable to onshore wind farms and not to offshore wind farms. Summary of the Invention
[0005] The purpose of this application is to provide a method, apparatus, equipment, medium, and product for optimizing reactive power in offshore wind farms, which can solve the problems of excessive reactive power, voltage exceeding limits, and increased active power loss in offshore wind farms.
[0006] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a method for optimizing the reactive power of offshore wind farms, including: at an initial moment, determining the offshore wind farms to participate in regulation based on the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster to the busbar of the target offshore wind farm cluster and the grid loss-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster to the grid loss-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster.
[0007] At the initial moment, the power of the wind turbines in each participating offshore wind farm is adjusted, and it is determined whether the output power of each participating offshore wind farm after adjustment reaches the reactive power demand target value corresponding to the initial moment, and the first judgment result is obtained; at any moment, each participating offshore wind farm corresponds to a reactive power demand target value.
[0008] If the first judgment result is negative, the adjustable reactive power determination step is executed in real time. The adjustable reactive power determination step is as follows: at the current moment, with the goal of all participating offshore wind farms reaching the reactive power demand target value corresponding to the current moment, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm. The objective function aims to minimize voltage deviation and active power loss. The upper and lower limits of the reactive power output of each participating offshore wind farm are calculated based on the charging capacitance of the submarine cable.
[0009] Secondly, this application provides a reactive power optimization device for offshore wind farms, including: an offshore wind farm determination module for participating in regulation, used to determine the offshore wind farms participating in regulation at an initial time based on the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster to the busbar of the target offshore wind farm cluster and the grid loss-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster to the grid loss-reactive power sensitivity of each offshore wind farm cluster.
[0010] The wind turbine regulation module is used to regulate the power of wind turbines in each participating offshore wind farm at the initial moment, and determine whether the output power of each participating offshore wind farm after regulation has reached the reactive power demand target value corresponding to the initial moment, and obtain the first judgment result; at any moment, each participating offshore wind farm corresponds to a reactive power demand target value.
[0011] The offshore wind farm reactive power optimization module is used to execute an adjustable reactive power determination step in real time if the first judgment result is negative. The adjustable reactive power determination step is as follows: at the current moment, with the goal of all participating offshore wind farms reaching the reactive power demand target value corresponding to the current moment, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm. The objective function aims to minimize voltage deviation and active power loss. The upper and lower limits of the reactive power output of each participating offshore wind farm are calculated based on the charging capacitance of the submarine cable.
[0012] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for optimizing reactive power in offshore wind farms.
[0013] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for optimizing reactive power in offshore wind farms.
[0014] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the aforementioned method for optimizing reactive power in offshore wind farms.
[0015] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a method, apparatus, equipment, medium, and product for optimizing reactive power in offshore wind farms. The objective function of this application aims to minimize voltage deviation and active power loss, thereby solving the problems of excessive reactive power, voltage exceeding limits, and increased active power loss. When calculating the upper and lower limits of the reactive power output of each participating offshore wind farm, this application considers the charging capacitance of the submarine cable, which can solve the problem of its inapplicability at sea. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a flowchart illustrating a reactive power optimization method for offshore wind farms, provided as an embodiment of this application.
[0018] Figure 2 A simplified diagram of an equivalent wind farm model provided in an embodiment of this application.
[0019] Figure 3 A topology diagram of an offshore wind power collection system provided in an embodiment of this application.
[0020] Figure 4 This is a schematic diagram of the model structure and power relationship of a DFIG provided in an embodiment of this application.
[0021] Figure 5 A reactive power limit diagram for a 6.8MW doubly-fed wind turbine provided in an embodiment of this application.
[0022] Figure 6This is an equivalent circuit model diagram of a submarine cable provided in an embodiment of this application.
[0023] Figure 7 A flowchart of an improved particle swarm optimization algorithm provided in an embodiment of this application.
[0024] Figure 8 A flowchart for selecting wind farms participating in reactive power regulation is provided as an embodiment of this application.
[0025] Figure 9 This is a control framework diagram of a reactive power optimization method for offshore wind farms provided in an embodiment of this application.
[0026] Figure 10 A comparison diagram of node voltages before and after compensation provided in an embodiment of this application.
[0027] Figure 11 A comparison diagram of active power loss before and after compensation provided for an embodiment of this application.
