A control method, device, medium and product for a virtual synchronous generator based on zero-pole configuration

Abstract

The present application discloses a control method, device, medium and product for a virtual synchronous generator based on zero-pole configuration, and relates to the technical field of control of new energy grid-connected converters. The present application sets the parameters of a proportional-integral controller, a feedforward coefficient of the active power difference and a feedforward coefficient of the active set value difference, so that the zero point of the first active power transfer function is equal to the second pole of the active loop, and the zero point of the second active power transfer function is equal to the second pole of the active loop, thereby canceling each other out, and reducing the first active power transfer function and the second active power transfer function to first-order systems, respectively, thereby making their parameter design simpler. At the same time, the present application determines the active loop poles by customizing the active power adjustment time, and then determines the proportional-integral controller parameters, and determines the reactive loop integral coefficient by customizing the reactive power adjustment time, so that the time can be flexibly customized.

Description

Technical Field

[0001] The present application relates to the technical field of new energy grid-connected converter control, and in particular to a control method, device, medium and product of a virtual synchronous generator based on zero-pole configuration. Background Art

[0002] As renewable energy penetration in power systems continues to increase, they face challenges such as decreased stability and reduced inertia. Against this backdrop, virtual synchronous generator (VSG) technology, which enables inverters to simulate the inertia of synchronous motors, has gained widespread application in power systems.

[0003] Existing VSG control methods struggle to address grid-connected power overshoot and the difficulty designing the settling time. Some studies have established small-signal models of the VSG for analysis and design of the power control loop, but the inertia time is not adjustable, and parameter optimization is limited to ensuring good dynamic performance. Adding a low-pass filter to the dynamic model to achieve inertia control transforms the system into a third-order system, complicating parameter design. Currently, no control method for grid-connected power overshoot addresses both simple parameter design and flexible settling time customization. Summary of the Invention

[0004] The purpose of this application is to provide a control method, device, medium and product for a virtual synchronous generator based on zero-pole configuration, which can simultaneously meet the two requirements of simple parameter design and flexible customization of adjustment time.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a control method for a virtual synchronous generator based on zero-pole configuration, comprising:

[0007] Obtaining voltage and current data and active customized adjustment time; the voltage and current data include: converter side output voltage, converter side output current and grid voltage; the customized adjustment time includes: active customized adjustment time and reactive customized adjustment time;

[0008] In combination with the grid-connected power calculation formula, the active gain coefficient and the reactive gain coefficient are determined according to the converter side output voltage and the grid voltage;

[0009] Determining a first pole of the active loop and a second pole of the active loop according to the active customized adjustment time, the active gain coefficient, and the steady-state output of active power;

[0010] Determine the integral controller parameters and the proportional controller parameters according to the first pole of the active loop, the second pole of the active loop and the active gain coefficient; wherein, Where, represents the integral controller parameters, represents the proportional controller parameters, A represents the active power gain coefficient, p 1 represents the first pole of the active loop, p 2 represents the second pole of the active loop;

[0011] According to the first transfer function of active power, the feedforward coefficient of the active power setting value is determined: ;in, Indicates the feedforward coefficient of the active setting value; Indicates the second pole of the active loop; Where, Indicates the first pole of the active loop; represents the steady-state output of active power when the system frequency changes by one unit Hertz; the first active power transfer function is a small signal transfer function obtained by taking the active set value as input; at this time, the zero point of the first active power transfer function is equal to the second pole of the active loop, and the first active power transfer function is a first-order control system;

[0012] According to the second transfer function of active power, the feedforward coefficient of active power difference is determined: ;in, The feedforward coefficient of the active power difference is represented by represents the active power droop coefficient; the active power difference is the product of the angular frequency difference and the active power droop coefficient; the angular frequency difference is the difference between the grid angular frequency and the rated angular frequency; the second active power transfer function is a small signal transfer function obtained with the active power difference as input; in this case, the zero point of the second active power transfer function is equal to the second pole of the active loop, and the second active power transfer function is a first-order control system;

[0013] According to the integral controller parameters, the proportional controller parameters, the feedforward coefficient of the active power setting value and the feedforward coefficient of the active power difference, the active power and the active power setting value are controlled to obtain the voltage phase angle of the converter;

[0014] Determining a reactive loop integral coefficient according to the reactive customized adjustment time and the reactive gain coefficient;

[0015] Reactive power control is performed based on the reactive loop integral coefficient, reactive power, reactive power set value, reactive difference, and rated voltage to obtain the voltage amplitude of the converter; wherein the reactive difference is the product of the voltage difference and the reactive droop coefficient; and the voltage difference is the difference between the grid voltage and the rated voltage after the grid voltage changes;

[0016] Performing voltage and current dual closed-loop control based on the converter side output voltage, the converter side output current, the converter voltage phase angle, and the converter voltage amplitude to obtain a voltage control variable of the converter;

[0017] A PWM signal of the converter is generated according to the voltage control variable of the converter and the high-frequency triangular carrier signal.

