A power compensation type analog armature virtual synchronous generator control method

Abstract

The application discloses a power compensation type analog armature virtual synchronous generator control method, relates to the technical field of grid-connected power generation control, and is applied to a three-phase inverter. The three-phase inverter is connected with an alternating current network of the same voltage level and supplies power to a power frequency alternating current load. The offset of active power output and a reference value is taken as input, a reactive power coupling compensation amount in a reactive power control loop is generated by simulating a transient armature reaction, a transient active power feedback compensation channel is set on the basis, transient voltage offset of a point of common coupling caused by the simulated transient armature reaction is inhibited, an adaptive damping algorithm is constructed, the increased inverter voltage reference angular frequency deviation after the transient active power feedback compensation is reduced, and therefore the voltage and frequency transient response of the virtual synchronous generator is improved.

Description

Technical Field

[0001] This invention relates to the field of grid-connected power generation control technology, specifically a power-compensated simulated armature virtual synchronous generator control method. Background Technology

[0002] With the rapid development of the new energy power generation industry, distributed new energy sources, represented by wind power and photovoltaics, are mostly connected to the AC grid through three-phase inverters. The control characteristics of the inverter directly determine the power supply stability and power quality of the grid-connected system. Traditional inverters mostly adopt grid-connected current control mode and do not have the inertia and damping support characteristics of synchronous generators. A high proportion of new energy access will significantly reduce the overall inertia level of the power grid and threaten the frequency stability of the power grid.

[0003] Virtual synchronous generator (VSR) technology simulates the electromechanical transient characteristics of a synchronous generator in inverter control, providing necessary inertia and damping support for the power grid. Therefore, it has been widely used in the field of renewable energy grid integration. However, most existing VSR control schemes neglect the actual transient armature reaction effect of a synchronous generator. That is, transient fluctuations in active power can trigger changes in armature reaction flux, leading to reactive power coupling components. This causes deviations in the reactive power control loop, ultimately resulting in excessive transient voltage fluctuations at the point of common coupling during power disturbances, making it difficult to meet the power supply requirements of sensitive loads.

[0004] Some existing studies have improved voltage transient characteristics by introducing active-reactive coupling compensation. However, most compensation schemes do not consider the negative impact of the compensation on the frequency transient response. Adding coupling compensation can easily lead to increased inverter voltage reference angular frequency deviation and increased frequency transient overshoot, making it difficult to simultaneously achieve good voltage and frequency transient response performance, and thus unsuitable for applications with high power supply stability requirements. Therefore, optimizing the virtual synchronous generator control strategy to leverage the advantages of simulated transient armature reaction coupling compensation while addressing its derived voltage and frequency transient problems has become a crucial technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a power-compensated analog armature virtual synchronous generator control method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A power-compensated analog armature virtual synchronous generator control method is applied to a three-phase inverter connected to an AC network of the same voltage level to supply power to a power frequency AC load. The method uses the deviation of active power output from a reference value as input, and generates reactive power coupling compensation in the reactive power control loop by simulating transient armature response. Based on this, a transient active power feedback compensation channel is set up to suppress the transient voltage deviation at the common coupling point caused by the simulated transient armature response. An adaptive damping algorithm is also constructed to reduce the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, thereby improving the voltage and frequency transient response of the virtual synchronous generator.

[0007] As a further preferred embodiment of the present invention, the following steps are included: Step 1: Establish the basic control equations of a virtual synchronous generator that include simulated transient armature reactions. The basic control equations include active power control equations and reactive power control equations, which are represented by equations (1.1) and (1.2), respectively: in: This is a virtual moment of inertia; This is the inverter voltage reference angular frequency; This is the rated angular frequency; This is the steady-state damping coefficient; This is a reference value for active power. To output active power; This is a reference value for reactive power. To output reactive power; This is a reference value for the inverter voltage amplitude. This is the rated voltage amplitude; Operator The symbol indicates an inverse Laplace transform on the frequency domain variable, and * indicates a convolution operation. Let be the transfer function of the PI controller in the reactive power control loop, and have In the formula, and These are the proportional and integral coefficients of the PI controller, respectively. For the Laplace operator; This is the reactive power coupling compensation amount, and has In the formula, To simulate the coupling coefficient of transient armature reaction, This represents the deviation of the active power output from the reference value. The armature response frequency transient signal is reconstructed based on the offset between the active power output and the reference value.

