Wind power plant reactive power self-balancing control method and device and electronic equipment

Abstract

The invention provides a reactive power self-balancing control method and device for a wind power plant and electronic equipment, and the method comprises the steps: obtaining the measurement data of the head end of each current collection feeder line of the wind power plant in any energy management control period, and enabling the head end of each current collection feeder line to be a collection point, close to one side of a booster station, on the current collection feeder line; based on the measurement data and line data of the current collection feeder lines, the total reactive power amount needing to be adjusted in any current collection feeder line is calculated, wherein the line data are impedance parameters of the current collection feeder lines; aiming at any current collection feeder, controlling each fan on the current collection feeder according to the total reactive power and the line data to perform reactive power self-balancing control, taking each current collection feeder as an independent control unit, taking the total reactive power at the head end of the feeder as a closed loop quantity, realizing a self-balancing target that the reactive power at the head end of the feeder is approximate to zero, and being small in communication burden and high in reliability. The control stability is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind farm control, in particular to a wind farm reactive power self-balancing control method and device and electronic equipment. BACKGROUND

[0002] Large-scale wind farms generally adopt the structure of multiple power collection feeders and booster stations; cable-type feeders have charging reactive power sending at light load, and overhead lines have inductive voltage drop and line loss problems at heavy load. The traditional method mostly uses automatic voltage control (AVC) to control the reactive power of wind turbine groups, static var generators (SVG), phase modulators and other devices at the grid connection point, and the internal reactive power of the feeder is not evenly distributed in space, leading to long-term high occupancy of SVG / phase modulators, high wear and energy consumption, voltage oscillation or overcompensation caused by communication delay / packet loss of centralized AVC, voltage fluctuation or out-of-limit at the end of the feeder, and back-and-forth circulation of reactive current on the power collection line, increasing line loss. SUMMARY

[0003] Therefore, the embodiments of the present application aim to provide a wind farm reactive power self-balancing control method and device and electronic equipment, which take each power collection feeder as an independent control unit, take the total amount of reactive power at the head of the feeder as a closed loop, and realize the self-balancing goal of approximately zero reactive power at the head of the feeder, with small communication burden and high control stability.

[0004] According to an aspect of the present application, an embodiment of the present application provides a wind farm reactive power self-balancing control method, which comprises: obtaining measurement data of the head of each power collection feeder of a wind farm in any controllable period, the head of the power collection feeder being a collection point close to the side of the booster station on the power collection feeder; calculating the total amount of reactive power that needs to be adjusted in any power collection feeder based on the measurement data and line data of the power collection feeder, the line data being impedance parameters of the power collection feeder; and controlling each wind turbine on the power collection feeder to perform reactive power self-balancing control according to the total amount of reactive power and the line data for any power collection feeder.

[0005] In an embodiment, the measurement data includes the reactive power at the head of the power collection feeder; and the calculation of the total amount of reactive power that needs to be adjusted in any power collection feeder based on the measurement data and line data of the power collection feeder comprises: calculating the difference between the target reactive power and the reactive power to obtain the reactive power deviation for any power collection feeder; determining a feedforward bias term according to the line data; and obtaining the total amount of reactive power that needs to be adjusted in the power collection feeder according to the reactive power deviation and the feedforward bias term.

[0006] In one embodiment, controlling each wind turbine on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data includes: determining the weighting factor of each wind turbine on the collector feeder; obtaining a reactive power reference value for any wind turbine on the collector feeder based on the total reactive power, the weighting factor, and the line data; and controlling the wind turbine to perform reactive power self-balancing control based on the reactive power reference value and the line data.

[0007] In one embodiment, obtaining the reactive power reference value of the wind turbine based on the total reactive power, the weighting factor, and the line data includes: calculating the product of the difference between the connection point voltage and the reference voltage of the wind turbine and the voltage adjustment gain, and calculating the sum of the product of the total reactive power and the weighting factor and the product to obtain the reactive power capacity value of the wind turbine; and applying a saturation function to determine the reactive power reference value of the wind turbine based on the reactive power capacity value and the upper limit of the reactive power capacity of the wind turbine.

[0008] In one embodiment, controlling the wind turbine to perform reactive power self-balancing control based on the reactive power reference value and the line data includes: determining the reactive current value based on the reactive power reference value; calculating the active current component and reactive current component of the wind turbine that satisfy a preset condition based on the reactive current value and the line data according to a preset priority order, wherein the preset priority order is that the priority of compliance constraints, self-balancing constraints, and active power command constraints decreases in that order, and the preset condition is that the squares of the active current component and the reactive current component are each less than or equal to the square of the maximum allowable current of the wind turbine converter; and controlling the wind turbine to operate based on the active current component and the reactive current component.

[0009] In one embodiment, determining the weight factor of each wind turbine on the collector feeder further includes: if the wind farm communication is restored after a power outage, the weight based on the previous energy management control cycle is approximated to the currently determined weight by a ramp.

[0010] In one embodiment, the method further includes: any of the collector feeders transmitting the uncompensated reactive power difference after self-balancing control to the automatic voltage control device of the wind farm through the energy management system; and the automatic voltage control device supplementing the reactive power difference.

[0011] In one embodiment, the method further includes: if the wind farm communication is abnormal, latching the total reactive power of each of the collector feeders in the previous energy management control cycle, using the total reactive power of the previous energy management control cycle as the total reactive power of the current cycle, and executing the step of controlling each wind turbine on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data.