[0018] Optionally, the active power gain coefficient is:

[0019] ;

[0020] in, A represents the active power gain coefficient, U C Indicates the output voltage on the converter side, U g Indicates the grid voltage, X Indicates the reactance value between the converter and the grid side;

[0021] The reactive gain coefficient:

[0022] ;

[0023] in, B Represents the reactive gain coefficient.

[0024] Optionally, according to the integral controller parameters, the proportional controller parameters, the feedforward coefficient of the active power setting value, and the feedforward coefficient of the active power difference, the active power and the active power setting value are subjected to active power control, and the formula for obtaining the voltage phase angle of the converter is:

[0025] ;

[0026] in, represents the voltage phase angle, represents the integral controller parameters, represents the proportional controller parameters, S Indicates the grid-connected power, P ref Indicates active reference value, p Indicates active power, Indicates the feedforward coefficient of the active setting value; The feedforward coefficient of the active power difference is represented by Indicates the active power setting value, P rd Indicates the active power difference, Indicates the rated angular frequency.

[0027] Optionally, according to the reactive loop integral coefficient, reactive power, reactive power setting value, reactive difference and rated voltage, a formula for obtaining the voltage amplitude of the converter is:

[0028] ;

[0029] in, represents the voltage amplitude of the converter, k iq Represents the reactive loop integral coefficient, q set Indicates the reactive power setting value, q rd Represents reactive power difference, q Represents reactive power, U n Indicates rated voltage.

[0030] Optionally, determining the first pole of the active loop and the second pole of the active loop according to the active customized adjustment time, the active gain coefficient, and the steady-state output of active power specifically includes:

[0031] The first pole of the active power loop is determined according to the active power customized adjustment time, and the formula is:

[0032] ;

[0033] in, Indicates the active customized adjustment time;

[0034] The second pole of the active loop is determined according to the active gain coefficient, the steady-state output of active power, and the first pole of the active loop. The formula is:

[0035] ;

[0036] in, A represents the active power gain coefficient, It indicates the steady-state output of active power when the system frequency changes by one unit Hertz.

[0037] Optionally, according to the reactive customized adjustment time and the reactive gain coefficient, a formula for determining the reactive loop integral coefficient is:

[0038] ;

[0039] in, Indicates reactive power customized adjustment time, B represents the reactive gain coefficient, k iq Indicates the reactive loop integral coefficient.

[0040] Optionally, generating a PWM signal of the converter according to the voltage control amount of the converter and a high-frequency triangular carrier signal specifically includes:

[0041] Convert the voltage control quantity of the converter into The voltage control quantity in the coordinate system is used to obtain the three-phase control quantity;

[0042] The three-phase control quantity is compared with the high-frequency triangular carrier signal; when the three-phase control quantity is greater than the high-frequency triangular carrier signal, the converter switching device is turned on; when the three-phase control quantity is less than the high-frequency triangular carrier signal, the converter switching device is turned off, generating the PWM signal of the converter.

[0043] In a second aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any one of the above-mentioned control methods for a virtual synchronous generator based on zero-pole configuration.

[0044] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-mentioned control methods for a virtual synchronous generator based on zero-pole configuration.

[0045] In a fourth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-mentioned control methods for a virtual synchronous generator based on zero-pole configuration.

