A control method and system for a reactive power compensator based on an offshore wind turbine generator

Abstract

The application discloses a control method and system of a reactive power compensator based on an offshore wind turbine, and relates to the technical field of reactive power compensator control. The method comprises the following steps: obtaining operation data of a reactive power compensator of an offshore wind turbine; calculating reactive power to be compensated for by the reactive power compensator according to the operation data, performing outer loop control on the reactive power compensator by using the reactive power to be compensated for, and converting the reactive power to be compensated for into a reference voltage signal of the reactive power compensator; generating a circulating current suppression signal of the reactive power compensator by using a second-order generalized integrator and a proportional-resonant controller to perform inner loop control; performing weighted calculation on the circulating current suppression signal and the reference voltage signal by using a dynamic weight distribution mechanism to generate a control signal of the reactive power compensator; and controlling the reactive power compensator based on the control signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reactive power compensator control, and mainly relates to a reactive power compensator control method and system based on an offshore wind turbine. BACKGROUND

[0002] With the transformation of global energy structure towards clean and low-carbon, offshore wind turbines have become an important development direction in the field of new energy power due to their high power generation efficiency, abundant resources and environmental friendliness. However, the large-scale grid connection of offshore wind power poses a serious challenge to the stability of the power grid, especially the problems of power grid voltage regulation and dynamic management of reactive power need to be solved.

[0003] Offshore wind farms are usually connected to the onshore power grid through long-distance submarine cables. The distributed capacitance characteristics of submarine cables will produce significant charging power, and the strong volatility of wind turbine output caused by natural conditions will make the system reactive power demand change frequently and substantially. In addition, the reactive power loss of internal equipment of offshore wind turbines (such as converters and transformers) further aggravates the voltage fluctuation of the power grid. The traditional reactive power compensation technology of onshore power grid lacks targeted design for complex offshore scenarios, and cannot effectively cope with the above problems.

[0004] Currently, existing control strategies mostly adopt a single mode (such as constant voltage or constant reactive power control), lack dynamic switching mechanism, and cannot adapt to the differentiated needs of different operating scenarios (such as normal working condition, voltage anomaly, and emergency fault). For example, in the case of severe voltage fluctuation, the constant reactive power mode cannot quickly adjust the compensation instruction to stabilize the voltage; while in the steady state operation, the constant voltage mode may cause insufficient circulating current suppression due to excessive compensation. In addition, the traditional method has limited effect on the circulating current suppression generated in the operation of the modular multilevel converter. The twice frequency and high frequency even harmonic components of the modular multilevel converter in the circulating current will significantly increase the bridge arm loss, cause current distortion, and reduce system efficiency and power quality; and the existing circulating current suppression technology (such as simple filtering or proportional integral control) cannot accurately separate the direct current component and alternating current component of the circulating current, and is prone to control parameter mismatching problem in complex harmonic environment.

[0005] In summary, there is an urgent need for a reactive power compensation control method that can dynamically coordinate voltage stability and circulating current suppression, adapt to multi-mode switching, and has efficient sub-module management capability, in order to improve the grid stability and operating economy of offshore wind turbines. SUMMARY

[0006] In order to solve the above problems existing in the prior art, the present application provides a reactive power compensator control method and system based on an offshore wind turbine.

[0007] The technical solution of the present application is as follows:

[0008] In one aspect, a control method of a reactive power compensator based on an offshore wind turbine generator, the method comprising:

[0009] obtaining operation data of the reactive power compensator of the offshore wind turbine generator;

[0010] calculating, according to the operation data, reactive power to be compensated by the reactive power compensator, and performing outer loop control on the reactive power compensator by using the reactive power to be compensated, and converting the reactive power to be compensated into a reference voltage signal of the reactive power compensator;

[0011] generating, by using a second-order generalized integrator and a quasi-proportional resonant controller, a circulating current suppression signal of the reactive power compensator for inner loop control;

[0012] performing weighted calculation on the circulating current suppression signal and the reference voltage signal by using a dynamic weight distribution mechanism to generate a control signal of the reactive power compensator;

[0013] controlling the reactive power compensator based on the control signal.