[0012] According to another aspect of the present invention, an embodiment of the present invention provides a reactive power self-balancing control device for a wind farm, the wind farm reactive power self-balancing control device comprising: a data acquisition unit, configured to acquire measurement data at the beginning of each collector feeder of the wind farm within any energy management control cycle, wherein the beginning of the collector feeder refers to the acquisition point on the collector feeder near the booster station; a reactive power calculation unit, configured to calculate the total reactive power that needs to be adjusted in any collector feeder based on the measurement data and the line data of the collector feeder, wherein the line data is the impedance parameter of the collector feeder; and a self-balancing unit, configured to control each wind turbine on the collector feeder to perform reactive power self-balancing control for any collector feeder according to the total reactive power and the line data.

[0013] According to another aspect of the present invention, an electronic device is provided in one embodiment of the present invention, comprising: a memory for storing an executable computer program; and a processor for calling and running the executable computer program from the memory, such that the processor executes the above-described wind farm reactive power self-balancing control method.

[0014] This invention provides a method, device, and electronic equipment for reactive power self-balancing control in a wind farm. Within any energy management control cycle, it acquires measurement data from the beginning of each collector feeder in the wind farm. The beginning of the collector feeder refers to the acquisition point on the feeder closest to the substation. Based on the measurement data and the line data of the collector feeder, it calculates the total reactive power that needs adjustment in any collector feeder. The line data refers to the impedance parameters of the collector feeder. For any given collector feeder, it controls each wind turbine on the feeder to perform reactive power self-balancing control according to the total reactive power and the line data. Each collector feeder is treated as an independent control unit, with the total reactive power at the feeder's beginning as the closed-loop quantity, achieving a self-balancing target where the reactive power at the feeder's beginning is approximately zero. This method has low communication overhead and high control stability. Attached Figure Description

[0015] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0016] Figure 1 The diagram shown is a flowchart of a wind farm reactive power self-balancing control method provided in an embodiment of this application.

[0017] Figure 2 The diagram shown is a structural schematic of a wind farm provided in an embodiment of this application.

[0018] Figure 3The diagram shown is an example of a reactive power self-balancing control method for a wind farm provided in an embodiment of this application.

[0019] Figure 4 The diagram shown is a structural schematic of a wind farm reactive power self-balancing control device provided in an embodiment of this application.

[0020] Figure 5 The diagram shown is a structural schematic of an electronic device provided in an embodiment of this application. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Furthermore, in exemplary embodiments, since the same reference numerals denote the same components having the same structure or the same steps of the same method, if one embodiment has been described by way of example, then in other exemplary embodiments only structures or methods different from those described in the embodiment will be described.

[0023] Throughout the specification and claims, when a component is described as being “connected” to another component, that component may be “directly connected” to the other component or “electrically connected” to the other component via a third component. Furthermore, unless explicitly stated otherwise, the term “comprising” and its corresponding terms should be understood only to include the stated component and not to exclude any other component.

[0024] In related technologies, large-scale wind farms generally adopt a structure with multiple collector feeders and step-up substations. Cable-type feeders generate reactive power during charging under light loads, while overhead lines suffer from inductive voltage drop and line loss under heavy loads. Traditionally, automatic voltage control (AVC) systems are used at the grid connection point to control the wind turbine group, static var generators (SVG), synchronous condensers, and other equipment to regulate reactive power. Uneven distribution of reactive power within the feeder leads to long-term high-percentage operation of the SVG / synchronous condenser, resulting in high wear and energy consumption. Centralized AVC systems are prone to voltage oscillations or overcompensation during communication delays / packet loss. The voltage at the point of connection (POI) meets the standard, but the voltage at the feeder end fluctuates or exceeds the limit, causing reactive current to circulate repeatedly on the collector lines, increasing line losses.

[0025] Figure 1The diagram shown is a flowchart illustrating a reactive power self-balancing control method for a wind farm according to an embodiment of this application. Figure 1 As shown, the reactive power self-balancing control method for this wind farm includes: Step S11: Within any energy management control cycle, acquire measurement data at the beginning of each collector feeder in the wind farm, where the beginning of the collector feeder refers to the collection point on the collector feeder that is closest to the booster station.

[0026] In wind farms, see Figure 2 The high-voltage side of the substation is connected to the power grid, while the low-voltage side is connected to multiple collector feeders, each equipped with multiple wind turbines. During a power grid transient fault, upon receiving a power grid dispatch command, the substation adjusts its reactive power output according to the command value for reactive power compensation. Wind farm reactive power control includes substation-level automatic voltage control and turbine-level automatic voltage control (AVC). The AVC system typically adjusts the setpoints of the wind farm's reactive power supply on a minute-level timescale, while turbine-level local control responds on millisecond to second-level timescales. In this embodiment, the wind turbines on the collector feeders autonomously compensate for line reactive power losses, while AVC controls other reactive power sources (such as SVG and synchronous condensers) and ensures that the voltage / reactive power at the grid connection point meets dispatch requirements.

[0027] After the wind farm configuration is completed, a collector feeder-wind turbine list is established, specifying the line parameters and measurement point locations for each collector feeder. The line parameters are the inductance R and reactance X values ​​of the collector feeder from the low-voltage side bus of the substation to each wind turbine location. The measurement point locations refer to the starting points of each collector feeder connected to the wind turbines on the low-voltage side of the substation. The line data for each collector feeder includes the voltage at each wind turbine connection point, the voltage reference value, the upper limit of the reactive power capacity of each wind turbine, and the line parameters, etc.