[0046] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0047] The present application provides a control method, device, medium and product for a virtual synchronous generator based on zero-pole configuration, the method comprising: obtaining voltage and current data and active customized adjustment time; the voltage and current data comprising: converter side output voltage, converter side output current and grid voltage; the customized adjustment time comprising: active customized adjustment time and reactive customized adjustment time; determining active gain coefficient and reactive gain coefficient according to the converter side output voltage and grid voltage in combination with a grid-connected power calculation formula; determining the first pole of the active loop and the second pole of the active loop according to the active customized adjustment time and the active gain coefficient and the steady-state output of active power; determining integral controller parameters and proportional controller parameters according to the first pole of the active loop, the second pole of the active loop and the active gain coefficient; wherein, Where, represents the integral controller parameters, represents the proportional controller parameters, A represents the active power gain coefficient,p 1 represents the first pole of the active loop, p 2 represents the second pole of the active loop; according to the first transfer function of active power, the feedforward coefficient of the active setting value is determined: ;in, Indicates the feedforward coefficient of the active setting value; Indicates the second pole of the active loop; Where, Indicates the first pole of the active loop; represents the steady-state output of active power when the system frequency changes by one hertz; the first active power transfer function is a small signal transfer function obtained by taking the active set value as input; at this time, the zero point of the first active power transfer function is equal to the second pole of the active loop, and the first active power transfer function is a first-order control system; based on the second active power transfer function, the feedforward coefficient of the active power difference is determined: ;in, The feedforward coefficient of the active power difference is represented by represents the active droop coefficient; the active difference is the product of the angular frequency difference and the active droop coefficient; the angular frequency difference is the difference between the grid angular frequency and the rated angular frequency; the second active power transfer function is a small signal transfer function obtained with the active difference as input; at this time, the zero point of the second active power transfer function is equal to the second pole of the active loop, and the second active power transfer function is a first-order control system; according to the integral controller parameters, the proportional controller parameters, the feedforward coefficient of the active setting value and the feedforward coefficient of the active difference, the active power and the active setting value are controlled to obtain the voltage phase angle of the converter; according to the reactive customization adjustment time and the reactive Gain coefficient, determine the reactive loop integral coefficient; perform reactive power control according to the reactive loop integral coefficient, reactive power, reactive power set value, reactive difference and rated voltage to obtain the voltage amplitude of the converter; wherein the reactive difference is the product of the voltage difference and the reactive droop coefficient; the voltage difference is the difference between the grid voltage and the rated voltage after the grid voltage changes; perform voltage and current dual closed-loop control according to the converter side output voltage, the converter side output current, the converter voltage phase angle and the converter voltage amplitude to obtain the converter voltage control quantity; generate the converter PWM signal according to the converter voltage control quantity and the high-frequency triangular carrier signal. This application reduces the active power loop to a first-order system by setting the proportional-integral controller parameters, thereby making its parameter design simpler. At the same time, this application determines the active loop pole by customizing the active power adjustment time, and then determines the proportional-integral controller parameters, and determines the reactive loop integral coefficient by customizing the reactive power adjustment time, so that the time can be flexibly customized. In other words, the time is associated with the control quantity of the final output, and the control quantity will change after the time changes. Therefore, this application can simultaneously meet the two requirements of simple parameter design and flexible customization of the adjustment time. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 This is a diagram of the application environment of a control method for a virtual synchronous generator based on zero-pole configuration in one embodiment of the present application.

[0050] Figure 2 A flowchart of a control method for a virtual synchronous generator based on zero-pole configuration is provided in accordance with an embodiment of the present application.

[0051] Figure 3A schematic diagram of the VSG control flow provided in one embodiment of the present application.

[0052] Figure 4 A schematic diagram of a VSG converter grid-connected to an embodiment of the present application.

[0053] Figure 5 A schematic diagram of VSG active power control provided in one embodiment of the present application.

[0054] Figure 6 A schematic diagram of VSG reactive power control provided in one embodiment of the present application.

[0055] Figure 7 A schematic diagram of a simulation waveform of a sudden change in active power and reactive power reference values ​​with a dynamic adjustment time of 1 s provided in an embodiment of the present application.

[0056] Figure 8 A schematic diagram of a simulation waveform of a sudden change in active power and reactive power reference values ​​with a dynamic adjustment time of 0.2s provided in an embodiment of the present application.

[0057] Figure 9 This is a schematic diagram of the active power and reactive power simulation waveforms when the grid frequency suddenly changes by 1 Hz provided in one embodiment of the present application.

[0058] Figure 10 This is a schematic diagram of the active power and reactive power simulation waveforms when the grid voltage suddenly changes to 5V according to an embodiment of the present application.

[0059] Figure 11 A schematic diagram of a robustness test simulation waveform when the grid voltage is 150V provided in one embodiment of the present application.

[0060] Figure 12 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0062] Existing VSG control methods have difficulty solving the problems of grid-connected power overshoot and difficulty in designing the adjustment time. Whether it is VSG control through simulating the rotor swing equation or droop control introducing inertia through a low-pass filter, its essence makes the active power loop a second-order system. The reference value tracking performance and grid frequency dynamic response of the second-order system usually show overshoot and oscillation. At the same time, the high coupling of the droop coefficient, inertia and damping coefficient also brings inconvenience to the controller design.