[0014] Preferably, the reactive power to be compensated includes self-reactive power loss of the wind power equipment, cable charging power compensation, and dynamic fluctuation gap, wherein:

[0015] the self-reactive power loss of the wind power equipment is expressed by a formula as follows:

[0016] ;

[0017] in the formula, represents the self-reactive power loss of the wind power equipment; represents active power of the i-th wind turbine; represents a tangent value of a power factor angle of the i-th wind turbine; represents an index value of the i-th wind turbine; represents the number of wind turbines; the cable charging power compensation is expressed by a formula as follows:

[0018] ;

[0019] ;

[0020] in the formula, represents the cable charging power compensation; represents an operating voltage of the cable; represents an angular frequency of the cable operation; represents a unit length capacitance of the cable; represents a length of the cable;

[0021] the dynamic fluctuation gap is expressed by a formula as follows:

[0022] ​​ ;

[0023] In the formula, represents a dynamic fluctuation gap; represents a first weight coefficient; represents a second weight coefficient; represents a change amount of the fan active power; represents a grid-connected point voltage deviation;

[0024] The reactive power to be compensated is expressed by a formula as follows:

[0025] ;

[0026] In the formula, represents the reactive power to be compensated.

[0027] Preferably, a circulating current suppression signal of the reactive power compensator is generated by using a second-order generalized integrator and a proportional-resonant controller for inner loop control, and specifically, the circulating current suppression signal is generated by:

[0028] The circulating current component is extracted by using the second-order generalized integrator, and specifically, the original circulating current flowing through the reactive power compensator is input into the second-order generalized integrator to extract a double-frequency alternating current component; the double-frequency alternating current component is subtracted from the original circulating current to obtain an error signal, wherein the error signal includes a high-frequency even harmonic component and a direct current component of the circulating current;

[0029] The error signal is input into a direct current integrator to filter out the high-frequency even harmonic component in the error signal and extract the direct current component;

[0030] The original circulating current is subtracted from the extracted direct current component to obtain an alternating current component including a double-frequency and a high-frequency even harmonic;

[0031] The alternating current component including the double-frequency and the high-frequency even harmonic is input into the proportional-resonant controller to generate the circulating current suppression signal.

[0032] Preferably, the circulating current suppression signal and the reference voltage signal are weightedly calculated by using a dynamic weight distribution mechanism, and specifically, the circulating current suppression signal and the reference voltage signal are weightedly calculated by:

[0033] The voltage stability weight and the circulating current suppression weight are set, and the voltage stability weight and the circulating current suppression weight are dynamically adjusted according to the grid-connected point voltage and the standard voltage;

[0034] If the difference between the grid-connected point voltage and the standard voltage exceeds a preset range, the voltage stability weight is increased, and the outer loop control generates a new reference voltage signal for reactive power compensation;

[0035] Otherwise, the circulating current suppression weight is increased, and the filter bandwidth of the second-order generalized integrator is adjusted, so that the inner loop control generates a new circulating current suppression signal for circulating current suppression.

[0036] In another aspect, the application also provides a reactive power compensator submodule sorting method based on an improved jump sorting algorithm, which comprises:

[0037] The submodules of the reactive power compensator are sorted by using the improved jump sorting algorithm to obtain a sorted submodule sequence;

[0038] The charging and discharging sequence of the submodules is controlled based on the sorted submodule sequence.

[0039] Preferably, the submodules of the reactive power compensator are sorted by using the improved jump sorting algorithm, specifically as follows:

[0040] The capacitor voltage of each submodule is collected in real time, and the extreme difference of the capacitor voltages of all the submodules is calculated; the dynamic threshold value judgment on the extreme difference is specifically as follows: when the extreme difference is greater than the upper limit of the preset capacitor voltage reference value, the sorting operation is triggered; when the extreme difference is less than the lower limit of the preset capacitor voltage reference value, the sorting operation is stopped;

[0041] The sorting operation is specifically as follows: the number of submodules, the scanning end point and the last exchange position are initialized, and the inner and outer loop controls are performed; the capacitor voltage of the current submodule is compared with the capacitor voltage of the next submodule of the current submodule, according to the comparison result, the positions of the two submodules are exchanged, and the last exchange position is updated as the position of the current submodule; at the end of each inner loop, the scanning end point is updated as the last exchange position;

[0042] If no exchange of the positions of the submodules is generated after one inner loop, it indicates that the sorting is completed, the loop is stopped, and the submodule sorting sequence is output.