[0008] This is a power reference value; This is the voltage reference value; reactive power reference value Reactive power coupling compensation amount and output reactive power Based on power reference value The reactive power deviation signal, after being standardized to per-unit value, is processed by the PI controller. The signal output by the PI controller is then used by a limiter to generate a reference value for the inverter voltage amplitude. ; Step 2: Set up a transient active power feedback compensation channel for the active power control loop described in Step 1, and adjust the output active power... A first-order low-pass filter is performed, and a transient active power feedback compensation amount is generated based on the difference in active power before and after filtering. The deviation of the active power output from the reference value divided by the rated angular frequency. Previously, the transient active power feedback compensation was subtracted from the offset to obtain the active power control equation characterized by equation (2.1): In equation (2.1) The transient active power feedback compensation is calculated based on the difference between the output active power and the filtered active power, and is expressed as equation (2.2): In equation (2.2) To output active power The filtered active power obtained after first-order low-pass filtering is represented by equation (2.3): in: This is the transient active power feedback compensation coefficient; Low-pass filter time constant; transient active power feedback compensation amount. The deviation between active power output and reference value They have the same dimensions; The transient active power feedback compensation amount Not directly involved in reactive power coupling compensation Instead of calculating, it is done by changing the output active power. The transient response causes the active power output to deviate from the reference value. This change indirectly regulates the transient signal of the armature response frequency. Coupling compensation amount with reactive power To suppress transient shifts in the common coupling point voltage caused by simulated transient armature reactions; Step 3: To address the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, an adaptive damping algorithm is constructed in the active power control loop to generate a nonlinear adaptive damping coefficient based on the inverter voltage reference angular frequency deviation. The steady-state damping coefficient in equation (2.1) is replaced by the aforementioned nonlinear adaptive damping coefficient. Thus, the active power control equation shown in equation (3.1) is obtained: In equation (3.1) The nonlinear adaptive damping coefficient generated by the adaptive damping algorithm is calculated based on the absolute value of the inverter voltage reference angular frequency deviation, and is expressed as equation (3.2): in: For additional damping gain coefficient; The sensitivity coefficient of the hyperbolic tangent function; Nonlinear adaptive damping coefficient The coefficient of friction increases with the absolute value of the inverter voltage reference angular frequency deviation, and approaches the steady-state damping coefficient when the deviation approaches zero. To enhance the transient damping of the virtual synchronous generator and reduce the inverter voltage reference angular frequency deviation; The nonlinear adaptive damping coefficient Used only to replace the steady-state damping coefficient in the active power control equation Reconstructing the armature response frequency transient signal The steady-state damping coefficient is still used. And the nonlinear adaptive damping coefficient Not directly involved in reactive power coupling compensation Calculation; The transient active power feedback compensation channel suppresses the transient voltage shift at the common coupling point caused by the simulated transient armature reaction, and the adaptive damping algorithm reduces the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, thereby improving the voltage and frequency transient response of the virtual synchronous generator.

[0009] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention introduces reactive power coupling compensation in the reactive power control loop of a virtual synchronous generator by simulating the transient armature reaction effect of a synchronous generator. This aligns with the actual physical characteristics of a synchronous generator at the principle level, fundamentally improving the voltage deviation problem caused by active power transient fluctuations. Regarding the common coupling point voltage transient deviation problem derived from the simulated transient armature reaction, the transient active power feedback compensation channel proposed in this invention only indirectly adjusts the coupling compensation amount by correcting the active power deviation input, without changing the calculation logic of the reactive power coupling compensation amount. This avoids negatively impacting the original simulated armature reaction compensation effect and effectively suppresses voltage transient fluctuations. Regarding the problem of increased inverter voltage reference angular frequency deviation after the introduction of compensation, the nonlinear adaptive damping algorithm used in this invention can automatically adjust the damping coefficient according to the frequency deviation. During transient processes, it provides stronger damping to suppress frequency deviation, and in steady state, it automatically returns to the original steady-state damping coefficient without affecting the system's steady-state operating characteristics. This solves the problem of frequency transient performance degradation after adding compensation and achieves synchronous optimization of voltage transient performance and frequency transient performance. Attached Figure Description

[0010] Figure 1 This is a block diagram of the control method of the present invention. Detailed Implementation

[0011] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Please see Figure 1 In this embodiment of the invention, a power-compensated simulated armature virtual synchronous generator control method is applied to a three-phase inverter. The three-phase inverter is connected to an AC network of the same voltage level to supply power to the power frequency AC load. Taking the deviation of the active power output from the reference value as input, the reactive power coupling compensation in the reactive power control loop is generated by simulating transient armature reaction. On this basis, a transient active power feedback compensation channel is set to suppress the transient voltage deviation of the common coupling point caused by the simulated transient armature reaction, and an adaptive damping algorithm is constructed to reduce the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, thereby improving the voltage and frequency transient response of the virtual synchronous generator.

