A grid-connected control method for energy storage virtual synchronous machine based on active power feedforward compensation

Abstract

To address the issue of unbalanced steady-state deviation and dynamic oscillation in the grid-connected active power of traditional energy storage virtual synchronous machines (VSMs) due to the coupling between their primary frequency regulation coefficient and virtual damping coefficient, this invention discloses a grid-connected control method for VSMs based on active power feedforward compensation. This control method utilizes active power fed forward to the grid-connected active power closed-loop control loop after passing through a first-order low-pass filter containing virtual inertia and primary frequency regulation coefficients. By adjusting the feedforward coefficient, the dynamic performance of the grid-connected active power of the VSM is optimized. This method offers advantages such as not affecting primary frequency regulation characteristics, not increasing the control system order, eliminating the need for differential calculations, and avoiding the risk of output frequency overshoot. It is applicable to grid-connected operation scenarios with energy storage converters such as lead-acid and lithium batteries configured on the DC side, as well as microgrids integrating such energy storage converters into distribution networks.

Description

Technical Field

[0001] This invention relates to the field of virtual synchronous generator control, and in particular to a grid-connected control method for a virtual synchronous generator based on active power feedforward compensation. It is applicable to grid-connected operation scenarios of energy storage converters configured with lead-acid, lithium batteries, etc. on the DC side, as well as microgrid access to distribution networks containing such energy storage converters. Background Technology

[0002] The virtual inertia control loop of a traditional virtual synchronized generator (VSG) makes its active power-frequency closed-loop control system a typical second-order oscillating system. Therefore, its grid-connected active power inevitably exhibits dynamic oscillations and power overshoot under both active power reference commands and grid frequency disturbances. Furthermore, while traditional VSGs can directly utilize virtual damping control loops and increase the virtual damping coefficient to suppress or eliminate the dynamic oscillations of grid-connected active power under these two disturbances, the coupling between its virtual damping coefficient and the primary frequency regulation coefficient means that its damping response performance and primary frequency regulation characteristics cannot be adjusted independently.

[0003] To this end, various studies have been conducted, such as the article entitled "Virtual Inertial Optimization Control Strategy Based on Frequency Stability Improvement", published in "Power System Protection and Control", Vol. 50, No. 12, 2022, pp. 126-133. This article proposes to add a first-order differential feedforward compensation link of active power and frequency to the forward channel of the traditional virtual synchronous machine active power-frequency control loop, thereby increasing the transient damping of the virtual synchronous machine grid-connected active power closed loop system to suppress its grid-connected active power dynamic oscillation and power overshoot. However, it does not consider the adverse effects of high-frequency harmonics generated by differential operations on the system.

[0004] The article, titled "d-axis current differential feedforward control for optimizing the dynamic characteristics of energy storage VSG", published in "Power System Technology" Vol. 46, No. 07, 2022, pp. 2510-2523, proposes to introduce a first-order low-pass filter into the first-order differential feedforward link of the grid-connected active current of the virtual synchronous machine. Although the introduced first-order low-pass filter can eliminate the high-frequency harmonics caused by the differential operation to a certain extent, it upgrades the order of the grid-connected active current closed-loop system of the virtual synchronous machine to the third order, which has the disadvantages of complex system parameter tuning process and output frequency overshoot.

[0005] The article, titled "A Transient Power Oscillation Suppression Strategy for Virtual Synchronous Generators Considering Overshoot," published in *Automation of Electric Power Systems*, Vol. 46, No. 11, 2022, pp. 131-141, proposes a control strategy for a virtual synchronous generator (FFC-VSG) based on active transient feedforward compensation. This FFC-VSG control strategy utilizes the difference method of a first-order lag element to construct a damping scheme based on active transient feedforward, eliminating the need for differential operations. However, the active closed-loop system of the FFC-VSG is still a third-order system, with relatively complex parameter design, and its output frequency still faces the risk of overshoot under the active reference command step.