[0043] Preferably, the charging and discharging sequence of the submodules is controlled based on the sorted submodule sequence, specifically as follows:

[0044] When the reactive power compensator is in the charging phase, the submodule with the capacitor voltage less than the preset charging threshold value is charged;

[0045] When the reactive power compensator is in the discharging phase, the submodule with the capacitor voltage greater than the preset discharging threshold value is discharged.

[0046] In another aspect, the application also provides a control system of a reactive power compensator based on an offshore wind turbine, which comprises a data acquisition module, a control signal generation module and a control module, wherein:

[0047] The data acquisition module is used for acquiring the operation data of the reactive power compensator of the offshore wind turbine; and the operation data is transmitted to the control signal generation module;

[0048] The control signal generation module is configured to calculate reactive power to be compensated for the reactive power compensator according to operation data, perform outer loop control on the reactive power compensator by using the reactive power to be compensated, and convert the reactive power to be compensated into a reference voltage signal of the reactive power compensator;

[0049] The second-order generalized integrator and the quasi-proportional-resonant controller are used to generate a circulating current suppression signal of the reactive power compensator for inner loop control.

[0050] The dynamic weight distribution mechanism is used to weight and calculate the circulating current suppression signal and the reference voltage signal to generate a control signal of the reactive power compensator.

[0051] The control module is configured to control the reactive power compensator based on the control signal.

[0052] In another aspect, the application further provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the control method of the reactive power compensator based on the offshore wind turbine when executing the program.

[0053] In another aspect, the application further provides a computer readable storage medium, which stores a computer program, and the program is executable on a processor to implement the control method of the reactive power compensator based on the offshore wind turbine.

[0054] Compared with the prior art, the application has the following beneficial effects:

[0055] 1) The application provides a control method and system of a reactive power compensator based on an offshore wind turbine, which realizes dynamic response to compensation demand by obtaining operation data of the reactive power compensator and calculating reactive power to be compensated, performs outer loop control by using the calculated reactive power, and converts the reactive power into a reference voltage signal, so that the compensator can adjust its output in real time, and the accuracy and timeliness of reactive power compensation are effectively improved.

[0056] 2) The application provides a control method and system of a reactive power compensator based on an offshore wind turbine, which realizes fine inner loop control on the reactive power compensator by introducing a second-order generalized integrator and a quasi-proportional-resonant controller, improves the accuracy of the system, ensures that the compensator can quickly and accurately track the reference signal, suppresses the generation of circulating current, and enhances the stability of the system.

[0057] 3) The application provides a control method and system of a reactive power compensator based on an offshore wind turbine, which uses a dynamic weight distribution mechanism to weight and calculate a circulating current suppression signal and a reference voltage signal, can optimize the control signal according to the real-time state of the system, ensures that the response of the reactive power compensator is more flexible and efficient, enhances the adaptability and robustness of the control system, and can effectively cope with fluctuations in system load and environment. Attached Figure Description

[0058] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0059] Figure 2 This is a framework diagram of a second-order generalized integrator according to an embodiment of the present invention;

[0060] Figure 3 This is a diagram illustrating the circulating current suppression effect of the reactive power compensator according to an embodiment of the present invention;

[0061] Figure 4 This is a comparison chart of the sub-module sorting algorithms in an embodiment of the present invention. Detailed Implementation

[0062] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0063] This invention provides the following technical solution: a control method and system based on a reactive power compensator for offshore wind turbines.

[0064] Example 1

[0065] See details Figure 1 This embodiment provides a control method based on the reactive power compensator of an offshore wind turbine, the specific steps of which include:

[0066] In this embodiment, the reactive power compensator is a modular multilevel converter. The modular multilevel converter adopts a modular design concept. By adjusting the number of its internal series sub-modules, it can flexibly adapt to different voltage and power level requirements.

[0067] S1. Obtain the operating data of the reactive power compensator of the offshore wind turbine;

[0068] The method further includes data cleaning of the running data, which includes handling missing values, outliers, and data format standardization.