[0028] Figure 12 This is a functional module diagram of a reactive power optimization device for an offshore wind farm, provided as another embodiment of this application.
[0029] Figure 13 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation
[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0031] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0032] In one exemplary embodiment, such as Figure 1 As shown, a method for optimizing reactive power in offshore wind farms is provided, including: Step 201: At an initial moment, based on the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the busbar of the target offshore wind power cluster's collection station, and the network loss-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to its active power losses, the offshore wind farms participating in the regulation are determined. The target offshore wind power cluster includes a collection station, a reactive power compensation device, and multiple offshore wind farms; all offshore wind farms are connected to the collection station through the reactive power compensation device.
[0033] Step 202: At the initial moment, adjust the power of the wind turbines in each participating offshore wind farm, and determine whether the output power of each participating offshore wind farm reaches the reactive power demand target value corresponding to the initial moment after adjustment, to obtain the first judgment result; at any given moment, each participating offshore wind farm corresponds to one reactive power demand target value. Wind power converters can be used to adjust the power of the wind turbines in each participating offshore wind farm.
[0034] Step 203: If the first judgment result is negative, then the adjustable reactive power determination step is executed in real time; the adjustable reactive power determination step is as follows: at the current moment, with the objective that each participating offshore wind farm reaches the reactive power demand target value corresponding to the current moment, the objective function is solved according to the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster. And the adjustable reactive power of each participating offshore wind farm. The objective function aims to minimize voltage deviation and active power loss. The upper and lower limits of reactive power output from each participating offshore wind farm are calculated based on the charging capacitance of the submarine cable. The adjustable reactive power of the reactive power compensation equipment within the target offshore wind farm cluster is also considered. And the adjustable reactive power of each participating offshore wind farm. Adjustments are made to the reactive power compensation equipment and each participating offshore wind farm. If the first judgment result is yes, the time is updated, and then the power of the wind turbines in each participating offshore wind farm is adjusted. It is then determined whether the output power of each participating offshore wind farm after adjustment has reached the reactive power demand target value corresponding to the initial time.
[0035] In another exemplary embodiment of this application, power regulation is performed on the wind turbines in each participating offshore wind farm. Specifically, for any participating offshore wind farm, the equivalent rated capacity and active power of the offshore wind farm are calculated based on the total number of wind turbines in the offshore wind farm, the rated power of the wind turbines, and the active power of the wind turbines.
[0036] The upper and lower limits of the reactive power output of the wind turbines in the offshore wind farm are determined based on the rated capacity and active power of the equivalent offshore wind farm.
[0037] The power of the wind turbines in the offshore wind farm is regulated within the upper and lower limits of the reactive power output of the wind turbines.
[0038] In practical applications, large-scale offshore wind farms typically consist of dozens of wind turbines, and the distribution of each turbine within the offshore wind farm is usually irregular. For simplified calculation, this application treats the interior of the offshore wind farm as an equivalent reactance, the equivalent model of which is as follows: Figure 2 As shown, a large offshore wind farm is equivalent to a single wind turbine to simplify subsequent calculations. Its turbine capacity, active power, and reactive power are superimposed for equivalence, and the calculation formula is as follows: ,in, This is the equivalent rated capacity of the offshore wind farm. This represents the total number of wind turbines in an offshore wind farm. This refers to the rated capacity of the fan. This represents the active power of the equivalent offshore wind farm. This refers to the active power of the wind turbine. This represents the reactive power of an equivalent offshore wind farm. This represents the reactive power of the wind turbine.
[0039] In practical applications, DFIG (Doubly Fed Induction Generator) wind power systems, such as Figure 4 As shown, from left to right, it consists of a wind turbine, gearbox, DFIG generator, rotor-side converter (RSC), grid-side converter (GSC), and power grid. According to the formula... Determine the upper and lower limits of the reactive power output of doubly-fed induction generators in offshore wind farms, such as... Figure 5 As shown. Among them, This refers to the reactive power output of doubly-fed wind turbines in offshore wind farms. This represents the lower limit of the reactive power output of doubly-fed induction generators in offshore wind farms. This is the upper limit of the reactive power output of doubly-fed wind turbines in offshore wind farms. Figure 4 middle, The mechanical power output of the wind turbine. , These are the active power and reactive power generated by the stator, respectively. , These are the active and reactive power flowing from the RSC to the rotor, respectively. , These are the active and reactive power injected into the GSC from the grid, respectively. , These represent the active and reactive power injected into the power grid by the doubly-fed wind turbine generator, respectively.
