Reactive power support control method and device of flywheel energy storage phase modifier

Abstract

The application belongs to the field of electric power, and discloses a kind of reactive support control method and device of flywheel energy storage phase modifier, comprising: obtaining grid-connected point voltage actual value and voltage reference value, and calculating voltage drop depth and voltage drop change rate;The normalized voltage drop depth and voltage drop change rate are input into T-S fuzzy parameter regulator, and real-time proportional gain and real-time differential gain are calculated by combining preset reference gain;The enabling logic of the conditional integration link containing recovery area criterion, boundary saturation criterion, mode switching criterion and error change rate criterion is constructed, and the conditional integration link is enabled when the four criteria are met simultaneously;The reactive main control quantity is generated through the proportional differential link of T-S fuzzy adjustment, and the outer layer reactive reference is obtained in combination with the output of the conditional integration link, to obtain the final reactive output after the reactive boundary constraint of the outer layer reactive reference, to control flywheel energy storage phase modifier to provide capacitive reactive support or inductive reactive absorption based on the final reactive output.

Description

Technical Field

[0001] This invention belongs to the field of power, and particularly relates to a reactive power support control method and device for a flywheel energy storage synchronous condenser. Background Technology

[0002] The flywheel energy storage synchronous condenser combines the millisecond-level power response capability of the flywheel energy storage unit with the dynamic reactive power support characteristics of the synchronous condenser. It can provide rapid voltage support for the power grid in scenarios such as short-circuit faults, voltage drops, and fluctuations in the grid connection of new energy sources. It is a key device to ensure the stable operation of a high-proportion new energy power grid.

[0003] In related technologies, the reactive power control scheme of flywheel energy storage synchronous condensers generally adopts a fixed-parameter PI controller, which directly converts the voltage deviation at the grid connection point into a reactive power reference value. While this scheme has a simple structure, it has significant drawbacks under complex grid conditions: First, the voltage sag depth, rate of change, and fault recovery process exhibit strong nonlinearity and time-varying characteristics. A fixed-parameter PI controller struggles to simultaneously meet the needs of rapid support in the initial fault phase and smooth convergence during the recovery phase, easily leading to insufficient support or over-adjustment oscillations. Second, the integral component easily accumulates integral values ​​during large disturbances, equipment output saturation, and switching between capacitive and inductive reactive power modes, resulting in reactive power reference tailing, backflip, or even equipment overload. Third, traditional schemes lack an integral memory processing mechanism during mode switching, easily generating inrush currents during the switching between capacitive support and inductive absorption, affecting grid stability. Summary of the Invention

[0004] In view of this, the present invention discloses a reactive power support control method and device for a flywheel energy storage synchronous condenser, which can solve the shortcomings of related technologies.

[0005] To achieve the above objectives, the present invention discloses the following technical solution: According to a first aspect of the present invention, a reactive power support control method for a flywheel energy storage synchronous condenser is proposed, comprising: Obtain the actual voltage value and voltage reference value at the grid connection point, and calculate the voltage drop depth and voltage drop rate. The normalized voltage drop depth and voltage drop rate are input into the TS fuzzy parameter regulator to obtain the proportional gain correction and differential gain correction, and the real-time proportional gain and real-time differential gain are calculated in combination with the preset reference gain. Construct an enable logic for a conditional integration loop that includes recovery zone criteria, boundary saturation criteria, mode switching criteria, and error change rate criteria. The conditional integration loop is enabled when all four criteria are met simultaneously, and frozen when any one criterion is not met. The reactive power main control quantity is generated by the proportional-derivative link of the TS fuzzy adjustment, and the outer reactive power reference is obtained by combining the output of the conditional integral link. After applying reactive power boundary constraints to the outer reactive power reference, the final reactive power output is obtained. Based on the final reactive power output, the flywheel energy storage synchronous condenser is controlled to provide capacitive reactive power support or inductive reactive power absorption.