[0013] Preferably, the method of the present invention specifically includes the following steps: Step 1: Establish the basic control equations of a virtual synchronous generator that include simulated transient armature reactions. The basic control equations include active power control equations and reactive power control equations, which are represented by equations (1.1) and (1.2), respectively: in: This is a virtual moment of inertia; This is the inverter voltage reference angular frequency; This is the rated angular frequency; This is the steady-state damping coefficient; This is a reference value for active power. To output active power; This is a reference value for reactive power. To output reactive power; This is a reference value for the inverter voltage amplitude. This is the rated voltage amplitude; Operator The symbol indicates an inverse Laplace transform on the frequency domain variable, and * indicates a convolution operation. Let be the transfer function of the PI controller in the reactive power control loop, and have In the formula, and These are the proportional and integral coefficients of the PI controller, respectively. For the Laplace operator; This is the reactive power coupling compensation amount, and has In the formula, To simulate the coupling coefficient of transient armature reaction, This represents the deviation of the active power output from the reference value. The armature response frequency transient signal is reconstructed based on the offset between the active power output and the reference value.

[0014] This is a power reference value; This is the voltage reference value; reactive power reference value Reactive power coupling compensation amount and output reactive power Based on power reference value The reactive power deviation signal, after being standardized to per-unit value, is processed by the PI controller. The signal output by the PI controller is then used by a limiter to generate a reference value for the inverter voltage amplitude. ; Step 2: Set up a transient active power feedback compensation channel for the active power control loop described in Step 1, and adjust the output active power... A first-order low-pass filter is performed, and a transient active power feedback compensation amount is generated based on the difference in active power before and after filtering. The deviation of the active power output from the reference value divided by the rated angular frequency. Previously, the transient active power feedback compensation was subtracted from the offset to obtain the active power control equation characterized by equation (2.1): In equation (2.1) The transient active power feedback compensation is calculated based on the difference between the output active power and the filtered active power, and is expressed as equation (2.2): In equation (2.2) To output active power The filtered active power obtained after first-order low-pass filtering is represented by equation (2.3): in: This is the transient active power feedback compensation coefficient; Low-pass filter time constant; transient active power feedback compensation amount. The deviation between active power output and reference value They have the same dimensions; The transient active power feedback compensation amount Not directly involved in reactive power coupling compensation Instead of calculating, it is done by changing the output active power. The transient response causes the active power output to deviate from the reference value. This change indirectly regulates the transient signal of the armature response frequency. Coupling compensation amount with reactive power To suppress transient shifts in the common coupling point voltage caused by simulated transient armature reactions; Step 3: To address the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, an adaptive damping algorithm is constructed in the active power control loop to generate a nonlinear adaptive damping coefficient based on the inverter voltage reference angular frequency deviation. The steady-state damping coefficient in equation (2.1) is replaced by the aforementioned nonlinear adaptive damping coefficient. Thus, the active power control equation shown in equation (3.1) is obtained: In equation (3.1) The nonlinear adaptive damping coefficient generated by the adaptive damping algorithm is calculated based on the absolute value of the inverter voltage reference angular frequency deviation, and is expressed as equation (3.2): in: For additional damping gain coefficient; The sensitivity coefficient of the hyperbolic tangent function; Nonlinear adaptive damping coefficient The coefficient of friction increases with the absolute value of the inverter voltage reference angular frequency deviation, and approaches the steady-state damping coefficient when the deviation approaches zero. To enhance the transient damping of the virtual synchronous generator and reduce the inverter voltage reference angular frequency deviation; The nonlinear adaptive damping coefficient Used only to replace the steady-state damping coefficient in the active power control equation Reconstructing the armature response frequency transient signal The steady-state damping coefficient is still used. And the nonlinear adaptive damping coefficient Not directly involved in reactive power coupling compensation Calculation; The transient active power feedback compensation channel suppresses the transient voltage shift at the common coupling point caused by the simulated transient armature reaction, and the adaptive damping algorithm reduces the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, thereby improving the voltage and frequency transient response of the virtual synchronous generator.