[0040] In another exemplary embodiment of this application, the upper and lower limits of the reactive power output of the offshore wind farm participating in the regulation are specifically determined as follows: for any offshore wind farm participating in the regulation, the total reactive power loss of the submarine cable corresponding to the offshore wind farm is calculated based on the charging capacitance of the submarine cable and the voltage of the offshore wind farm after passing through the submarine cable.
[0041] The total reactive power loss inside the offshore wind farm is calculated based on the total reactive power loss of the submarine cable corresponding to the offshore wind farm and the reactive power loss of a single transformer within the offshore wind farm.
[0042] Based on the total reactive power loss within the offshore wind farm, the upper and lower limits of the reactive power output of each wind turbine in the offshore wind farm, and the upper and lower limits of the reactive power output of the reactive power compensation equipment within the target offshore wind power cluster, the upper and lower limits of the reactive power output of the offshore wind farm are calculated.
[0043] In practical applications, due to the large number of wind turbines in offshore wind farms, the corresponding number of box-type transformers is also large, so their reactive power loss cannot be ignored. By performing an equivalent transformation on the transformer and calculating the reactive power loss, the equivalent circuit is as follows: Figure 3 As shown. Figure 3 Among them, 5 offshore wind farms ( Figure 5 The offshore wind farms (shown as nodes in the diagram) are aggregated into an offshore wind power cluster through a collection station. The total installed capacity of this offshore wind power cluster is 800MW, and all offshore wind farms are connected to the collection station through a Static Var Generator (SVG) (a type of reactive power compensation device).
[0044] According to the formula calculate and ,in, This represents the reactive power loss on the short-circuit impedance of the transformer in the j-th offshore wind farm. S represents the active power loss on the short-circuit impedance of the transformer in the j-th offshore wind farm. j U represents the power flowing through the short-circuit impedance of the j-th wind farm. j Let be the actual voltage of the j-th offshore wind farm. Let be the active power and reactive power of the j-th offshore wind farm, respectively. These are the short-circuit resistance and short-circuit reactance of the transformer in the j-th offshore wind farm, respectively. This is a constant reactive power loss, and the data is obtained directly from the transformer manufacturer.
[0045] Reactive power loss of a single transformer in the j-th offshore wind farm According to the formula Calculated.
[0046] In practical applications, the loss of submarine cables, and its equivalent circuit, are as follows: Figure 6 As shown, Figure 6 middle For the equivalent line impedance of 220kV, Given the charging capacitance of the submarine cable and the voltage of the offshore wind farm after passing through the submarine cable, calculate the total reactive power loss of the submarine cable corresponding to the j-th offshore wind farm. The specific formula is as follows: ,in, Let be the actual voltage of the j-th offshore wind farm. This indicates the reactance of a 35kV submarine cable. These represent the power losses at the beginning and end admittances of the line, respectively. , , This indicates the charging capacitance of the submarine cable. Let be the voltage of the j-th subsea wind farm after passing through a 220kV submarine cable. R represents the resistance of the 220kV submarine cable, and X represents the reactance of the 220kV submarine cable.
[0047] In practical applications, the total reactive power loss within the offshore wind farm is calculated based on the total reactive power loss of the submarine cables corresponding to the offshore wind farm and the reactive power loss of a single transformer within the offshore wind farm. Specifically, according to the formula calculate.
[0048] In practical applications, based on the total reactive power loss within the offshore wind farm, the upper and lower limits of the reactive power output of each wind turbine in the offshore wind farm, and the upper and lower limits of the reactive power output of the reactive power compensation equipment within the target offshore wind power cluster, the upper limit of the reactive power output of the j-th offshore wind farm is calculated. and lower limit Specifically, according to the formula Calculate, where, For the j-th offshore wind farm The upper and lower limits of the reactive power output of the typhoon turbines, where N represents the total number of wind turbines in the j-th offshore wind farm. Let represent the total reactive power loss within the j-th offshore wind farm. The upper and lower limits of reactive power output by reactive power compensation equipment within the target offshore wind power cluster.