[0006] According to a second aspect of the present invention, a reactive power support control device for a flywheel energy storage phase shifter is provided, comprising: Acquisition Unit: Acquires the actual voltage value and voltage reference value at the grid connection point, and calculates the voltage drop depth and voltage drop rate. Calculation unit: Input the normalized voltage drop depth and voltage drop change rate into the TS fuzzy parameter regulator to obtain the proportional gain correction amount and the derivative gain correction amount, and calculate the real-time proportional gain and real-time derivative gain in combination with the preset reference gain. Construction Unit: Constructs the enabling logic of a conditional integration loop containing recovery region criteria, boundary saturation criteria, mode switching criteria, and error change rate criteria. The conditional integration loop is enabled when all four criteria are met simultaneously, and frozen when any one criterion is not met. Constraint Unit: The reactive main control quantity is generated by the proportional derivative element of TS fuzzy adjustment, and the outer reactive reference is obtained by combining the output of the conditional integral element. After applying reactive boundary constraints to the outer reactive reference, the final reactive output is obtained. Based on the final reactive output, the flywheel energy storage synchronous condenser is controlled to provide capacitive reactive support or inductive reactive absorption.

[0007] According to a third aspect of the present invention, an electronic device is provided, comprising: processor; Memory used to store processor-executable instructions; The processor implements the steps of the method as described in the first aspect by running the executable instructions.

[0008] According to a fourth aspect of the invention, a computer-readable storage medium is provided having computer instructions stored thereon that, when executed by a processor, implement the steps of the method as described in the first aspect.

[0009] As can be seen from the above technical solutions, the beneficial effects of the flywheel energy storage synchronous condenser reactive power support control method and device disclosed in this invention are as follows: On the one hand, the TS fuzzy parameter regulator adjusts the proportional and derivative gains online according to the voltage drop depth and rate of change. When the voltage drop is deep and the change is rapid in the early stage of the fault, the proportional gain is automatically increased to improve the support speed. At the same time, the derivative gain is increased to provide damping to suppress overshoot, which solves the problem of insufficient dynamic performance of fixed parameter PI control, thereby speeding up the fault response time.

[0010] On the other hand, the integral link is enabled and disabled by four conditions: the integral link is only enabled to eliminate steady-state error when the system enters the recovery zone, the equipment has not reached the output boundary, the operating mode is stable, and the voltage change slows down; the integral link is frozen under other operating conditions, which avoids the reactive power tailing and over-adjustment problems caused by the accumulation of integral link in the transient process of traditional PI control; at the same time, the integral link is reset / attenuated when switching modes, thereby reducing the inrush current of capacitive / inductive reactive power switching.

[0011] In addition, reactive power boundary constraints ensure that the final output does not exceed the physical limits of the equipment, and combined with the anti-integral saturation correction mechanism, the equipment is prevented from overloading. In the early stage of the fault, the fuzzy PD link provides the main support, and in the recovery stage, the conditional integral eliminates the residual error, which takes into account both transient response speed and steady-state control accuracy. It is suitable for a variety of complex scenarios such as grid short circuit, voltage drop, and new energy fluctuations. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a flywheel energy storage phase converter provided in an exemplary embodiment; Figure 2 This is a flowchart of a reactive power support control method for a flywheel energy storage synchronous condenser, provided as an exemplary embodiment. Figure 3 This is a flowchart of another reactive power support control method for a flywheel energy storage synchronous condenser provided in an exemplary embodiment; Figure 4 This is a schematic diagram of a membership function in TS fuzzy parameter adjustment provided in an exemplary embodiment; Figure 5 This is a schematic diagram of a normalized output parameter surface in TS fuzzy parameter adjustment provided by an exemplary embodiment; Figure 6 This is a schematic diagram of a normalized output parameter surface in another TS fuzzy parameter adjustment provided in an exemplary embodiment; Figure 7 This is a schematic diagram of the reactive power support control principle of a flywheel energy storage synchronous condenser provided in an exemplary embodiment; Figure 8 This is a schematic diagram of a recovery region criterion for conditional integration provided in an exemplary embodiment; Figure 9 This is a schematic diagram of a boundary saturation criterion for conditional integrals provided in an exemplary embodiment; Figure 10 This is a schematic diagram of a mode switching criterion for conditional integration provided in an exemplary embodiment; Figure 11 This is a schematic diagram of an error rate criterion for conditional integrals provided in an exemplary embodiment; Figure 12This is a schematic structural diagram of a device provided in an exemplary embodiment; Figure 13 This is a block diagram of a reactive power support control device for a flywheel energy storage synchronous condenser, provided as an exemplary embodiment. Detailed Implementation

[0013] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of the present invention as detailed in the appended claims.

[0014] It should be noted that the steps of the corresponding methods in other embodiments are not necessarily performed in the order shown and described in this invention. In some other embodiments, the methods may include more or fewer steps than those described in this invention. Furthermore, a single step described in this invention may be broken down into multiple steps in other embodiments; and multiple steps described in this invention may be combined into a single step in other embodiments.