[0028] In this embodiment, the energy management control cycle is defined as one reactive power self-balancing control cycle for a wind farm. Within any energy management control cycle, measurement data is collected at the beginning of each collector feeder on the low-voltage side of the substation. The beginning of the collector feeder refers to the collection point on the collector feeder closest to the substation. The measurement data includes, but is not limited to: active power collected at the beginning of the collector feeder, reactive power collected at the beginning of the collector feeder, and voltage collected at the beginning of the collector feeder.

[0029] Step S12: Calculate the total reactive power that needs to be adjusted in any collector feeder based on the measurement data and the line data of the collector feeder, where the line data is the impedance parameter of the collector feeder.

[0030] The reactive power collected at the beginning of the collector feeder is the reactive power output of the collector feeder in the current energy management control cycle. Based on the target reactive power of the collector feeder, the current reactive power, and the line data, the total amount of reactive power that needs to be adjusted in the collector feeder can be determined, which can facilitate the subsequent reactive power self-balancing control of each wind turbine.

[0031] Step S13: For any of the aforementioned collector feeders, control each wind turbine on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data.

[0032] For any of the aforementioned collector feeders, after obtaining the total reactive power that needs adjustment for that feeder, this total reactive power needs to be allocated to each wind turbine on that feeder. When performing reactive power self-balancing control on each wind turbine, the hardware requirements of each wind turbine need to be considered, and the reactive power injection logic of each wind turbine also needs to be satisfied. This application embodiment achieves reactive power self-balancing of the collector feeder by adjusting the active current component and reactive current component of each wind turbine while satisfying hardware constraints and reactive power injection constraints.

[0033] This invention provides a reactive power self-balancing control method for wind farms. Within any energy management control cycle, measurement data is acquired at the beginning of each collector feeder in the wind farm. The beginning of the collector feeder refers to the acquisition point on the collector feeder closest to the substation. Based on the measurement data and the line data of the collector feeder, the total reactive power to be adjusted in any collector feeder is calculated. The line data refers to the impedance parameters of the collector feeder. For any collector feeder, each wind turbine on the feeder is controlled to perform reactive power self-balancing control according to the total reactive power and the line data. This method allows each collector feeder to be treated as an independent control unit, achieving a self-balancing target where the reactive power at the feeder beginning is approximately zero, with high control stability.

[0034] In one embodiment, the measurement data includes the reactive power at the beginning of the collector feeder. The step of calculating the total reactive power to be adjusted in any collector feeder based on the measurement data and the line data of the collector feeder includes: for any collector feeder, calculating the difference between the target reactive power and the reactive power to obtain the reactive power deviation; determining a feedforward bias term based on the line data; and obtaining the total reactive power to be adjusted in the collector feeder based on the reactive power deviation and the feedforward bias term.

[0035] The target reactive power can be the reactive power that needs to be compensated for by each collector feeder, as determined by the power grid dispatch instructions. The measurement data collected at the beginning of any k-th collector feeder includes: the reactive power at the beginning of the collector feeder. Active power and voltage For any k-th collector feeder, the difference between the target reactive power and the actual reactive power can be calculated to obtain the reactive power deviation: in, The reactive power deviation of the k-th collector feeder is... Let the target reactive power of the k-th collector feeder be , This represents the reactive power collected at the beginning of the k-th collector feeder. It should be noted that data acquisition and error calculation are performed synchronously. Strictly speaking, there will be a communication cycle difference between reactive power acquisition and error calculation. This time depends on the communication protocol used, and the communication duration generally does not exceed 100ms.

[0036] The feedforward bias term is mainly used to offset the reactive power caused by the charging capacitor (cable) or the reactive power caused by the inductive voltage drop (overhead line). The feedforward bias term is related to the line data of the collector feeder. Specifically, ,in, For the feedforward bias term of the k-th collector feeder, Let be the voltage of the k-th collector feeder. Capacitance per unit length of phase (F / m). The length (m) of the collector feeder. Angular frequency, , This is the cutoff frequency.

[0037] After obtaining the reactive power deviation and feedforward bias term, the total reactive power that needs to be adjusted in the collector feeder can be calculated based on these terms. The integral term within one acquisition cycle can be obtained from the reactive power deviation; a weighted sum of the reactive power, the integral term, and the feedforward bias term is then performed to obtain the total reactive power that needs to be adjusted in the collector feeder. The formula for calculating the total reactive power is as follows: in, Let be the total reactive power that needs to be adjusted in the k-th collector feeder. and This is a weighting factor, and its specific value can be set as needed. This allows for accurate determination of the total reactive power that needs adjustment in each collector feeder.

[0038] Obtain the total reactive power Then, the total reactive power will be obtained. The broadcast is sent to all wind turbines on the collector feeder line, and subsequent control of each wind turbine can be based on this total reactive power. Perform self-balancing control.

[0039] In one embodiment, controlling the wind turbines on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data includes: determining the weighting factor for each wind turbine on the collector feeder; obtaining a reactive power reference value for any wind turbine on the collector feeder based on the total reactive power, the weighting factor, and the line data; and controlling the wind turbine to perform reactive power self-balancing control based on the reactive power reference value and the line data. The total reactive power is allocated through corresponding weighting factors, and the final reactive power reference value to be output by each wind turbine on the collector feeder is determined by combining the line data, thus controlling each wind turbine to output the corresponding reactive power reference value while satisfying line constraints. This is achieved by using only a single broadcast scalar, namely the total reactive power. It allocates reactive power based on the wind turbine's own performance, unaffected by other control parameters, using the reactive power at the feeder head as the closed-loop quantity to achieve reactive power self-balancing at the feeder level. This results in high control stability.