[0006] The article, titled “A reference-feedforward-based damping method for virtual synchronous generator control”, by YUY, CHAUDHARY SK, TINAJERO G DA, et al., IEEE Transactions on Power Electronics, 2022, 37(7), 7566–7571 (“A reference-feedforward-based damping method for virtual synchronous generator control”, IEEE Journal of Power Electronics, Vol. 37, No. 7, 2022, pp. 7566–7571), proposes a transient damping strategy based on active power reference command composite differential feedforward compensation, with the goal of designing the virtual synchronous generator active power closed-loop system as a typical second-order system. The differential feedforward compensation parameter tuning of this control strategy has the advantages of being intuitive and simple, but it is not suitable for the operating conditions of grid frequency disturbance.

[0007] As can be seen from the above, although the existing technology has solved the problems of grid-connected active dynamic oscillation and power overshoot under the conditions of active reference command and grid frequency disturbance of traditional energy storage virtual synchronous machine, it still has disadvantages such as steady-state deviation of grid-connected active power, harmonic amplification introduced by differential operation, output frequency overshoot, and complex parameter design and limited application conditions due to the increase of system order. Summary of the Invention

[0008] To overcome the limitations of various technical solutions presented in the background art, this invention addresses the problem that traditional energy storage virtual synchronous machines (VSMs) suffer from both steady-state deviation and dynamic oscillations due to the coupling between their primary frequency regulation coefficient and virtual damping coefficient. It provides a grid-connected control method for VSMs based on active power feedforward compensation. This method optimizes the dynamic performance of the VSM's grid-connected active power without affecting primary frequency regulation characteristics, increasing the control system order, requiring no differential calculations, eliminating the risk of output frequency overshoot, and is applicable to both active power reference commands and grid frequency disturbances.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A grid-connected control method for an energy storage virtual synchronous machine based on active power feedforward compensation includes the following steps:

[0011] Step 1, Calculate the feedforward compensation amount, and use the active power reference command P of the energy storage virtual synchronous machine. ref Subtract the grid-connected active power P of the energy storage virtual synchronous machine e The power difference ΔP between the two is obtained as the input of the feedforward compensation control. The power difference ΔP is then processed through a circuit containing the virtual inertia coefficient J and the primary frequency modulation coefficient k. ω , and feedforward coefficient k d The compensation amount δ for feedforward compensation control is obtained after the first-order low-pass filter stage. d ;

[0012] Step 2, Rotor Motion Equation: The power difference ΔP obtained in Step 1 is processed through a system including the virtual inertia coefficient J and the primary frequency modulation coefficient k. ω After a first-order low-pass filter with virtual damping coefficient D, the angular frequency deviation Δω is obtained. The angular frequency deviation Δω is added to the grid rated angular frequency ω0 to obtain the output angular frequency ω of the energy storage virtual synchronous machine.

[0013] Step 3: Subtract the grid angular frequency ω from the output angular frequency ω of the energy storage virtual synchronizer obtained in Step 2. g The work angle δ is then obtained through integration. g , the work angle δ g Add the compensation amount δ obtained in step 1 d The power factor angle δ of the energy storage virtual synchronous machine is obtained;

[0014] Step 4: Multiply the power factor angle δ of the energy storage virtual synchronous machine obtained in Step 3 by the synchronization voltage coefficient K to obtain the grid-connected active power P of the energy storage virtual synchronous machine. e ;

[0015] Step 5: The output angular frequency ω of the energy storage virtual synchronous machine obtained in Step 2 is integrated and then added to the compensation amount δ obtained in Step 1. dThe output phase θ of the energy storage virtual synchronous machine is obtained, and the output phase θ is used as the phase for dq coordinate transformation to obtain the voltage reference command E in the dq coordinate system for the reactive power control loop. * dq Performing a dq coordinate transformation yields the three-phase voltage modulation signal E in the abc coordinate system. * abc Then, the three-phase voltage modulation signal E * abc The drive signal for the inverter bridge switching transistors of the energy storage converter is generated through the SVPWM modulation stage.

[0016] Preferably, the formula used to calculate the input power difference ΔP in step 1 for the feedforward compensation control is:

[0017] ΔP=P ref -P e ,

[0018] The compensation amount δ of feedforward compensation control d The calculation formula used is:

[0019]

[0020] In the formula, s is the Laplace operator.

[0021] Preferably, the formula used to calculate the angular frequency deviation Δω in step 2 is:

[0022]

[0023] The formula for calculating the output angular frequency ω of the energy storage virtual synchronous machine is as follows:

[0024] ω = Δω + ω0,

[0025] In the formula, s is the Laplace operator.