[0015] To address the shortcomings in related technologies, this invention proposes a reactive power support control method and device for a flywheel energy storage synchronous condenser.

[0016] Figure 1 This is a schematic diagram of a flywheel energy storage phase shifter provided in an exemplary embodiment. For example... Figure 1 As shown, the flywheel energy storage synchronous condenser includes a flywheel that stores mechanical energy in a high-speed rotating manner, and is connected to the power grid through an asynchronous motor and stator and rotor converters. The reactive power regulation of the flywheel energy storage synchronous condenser is not achieved by increasing or decreasing the DC excitation voltage, but rather by adjusting the rotor voltage, amplitude, frequency, and phase through the rotor-side converter, thereby changing the reactive current output on the stator side.

[0017] Figure 2 This is a flowchart illustrating a reactive power support control method for a flywheel energy storage synchronous condenser, as provided in an exemplary embodiment. Figure 2 As shown, the method may include the following steps: Step 201: Obtain the actual voltage value and voltage reference value at the grid connection point, and calculate the voltage drop depth and voltage drop change rate.

[0018] Specifically, calculating the voltage sag depth and voltage sag rate includes: determining the stator voltage amplitude at the grid connection point as the actual voltage value, determining the rated voltage as the nominal voltage, and introducing a voltage retention coefficient as the ratio of the actual voltage value to the nominal voltage value; then the voltage sag depth is 1 minus the voltage retention coefficient; the voltage sag rate is calculated using a discrete difference method, where the voltage sag rate is the difference between the voltage sag depth of the current control cycle and the voltage sag depth of the previous control cycle, divided by the control sampling period.

[0019] First, the stator voltage amplitude at the flywheel energy storage phase-converter grid connection point is collected. Rated voltage is The voltage deviation was obtained. At the same time, a voltage retention factor is introduced. The voltage drop depth can be obtained. Further, the voltage sag rate is introduced. As a supplementary criterion: ; The voltage sag rate Calculated using discrete difference method: ; in, To control the sampling period, The current voltage drop depth, The voltage drop depth at the previous moment. (Variable) Used to reflect the magnitude of the current voltage drop. Used to depict the changing trend of voltage drops.

[0020] In one embodiment, before the voltage drop depth and voltage drop rate of change are input to the TS fuzzy parameter regulator, the method further includes: determining a normalized base value for the voltage drop depth and a normalized base value for the voltage drop rate of change; performing amplitude limiting processing on the input values ​​using a limiting function; dividing the voltage drop depth by its normalized base value and limiting it to the range of negative one to positive one to obtain a normalized voltage drop depth; dividing the voltage drop rate of change by its normalized base value and limiting it to the range of negative one to positive one to obtain a normalized voltage drop rate of change, so as to achieve a unified mapping of inputs with different dimensions, and obtaining the normalized voltage drop depth and voltage drop rate of change.

[0021] This invention uses the TS fuzzy parameter adjustment method to... and Adaptive correction is performed. The input variables are normalized. The normalized voltage drop depth is defined as: ; The normalized voltage sag rate is: ; in, and These are the normalized base values ​​for voltage sag depth and voltage sag rate of change, respectively. Represents the amplitude limiting function. Voltage sag depth Voltage sag rate. Through normalization, control inputs with different dimensions can be mapped to the same range, facilitating fuzzy rule design and parameter adjustment.

[0022] Step 202: Input the normalized voltage drop depth and voltage drop change rate into the TS fuzzy parameter regulator to obtain the proportional gain correction amount and the derivative gain correction amount, and calculate the real-time proportional gain and real-time derivative gain in combination with the preset reference gain.

[0023] In one embodiment, the construction of the TS fuzzy parameter regulator includes: dividing the normalized voltage drop depth and the normalized voltage drop change rate into three fuzzy subsets—negative, zero, and positive—and using a piecewise linear membership function to characterize the membership degree of each subset; wherein, the two input variables form nine local working regions, each local working region corresponding to a linear output model of the proportional gain normalization correction and the differential gain normalization correction; obtaining the normalized gain correction by normalizing the normalized weights through rule activation weights, and restoring the actual gain correction by combining it with a preset maximum correction amplitude; determining the real-time proportional gain by the sum of the preset proportional reference gain and the proportional gain correction, and determining the real-time differential gain by the sum of the preset differential reference gain and the differential gain correction.