[0069] S2. Calculate the reactive power that the reactive power compensator needs to compensate based on the operating data, and use the reactive power that needs to be compensated to perform outer loop control on the reactive power compensator, converting the reactive power that needs to be compensated into a reference voltage signal for the reactive power compensator.

[0070] S21, the reactive power to be compensated includes wind power equipment itself reactive loss, sea cable charging power compensation and dynamic fluctuation gap, wherein:

[0071] S211, the wind power equipment itself reactive loss, expressed in formula as:

[0072] ;

[0073] In the formula, represents the wind power equipment itself reactive loss; represents the active power of the first wind turbine; represents the power factor angle tangent value of the first wind turbine; represents the index value of the first wind turbine; represents the number of wind turbines;

[0074] S212, the sea cable charging power compensation, expressed in formula as:

[0075] ;

[0076] In the formula, represents the sea cable charging power compensation; represents the sea cable operating voltage; represents the angular frequency of the sea cable operation; represents the sea cable unit length capacitance; represents the sea cable length;

[0077] S213, the dynamic fluctuation gap, expressed in formula as:

[0078] ;

[0079] In the formula, represents the dynamic fluctuation gap; represents the first weight coefficient; represents the second weight coefficient; represents the change amount of wind turbine active power; represents the grid-connected point voltage deviation;

[0080] S22, the reactive power to be compensated, expressed in formula as:

[0081] ;

[0082] In the formula, represents the reactive power to be compensated;

[0083] ​​​S23, set the trigger condition of different control modes, wherein the control modes include constant voltage mode, constant reactive mode and emergency mode;

[0084] In the embodiment, the trigger condition of the constant voltage mode is specifically that when the grid-connected point voltage deviation exceeds ±5% of the preset rated value;

[0085] The trigger condition of the constant reactive mode is specifically that when the grid-connected point voltage deviation is less than ±2% of the preset rated value;

[0086] The trigger condition of the emergency mode is specifically that when the grid-connected point voltage deviation exceeds ±10% of the preset rated value or the AC frequency of the grid-connected point power grid exceeds the upper and lower limits of the preset AC frequency;

[0087] In the embodiment, the upper limit of the preset AC frequency is 51Hz, and the lower limit of the preset AC frequency is 49Hz;

[0088] S24, according to the reactive power to be compensated and the trigger conditions corresponding to different control modes, the reference voltage signals of the reactive compensators in different control modes are calculated;

[0089] The reference voltage signal of the reactive compensator in the constant voltage mode is expressed by the following formula:

[0090] ;

[0091] In the formula, The reference voltage signal is represented by Vref; The standard voltage is represented by V; The preset proportional coefficient is represented by Kp; The preset integral coefficient is represented by Ki; The grid-connected point voltage is represented by V; The reactive voltage conversion coefficient is represented by K; The actual reactive power is represented by Q;

[0092] The reference voltage signal of the reactive compensator in the constant reactive mode is expressed by the following formula:

[0093] ;

[0094] In the emergency mode, the maximum capacitive or inductive reactive power is directly outputted. Specifically, when the grid-connected point voltage is lower than-10% of the preset rated value, the reactive compensator outputs inductive reactive power to help improve the voltage; when the grid-connected point voltage exceeds +10% of the preset rated value, the reactive compensator outputs capacitive reactive power to absorb excess reactive power and reduce the voltage;

[0095] The response time of the emergency mode is less than 10ms;

[0096] S3, please refer to Figure 2The circulating current suppression signal of the reactive power compensator is generated by using a second-order generalized integrator and a proportional-resonant controller for inner loop control.

[0097] The circulating current of each phase of the modular multilevel converter is composed of two parts, one part is a DC component, and the other part is an AC component; the DC component is responsible for achieving the balance of three-phase power and plays an indispensable role in the process of active power transmission, so it does not need to be suppressed; during the operation of the modular multilevel converter, the AC component will cause the bridge arm loss to increase significantly, and then the bridge arm current will appear distortion phenomenon, the current distortion not only has a negative impact on the normal work of the bridge arm, but also seriously damages the quality of current and voltage, and threatens the stable operation of the whole system;

[0098] The circulating current of each phase is expressed by a formula as follows:

[0099] ;

[0100] ;

[0101] ;