[0049] In another exemplary embodiment of this application, the offshore wind farms participating in the regulation are determined based on the voltage-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster to the busbar of the target offshore wind power cluster and the network loss-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster to its active power losses. Figure 8 As shown, this specifically includes: using the Newton-Raphson power flow calculation method to determine the voltage-reactive sensitivity of each offshore wind farm in the target offshore wind power cluster to the busbar of the target offshore wind power cluster, as well as the network loss-reactive sensitivity of each offshore wind farm in the target offshore wind power cluster to the active power loss.
[0050] The priority of each offshore wind farm in the target offshore wind power cluster is determined based on the voltage-reactive power sensitivity of each offshore wind farm to the busbar of the target offshore wind power cluster and the grid loss-reactive power sensitivity of each offshore wind farm to the active power loss of each offshore wind farm in the target offshore wind power cluster.
[0051] The offshore wind farms participating in the regulation are determined based on their priority within the target offshore wind power cluster.
[0052] In practical applications, the Newton-Raphson power flow calculation method is used to determine the voltage-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster to the busbar of the target offshore wind power cluster, as well as the network loss-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster to its active power losses. The implementing entity is the wind farm energy management system, and the key steps are: according to the formula... Calculate the voltage-reactive power sensitivity matrix , This includes the voltage-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster to the busbar of the target offshore wind power cluster, among which J QV This represents the partial derivative of reactive power Q with respect to voltage U. J Qθ Represents reactive power Q relative to phase The partial derivatives, J Pθ Indicates active power phase The partial derivatives, J PV Indicates active power The partial derivative with respect to voltage U. Used to quantify the impact of reactive power output at each node on the bus voltage, and to screen for sensitive nodes. Q represents the total active and reactive power generated by the offshore wind farm, and U and Q represent the total active and reactive power generated by the offshore wind farm. It refers to the voltage and phase of the offshore wind farm connected to the grid.
[0053] According to the formula Calculate the network loss-reactive power sensitivity matrix , This includes the sensitivity of active power loss to the grid loss-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster, among which... This represents the partial derivative of active power with respect to reactive power. This represents the partial derivative of active power with respect to phase. This represents the partial derivative of active power with respect to voltage. This represents the Jacobian matrix. It is used to evaluate the control effect of reactive power regulation on the active power loss of the system.
[0054] In practical applications, the priority of each offshore wind farm within the target offshore wind power cluster is determined based on its voltage-reactive power sensitivity to the busbar of the target offshore wind power cluster and its active power loss sensitivity to the grid loss-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster. Specifically, this involves normalization processing. and According to the formula Calculate the priority of the j-th offshore wind farm within the target offshore wind power cluster. . and These are the weighting coefficients. After normalization The value in column j represents the voltage-reactive power sensitivity of the j-th offshore wind farm within the target offshore wind power cluster to the busbar of the target offshore wind power cluster's collection station. After normalization The value corresponding to the j-th row represents the network loss-reactive power sensitivity of the j-th offshore wind farm within the target offshore wind power cluster.
[0055] In another exemplary embodiment of this application, The calculation process for the reactive power demand target value corresponding to the j-th offshore wind farm participating in regulation at time j is as follows: based on the target voltage at the central point... Voltage at the grid connection point of offshore wind farms , The voltage of the j-th offshore wind farm participating in regulation after passing through the submarine cable Total reactive power of offshore wind farms and submarine cable reactance calculate The target reactive power demand for the j-th offshore wind farm participating in regulation at time j Specifically, according to the formula... calculate. The voltage of the j-th offshore wind farm participating in regulation after passing through the submarine cable is: The voltage of the j-th subsea wind farm after passing through the 220kV submarine cable at time j.
[0056] In another exemplary embodiment of this application, at the current moment, with the objective of all participating offshore wind farms reaching the reactive power demand target value corresponding to the current moment, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm. Specifically, at the current moment, with the objective of all participating offshore wind farms reaching the reactive power demand target value corresponding to the current moment, the particle swarm optimization algorithm is used to solve the objective function based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm.