[0024] In this embodiment, and They are all divided into negative, zero, positive, etc. A fuzzy set is defined, and a piecewise linear membership function is used to implement it. Since each of the two inputs has... A fuzzy subset, thus forming the joint input space. For each local working region, a linear consequent model with proportional gain correction and differential gain correction is constructed. Figure 4 This is for constructing the membership function in the TS fuzzy parameter adjuster, and Figure 5 and Figure 6 This is the TS fuzzy normalized output parameter surface. In the TS fuzzy parameter adjuster, with... and As input, output the proportional gain correction amount respectively. and differential gain correction .

[0025] Specifically, first define the normalization correction: ; in and This is the normalized value. Then, it is restored to the actual correction amount using a scaling factor: ; in and These are the maximum correction values ​​for the proportional gain and the derivative gain, respectively. and These are the proportional gain correction amount obtained from fuzzy adjustment and the differential gain correction amount obtained from fuzzy adjustment, respectively.

[0026] Therefore, the proportional gain and derivative gain after parameter adjustment can be expressed as: ; in and As the reference gain, and These represent the proportional gain correction and the derivative gain correction obtained from fuzzy regulation, respectively. This form indicates that the controller gain is no longer a fixed value, but is composed of the reference value and the fuzzy regulation correction. Ultimately, the TS fuzzy regulation PD element can be obtained as follows: ; in The proportional gain after fuzzy adjustment is the reference value plus the normalized correction amount. , The differential gain after fuzzy adjustment is the reference value plus the normalized correction amount. .

[0027] This formula indicates that the outer reactive power main controller adopts a fuzzy parameter adjustment PD structure, in which the proportional gain and derivative gain are adaptively adjusted online according to the voltage drop depth and its rate of change, so that the flywheel synchronous condenser can take into account speed, damping and operating condition adaptability during the fault support stage.

[0028] Step 203: Construct an enabling logic for a conditional integral circuit that includes a recovery region criterion, a boundary saturation criterion, a mode switching criterion, and an error change rate criterion. The conditional integral circuit is enabled when all four criteria are met simultaneously, and frozen when any one criterion is not met.

[0029] Step 204: Generate the reactive main control quantity through the proportional derivative link of TS fuzzy adjustment, obtain the outer reactive reference by combining the output of the conditional integral link, obtain the final reactive output after applying reactive boundary constraints to the outer reactive reference, and control the flywheel energy storage synchronous condenser to provide capacitive reactive support or inductive reactive absorption based on the final reactive output.

[0030] Figure 7 This is a schematic diagram of the reactive power support control principle of a flywheel energy storage synchronous condenser provided in an exemplary embodiment. The reactive power compensation is controlled by coupling the TS fuzzy adjustment PD stage with conditional integral control. The conditional integral control flow is as follows: In the early stages of a fault, due to the large voltage drop depth or high rate of change, the integral stage is not engaged, and only the TS fuzzy control of the PD stage is used. Although this can effectively achieve rapid support and transient damping in the early stages of a fault, a small residual steady-state error may still exist in the system voltage after the fault is cleared. If the integral action is completely eliminated, the steady-state recovery accuracy will be insufficient; however, if ordinary integral is used directly, the integral accumulation problem during the large disturbance stage of the fault will be reintroduced.

[0031] Therefore, this invention does not employ a continuously engaged integral stage, but rather treats integration as a constrained recovery and compensation stage. For this purpose, the integral state variable is defined as follows: Then the outer reactive power control law is extended to ; in, This represents the original reactive power reference generated by the outer controller. For proportional gain, Voltage sag depth Differential gain, Voltage sag rate of change This is an integral compensation item.

[0032] As the fault is gradually resolved and the system enters the recovery phase, the controller checks whether the recovery zone criterion, boundary saturation criterion, mode switching criterion, and error change rate criterion are simultaneously satisfied. These four criteria are defined as follows: , , , .

[0033] Specifically, the recovery zone criterion is that the absolute value of the voltage drop depth is less than or equal to a preset recovery zone threshold; the boundary saturation criterion is that the absolute value of the original reactive power reference generated by the outer controller is less than the value of the reactive power output boundary function that changes with the voltage retention coefficient minus a preset boundary margin; the mode switching criterion is determined to be satisfied if the current operating mode is equal to the previous operating mode for a preset number of consecutive times, otherwise it is determined to be unsatisfactory; the error change rate criterion is that the absolute value of the voltage drop change rate is less than or equal to a preset error change rate threshold.