[0063] This application proposes a virtual synchronous generator control method with flexible customization of adjustment time and good transient and steady-state performance. It has good transient and steady-state performance and is used to solve the problems of power overshoot, inflexible customization of adjustment time and difficult parameter design in existing control methods.

[0064] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0065] The control method of the virtual synchronous generator based on zero-pole configuration provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, or it can be integrated on the server 104, or it can be placed on the cloud or other servers. Among them, the terminal 102 can be, but is not limited to, various desktop computers, laptops, smart phones, tablets, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server 104 can be implemented as an independent server or a server cluster consisting of multiple servers, or it can be a cloud server.

[0066] In an exemplary embodiment, Figure 2 As shown, a control method for a virtual synchronous generator based on zero-pole configuration is provided. The method is executed by a computer device, specifically a computer device such as a terminal or a server, or a terminal and a server. In the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used to illustrate the process, including the following steps S1 to S11.

[0067] S1. Obtain voltage and current data and active customized adjustment time; the voltage and current data include: converter side output voltage, converter side output current and grid voltage; the customized adjustment time includes: active customized adjustment time and reactive customized adjustment time.

[0068] See also Figure 3 In this embodiment, the virtual synchronous generator includes: an inverter, a converter and a filter circuit. In this embodiment, the output voltage of the VSG converter side is obtained. , output current and phase angle , the voltage at the grid outlet and phase angle , grid angular frequency , thereby obtaining the converter side voltage and grid side voltage difference ( - ) and the phase angle difference between the converter side and the grid side .

[0069] S2. Determine the active gain coefficient and the reactive gain coefficient according to the converter side output voltage and the grid voltage in combination with the grid-connected power calculation formula.

[0070] See also Figure 4 ,by Figure 4 Explain the connection between the inverter, converter, filter circuit and power grid. After the filter removes the switching frequency harmonics, the VSG converter can be equivalent to a voltage source, and its terminal voltage is , through the grid impedance Connect to the grid, the grid voltage is ; is the grid-connected power, For merit, For no work; is the phase angle at the converter outlet side, is the phase angle at the grid export side, The converter switching signal generated in this embodiment is R g Represents the grid-connected resistance, L g represents the grid-connected inductance, X g Represents the grid-connected reactance, j The unit representing the imaginary number, Represents the angular frequency.

[0071] Considering the grid impedance meets Much greater than When the grid power It can be expressed by the following formula, where and are the amplitudes of the converter terminal voltage and the grid voltage respectively, is the phase angle difference between the converter terminal voltage and the grid voltage.

[0072] ;

[0073] This formula can be used to derive , .

[0074] in, A represents the active power gain coefficient, U C Indicates the output voltage on the converter side, U g Indicates the grid voltage, X Indicates the reactance value between the converter and the grid side, B Represents the reactive gain coefficient.

[0075] S3. Determine a first pole of the active loop and a second pole of the active loop according to the active customized adjustment time, the active gain coefficient, and the steady-state output of active power.

[0076] See also Figure 5 , Figure 5 It is the active power control process. Figure 5 middle is the rated angular frequency, and are the grid angular frequency and the actual angular frequency respectively; is the grid angular frequency and rated angular frequency Difference; is the actual angular frequency and rated angular frequency Difference; and are the grid voltage amplitude and the rated voltage amplitude respectively; is the sum of the active power droop coefficients; is the active reference value, and They are active power setting value and active power difference respectively; and are the integral coefficient and proportional coefficient of the active loop respectively; is the phase angle of the active loop output; and Active power setting value and merit difference The feedforward coefficient of is the power angle difference.

[0077] First, determine the active power droop coefficient .use It indicates the steady-state output of active power when the system frequency changes by unit Hertz. With rated angular frequency Difference and active droop coefficient The product is the active power difference .

[0078] .

[0079] Get the small signal transfer function related to active power control. As input, we get the first transfer function of active power ; Based on grid angular frequency With rated angular frequency The difference The second transfer function of active power is obtained as input .

[0080] ;

[0081] in, 、 They are The two poles (the first pole of the active loop and the second pole of the active loop), for The zero point of for Zero point.

[0082] Determine the first pole of the active loop . The time can be adjusted by active customization without overshoot Determine the time for active customization and adjustment Generally, it is given according to actual engineering requirements. According to the general definition of adjustment time, the first pole can be determined by the following formula :

[0083] ;

[0084] in, Indicates the active power customized adjustment time.

[0085] Determine the second pole of the active loop according to the active gain coefficient, the steady-state output of active power and the first pole of the active loop , the formula is:

[0086] ;

[0087] in, A represents the active power gain coefficient, It indicates the steady-state output of active power when the system frequency changes by one unit Hertz.