[0057] In practical applications, the objective function F is: , and These are the weighting coefficients for multiple objectives. This indicates the minimum voltage deviation. This indicates minimal network loss. Indicates the voltage deviation at the grid connection point. , This represents the voltage deviation at the node. , This represents the active power loss of the entire offshore wind power cluster. min() means taking the minimum value. This refers to the number of offshore wind farms within an offshore wind power cluster. The voltage specified for the j-th wind farm via the 220kV submarine cable is pre-set. For the first The actual voltage of each offshore wind farm No. The specified voltage for each offshore wind farm is preset. Indicates the electrical conductance between the grid connection point and the j-th offshore wind farm. The susceptance between the grid connection point and the j-th offshore wind farm This represents the phase of the voltage of the j-th offshore wind farm. The specified phase of the voltage of the j-th offshore wind farm is preset.
[0058] The constraints on the objective function include: power flow equation constraints: .in: Indicates the voltage at the grid connection point. .
[0059] Voltage safety constraints: .
[0060] Equipment adjustment constraints: , and These are the upper and lower limits of the adjustable reactive power of the SVG, respectively; and These are the upper and lower limits of the adjustable reactive power for the j-th offshore wind farm, respectively.
[0061] In practical applications, the particle swarm optimization algorithm is used to solve the problem according to the specific formula. Inertia weights at iteration number t Dynamic adjustment, initial value =0.9, Termination Value =0.4, T max This represents the upper limit of the number of iterations. According to the formula... The learning factors c1 and c2 are adaptively adjusted. The specific process is as follows: Figure 7 As shown, input the raw data (raw data includes the active power output of the wind turbine, parameters of the submarine cable, parameters of the transformer, and the length of the line). Initialize the position and velocity of the particle swarm (position is...). , ,satisfy , Let represent the adjustable reactive power of the j-th offshore wind farm participating in regulation; the velocity is the regulation step size. Calculate the fitness function for each particle and find the optimal position of the particle at its current state. ) and global optimal position ( The velocity and position of the particles are updated based on inertia weights and learning factors. The fitness function value for each particle is calculated and updated. and Determine if the number of iterations has reached the specified upper limit. If yes, output the optimization result; otherwise, return the steps to update the particle's velocity and position based on the inertia weights and learning factor.
[0062] Current research on reactive power optimization in wind farms mainly focuses on onshore wind farms and single-objective optimization of individual wind farms. This single-objective optimization method only considers factors such as voltage or grid loss, which is too simplistic and has low convergence accuracy and slow convergence speed. This application uses particle swarm optimization to solve the problems of low convergence accuracy and slow convergence speed. Furthermore, this application optimizes multiple offshore wind farms, making it a multi-wind farm optimization.
[0063] This application estimates the reactive power demand of the collection station through central point voltage control and selects wind farms to participate in regulation based on sensitivity analysis, thereby optimizing the voltage quality at the grid connection point and reducing losses. This application achieves voltage stability and improved economic efficiency through multi-device collaborative control. To reduce central point voltage control errors, optimize the voltage quality at the offshore wind farm grid connection point, and improve the economic efficiency of the power grid system, this application establishes a reactive power optimization model (objective function and constraints). This application not only improves the voltage level and grid security level of offshore wind power clusters but also further reduces active power losses, effectively reducing the operating costs of offshore wind power clusters.
[0064] The SVG regulation in this application follows a priority order: wind turbine first, then SVG device. That is, the reactive power regulation capacity of the wind turbine itself is used first, and the SVG device is only activated when the reactive power regulation capacity of the wind turbine reaches its upper or lower limit and still cannot meet the reactive power demand target value. Only when this occurs will the SVG (Static Var Generator) be activated for supplementary adjustments. This maximizes the utilization of the wind turbine's free reactive power resources, reduces the frequency of SVG activations, and thus lowers equipment wear and system operating costs. The flowchart of the entire method is as follows: Figure 9 As shown.
[0065] SVG adjustment is not a one-time event, but rather occurs within a dynamic closed loop. It monitors the bus voltage in real time. And wind farm power fluctuations. The reactive power demand target value will be calculated in real time based on these monitoring data and dynamically updated. This triggers a new round of solution steps, yielding new results. and This allows the SVG to adapt to the fluctuations in wind power and the time-varying nature of the system state, always keeping the system operating in an optimal or near-optimal state.