[0026] Preferably, the work angle δ in step 3 g The calculation formula used is:

[0027]

[0028] The formula for calculating the power factor angle δ of the energy storage virtual synchronous machine is:

[0029] δ=δ g +δ d ,

[0030] In the formula, s is the Laplace operator.

[0031] Preferably, the grid-connected active power P of the energy storage virtual synchronous machine in step 4 is... e The calculation formula used is:

[0032]

[0033] In the formula, U g E is the voltage amplitude of the grid, E is the voltage amplitude of the energy storage virtual synchronous machine output, and X is the line equivalent inductive reactance.

[0034] Preferably, the formula used to calculate the output phase θ of the energy storage virtual synchronizer in step 5 is:

[0035]

[0036] In the formula, s is the Laplace operator.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides a grid-connected control method for an energy storage virtual synchronous machine based on active power feedforward compensation. This method utilizes active power that is fed forward to the grid-connected active power closed-loop control loop after passing through a first-order low-pass filter containing virtual inertia coefficients and primary frequency regulation coefficients. By adjusting the feedforward coefficients, the dynamic performance of the grid-connected active power of the energy storage virtual synchronous machine is optimized. This method has the advantages of not affecting the primary frequency regulation characteristics, not increasing the order of the control system, not requiring differential calculations, eliminating the risk of output frequency overshoot, and balancing both active power reference commands and grid frequency disturbances. This control method is applicable to grid-connected operation scenarios of energy storage converters with DC side configurations of lead-acid, lithium batteries, etc., as well as microgrid access to distribution networks containing such energy storage converters. Attached Figure Description

[0039] Figure 1 This is an equivalent control structure diagram of the grid-connected active power closed loop of the energy storage virtual synchronous machine according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram illustrating the calculation of the compensation amount in feedforward compensation control.

[0041] Figure 3 This is a schematic diagram of coordinate transformation and modulation according to an embodiment of the present invention.

[0042] Figure 4 This is a comparison of simulation waveforms of the energy storage converter before and after adopting this invention.

[0043] Figure 5 This is a comparison of experimental waveforms before and after the energy storage converter adopted this invention. Detailed Implementation

[0044] The following detailed embodiments will be further described in conjunction with the above-mentioned figures, as follows:

[0045] Please see Figure 1 The present invention proposes a grid-connected control method for an energy storage virtual synchronous machine based on active power feedforward compensation, comprising the following steps:

[0046] Step 1, calculate the feedforward compensation amount, such as Figure 2 As shown, the active power reference command P of the energy storage virtual synchronous machine is... ref Subtract the grid-connected active power P of the energy storage virtual synchronous machine e The power difference ΔP between the two is obtained as the input of the feedforward compensation control. The power difference ΔP is then processed through a circuit containing the virtual inertia coefficient J and the primary frequency modulation coefficient k. ω , and feedforward coefficient k d The compensation amount δ for feedforward compensation control is obtained after the first-order low-pass filter stage. d .

[0047] The formula for calculating the input power difference ΔP in feedforward compensation control is as follows:

[0048] ΔP=P ref -P e ,

[0049] The compensation amount δ of feedforward compensation control d The calculation formula used is:

[0050]

[0051] In the formula, s is the Laplace operator.

[0052] Step 2, Rotor Motion Equation: The power difference ΔP obtained in Step 1 is processed through a system including the virtual inertia coefficient J and the primary frequency modulation coefficient k. ω After a first-order low-pass filter with virtual damping coefficient D, the angular frequency deviation Δω is obtained. The angular frequency deviation Δω is then added to the grid rated angular frequency ω0 to obtain the output angular frequency ω of the energy storage virtual synchronous machine.

[0053] The formula used to calculate the angular frequency deviation Δω is as follows:

[0054]

[0055] The formula for calculating the output angular frequency ω of the energy storage virtual synchronous machine is as follows:

[0056] ω = Δω + ω0,

[0057] In the formula, s is the Laplace operator.

[0058] Step 3: Subtract the grid angular frequency ω from the output angular frequency ω of the energy storage virtual synchronizer obtained in Step 2. g The work angle δ is then obtained through integration. g , the work angle δ g Add the compensation amount δ obtained in step 1 d The power factor angle δ of the energy storage virtual synchronous machine is obtained.