[0088] S4, determining the integral controller parameters and the proportional controller parameters according to the first pole of the active loop, the second pole of the active loop and the active gain coefficient; wherein, Where, represents the integral controller parameters, represents the proportional controller parameters, A represents the active power gain coefficient, p 1 represents the first pole of the active loop, p 2 represents the second pole of the active loop.

[0089] and Used to achieve power following, grid frequency phase angle synchronization and inertia support.

[0090] .

[0091] S5. Determine the feedforward coefficient of the active power setting value according to the first active power transfer function: ;in, Indicates the feedforward coefficient of the active setting value; Indicates the second pole of the active loop; Where, Indicates the first pole of the active loop; Indicates the system frequency (in this embodiment, the system here is specifically as follows Figure 4 In such a system (i.e., a system in which an inverter power supply passes through a converter and is connected to a power grid via a filter circuit), when the unit hertz changes, the steady-state output of active power (which can be directly obtained) is such that the first active power transfer function is a small signal transfer function obtained by taking the active power set value as input. At this time, the zero point of the first active power transfer function is equal to the second pole of the active loop, and the first active power transfer function is a first-order control system.

[0092] Determine the active power setpoint The feedforward coefficient .when The first transfer function of active power control can be Achieving Zero Point and the extremes Cancellation, so that the first transfer function of VSG active power Reduced to a first-order control system.

[0093] Active power set value Feedforward coefficient Determined by the following formula:

[0094] ;

[0095] in, Indicates the feedforward coefficient of the active setting value; Indicates the second pole of the active loop; Where, Indicates the first pole of the active loop; It indicates the steady-state output of active power when the system frequency changes by one unit Hertz.

[0096] Through the above parameter configuration, the active power first transfer function Reduced to a first-order control system.

[0097] S6. Determine the feedforward coefficient of the active power difference based on the second active power transfer function: ;in, The feedforward coefficient of the active power difference is represented by represents the active power droop coefficient; the active power difference is the product of the angular frequency difference and the active power droop coefficient; the angular frequency difference is the difference between the grid angular frequency and the rated angular frequency (these two frequencies can be obtained through a phase-locked loop); the second active power transfer function is a small signal transfer function obtained with the active power difference as input; at this time, the zero point of the second active power transfer function is equal to the second pole of the active loop, and the second active power transfer function is a first-order control system.

[0098] Determine the active power difference The feedforward coefficient .when The second transfer function of active power can be made Achieving Zero Point and the extremes Cancellation, so that the VSG active power second transfer function Reduced to a first-order control system.

[0099] Merit difference The feedforward coefficient Determined by the following formula:

[0100] ;

[0101] in, The feedforward coefficient of the active power difference is represented by Indicates the active power droop coefficient.

[0102] Through the above parameter configuration, the second transfer function of active power Reduced to a first-order control system.

[0103] The first-order control system after final reduction is: .

[0104] S7. Perform active power control on the active power and the active power setting value according to the integral controller parameters, the proportional controller parameters, the feedforward coefficient of the active power setting value, and the feedforward coefficient of the active power difference to obtain the voltage phase angle of the converter.

[0105] In this embodiment, the active power Active power setting value Input active power control to obtain the voltage phase angle of VSG converter :

[0106] ;

[0107] in, represents the voltage phase angle, represents the integral controller parameters, represents the proportional controller parameters, S Indicates the grid-connected power, P ref represents the active reference value (in this embodiment, it is given according to the active power required by the load in the system. The active reference value is the amount of active power required by the load). P represents active power. Indicates the feedforward coefficient of the active setting value; The feedforward coefficient of the active power difference is represented by Indicates the active power setting value, P rd Indicates the active power difference, Indicates the rated angular frequency.

[0108] S8. Determine a reactive loop integral coefficient according to the reactive customized adjustment time and the reactive gain coefficient.

[0109] See also Figure 6 , which is the reactive power control block diagram, is the voltage amplitude output by the reactive loop, is the output voltage amplitude and its grid voltage The amplitude difference, is the grid voltage and rated voltage The amplitude difference; Reactive power droop coefficient; and They are reactive power set value and reactive power difference respectively; is the integral coefficient of the reactive loop.

[0110] Determine the reactive droop factor The reactive power droop coefficient is determined by the reactive power generated by the system after the grid voltage changes, as shown in the following formula. With rated voltage The difference is calculated and compared with the reactive droop coefficient Obtain reactive power difference .

[0111] ;

[0112] Among them, Δ Q Indicates the reactive power required for unit voltage change, Δ U max Indicates the range of voltage variation allowed by the power grid.