[0034] like Figure 8 As shown, the recovery zone criterion is: ; in As a criterion for the recovery zone, The threshold for the recovery area. This represents the voltage drop depth.

[0035] like Figure 9 As shown, the boundary saturation criterion is: ; in As a boundary saturation criterion, For reactive power boundary function, For boundary margin, The original reactive power reference generated for the outer controller.

[0036] like Figure 10 As shown, the mode switching criterion is: ; in As a criterion for mode switching, This indicates the system's operating mode. This is the current operating mode. The operating mode of the previous moment, when the condition is met. and Equality is maintained After that, The value will be 1 if it is set to 1, otherwise 0. In this case, the value will be 0. For example, this time...

[0037] like Figure 11 As shown, the criterion for the rate of change of error is: ; in As the criterion for the rate of change of error, The threshold for the rate of change of error. This represents the rate of change of voltage sag.

[0038] The conditional integral stage is updated using an anti-integral saturation correction method. The integral state is calculated as follows: when all four criteria are met simultaneously, the integral state is the integral of the voltage deviation multiplied by the anti-integral saturation coefficient and the difference between the final reactive power output and the original reactive power reference value; when any criterion is not met, the integral state is frozen; wherein, the voltage deviation is the nominal voltage value minus the actual voltage value, and the anti-integral saturation coefficient is used to suppress the integral saturation effect; when the system operating mode switches between capacitive reactive power support and inductive reactive power absorption, the integral state is reset or attenuated: when the mode is switched in reverse, the integral state is reset to zero; when the mode is slightly adjusted, the integral state is multiplied by an attenuation coefficient between zero and one.

[0039] The total integral enabling coefficient can be obtained as follows: The integral stage is enabled only when all the above criteria are met, as shown in the following equation: ; in This represents a conditional integrator. As an anti-integral saturation coefficient, This serves as the final reactive power reference after reactive power boundary constraints. The original reactive power reference generated for the outer controller.

[0040] This conditional integral is used to eliminate residual steady-state error. If any condition is not met, the integral state is frozen to prevent the integral from accumulating in the non-stationary phase and entering the control output.

[0041] In this embodiment, The original reactive power reference generated for the outer controller is used to output the final reactive power reference after applying reactive power boundary constraints. ,and If it approaches the device's physical limit, then... The term performs a reverse correction on the integral state, thereby achieving resistance to integral saturation.

[0042] The final reactive power output is input to the inner current controller or excitation controller of the flywheel energy storage synchronous condenser to generate the quadrature and direct axis reference quantities of the rotor-side converter. The power conversion unit is then driven by pulse width modulation to achieve rapid adjustment of the reactive power output.

[0043] If the system operating mode switches from capacitive reactive power support to inductive reactive power absorption, or vice versa, then the integral state will be adjusted accordingly. Perform a reset or attenuation, with reverse switching preferably allowing This completely clears the points memory from the previous mode; minor mode adjustments can... To balance smoothness and memory retention.

[0044] Based on this, the final output will be... The current is fed into the inner current controller of the flywheel energy storage phase converter. The inner controller, according to... Generate excitation current reference value or converter The axis reference value, driven by PWM modulation, drives the power conversion unit to achieve rapid execution of reactive power output from the switching camera. This structure realizes a complete closed-loop chain from fault identification / voltage drop depth generation, to rapid fuzzy adjustment PD support, to conditional integral recovery compensation, to reactive power boundary constraints, and finally to rapid execution of the inner layer.

[0045] On one hand, this invention uses a TS fuzzy parameter regulator to adjust the proportional and derivative gains online based on the voltage drop depth and rate of change. In the initial stage of a fault, when the voltage drop is deep and the change is rapid, the proportional gain is automatically increased to improve the support speed, while the derivative gain is increased to provide damping and suppress overshoot. This solves the problem of insufficient dynamic performance in fixed-parameter PI control, thereby accelerating fault response time. On the other hand, it uses a four-condition enable logic to constrain the integration stage: the integration stage is only engaged to eliminate steady-state errors when the system enters the recovery zone, the equipment has not reached its output boundary, the operating mode is stable, and the voltage change slows down; under other operating conditions, the integration stage is frozen, avoiding the reactive power tailing and overshoot problems caused by integral accumulation during transient processes in traditional PI control. Simultaneously, the integral state is reset / attenuated during mode switching, thereby reducing the inrush current during capacitive / inductive reactive power switching. In addition, reactive power boundary constraints ensure that the final output does not exceed the physical limits of the equipment, and combined with the anti-integral saturation correction mechanism, the equipment is prevented from overloading. In the early stage of the fault, the fuzzy PD link provides the main support, and in the recovery stage, the conditional integral eliminates the residual error, which takes into account both transient response speed and steady-state control accuracy. It is suitable for a variety of complex scenarios such as grid short circuit, voltage drop, and new energy fluctuations.