[0059] Wherein, the work angle δ g The calculation formula used is:

[0060]

[0061] The formula for calculating the power factor angle δ of the energy storage virtual synchronous machine is:

[0062] δ=δ g +δ d ,

[0063] In the formula, s is the Laplace operator.

[0064] Step 4: Multiply the power factor angle δ of the energy storage virtual synchronous machine obtained in Step 3 by the synchronization voltage coefficient K to obtain the grid-connected active power P of the energy storage virtual synchronous machine. e .

[0065] Among them, the grid-connected active power P of the energy storage virtual synchronous machine e The calculation formula used is:

[0066]

[0067] In the formula, U g E is the voltage amplitude of the grid, E is the voltage amplitude of the energy storage virtual synchronous machine output, and X is the line equivalent inductive reactance.

[0068] Step 5, as follows Figure 3 As shown, the output angular frequency ω of the energy storage virtual synchronous machine obtained in step 2 is integrated and then added to the compensation amount δ obtained in step 1. d The output phase θ of the energy storage virtual synchronous machine is obtained, and the output phase θ is used as the phase for dq coordinate transformation to obtain the voltage reference command E in the dq coordinate system for the reactive power control loop. * dq Performing a dq coordinate transformation yields the three-phase voltage modulation signal E in the abc coordinate system. * abc Then, the three-phase voltage modulation signal E * abc The drive signal for the inverter bridge switching transistors of the energy storage converter is generated through the SVPWM modulation stage.

[0069] The formula for calculating the output phase θ of the energy storage virtual synchronizer is as follows:

[0070]

[0071] In the formula, s is the Laplace operator.

[0072] Example

[0073] To verify the control effect of the proposed active power feedforward compensation-based virtual synchronous generator (APFC-VSG) grid-connected control method, simulation and experimental comparison tests were conducted on the proposed APFC-VSG grid-connected control method, the traditional virtual synchronous generator (TVSG) grid-connected control method, and the existing active power transient feedforward compensation-based virtual synchronous generator (FFC-VSG) grid-connected control method (the control method mentioned in the background art entitled "Transient Power Oscillation Suppression Strategy Considering Overshoot of Virtual Synchronous Generator"). The details are as follows:

[0074] First, the relevant parameters are set. In this embodiment, the relevant parameter settings in the APFC-VSG grid-connected control method of the present invention are as follows:

[0075] The rated capacity of the energy storage virtual synchronous machine is 100kVA, and the active power reference command P... ref The power supply is 20kW, the grid's rated angular frequency ω0 is 314.16 rad / s, and the virtual inertia coefficient J is 6 kg·m. 2 The primary frequency modulation coefficient k ω The voltage amplitude is 15915.5 J / rad, and the grid voltage amplitude is U. g Given a voltage of 311V, an output voltage amplitude E of 311V from the energy storage virtual synchronizing machine, and a line equivalent inductive reactance X of 0.1Ω, the synchronization voltage coefficient K = 1.5U. g E / X is 1450815. In this embodiment, the grid-connected active power closed-loop equivalent control system of the energy storage virtual synchronous machine is set as a critically damped or overdamped system to ensure that the grid-connected active power of the energy storage virtual synchronous machine achieves the effect of no steady-state deviation and no dynamic oscillation under the condition that the virtual damping coefficient D is 0. That is, the virtual damping coefficient D is set to 0. The purpose of this setting is to eliminate the primary frequency regulation coefficient k. ω The problem of grid-connected active power steady-state deviation introduced by coupling with the virtual damping coefficient D. Combined with... Figure 1 And through a complex formula derivation process, the feedforward coefficient k d The range of values ​​is Here, k d Set it to 0.1.

[0076] Next, a simulation is performed, in which two operating conditions are set up, as follows:

[0077] Simulation condition 1 is set as follows: Initially, the energy storage virtual synchronous machine outputs 20kW of grid-connected active power and maintains stable operation, while the grid frequency remains constant at 50Hz. At 3 seconds, the active power reference command P... ref From 20kW to 60kW;

[0078] Simulation condition 2 is set as follows: at the initial moment, the grid frequency remains unchanged at 50Hz, the energy storage virtual synchronous machine outputs 20kW of grid-connected active power and maintains stable operation, and at 3s, the grid frequency drops from 50Hz to 49.95Hz.