[0040] On any collector feeder, the larger the weighting factor of the wind turbine, the more reactive power it compensates. For any wind turbine on the collector feeder, the total reactive power can be allocated according to the weighting factor, and the required reactive power reference value for the wind turbine can be determined by combining the wind turbine's hardware and software conditions. Then, reactive power self-balancing control can be achieved based on this reactive power reference value and the constraints of the collector feeder and the wind turbine. The weighting factor can be obtained in various ways. In one embodiment, the weighting factor of each wind turbine on the collector feeder can be determined using any of the following methods: The weighting factors of each fan on the collector feeder are evenly distributed; The weighting factor of each wind turbine is allocated proportionally to the remaining reactive power margin of each wind turbine. The equivalent impedance value of each wind turbine to the beginning of the collector feeder is determined based on the electrical distance from each wind turbine to the beginning of the collector feeder, and the weighting factor of each wind turbine is determined based on the equivalent impedance value.

[0041] The weighting factor of each wind turbine on the collector feeder can be evenly distributed. In this case, the weighting factor of each wind turbine is independent of its position on the collector feeder, and all wind turbines have the same weighting factor, meaning that the total reactive power is evenly distributed among all wind turbines. This method can be used to determine the weighting factor when each wind turbine has a large remaining reactive power margin and the line constraints are met. It simplifies the process and improves the efficiency of reactive power compensation.

[0042] Due to the influence of the location of each wind turbine on the collector feeder and the performance of the turbines themselves, the remaining reactive power margin of each turbine may vary. Therefore, a weighting factor can be allocated to each wind turbine proportionally based on its remaining reactive power margin, thereby allocating the total reactive power. This method can be considered when the remaining reactive power margins of each wind turbine are uneven, or when some turbines have insufficient remaining reactive power margins, to determine the weighting factor of each turbine, thereby improving reactive power compensation efficiency.

[0043] Furthermore, since each wind turbine is located at a different position on the collector feeder, meaning the electrical distance from each turbine to the beginning of the feeder is not the same, the equivalent impedance values ​​from each turbine to the beginning of the feeder are also different. Therefore, a weighting factor for each turbine can be determined based on these equivalent impedance values. The allocation mechanism is that the shorter the electrical distance from the turbine to the low-voltage side of the main transformer (smaller |Z|), the greater the impact of the reactive power injected by that turbine on the low-voltage side of the main transformer, i.e., the more effective it is, and therefore a larger proportion should be allocated to it. In one embodiment, the equivalent impedance value between each wind turbine and the beginning of the collector feeder can be defined as... The equivalent impedance value is the combined equivalent impedance of the series impedance / parallel admittance along the path from the wind turbine bus to the low-voltage side of the main transformer. Based on this equivalent impedance value, the weighting factor can be calculated using the following formula: in, Let i be the weighting factor for the i-th wind turbine on the collector feeder line. That is, the sum of the weight factors of all wind turbines on any k-th collector feeder line equals 1. Let be the equivalent impedance modulus between the i-th fan on the collector feeder and the beginning of the collector feeder. Let be the equivalent impedance value between the i-th wind turbine on the collector feeder and the beginning of the collector feeder. The weighting factor for each wind turbine is assigned based on the electrical distance from each wind turbine to the beginning of the collector feeder. This fully considers the actual situation of each wind turbine, making the weighting factor allocation closer to the line characteristics of the collector feeder, improving the accuracy of the weighting factor allocation, and helping to improve the efficiency and accuracy of reactive power compensation.

[0044] After determining the weighting factors of each wind turbine on the collector feeder, the total reactive power can be allocated according to the weighting factors, and the required reactive power reference value for each wind turbine on the collector feeder can be obtained by combining the line data. In one embodiment, optionally, the product of the difference between the connection point voltage and the reference voltage of the wind turbine and the voltage adjustment gain is calculated, and the sum of the product of the total reactive power and the weighting factors and the product is calculated to obtain the reactive power capacity value of the wind turbine; the reactive power reference value of the wind turbine is determined by applying a saturation function based on the reactive power capacity value and the upper limit of the reactive power capacity of the wind turbine.

[0045] The required reactive power reference value for each wind turbine on the collector feeder line is related to the reactive power capacity value allocated from the total reactive power based on a weighting factor, and is also constrained by the wind turbine hardware, meaning it must be within the wind turbine's capacity range. Based on this, the required reactive power reference value for each wind turbine is calculated using the following formula: in, Let i be the reactive power reference value that the i-th wind turbine needs to output. Let be the weighting factor for the i-th wind turbine. Let be the voltage at the connection point of the i-th fan (pu, per unit value). The voltage regulation gain (MVAr / pu) is used to suppress terminal voltage deviations by setting the voltage-reactive power correction for each wind turbine unit. This is the current collector feeder voltage reference value (pu), default 1.00 pu. This represents the upper limit of reactive power capacity of the i-th wind turbine under its current active power output / current limit, determined by the turbine's PQ capacity curve / current limit; the upper and lower limits can be asymmetrical. Fast and precise reactive power regulation is achieved through a feedforward + PI control and weighted allocation mechanism.

[0046] After obtaining the reactive power reference value for each wind turbine on the collector feeder line, each wind turbine can perform reactive power self-balancing control based on the reactive power reference value and line data. Reactive power self-balancing control of each wind turbine can only be performed if equipment current / thermal constraints, reactive current injection logic constraints, etc., are met. In one embodiment, optionally, the reactive current value is determined based on the reactive power reference value; the active current component and reactive current component of the wind turbine satisfying preset conditions are solved based on the reactive current value and the line data according to a preset priority order, wherein the preset priority order is that the priority of compliance constraints, self-balancing constraints, and active power command constraints decreases in that order; the preset condition is that the squares of the active current component and the reactive current component are each less than or equal to the square of the maximum allowable current of the wind turbine converter; the wind turbine is controlled to operate based on the active current component and the reactive current component.