[0113] Customize reactive power and adjust the time. Determine its reactive power customized adjustment time :

[0114] ;

[0115] in, Indicates the reactive power adjustment time that can be flexibly customized when the reactive power changes. B represents the reactive gain coefficient, k iq Indicates the reactive loop integral coefficient.

[0116] S9. Perform reactive power control according to the reactive loop integral coefficient, reactive power, reactive power setting value, reactive difference and rated voltage to obtain the voltage amplitude of the converter; wherein the reactive difference is the product of the voltage difference and the reactive droop coefficient; the voltage difference is the difference between the grid voltage and the rated voltage when the grid voltage changes.

[0117] In this embodiment, the reactive power and reactive power setting value , obtain the voltage amplitude of the VSG converter :

[0118] ;

[0119] in, represents the voltage amplitude of the converter, k iq Represents the reactive loop integral coefficient, q set Indicates the reactive power setting value, q rd Represents reactive power difference, q Represents reactive power, U n Indicates rated voltage.

[0120] S10. Perform voltage-current dual closed-loop control according to the converter-side output voltage, the converter-side output current, the converter voltage phase angle, and the converter voltage amplitude to obtain a voltage control variable of the converter.

[0121] In this embodiment, according to the collected commutation side output voltage and output current After the signal is Park transformed, the output voltage of the converter in the dq coordinate system is obtained. and output current .

[0122] According to the converter output voltage in the dq coordinate system and output current , and the voltage amplitude of the VSG converter and the voltage phase angle of the VSG converter , perform voltage and current double closed-loop control, and obtain the voltage control quantity of the VSG converter in the dq coordinate system and .

[0123] S11 . Generate a PWM signal for the converter according to the voltage control variable of the converter and a high-frequency triangular carrier signal.

[0124] According to the voltage control quantity of the VSG converter in the dq coordinate system and Perform Park inverse transform to obtain Voltage control quantity in the coordinate system (Three-phase control quantity).

[0125] The three-phase control quantity is compared with the high-frequency triangular carrier signal; when the three-phase control quantity is greater than the high-frequency triangular carrier signal, the converter switching device is turned on; when the three-phase control quantity is less than the high-frequency triangular carrier signal, the converter switching device is turned off, generating the PWM signal of the converter.

[0126] Generally speaking, this application sets the parameters of the proportional-integral controller, the feedforward coefficient of the active power difference, and the feedforward coefficient of the active set value difference, so that the zero point of the first active power transfer function is equal to the second pole of the active loop, and the zero point of the second active power transfer function is equal to the second pole of the active loop, thereby canceling each other out, and reducing the first active power transfer function and the second active power transfer function to first-order systems, respectively, thereby making their parameter design simpler. At the same time, this application determines the active loop pole by customizing the active power adjustment time, and then determines the proportional-integral controller parameters, and determines the reactive loop integral coefficient by customizing the reactive power adjustment time, so that the time can be flexibly customized.

[0127] In this embodiment, 、 、 、 The adjustment factors designed for this embodiment have the following functions.

[0128] First, through adjustment and The value of can effectively reduce the VSG active control loop from a second-order system to a first-order system, thereby achieving the control goal of no overshoot in power output.

[0129] Second, it can be flexibly configured in combination with the diverse dynamic response requirements in engineering practice. 、 The value of 、 Customized design ensures that the dynamic response performance of the VSG system meets the time index requirements of specific application scenarios.

[0130] This embodiment proposes a control method for a virtual synchronous generator based on zero-pole configuration. Through the rational configuration of zeros and poles, this control strategy achieves superior transient and steady-state performance when the VSG grid-connected power undergoes a sudden change. Furthermore, control parameters can be flexibly designed and dynamically adjusted based on actual regulation time requirements, thereby improving the applicability and reliability of the VSG control strategy. Its unique features include:

[0131] A proportional-integral droop controller is designed based on the traditional VSG control strategy to alleviate the adjustment contradiction between the droop coefficient and the damping coefficient.

[0132] The proposed new control structure adopts a feedforward control loop, thereby reducing the traditional second-order VSG control to first-order control, so that the system can meet the functional requirements of no overshoot in different working scenarios.

[0133] Through the reasonable configuration of zeros and poles, the response time can be flexibly customized while ensuring that the system responds without overshoot, thereby adapting to the differentiated response time requirements in different scenarios.

[0134] In addition, in order to verify the effectiveness of this application, this embodiment also built a system in which a single VSG converter was connected to the grid. The simulation parameters and control parameter configurations are shown in Tables 1 and 2. The system was operated under three different working conditions to prove the effectiveness of the control strategy of this embodiment.