[0102] In the formula, I represents the circulating current of each phase; I DC represents the DC component current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current; I n represents the index value of the nth circulating current;

[0103] S31, a second-order generalized integrator is used to extract the circulating current component, specifically, the original circulating current flowing through the reactive power compensator is input into the second-order generalized integrator to extract the double-frequency AC component; the double-frequency AC component is subtracted from the original circulating current to obtain an error signal, wherein the error signal includes high-frequency even harmonic components and a DC component of the circulating current;

[0104] The error signal is input into a DC integrator to filter out the high-frequency even harmonic components in the error signal and extract the DC component;

[0105] Subtracting the original circulating current from the extracted DC component, an AC component containing the second harmonic and high-frequency even order is obtained, which is expressed as:

[0106] , ;

[0107] In the formula, represents the AC component of the circulating current of the first phase; represents the circulating current of the first phase; represents a control constant; represents a Laplace operator; represents the angular frequency of the second-order generalized integrator; represents the index value of the circulating current of the first phase;

[0108] In the embodiment, the angular frequency of the second-order generalized integrator is fixed as ;

[0109] S32, input the AC component containing the second harmonic and high-frequency even order into a quasi-proportional resonant controller to generate a circulating current suppression signal, which is expressed as:

[0110] ;

[0111] ;

[0112] In the formula, represents the circulating current suppression signal of the first phase; represents the transfer function of the quasi-proportional resonant controller; represents a resonant coefficient; represents a proportional gain coefficient; represents a cutoff angular frequency; represents a resonant angular frequency;

[0113] The circulating current suppression signal needs to be adjusted to suppress the circulating current by switching the state of the reactive power compensator sub-module, and the balance of the voltage of the reactive power compensator sub-module can reduce the interference of the circulating current harmonic component on the suppression effect;

[0114] S4, weighted calculation of the circulating current suppression signal and the reference voltage signal is performed by using a dynamic weight distribution mechanism to generate a control signal of the reactive power compensator;

[0115] The control signal of the reactive power compensator is expressed as:

[0116] ;

[0117] In the formula, A control signal of a reactive power compensator is represented. A voltage stability weight is represented. A circulating current suppression weight is represented.

[0118] The voltage stability weight and the circulating current suppression weight are set and dynamically adjusted according to a grid-connected point voltage and a standard voltage.

[0119] If a difference between the grid-connected point voltage and the standard voltage exceeds a preset range, the voltage stability weight is increased, and a new reference voltage signal is generated by outer loop control for reactive power compensation.

[0120] Otherwise, the circulating current suppression weight is increased, and a new circulating current suppression signal is generated by inner loop control for circulating current suppression by adjusting a filter bandwidth of a second-order generalized integrator.

[0121] Specifically, the formula is represented as:

[0122]

[0123]

[0124] S5, control the reactive power compensator based on the control signal.

[0125] S6, please refer to Figure 3 In the embodiment, after the circulating current suppression is started at 0.3 seconds, the peak value and the root mean square value of the circulating current are significantly reduced, the steady-state residual amount is obviously reduced, and the convergence time is shortened.

[0126] Embodiment 2

[0127] The embodiment provides a reactive power compensator submodule sorting method based on an improved jump sorting algorithm, and specific steps include:

[0128] In the embodiment, in order to improve the effect of the reactive power compensator in circulating current suppression, the improved sorting algorithm is used to sort the submodules of the reactive power compensator, so that the execution effect of the circulating current suppression is improved through submodule voltage balancing; based on the sorted reactive power compensator, the stability of the output voltage is enhanced, the reactive power compensation accuracy is guaranteed, and the bridge arm loss is reduced.

[0129] T1, the improved jump sorting algorithm is used to sort the submodules of the reactive power compensator, and a sorted submodule sequence is obtained.

[0130] The charge and discharge sequence of the submodule is controlled based on the sorted submodule sequence.

[0131] T11, the improved jump sorting algorithm is used to sort the submodules of the reactive power compensator, and the specific steps are as follows:

[0132] ​​T111, collecting the capacitor voltage of each sub-module in real time, calculating the extreme difference of the capacitor voltage of all sub-modules, denoted as , wherein represents the upper limit of the capacitor voltage of the sub-module, represents the lower limit of the capacitor voltage of the sub-module;

[0133] The dynamic threshold judgment on the extreme difference is specifically: when the extreme difference is greater than the upper limit of the preset capacitor voltage reference value, the sorting operation is triggered; when the extreme difference is less than the lower limit of the preset capacitor voltage reference value, the sorting operation is stopped.