[0047] The reactive current value determined based on the reactive current reference value is the reactive current value expected by the wind turbine to achieve self-balancing. That is, it is the reactive current reference value calculated by the local controller of the collector feeder to compensate for reactive power losses on the collector feeder. The reactive current value can be calculated using the following formula. : Then, based on the calculated reactive current value and line data, the active and reactive current components of the wind turbine that meet the preset conditions are solved according to a preset priority order. The preset priority order is as follows: compliance constraints, self-balancing constraints, and active power command constraints, with the priority decreasing in that order. That is, compliance constraints are satisfied first, which are the equipment current / thermal constraints. The equipment current / thermal constraints have the highest priority; the execution of other control strategies must be within the limits of these thermal constraints. Thermal constraints are hardware constraints of equipment such as wind turbines, and these constraints take effect in real time as long as the equipment is operating normally in grid connection. The LVRT / HVRT reactive power injection logic has the second priority and is generally triggered only when the grid voltage is higher than 1.1 pu or lower than 0.9 pu. In this case, the active power output priority is lower than the reactive power, and the reactive power capacity of the wind turbine is greater than the reactive power capacity boundary under the self-balancing condition of the collector feeder. The preset condition is that the squares of the active current component and the reactive current component are each less than or equal to the square of the maximum allowable current of the wind turbine converter, that is, the current of the wind turbine converter determined by the wind turbine based on the active current component and the reactive current component is not greater than the maximum allowable current of the wind turbine converter.

[0048] In one embodiment, the line data includes a minimum reactive current and a maximum allowable current of the wind turbine converter; based on the minimum reactive current, the maximum allowable current, and the reactive current value, a simplified quadratic programming problem is solved for each sampling period as follows: satisfy in, This represents the active current component of the wind turbine. This represents the reactive current component of the wind turbine. This represents the minimum reactive current of the wind turbine. The reactive current value required for the wind turbine to achieve self-balancing. This is a reference value for the active current of the wind turbine. , , The corresponding weighting coefficients are: the first term represents compliance constraints, the second represents self-balancing control terms, and the third represents active power instructions. Greater than ,and Greater than This reflects that compliance (grid connection requirements) has the highest priority, followed by self-balancing, and active power control has the lowest priority. This is the maximum allowable current for the wind turbine converter.

[0049] Based on the above secondary planning, the active current components of each wind turbine on the collector feeder are determined. The reactive current component of the wind turbine Then, based on the active current component The reactive current component of the wind turbine Determine the current of each wind turbine converter and control each wind turbine to operate at that current to complete the reactive power compensation of the collector feeder and realize the reactive power self-balancing control of the wind farm.

[0050] It should be noted that when reactive power compensation is normal, meaning each collector feeder can perform the required reactive power compensation, the reactive power at the head end of the collector feeder is locked at the feeder layer. When the reactive power is close to zero, the AVC is responsible for regulating the grid connection point voltage / reactive power, mainly utilizing reactive power resources such as SVG / synchronous condenser. However, if the wind turbine's reactive power capacity is insufficient, the AVC can request the wind turbine to provide more reactive power, increasing the minimum reactive current of the wind turbine. As for the minimum reactive current of the wind turbine... Whether the value is positive or negative depends on the direction of reactive power. Since the weighting coefficient w1 is the largest, each wind turbine will prioritize fulfilling this instruction.

[0051] If the wind turbines still cannot fully compensate for the reactive power losses in the lines, i.e., self-balancing cannot be achieved, the EMS at the feeder level will also report a reactive power deficit, which is then supplemented by the AVC. Based on this, in one embodiment, optionally, any of the aforementioned collector feeders transmits the uncompensated reactive power difference after self-balancing control to the automatic voltage control device of the wind farm through the energy management system; the automatic voltage control device then supplements the reactive power difference. The feeder level cannot achieve so-called self-balancing, meaning the reactive power generated by the wind turbines is insufficient to compensate for the reactive power losses generated on the lines. If necessary, active power can be sacrificed to release reactive power. For example, if the reactive power dispatch command received by the AVC is large, and the reactive power output of the wind farm's SVG and wind turbines has reached its limit, then the active power output of the wind turbines can be reduced to meet the requirements of the grid dispatch AVC reactive power command. This application embodiment, by introducing a "hard constraint priority" mechanism, ensures equipment safety and system stability. Through coordinated control of the collector feeders and the wind farm's AVC, optimized scheduling of reactive power resources can be achieved.

[0052] The following details an example of reactive power self-balancing control in a wind farm, such as... Figure 3 As shown, the reactive power self-balancing control method for wind farms includes: Step 300: Begin.

[0053] Complete the on-site configuration of the wind farm: Establish a collector feeder-wind turbine list, and mark the line parameters and measurement point locations for each collector feeder. The line parameters are the inductance R and reactance X values ​​of the collector feeder from the low-voltage side bus of the substation to each wind turbine location. The measurement point locations refer to the starting points of each collector feeder connected to the wind turbine on the low-voltage side of the substation.

[0054] Step 301: Parameter initialization.

[0055] Calculate the feedforward term based on the line impedance parameters. Initial values; calculate the weighting factor for each wind turbine based on electrical distance. .