[0135]

[0136] Table 2 Control parameters

[0137]

[0138] Working condition 1: The system power reference value changes suddenly. Figure 7 The following is a simulation waveform of the sudden change of active power and reactive power reference values ​​with a dynamic adjustment time of 1s. The active power and reactive power reference values ​​suddenly increase by 5kW (5kVar) at 2s and recover at 3.5s. Figure 7It can be seen that the dynamic adjustment time is 1s and there is no overshoot in the dynamic process, which is consistent with the theoretical design results. The reference value mutation waveform with a dynamic adjustment time of 0.2s is as follows Figure 8 shown.

[0139] Working condition 2: When a small disturbance occurs in the power grid. Figure 9 The figure shows the simulated waveforms of active power and reactive power when the grid frequency suddenly changes by 1Hz. Figure 9 It can be seen that when the grid frequency increases / decreases suddenly, the grid-connected inverter can automatically reduce / increase the power generation. times the active power, and there is no overshoot in the dynamic process, realizing the grid frequency support function. Figure 10 The following are the simulated waveforms of active power and reactive power when the grid voltage suddenly changes to 5V. The inverter responds to the grid voltage change and automatically reduces / increases power. times the reactive power, realizing the reactive power droop function.

[0140] Working condition 3: When a large disturbance occurs in the power grid. Figure 11 The figure shows the robustness test simulation waveform when the grid voltage drops to 150V and the dynamic adjustment time is set to 0.5s. Figure 11 It can be seen that the active power waveform only has a slight overshoot and the adjustment time is still 0.5s, and the reactive power waveform still shows the response characteristics of the first-order system, which shows that the proposed power control strategy has certain robustness.

[0141] This embodiment designs a control method for a virtual synchronous generator based on zero-pole configuration and introduces a feedforward coefficient into the active power control loop of the VSG. and , so that the zero poles can be freely configured. Through the reasonable configuration of the zero poles, the traditional VSG control strategy is reduced to a first-order control system, thereby achieving flexible customization of the dynamic adjustment time and eliminating the system overshoot. In addition, the droop coefficient is achieved The change of does not affect the dynamic performance of power control, and the dynamic performance of reactive power control can be Flexible adjustment: This strategy provides a strong guarantee for the stable operation of VSG in grid-connected mode, while meeting the actual requirements for adjustment time in different engineering application scenarios.

[0142] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 12As shown. The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a control method for a virtual synchronous generator based on zero-pole configuration is implemented.

[0143] Those skilled in the art will understand that Figure 12 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0144] In an exemplary embodiment, a computer device is further provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program.

[0145] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0146] In an exemplary embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0147] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0148] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0149] The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may include, but are not limited to, general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic units, data processing logic units based on quantum computing, and the like.

[0150] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0151] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A control method for a virtual synchronous generator based on zero-pole configuration, characterized in that: include: Obtain voltage and current data and customized active power adjustment time; The voltage and current data include: converter side output voltage, converter side output current and grid voltage; the customized adjustment time includes: active customized adjustment time and reactive customized adjustment time; In combination with the grid-connected power calculation formula, the active gain coefficient and the reactive gain coefficient are determined according to the converter side output voltage and the grid voltage; Determining a first pole of the active loop and a second pole of the active loop according to the active customized adjustment time, the active gain coefficient, and the steady-state output of active power; Determine the integral controller parameters and the proportional controller parameters according to the first pole of the active loop, the second pole of the active loop and the active gain coefficient; wherein, Where, represents the integral controller parameters, represents the proportional controller parameters, A represents the active power gain coefficient, p 1 represents the first pole of the active loop, p 2 represents the second pole of the active loop; According to the first transfer function of active power, the feedforward coefficient of the active power setting value is determined: ;in, Indicates the feedforward coefficient of the active setting value; Indicates the second pole of the active loop; Where, Indicates the first pole of the active loop; represents the steady-state output of active power when the system frequency changes by one unit Hertz; the first active power transfer function is a small signal transfer function obtained by taking the active set value as input; at this time, the zero point of the first active power transfer function is equal to the second pole of the active loop, and the first active power transfer function is a first-order control system; According to the second transfer function of active power, the feedforward coefficient of active power difference is determined: ;in, The feedforward coefficient of the active power difference is represented by represents the active power droop coefficient; the active power difference is the product of the angular frequency difference and the active power droop coefficient; the angular frequency difference is the difference between the grid angular frequency and the rated angular frequency; the second active power transfer function is a small signal transfer function obtained with the active power difference as input; in this case, the zero point of the second active power transfer function is equal to the second pole of the active loop, and the second active power transfer function is a first-order control system; According to the integral controller parameters, the proportional controller parameters, the feedforward coefficient of the active power setting value and the feedforward coefficient of the active power difference, the active power and the active power setting value are controlled to obtain the voltage phase angle of the converter; Determining a reactive loop integral coefficient according to the reactive customized adjustment time and the reactive gain coefficient; Reactive power control is performed based on the reactive loop integral coefficient, reactive power, reactive power set value, reactive difference, and rated voltage to obtain the voltage amplitude of the converter; wherein the reactive difference is the product of the voltage difference and the reactive droop coefficient; and the voltage difference is the difference between the grid voltage and the rated voltage after the grid voltage changes; Performing voltage and current dual closed-loop control based on the converter side output voltage, the converter side output current, the converter voltage phase angle, and the converter voltage amplitude to obtain a voltage control variable of the converter; A PWM signal of the converter is generated according to the voltage control variable of the converter and the high-frequency triangular carrier signal.