[0134] In the embodiment, when , the sorting operation is triggered, wherein is the capacitor voltage reference value; when , the sorting operation is stopped.

[0135] T112, the sorting operation is specifically initializing the number of sub-modules as , the scanning end point is the position of the last sub-module, that is, the current scanning end point is , and the last exchange position is -1.

[0136] Outer and inner loop controls are performed, wherein the outer loop control is specifically performing rounds of traversal; the inner loop control is specifically that in each round of traversal, the first sub-module is scanned to the current scanning end point; the capacitor voltage of the current sub-module is compared with the capacitor voltage of the next sub-module of the current sub-module, and if , it indicates that the capacitor voltage of the current sub-module is greater than the capacitor voltage of the next sub-module of the current sub-module , the positions of the two sub-modules are exchanged, and the last exchange position is updated to the position of the current sub-module.

[0137] At the end of each inner loop, the scanning end point is updated to the last exchange position.

[0138] If no exchange of the positions of the sub-modules is generated after one inner loop, it indicates that the sorting is completed, the loop is stopped, and the sub-module sorting sequence is output.

[0139] T12, based on the sorted sub-module sequence, the charging and discharging sequence of the sub-modules is controlled, specifically:

[0140] When the reactive power compensator is in the charging phase, the sub-modules with the capacitor voltage less than the preset charging threshold value are charged.

[0141] When the reactive power compensator is in the discharging phase, the sub-modules with the capacitor voltage greater than the preset discharging threshold value are discharged.

[0142] T2, please refer to Figure 4 In this embodiment, after adjusting the sub-modules of the reactive power compensator using the improved jump algorithm, the extreme difference of the capacitor voltage of the sub-module is smaller than that of the sub-module capacitor voltage using traditional algorithms (such as bubble algorithm, quick sort algorithm, etc.) or without using an algorithm within the same sampling time.

[0143] The smaller the extreme difference of the capacitor voltage of the submodule, the better the circulating current suppression effect of the reactive power compensator.

[0144] Example 3:

[0145] This embodiment provides a control system based on a reactive power compensator for offshore wind turbines. The system includes a data acquisition module, a control signal generation module, and a control module, wherein:

[0146] The data acquisition module is used to acquire the operating data of the reactive power compensator of the offshore wind turbine; and transmit the operating data to the control signal generation module.

[0147] The control signal generation module is used to calculate the reactive power that the reactive power compensator needs to compensate based on the operating data, and to use the reactive power that needs to be compensated to perform outer loop control on the reactive power compensator, converting the reactive power that needs to be compensated into a reference voltage signal for the reactive power compensator.

[0148] The circulating current suppression signal of the reactive power compensator is generated by using a second-order generalized integrator and a quasi-proportional resonant controller for inner-loop control.

[0149] The circulating current suppression signal and the reference voltage signal are calculated by weighting them using a dynamic weighting allocation mechanism to generate the control signal for the reactive power compensator.

[0150] The control module is used to control the reactive power compensator based on the control signal.

[0151] Example 4:

[0152] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements a control method for a reactive power compensator based on an offshore wind turbine as described in any embodiment of the present invention.

[0153] Example 5:

[0154] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a control method for a reactive power compensator based on an offshore wind turbine as described in any embodiment of the present invention.

[0155] It is worth mentioning that the system, electronic device and computer readable storage medium described in the present application are based on the same principle as the method described in embodiment 1, and will not be described here.

[0156] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation made by using the content of the specification and drawings, or directly or indirectly applied to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A control method for a reactive power compensator based on an offshore wind turbine generator, characterized by, The method comprises: acquiring operation data of a reactive power compensator of an offshore wind turbine; calculating reactive power to be compensated for by the reactive power compensator according to the operation data, performing outer loop control on the reactive power compensator by using the reactive power to be compensated for, and converting the reactive power to be compensated for into a reference voltage signal of the reactive power compensator; generating a circulating current suppression signal of the reactive power compensator by using a second-order generalized integrator and a quasi-proportional-resonant controller to perform inner loop control; performing weighted calculation on the circulating current suppression signal and the reference voltage signal by using a dynamic weight distribution mechanism to generate a control signal of the reactive power compensator; controlling the reactive power compensator based on the control signal.