[0056] Step 302: Feeder data acquisition.

[0057] To ensure consistent time synchronization, the wind turbines and the Energy Management System (EMS) perform network communication IP time synchronization, guaranteeing that the timestamps of the data are identical. Then, the reactive power at the beginning of each collector feeder is collected. Active power and voltage Furthermore, outlier removal is performed. For example, if the reactive power value of some sampling points deviates significantly from the sampling values ​​in previous and subsequent cycles, removing outliers can prevent abnormal operations or equipment failures from interfering with the optimization algorithm.

[0058] Step 303: Calculate the weight factor for a single machine.

[0059] Calculate the weighting factor in each energy management control cycle. The total reactive power that needs to be adjusted in the collector feeder The specific calculation method is described above and will not be repeated here.

[0060] Step 304: Determine whether the current feeder acquisition is valid data. If yes, proceed to step 305; otherwise, proceed to step 306.

[0061] Determine whether the measurement data collected from the current collector feeder is valid so that abnormal data can be removed in a timely manner, avoiding interference from abnormal operation or equipment failure on the optimization algorithm.

[0062] Step 305: EMS cycle calculation and Then proceed to step 307.

[0063] The EMS of the collector feeder layer calculates the reactive power deviation of the current collector feeder in each power control cycle. The total reactive power that needs to be adjusted for the current collector feeder The calculation method is the same as before, and will not be repeated here.

[0064] Step 306: Mark the exception. Then proceed to step 307.

[0065] If the measurement data collected for the current collector feeder is determined to be invalid, it is marked as abnormal and the abnormal data can be removed.

[0066] Step 307: Calculate the corresponding weight for each wind turbine according to the preset weight. .

[0067] The preset weights are the weighting factors for each wind turbine calculated earlier. Each wind turbine is determined according to a weighting factor. By combining the line data, the required reactive power output reference value of the wind turbine can be determined. The calculation method is the same as the previous method, and will not be repeated here.

[0068] Step 308: The wind turbine group cannot achieve self-balancing, and the AVC compensates for the shortfall. Then return to step 303.

[0069] The reactive power reference value required for each wind turbine is calculated. Self-balancing control is performed, using the same method described previously. If the wind turbine group cannot achieve self-balancing, the EMS at the feeder level will also report a reactive power deficit, which will be supplemented by the AVC. Then, return to step 303 to perform reactive power self-balancing processing for the next energy management control cycle.

[0070] During actual operation, wind farms inevitably encounter communication abnormalities between the collector feeders and the power station. Therefore, in one embodiment, the method may optionally further include: if the wind farm communication is abnormal, latching the total reactive power of each collector feeder in the previous energy management control cycle, using the total reactive power of the previous energy management control cycle as the total reactive power of the current cycle, and executing the step of controlling the wind turbines on the collector feeders to perform reactive power self-balancing control based on the total reactive power and the line data. If the wind farm communication is abnormal, it indicates that the required reactive power adjustment for the current energy management control cycle cannot be obtained. At this point, the total reactive power of the previous energy management control cycle can be latched and used as the total reactive power of the current energy management control cycle for reactive power self-balancing control of the current energy management control cycle. In this way, the wind turbine unit degenerates into local voltage-reactive power control, and compliance / hardware constraints are still effective. Compliance means meeting the reactive power support requirements during high and low voltage grid crossings and the dispatch reactive power instructions issued to the AVC. Hardware constraints are the maximum current of the wind turbine converter. Exceeding this limit will burn out the equipment, which can ensure the stability and safety of the system.

[0071] After the wind farm communication is restored following a power outage, to prevent the reactive power total amount that needs to be adjusted in each collector feeder in the reactive power command, In one embodiment, if communication with the wind farm is restored after a power outage, the weights from the previous energy management control cycle are approximated by a ramp to the currently determined weights. The specific value of the ramp can be set as needed; generally, a slow ramp approximation of the latest reactive power command over 5-10 seconds is sufficient. This prevents sudden step jumps in commands after communication is suddenly restored, which could cause system instability.

[0072] This invention provides a wind farm reactive power self-balancing control method that uses the low-voltage side of the transformer substation as the boundary and treats each collector feeder as an independent control unit. This achieves a self-balancing target where the reactive power at the feeder's initiation point is approximately zero. Through layered decoupling, the rapid feeder self-balancing is separated from the slow station AVC target, thus avoiding control conflicts. During the self-balancing process, only one scalar is broadcast: the total reactive power that needs to be adjusted in each collector feeder. With low communication burden, it uses the reactive power at the feeder head as the closed-loop quantity to achieve reactive power self-balancing at the feeder layer, resulting in high control stability. The weighting factors of each wind turbine can be allocated based on electrical distance / equivalent reactance, making the allocation of weighting factors closer to the line characteristics and physically interpretable. By adopting feedforward + PI control and weighting allocation mechanism, it achieves fast and accurate reactive power regulation. At the same time, the introduction of a "hard constraint priority" mechanism can ensure equipment safety and system stability. During the self-balancing process, the collector feeder and the station AVC work together to achieve optimized scheduling of reactive power resources. In the event of communication anomalies, it can degrade operation, ensuring system safety and high robustness.