2. The control method of a virtual synchronous generator based on zero-pole configuration according to claim 1, characterized in that: The active gain coefficient: ； in, A represents the active power gain coefficient, U C Indicates the output voltage on the converter side, U g Indicates the grid voltage, X Indicates the reactance value between the converter and the grid side; The reactive gain coefficient: ； in, B Represents the reactive gain coefficient.

3. The control method of a virtual synchronous generator based on zero-pole configuration according to claim 1, characterized in that: According to the integral controller parameters, the proportional controller parameters, the feedforward coefficient of the active power setting value, and the feedforward coefficient of the active power difference, the active power and the active power setting value are subjected to active power control, and the voltage phase angle of the converter is obtained by the formula: ； in, represents the voltage phase angle, represents the integral controller parameters, represents the proportional controller parameters, S Indicates the grid-connected power, P ref Indicates active reference value, p Indicates active power, Indicates the feedforward coefficient of the active setting value; The feedforward coefficient of the active power difference is represented by Indicates the active power setting value, P rd Indicates the active power difference, Indicates the rated angular frequency.

4. The control method of a virtual synchronous generator based on zero-pole configuration according to claim 1, characterized in that: According to the reactive loop integral coefficient, reactive power, reactive power setting value, reactive difference and rated voltage, the formula for obtaining the voltage amplitude of the converter is: ； in, represents the voltage amplitude of the converter, k iq Represents the reactive loop integral coefficient, q set Indicates the reactive power setting value, q rd Represents reactive power difference, q Represents reactive power, U n Indicates rated voltage.

5. The control method of a virtual synchronous generator based on zero-pole configuration according to claim 1, characterized in that: Determining the first pole of the active loop and the second pole of the active loop according to the active customized adjustment time, the active gain coefficient, and the steady-state output of the active power specifically includes: The first pole of the active power loop is determined according to the active power customized adjustment time, and the formula is: ； in, Indicates the active customized adjustment time; The second pole of the active loop is determined according to the active gain coefficient, the steady-state output of active power, and the first pole of the active loop. The formula is: ； in, A represents the active power gain coefficient, It indicates the steady-state output of active power when the system frequency changes by one unit Hertz.

6. The control method of a virtual synchronous generator based on zero-pole configuration according to claim 1, characterized in that: According to the reactive customized adjustment time and the reactive gain coefficient, the formula for determining the reactive loop integral coefficient is: ； in, Indicates reactive power customized adjustment time, B represents the reactive gain coefficient, k iq Indicates the reactive loop integral coefficient.

7. The control method of a virtual synchronous generator based on zero-pole configuration according to claim 1, characterized in that: Generating a PWM signal of the converter according to the voltage control amount of the converter and the high-frequency triangular carrier signal specifically includes: Convert the voltage control quantity of the converter into The voltage control quantity in the coordinate system is used to obtain the three-phase control quantity; The three-phase control quantity is compared with the high-frequency triangular carrier signal; when the three-phase control quantity is greater than the high-frequency triangular carrier signal, the converter switching device is turned on; when the three-phase control quantity is less than the high-frequency triangular carrier signal, the converter switching device is turned off, generating the PWM signal of the converter.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control method of a virtual synchronous generator based on zero-pole configuration according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the control method of the virtual synchronous generator based on zero-pole configuration according to any one of claims 1 to 7 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the control method of the virtual synchronous generator based on zero-pole configuration according to any one of claims 1 to 7 is implemented.

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