[0066] By adopting the technical solution of this application, the comprehensive optimization of reactive power and voltage in wind power grid integration under voltage balance conditions mainly demonstrates two advantages, such as... Figure 10 and Figure 11 As shown, firstly, regarding the improvement of active power losses, under different operating conditions, the active power losses of wind power grid integration are reduced by a minimum of 0.208% and a maximum of 19.833% compared to before reactive power compensation. These data strongly demonstrate the effectiveness of this application in reducing active power losses. Secondly, regarding voltage improvement, this application can not only control the voltage at the central point within the allowable error range, but also control the voltage at each wind farm grid connection point within the safe range and simultaneously improve balance.
[0067] Based on the same inventive concept, this application also provides an offshore wind farm reactive power optimization device for implementing the above-mentioned offshore wind farm reactive power optimization method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more offshore wind farm reactive power optimization device embodiments provided below can be found in the limitations of the offshore wind farm reactive power optimization method above, and will not be repeated here.
[0068] In one exemplary embodiment, such as Figure 12 As shown, a reactive power optimization device for offshore wind farms is provided, comprising: an offshore wind farm determination module, used to determine the offshore wind farms to be regulated at an initial time based on the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster to the busbar of the target offshore wind farm cluster and the grid loss-reactive power sensitivity of each offshore wind farm in the target offshore wind farm cluster to the grid loss-reactive power sensitivity of each offshore wind farm cluster.
[0069] The wind turbine regulation module is used to regulate the power of wind turbines in each participating offshore wind farm at the initial moment, and determine whether the output power of each participating offshore wind farm after regulation has reached the reactive power demand target value corresponding to the initial moment, and obtain the first judgment result; at any moment, each participating offshore wind farm corresponds to a reactive power demand target value.
[0070] The offshore wind farm reactive power optimization module is used to execute an adjustable reactive power determination step in real time if the first judgment result is negative. The adjustable reactive power determination step is as follows: at the current moment, with the goal of all participating offshore wind farms reaching the reactive power demand target value corresponding to the current moment, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm. The objective function aims to minimize voltage deviation and active power loss. The upper and lower limits of the reactive power output of each participating offshore wind farm are calculated based on the charging capacitance of the submarine cable.
[0071] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 13As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores reactive power optimization data for offshore wind farms. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a reactive power optimization method for offshore wind farms.
[0072] Those skilled in the art will understand that Figure 13 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0073] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method embodiments.
[0074] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the above-described method embodiments.
[0075] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the above-described method embodiments.
[0076] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.
[0077] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).
[0078] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, etc., and are not limited to these.
[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0080] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for optimizing reactive power in offshore wind farms, characterized in that, The reactive power optimization method for offshore wind farms includes: At the initial moment, the offshore wind farms participating in the regulation are determined based on the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the busbar of the target offshore wind power cluster and the network loss-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the grid loss-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster. At the initial moment, the power of the wind turbines in each participating offshore wind farm is adjusted, and it is determined whether the output power of each participating offshore wind farm after adjustment reaches the reactive power demand target value corresponding to the initial moment, and the first judgment result is obtained; at any moment, one participating offshore wind farm corresponds to one reactive power demand target value. If the first judgment result is negative, the adjustable reactive power determination step is executed in real time. The adjustable reactive power determination steps are as follows: At the current moment, with the objective that all participating offshore wind farms reach the reactive power demand target value corresponding to the current moment, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm; the objective function aims to minimize voltage deviation and active power loss; the upper and lower limits of the reactive power output of each participating offshore wind farm are calculated based on the charging capacitance of the submarine cable.
2. The reactive power optimization method for offshore wind farms according to claim 1, characterized in that, Power regulation is performed on the wind turbines within each participating offshore wind farm, specifically as follows: For any offshore wind farm participating in regulation, the equivalent rated capacity and active power of the offshore wind farm are calculated based on the total number of wind turbines, the rated power of the wind turbines, and the active power of the wind turbines. The upper and lower limits of the reactive power output of the wind turbines in the offshore wind farm are determined based on the rated capacity and active power of the equivalent offshore wind farm. The power of the wind turbines in the offshore wind farm is regulated within the upper and lower limits of the reactive power output of the wind turbines.