[0073] In a wind farm reactive power self-balancing control method provided by this invention, measurement data is acquired at the beginning of each collector feeder in the wind farm within any energy management control cycle. The beginning of the collector feeder refers to the acquisition point on the collector feeder closest to the substation. Based on the measurement data and the line data of the collector feeder, the total reactive power that needs to be adjusted in any collector feeder is calculated. The line data refers to the impedance parameters of the collector feeder. For any collector feeder, each wind turbine on the collector feeder is controlled to perform reactive power self-balancing control according to the total reactive power and the line data. Each collector feeder is treated as an independent control unit, and the total reactive power at the beginning of the feeder is used as the closed-loop quantity to achieve the self-balancing target of approximately zero reactive power at the beginning of the feeder. This method has low communication burden and high control stability.

[0074] Figure 4 The diagram shown is a structural schematic of a wind farm reactive power self-balancing control device according to an embodiment of this application. Figure 4 As shown, the reactive power self-balancing control device 400 for wind farms includes: The data acquisition unit 401 is used to acquire measurement data at the beginning of each collector feeder in the wind farm during any energy management control cycle. The beginning of the collector feeder refers to the collection point on the collector feeder that is closer to the booster station. The reactive power calculation unit 402 is used to calculate the total reactive power that needs to be adjusted in any collector feeder based on the measurement data and the line data of the collector feeder, wherein the line data is the impedance parameter of the collector feeder. The self-balancing unit 403 is used to control the reactive power self-balancing of each wind turbine on any of the aforementioned collector feeders based on the total reactive power and the line data.

[0075] In one embodiment, the measurement data includes the reactive power at the beginning of the collector feeder; the reactive power calculation unit 402 is used to: calculate the difference between the target reactive power and the reactive power for any collector feeder to obtain the reactive power deviation; determine the feedforward bias term based on the line data; and obtain the total reactive power that needs to be adjusted in the collector feeder based on the reactive power deviation and the feedforward bias term.

[0076] In one embodiment, the self-balancing unit 403 is used to: determine the weighting factor of each wind turbine on the collector feeder; for any wind turbine on the collector feeder, obtain the reactive power reference value of the wind turbine based on the total reactive power, the weighting factor, and the line data; and control the wind turbine to perform reactive power self-balancing control based on the reactive power reference value and the line data.

[0077] In one embodiment, the self-balancing unit 403 is further configured to: calculate the product of the difference between the access point voltage and the reference voltage of the wind turbine and the voltage adjustment gain, and calculate the sum of the product of the total reactive power and the weighting factor and the product to obtain the reactive power capacity value of the wind turbine; and apply a saturation function to determine the reactive power reference value of the wind turbine based on the reactive power capacity value and the upper limit of the reactive power capacity of the wind turbine.

[0078] In one embodiment, the self-balancing unit 403 is further configured to: determine the reactive current value based on the reactive reference value; solve for the active current component and reactive current component of the wind turbine that satisfy a preset condition based on the reactive current value and the line data according to a preset priority order, wherein the preset priority order is that the priority of compliance constraints, self-balancing constraints and active power command constraints decreases in sequence, and the preset condition is that the squares of the active current component and the reactive current component are each less than or equal to the square of the maximum allowable current of the wind turbine converter; and control the wind turbine to operate based on the active current component and the reactive current component.

[0079] In one embodiment, the self-balancing unit 403 is further configured to: if the wind farm communication is restored after a power outage, approximate the currently determined weights based on the weights of the previous energy management control cycle using a ramp.

[0080] In one embodiment, the self-balancing unit 403 is further configured to: transmit the uncompensated reactive power difference after self-balancing control to the automatic voltage control device of the wind farm through any of the collector feeders via the energy management system; and compensate for the reactive power difference through the automatic voltage control device.

[0081] In one embodiment, the self-balancing unit 403 is further configured to: if the wind farm communication is abnormal, latch the total reactive power of each of the collector feeders in the previous energy management control cycle, use the total reactive power of the previous energy management control cycle as the total reactive power of the current cycle, and execute the step of controlling each wind turbine on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data.

[0082] This invention provides a reactive power self-balancing control device for wind farms. An application data acquisition unit acquires feeder data from each collector feeder in the wind farm. This feeder data includes line data and measurement data at the beginning of the collector feeder, where the beginning of the collector feeder refers to the acquisition point on the feeder closest to the substation. An application reactive power calculation unit calculates the total reactive power that needs adjustment for any collector feeder based on the measurement data and the line data. The line data represents the impedance parameters of the collector feeder. An application self-balancing unit controls each wind turbine on any collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data. Each collector feeder is treated as an independent control unit, with the total reactive power at the beginning of the feeder as the closed-loop quantity, achieving a self-balancing target where the reactive power at the beginning of the feeder is approximately zero. This method has low communication overhead and high control stability.

[0083] According to another aspect of the present invention, one embodiment of the present invention provides an electronic device, Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0084] For example, such as Figure 5 As shown, the electronic device includes a memory 501 and a processor 502. The memory 501 stores an executable computer program 5011, and the processor 502 is used to call and execute the executable computer program 5011 from the memory, so that the processor 502 executes a wind farm reactive power self-balancing control method.

[0085] This embodiment can divide the electronic device into functional modules according to the above method embodiment. For example, each module can correspond to a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and is only a logical functional division. In actual implementation, there may be other division methods.

[0086] When each functional module is divided according to its corresponding function, the electronic device may include: a data acquisition unit, a reactive power calculation unit, and a self-balancing unit, etc.

[0087] It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0088] The electronic device provided in this embodiment is used to execute the above-described wind farm reactive power self-balancing control method, and thus can achieve the same effect as the above-described implementation method.

[0089] When using integrated units, the electronic device may include a processing module and a storage module. The processing module is used to control and manage the operation of the electronic device. The storage module is used to support the execution of corresponding computer programs and data by the electronic device.