[0015] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0016] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A power-compensated analog armature virtual synchronous generator control method, applied to a three-phase inverter, wherein the three-phase inverter is connected to an AC network of the same voltage level to supply power to a power frequency AC load, characterized in that, Using the offset between the active power output and the reference value as input, reactive power coupling compensation in the reactive power control loop is generated by simulating transient armature reaction. Based on this, a transient active power feedback compensation channel is set up to suppress the transient voltage offset of the common coupling point caused by the simulated transient armature reaction. An adaptive damping algorithm is constructed to reduce the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, thereby improving the voltage and frequency transient response of the virtual synchronous generator.

2. The power-compensated simulated armature virtual synchronous generator control method according to claim 1, characterized in that, It includes the following steps: Step 1: Establish the basic control equations of a virtual synchronous generator that include simulated transient armature reactions. The basic control equations include active power control equations and reactive power control equations, which are represented by equations (1.1) and (1.2), respectively: in: This is a virtual moment of inertia; This is the inverter voltage reference angular frequency; This is the rated angular frequency; This is the steady-state damping coefficient; This is a reference value for active power. To output active power; This is a reference value for reactive power. To output reactive power; This is a reference value for the inverter voltage amplitude. This is the rated voltage amplitude; Operator The symbol indicates an inverse Laplace transform on the frequency domain variable, and * indicates a convolution operation. Let be the transfer function of the PI controller in the reactive power control loop, and have In the formula, and These are the proportional and integral coefficients of the PI controller, respectively. For the Laplace operator; This is the reactive power coupling compensation amount, and has In the formula, To simulate the coupling coefficient of transient armature reaction, This represents the deviation of the active power output from the reference value. The armature response frequency transient signal is reconstructed based on the offset between the active power output and the reference value. This is a power reference value; This is the voltage reference value; reactive power reference value Reactive power coupling compensation amount and output reactive power Based on power reference value The reactive power deviation signal, after being standardized to per-unit value, is processed by the PI controller. The signal output by the PI controller is then used by a limiter to generate a reference value for the inverter voltage amplitude. ; Step 2: Set up a transient active power feedback compensation channel for the active power control loop described in Step 1, and adjust the output active power... A first-order low-pass filter is performed, and a transient active power feedback compensation amount is generated based on the difference in active power before and after filtering. The deviation of the active power output from the reference value divided by the rated angular frequency. Previously, the transient active power feedback compensation was subtracted from the offset to obtain the active power control equation characterized by equation (2.1): In equation (2.1) The transient active power feedback compensation is calculated based on the difference between the output active power and the filtered active power, and is expressed as equation (2.2): In equation (2.2) To output active power The filtered active power obtained after first-order low-pass filtering is represented by equation (2.3): in: This is the transient active power feedback compensation coefficient; Low-pass filter time constant; transient active power feedback compensation amount. The deviation between active power output and reference value They have the same dimensions; The transient active power feedback compensation amount Not directly involved in reactive power coupling compensation Instead of calculating, it is done by changing the output active power. The transient response causes the active power output to deviate from the reference value. This change indirectly regulates the transient signal of the armature response frequency. Coupling compensation amount with reactive power To suppress transient shifts in the common coupling point voltage caused by simulated transient armature reactions; Step 3: To address the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, an adaptive damping algorithm is constructed in the active power control loop to generate a nonlinear adaptive damping coefficient based on the inverter voltage reference angular frequency deviation. The steady-state damping coefficient in equation (2.1) is replaced by the aforementioned nonlinear adaptive damping coefficient. Thus, the active power control equation shown in equation (3.1) is obtained: In equation (3.1) The nonlinear adaptive damping coefficient generated by the adaptive damping algorithm is calculated based on the absolute value of the inverter voltage reference angular frequency deviation, and is expressed as equation (3.2): in: For additional damping gain coefficient; The sensitivity coefficient of the hyperbolic tangent function; Nonlinear adaptive damping coefficient The coefficient of friction increases with the absolute value of the inverter voltage reference angular frequency deviation, and approaches the steady-state damping coefficient when the deviation approaches zero. To enhance the transient damping of the virtual synchronous generator and reduce the inverter voltage reference angular frequency deviation; The nonlinear adaptive damping coefficient Used only to replace the steady-state damping coefficient in the active power control equation Reconstructing the armature response frequency transient signal The steady-state damping coefficient is still used. And the nonlinear adaptive damping coefficient Not directly involved in reactive power coupling compensation Calculation; The transient active power feedback compensation channel suppresses the transient voltage shift at the common coupling point caused by the simulated transient armature reaction, and the adaptive damping algorithm reduces the increased inverter voltage reference angular frequency deviation after adding transient active power feedback compensation, thereby improving the voltage and frequency transient response of the virtual synchronous generator.

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