[0046] Figure 12 This is a schematic structural diagram of a device provided in an exemplary embodiment. Please refer to... Figure 12 At the hardware level, the device includes a processor 1202, an internal bus 1204, a network interface 1206, memory 1208, and non-volatile memory 1210, and may also include other hardware required for its functions. One or more embodiments of the present invention can be implemented in software, for example, the processor 1202 reads the corresponding computer program from the non-volatile memory 1210 into the memory 1208 and then runs it. Of course, in addition to software implementation, one or more embodiments of the present invention do not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0047] Please refer to Figure 13 A reactive power support control device for a flywheel energy storage synchronous condenser can be applied to, for example... Figure 13 The device shown, in order to implement the technical solution of the present invention, includes: The acquisition unit 1301 is used to acquire the actual voltage value and voltage reference value at the grid connection point, and to calculate the voltage drop depth and voltage drop change rate. The calculation unit 1302 is used to input the normalized voltage drop depth and voltage drop change rate into the TS fuzzy parameter regulator to obtain the proportional gain correction amount and the differential gain correction amount, and calculate the real-time proportional gain and real-time differential gain in combination with the preset reference gain. The construction unit 1303 is used to construct the enable logic of the conditional integration loop, which includes the recovery area criterion, the boundary saturation criterion, the mode switching criterion, and the error change rate criterion. The conditional integration loop is enabled when all four criteria are met, and the conditional integration loop is frozen when any one criterion is not met. The constraint unit 1304 is used to generate the main reactive power control quantity through the proportional derivative link of TS fuzzy adjustment, and obtain the outer reactive power reference by combining the output of the conditional integral link. After applying reactive power boundary constraints to the outer reactive power reference, the final reactive power output is obtained, and the flywheel energy storage synchronous condenser is controlled based on the final reactive power output to provide capacitive reactive power support or inductive reactive power absorption.

[0048] Optionally, the acquisition unit 1301 is specifically used for: The stator voltage amplitude at the grid connection point is determined as the actual voltage value, the rated voltage is determined as the nominal voltage, and a voltage retention factor is introduced as the ratio of the actual voltage value to the nominal voltage value. Then the voltage drop depth is 1 minus the voltage retention factor. The voltage drop rate is calculated using a discrete difference method. The voltage drop rate is the difference between the voltage drop depth of the current control cycle and the voltage drop depth of the previous control cycle, divided by the control sampling cycle.

[0049] Optionally, before the voltage sag depth and voltage sag rate of change are input to the TS fuzzy parameter regulator, the device further includes: The determination unit 1305 is used to determine the normalized base value of voltage drop depth and the normalized base value of voltage drop change rate, and to perform amplitude limiting processing on the input value through the amplitude limiting function; The first limiting unit 1306 is used to limit the voltage drop depth to the range of negative one to positive one after dividing the voltage drop depth by its normalized base value, so as to obtain the normalized voltage drop depth. The second limiting unit 1307 is used to limit the voltage drop change rate to the range of negative one to positive one after dividing it by its normalized base value, so as to obtain the normalized voltage drop change rate, thereby realizing the unified mapping of inputs with different dimensions, and obtaining the normalized voltage drop depth and voltage drop change rate.

[0050] Optionally, the computing unit 1302 is specifically used for: The normalized voltage drop depth and normalized voltage drop change rate are divided into three fuzzy subsets: negative, zero, and positive. A piecewise linear membership function is used to characterize the membership degree of each subset. The two input variables form nine local working regions, and each local working region corresponds to a linear output model of the proportional gain normalization correction and the differential gain normalization correction. The normalized gain correction is obtained by normalizing the weights through rule activation weights and then combining it with the preset maximum correction value to restore the actual gain correction. The sum of the preset proportional reference gain and the proportional gain correction is determined as the real-time proportional gain, and the sum of the preset differential reference gain and the differential gain correction is determined as the real-time differential gain.