2. A control method of a reactive power compensator based on an offshore wind turbine generator according to claim 1, characterized by, The reactive power to be compensated for includes self-reactive power loss of the wind power equipment, cable charging power compensation, and dynamic fluctuation gap, wherein: The self-reactive power loss of the wind power equipment is expressed by a formula as follows: ； In the formula, represents the reactive power loss of the wind power equipment itself; represents the active power of the wind turbine; represents the power factor angle tangent value of the wind turbine; represents the index value of the wind turbine; represents the number of wind turbines; The cable charging power compensation is expressed by a formula as follows: ； wherein represents the sea cable charging power compensation; represents the sea cable operating voltage; represents the sea cable operating angular frequency; represents the sea cable unit length capacitance; represents the sea cable length; The dynamic fluctuation gap is expressed by a formula as follows: ； In the formula, represents a dynamic fluctuation gap; represents a first weight coefficient; represents a second weight coefficient; represents a change amount of fan active power; represents a grid-connected point voltage deviation; The reactive power to be compensated for is expressed by a formula as follows: ； In the formula, represents the reactive power to be compensated.

3. A control method of a reactive power compensator based on an offshore wind turbine generator according to claim 1, characterized by, The inner loop control on the reactive power compensator by using the second-order generalized integrator and the quasi-proportional-resonant controller comprises: extracting a circulating current component by using the second-order generalized integrator, specifically, inputting original circulating current flowing through the reactive power compensator into the second-order generalized integrator to extract a double-frequency alternating current component; and subtracting the double-frequency alternating current component from the original circulating current to obtain an error signal, wherein the error signal includes a high-frequency even harmonic component and a direct current component of the circulating current; inputting the error signal into a direct current integrator to filter the high-frequency even harmonic component in the error signal and extract the direct current component; subtracting the extracted direct current component from the original circulating current to obtain an alternating current component containing double-frequency and high-frequency even components; inputting the alternating current component containing double-frequency and high-frequency even components into the quasi-proportional-resonant controller to generate the circulating current suppression signal.

4. The method of claim 1, wherein, The weighted calculation on the circulating current suppression signal and the reference voltage signal by using the dynamic weight distribution mechanism comprises: setting a voltage stability weight and a circulating current suppression weight, and dynamically adjusting the voltage stability weight and the circulating current suppression weight according to a grid-connected point voltage and a standard voltage; if a difference between the grid-connected point voltage and the standard voltage exceeds a preset range, increasing the voltage stability weight to enable the outer loop control to generate a new reference voltage signal for reactive power compensation; otherwise, increasing the circulating current suppression weight to adjust a filter bandwidth of the second-order generalized integrator and enable the inner loop control to generate a new circulating current suppression signal for circulating current suppression.

5. A control system for a reactive power compensator based on an offshore wind turbine generator, characterized by The system comprises a data acquisition module, a control signal generation module, and a control module, wherein: the data acquisition module is configured to acquire operation data of a reactive power compensator of an offshore wind turbine; and transmit the operation data to the control signal generation module; the control signal generation module is configured to calculate reactive power to be compensated for by the reactive power compensator according to the operation data, perform outer loop control on the reactive power compensator by using the reactive power to be compensated for, and convert the reactive power to be compensated for into a reference voltage signal of the reactive power compensator; generate a circulating current suppression signal of the reactive power compensator by using a second-order generalized integrator and a quasi-proportional-resonant controller to perform inner loop control; The dynamic weight distribution mechanism is used to weight the circulating current suppression signal and the reference voltage signal to generate a control signal of the reactive power compensator. The control module is configured to control the reactive power compensator based on the control signal.

6. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the control method of the reactive power compensator based on the offshore wind turbine as claimed in any one of claims 1 to 4.

7. A computer readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the control method of the reactive power compensator based on the offshore wind turbine as claimed in any one of claims 1 to 4.

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