[0090] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits as disclosed in this application. The processor may also be a combination of computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and microprocessors, etc., and the storage module may be a memory.

[0091] This embodiment also provides a computer-readable storage medium (including but not limited to disk storage, CD-ROM, optical storage, etc.) storing computer program code. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement the wind farm reactive power self-balancing control method provided in the above embodiment. The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, Digital Video Discs (DVDs), CompactDisc Read-Only Memory (CD-ROMs), microdrives, and magneto-optical disks, read-only memory (ROMs), random access memory (RAMs), erasable programmable read-only memory (EPROMs), electrically erasable programmable read-only memory (EEPROMs), dynamic random access memory (DRAMs), video random access memory (VRAMs), flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0092] This embodiment also provides a computer program product. When the computer program product is run on a computer, it causes the computer to perform the above-mentioned related steps to realize the wind farm reactive power self-balancing control method provided in the above embodiment.

[0093] The beneficial effects of the above embodiments can be referred to the beneficial effects of the corresponding methods provided above, and will not be repeated here.

[0094] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0095] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0096] It should also be noted that in the apparatus or equipment of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0097] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0098] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for reactive power self-balancing control in a wind farm, characterized in that, The method includes: Within any energy management control cycle, acquire measurement data at the beginning of each collector feeder in the wind farm, where the beginning of the collector feeder refers to the collection point on the collector feeder that is closest to the booster station. Based on the measurement data and the line data of the collector feeder, calculate the total reactive power that needs to be adjusted in any collector feeder, where the line data is the impedance parameter of the collector feeder; For any of the aforementioned collector feeders, the reactive power self-balancing control of each wind turbine on the collector feeder is controlled based on the total reactive power and the line data.

2. The method according to claim 1, characterized in that, The measurement data includes the reactive power at the beginning of the collector feeder; the calculation of the total reactive power that needs to be adjusted in any collector feeder based on the measurement data and the line data of the collector feeder includes: For any of the aforementioned collector feeders, the difference between the target reactive power and the stated reactive power is calculated to obtain the reactive power deviation; Determine the feedforward bias term based on the line data; The total reactive power that needs to be adjusted in the collector feeder is obtained based on the reactive power deviation and the feedforward bias term.

3. The method according to claim 1, characterized in that, The step of controlling each wind turbine on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data includes: Determine the weighting factor for each fan on the collector feeder; For any wind turbine on the collector feeder, the reactive power reference value of the wind turbine is obtained based on the total reactive power, the weighting factor, and the line data. The wind turbine is controlled to perform reactive power self-balancing control based on the reactive power reference value and the line data.

4. The method according to claim 3, characterized in that, The step of obtaining the reactive power reference value of the wind turbine based on the total reactive power, the weighting factor, and the line data includes: Calculate the product of the difference between the connection point voltage and the reference voltage of the wind turbine and the voltage adjustment gain, and calculate the sum of the product of the total reactive power and the weighting factor and the product to obtain the reactive power capacity value of the wind turbine. The reactive power reference value of the fan is determined by applying a saturation function based on the reactive power value and the upper limit of the reactive power of the fan.

5. The method according to claim 3, characterized in that, The control of the wind turbine to perform reactive power self-balancing control based on the reactive power reference value and the line data includes: Determine the reactive current value based on the aforementioned reactive reference value; Based on the reactive current value and the line data, the active current component and reactive current component of the wind turbine that meet the preset conditions are solved according to the preset priority order. The preset priority order is that the priority of compliance constraint, self-balancing constraint and active power command constraint decreases in sequence. The preset condition is that the squares of the active current component and the reactive current component are each less than or equal to the square of the maximum allowable current of the wind turbine converter. The wind turbine is controlled to operate based on the active current component and the reactive current component.

6. The method according to claim 3, characterized in that, The determination of the weighting factor for each wind turbine on the collector feeder also includes: If the wind farm communication is restored after a power outage, the weights based on the previous energy management control cycle will be approximated to the currently determined weights using a ramp-down approach.

7. The method according to claim 1, characterized in that, The method further includes: Any of the aforementioned collector feeders transmits the uncompensated reactive power difference after self-balancing control to the automatic voltage control device of the wind farm through the energy management system. The reactive power difference is compensated by the automatic voltage control device.

8. The method according to claim 1, characterized in that, The method further includes: If the wind farm communication is abnormal, the total reactive power of each of the aforementioned collector feeders in the previous energy management control cycle is latched, the total reactive power of the previous energy management control cycle is used as the total reactive power of the current cycle, and the step of controlling each wind turbine on the collector feeder to perform reactive power self-balancing control based on the total reactive power and the line data is executed.

9. A reactive power self-balancing control device for wind farms, characterized in that, The wind farm reactive power self-balancing control device includes: The data acquisition unit is used to acquire measurement data at the beginning of each collector feeder in the wind farm during any energy management control cycle. The beginning of the collector feeder refers to the collection point on the collector feeder that is closer to the booster station. The reactive power calculation unit is used to calculate the total reactive power that needs to be adjusted in any collector feeder based on the measurement data and the line data of the collector feeder, wherein the line data is the impedance parameter of the collector feeder; The self-balancing unit is used to control the reactive power self-balancing of each wind turbine on any of the aforementioned collector feeders based on the total reactive power and the line data.

10. An electronic device, characterized in that, The electronic device includes: Memory, used to store executable computer programs; A processor is configured to call and run the executable computer program from the memory, such that the processor performs the wind farm reactive power self-balancing control method as described in any one of claims 1-8.

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