[0051] Optional, The recovery zone criterion is that the absolute value of the voltage drop depth is less than or equal to a preset recovery zone threshold. The boundary saturation criterion is that the absolute value of the original reactive power reference generated by the outer controller is less than the value of the reactive power output boundary function that varies with the voltage retention coefficient minus the preset boundary margin. The mode switching criterion is determined to be satisfied if the current operating mode is continuously equal to the previous operating mode for a preset number of times; otherwise, it is determined not to be satisfied. The error change rate criterion is that the absolute value of the voltage drop change rate is less than or equal to a preset error change rate threshold.

[0052] Optionally, the conditional integration element is updated using an anti-integral saturation correction method, and the integration state is calculated as follows: When all four criteria are met simultaneously, the integral state is the integral of the voltage deviation multiplied by the anti-integral saturation coefficient and the difference between the final reactive power output and the original reactive power reference value. The integration state is frozen when any criterion is not met. Wherein, the voltage deviation is the nominal voltage value minus the actual voltage value, and the anti-integral saturation coefficient is used to suppress the integral saturation effect; When the system operating mode switches between capacitive reactive power support and inductive reactive power absorption, the integral state is reset or attenuated: when the mode switches in reverse, the integral state is reset to zero; when the mode is slightly adjusted, the integral state is multiplied by an attenuation coefficient between zero and one.

[0053] Optionally, the device further includes: The generation unit 1308 is used to input the final reactive power output to the inner current controller or excitation controller of the flywheel energy storage synchronous condenser, generate the quadrature and direct axis reference quantities of the rotor-side converter, and drive the power conversion unit through pulse width modulation to realize rapid adjustment of reactive power output.

[0054] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, which can take the form of a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email sending and receiving device, game console, tablet computer, wearable device, or any combination of these devices.

[0055] In a typical configuration, a computer includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0056] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0057] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0058] For any other form of computer-readable medium (or computer-readable storage medium) as described above, computer instructions may be stored thereon, which, when executed by a processor, implement one or more of the above embodiments, thereby realizing the technical solution of the present invention.

[0059] The present invention also proposes a computer program that, when executed by a processor, implements one or more of the embodiments described above, thereby realizing the technical solution of the present invention. This computer program may be specifically recorded on the above-described or other computer-readable media, and the present invention does not impose any limitations on this.

[0060] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The foregoing has described specific embodiments of the invention. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than that shown in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0062] The terminology used in one or more embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in one or more embodiments of the invention and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0063] It should be understood that although the terms first, second, third, etc., may be used to describe various information in one or more embodiments of the present invention, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of one or more embodiments of the present invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0064] The above description is merely a preferred embodiment of one or more embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of the present invention should be included within the protection scope of one or more embodiments of the present invention.

Claims

1. A reactive power support control method for a flywheel energy storage synchronous condenser, characterized in that, include: Obtain the actual voltage value and voltage reference value at the grid connection point, and calculate the voltage drop depth and voltage drop rate. The normalized voltage drop depth and voltage drop rate are input into the TS fuzzy parameter regulator to obtain the proportional gain correction and differential gain correction, and the real-time proportional gain and real-time differential gain are calculated in combination with the preset reference gain. Construct an enable logic for a conditional integration loop that includes recovery zone criteria, boundary saturation criteria, mode switching criteria, and error change rate criteria. The conditional integration loop is enabled when all four criteria are met simultaneously, and frozen when any one criterion is not met. The reactive power main control quantity is generated by the proportional-derivative link of the TS fuzzy adjustment, and the outer reactive power reference is obtained by combining the output of the conditional integral link. After applying reactive power boundary constraints to the outer reactive power reference, the final reactive power output is obtained. Based on the final reactive power output, the flywheel energy storage synchronous condenser is controlled to provide capacitive reactive power support or inductive reactive power absorption.

2. The method according to claim 1, characterized in that, The calculation of voltage sag depth and voltage sag rate includes: The stator voltage amplitude at the grid connection point is determined as the actual voltage value, the rated voltage is determined as the nominal voltage, and a voltage retention factor is introduced as the ratio of the actual voltage value to the nominal voltage value. Then the voltage drop depth is 1 minus the voltage retention factor. The voltage drop rate is calculated using a discrete difference method. The voltage drop rate is the difference between the voltage drop depth of the current control cycle and the voltage drop depth of the previous control cycle, divided by the control sampling cycle.