3. The reactive power optimization method for offshore wind farms according to claim 1, characterized in that, Based on the voltage-reactive power sensitivity of each offshore wind farm within the target offshore wind power cluster to the busbar of the target offshore wind power cluster, and the active power loss sensitivity of each offshore wind farm within the target offshore wind power cluster to the grid loss-reactive power sensitivity, the offshore wind farms participating in the regulation are determined, specifically including: The Newton-Raphson power flow calculation method is used to determine the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the busbar of the target offshore wind power cluster, as well as the network loss-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the active power loss. The priority of each offshore wind farm in the target offshore wind power cluster is determined based on the voltage-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the bus of the substation in the target offshore wind power cluster and the network loss-reactive power sensitivity of each offshore wind farm in the target offshore wind power cluster to the active power loss. The offshore wind farms participating in the regulation are determined based on their priority within the target offshore wind power cluster.
4. The reactive power optimization method for offshore wind farms according to claim 1, characterized in that, The upper and lower limits of the reactive power output of the offshore wind farms involved in regulation are determined as follows: For any offshore wind farm participating in regulation, the total reactive power loss of the submarine cable corresponding to the offshore wind farm is calculated based on the charging capacitance of the submarine cable and the voltage of the offshore wind farm after passing through the submarine cable. Calculate the total reactive power loss inside the offshore wind farm based on the total reactive power loss of the submarine cable corresponding to the offshore wind farm and the reactive power loss of a single transformer in the offshore wind farm. Based on the total reactive power loss within the offshore wind farm, the upper and lower limits of the reactive power output of each wind turbine in the offshore wind farm, and the upper and lower limits of the reactive power output of the reactive power compensation equipment within the target offshore wind power cluster, the upper and lower limits of the reactive power output of the offshore wind farm are calculated.
5. The reactive power optimization method for offshore wind farms according to claim 1, characterized in that, At the current moment, with the objective of ensuring that all participating offshore wind farms meet their corresponding reactive power demand, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm. This yields the adjustable reactive power of the reactive power compensation equipment within the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm. Specifically: At the current moment, with the goal of all participating offshore wind farms reaching the corresponding reactive power demand target value, the particle swarm optimization algorithm is used to solve the objective function based on the upper and lower limits of the reactive power output of each participating offshore wind farm at the current moment. This yields the adjustable reactive power of the reactive power compensation equipment within the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm.
6. The reactive power optimization method for offshore wind farms according to claim 1, characterized in that, The calculation process for the reactive power demand target value corresponding to the j-th offshore wind farm participating in regulation at time j is as follows: Based on the target voltage at the central point, the grid connection voltage of the offshore wind farm, Calculations of the voltage, total reactive power of the offshore wind farm, and reactance of the submarine cable for the j-th offshore wind farm participating in regulation at time j. The reactive power demand target value corresponding to the j-th offshore wind farm participating in regulation at time j.
7. A reactive power optimization device for offshore wind farms, characterized in that, The offshore wind farm reactive power optimization device includes: The offshore wind farm determination module is used to determine the offshore wind farms participating in the regulation at the initial moment based on the voltage-reactive sensitivity of each offshore wind farm in the target offshore wind power cluster to the busbar of the target offshore wind power cluster and the grid loss-reactive sensitivity of each offshore wind farm in the target offshore wind power cluster to the grid loss-reactive sensitivity of each offshore wind farm in the target offshore wind power cluster. The wind turbine regulation module is used to regulate the power of wind turbines in each participating offshore wind farm at the initial moment, and determine whether the output power of each participating offshore wind farm after regulation has reached the reactive power demand target value corresponding to the initial moment, and obtain the first judgment result; at any moment, each participating offshore wind farm corresponds to a reactive power demand target value. The offshore wind farm reactive power optimization module is used to execute an adjustable reactive power determination step in real time if the first judgment result is negative. The adjustable reactive power determination step is as follows: at the current moment, with the goal of all participating offshore wind farms reaching the reactive power demand target value corresponding to the current moment, the objective function is solved based on the upper and lower limits of the reactive power output of each participating offshore wind farm to obtain the adjustable reactive power of the reactive power compensation equipment in the target offshore wind power cluster and the adjustable reactive power of each participating offshore wind farm. The objective function aims to minimize voltage deviation and active power loss. The upper and lower limits of the reactive power output of each participating offshore wind farm are calculated based on the charging capacitance of the submarine cable.
8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the reactive power optimization method for offshore wind farms according to any one of claims 1-6.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the reactive power optimization method for offshore wind farms as described in any one of claims 1-6.
10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the reactive power optimization method for offshore wind farms as described in any one of claims 1-6.