3. The method according to claim 1, characterized in that, Before the voltage sag depth and voltage sag rate of change are input to the TS fuzzy parameter regulator, the method further includes: Determine the normalized baseline values ​​for voltage sag depth and voltage sag rate of change, and then apply a limiting function to the input values ​​for limiting. Divide the voltage drop depth by its normalized base value and limit it to the range of negative one to positive one to obtain the normalized voltage drop depth. Dividing the voltage drop rate by its normalized base value and limiting it to the range of negative one to positive one, we obtain the normalized voltage drop rate, which achieves a unified mapping of inputs with different dimensions, and thus obtains the normalized voltage drop depth and voltage drop rate.

4. The method according to claim 1, characterized in that, The normalized voltage drop depth and voltage drop rate are input into the TS fuzzy parameter regulator to obtain the proportional gain correction and differential gain correction, and combined with a preset reference gain to obtain the real-time proportional gain and real-time differential gain, including: The normalized voltage drop depth and normalized voltage drop change rate are divided into three fuzzy subsets: negative, zero, and positive. A piecewise linear membership function is used to characterize the membership degree of each subset. The two input variables form nine local working regions, and each local working region corresponds to a linear output model of the proportional gain normalization correction and the differential gain normalization correction. The normalized gain correction is obtained by normalizing the weights through rule activation weights and then combining it with the preset maximum correction value to restore the actual gain correction. The sum of the preset proportional reference gain and the proportional gain correction is determined as the real-time proportional gain, and the sum of the preset differential reference gain and the differential gain correction is determined as the real-time differential gain.

5. The method according to claim 1, characterized in that, The recovery zone criterion is that the absolute value of the voltage drop depth is less than or equal to a preset recovery zone threshold. The boundary saturation criterion is that the absolute value of the original reactive power reference generated by the outer controller is less than the value of the reactive power output boundary function that varies with the voltage retention coefficient minus the preset boundary margin. The mode switching criterion is determined to be satisfied if the current operating mode is continuously equal to the previous operating mode for a preset number of times; otherwise, it is determined not to be satisfied. The error change rate criterion is that the absolute value of the voltage drop change rate is less than or equal to a preset error change rate threshold.

6. The method according to claim 1, characterized in that, The conditional integration step is updated using an anti-integral saturation correction method, and the integration state is calculated as follows: When all four criteria are met simultaneously, the integral state is the integral of the voltage deviation multiplied by the anti-integral saturation coefficient and the difference between the final reactive power output and the original reactive power reference value. The integration state is frozen when any criterion is not met. Wherein, the voltage deviation is the nominal voltage value minus the actual voltage value, and the anti-integral saturation coefficient is used to suppress the integral saturation effect; When the system operating mode switches between capacitive reactive power support and inductive reactive power absorption, the integral state is reset or attenuated: when the mode switches in reverse, the integral state is reset to zero; when the mode is slightly adjusted, the integral state is multiplied by an attenuation coefficient between zero and one.

7. The method according to claim 1, characterized in that, The method further includes: The final reactive power output is input to the inner current controller or excitation controller of the flywheel energy storage synchronous condenser to generate the quadrature and direct axis reference quantities of the rotor-side converter. The power conversion unit is then driven by pulse width modulation to achieve rapid adjustment of the reactive power output.

8. A reactive power support control device for a flywheel energy storage synchronous condenser, characterized in that, include: Acquisition Unit: Acquires the actual voltage value and voltage reference value at the grid connection point, and calculates the voltage drop depth and voltage drop rate. Calculation unit: Input the normalized voltage drop depth and voltage drop change rate into the TS fuzzy parameter regulator to obtain the proportional gain correction amount and the derivative gain correction amount, and calculate the real-time proportional gain and real-time derivative gain in combination with the preset reference gain. Construction Unit: Constructs the enabling logic of a conditional integration loop containing recovery region criteria, boundary saturation criteria, mode switching criteria, and error change rate criteria. The conditional integration loop is enabled when all four criteria are met simultaneously, and frozen when any one criterion is not met. Constraint Unit: The reactive main control quantity is generated by the proportional derivative element of TS fuzzy adjustment, and the outer reactive reference is obtained by combining the output of the conditional integral element. After applying reactive boundary constraints to the outer reactive reference, the final reactive output is obtained. Based on the final reactive output, the flywheel energy storage synchronous condenser is controlled to provide capacitive reactive support or inductive reactive absorption.

9. An electronic device, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor implements the steps of the method as described in any one of claims 1-7 by executing the executable instructions.

10. A computer-readable storage medium storing computer instructions thereon, characterized in that, When executed by the processor, this instruction implements the steps of the method as described in any one of claims 1-7.

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