[0079] Based on the above simulation conditions, the following is obtained: Figure 4 The simulation comparison diagram shown below, in which, Figure 4 (a) Simulation comparison results obtained corresponding to simulation condition 1. Figure 4 (b) Simulation comparison results corresponding to simulation condition 2. In the figure, APFC-VSG represents the grid-connected control method of energy storage virtual synchronous machine based on active power feedforward compensation proposed in this invention, TVSG represents the traditional grid-connected control method of energy storage virtual synchronous machine, and FFC-VSG represents the existing grid-connected control method of virtual synchronous machine based on active power transient feedforward compensation. That is, the curve pointed to by TVSG is the simulation waveform diagram of using the traditional grid-connected control method of energy storage virtual synchronous machine, the curve pointed to by FFC-VSG is the simulation waveform diagram of using the existing grid-connected control method of virtual synchronous machine based on active power transient feedforward compensation, the curve pointed to by FFC-VSG and the curve pointed to by TVSG are both simulation waveform diagrams before using this invention, and the curve pointed to by APFC-VSG is the simulation waveform diagram after using this invention, specifically the simulation waveform diagram of using the grid-connected control method of energy storage virtual synchronous machine based on active power feedforward compensation proposed in this invention.

[0080] according to Figure 4 (a) It can be seen that when D=0 is set for TVSG, the grid-connected active power closed-loop control system of the energy storage virtual synchronous machine is an underdamped system. Therefore, the grid-connected active power and output frequency of the energy storage virtual synchronous machine are related to the active power reference command P. ref Significant dynamic oscillations and overshoot are observed when a 40kW step disturbance occurs. Furthermore, after adding virtual damping D=284.5, the grid-connected active power closed-loop control system enters an overdamped state. Therefore, the grid-connected active power and output frequency are related to the active power reference command P. ref No dynamic oscillations were observed during a 40kW step disturbance; both FFC-VSG and APFC-VSG operated under the active power reference command P. ref When a 40kW step disturbance occurs, both can ensure that the grid-connected active power of the energy storage virtual synchronous machine does not exhibit dynamic oscillation or power overshoot. Both have a faster dynamic response speed in grid-connected active power compared to TVSG (D=284.5). However, at this time, the output frequency of FFC-VSG has a frequency overshoot amplitude of 0.23Hz, and its frequency overshoot amplitude is approximately 7.6 times that of APFC-VSG (0.03Hz) proposed in this invention. Therefore, while FFC-VSG can suppress grid-connected active power dynamic oscillation, it still has the risk of frequency overshoot, while APFC-VSG of this invention does not have the risk of output frequency overshoot.

[0081] According to Figure 4 (b) It can be seen that when D=0 is set for TVSG, the grid-connected active power and output frequency of the energy storage virtual synchronous machine both exhibit dynamic oscillation and overshoot under grid frequency step disturbances. However, after setting D=284.5, the grid-connected active power and output frequency of the energy storage virtual synchronous machine do not exhibit dynamic oscillation and overshoot under grid frequency step disturbances. However, the introduction of D causes a steady-state deviation of 28.1kW in the grid-connected active power. Both FFC-VSG and APFC-VSG can ensure that the grid-connected active power and output frequency of the energy storage virtual synchronous machine do not exhibit dynamic oscillation and overshoot under grid frequency step disturbances. Compared with TVSG (D=284.5), neither of them introduces a steady-state error in their grid-connected active power. Moreover, APFC-VSG has the smallest frequency change rate compared to FFC-VSG. Therefore, the APFC-VSG proposed in this invention also has the best frequency dynamic response performance under grid frequency step disturbances.

[0082] Then, the experiment was conducted, as follows:

[0083] The experimental operating condition is set to the active power reference command P of the energy storage virtual synchronous machine. ref The two types of jumps—from 20kW to 60kW and from 50Hz to 49.95Hz—correspond one-to-one with the simulated operating conditions.

[0084] Based on the above working conditions, the following is obtained: Figure 5 The experimental comparison diagram shown shows that, Figure 5 (a) is the active reference instruction P ref Experimental comparison results from 20kW to 60kW Figure 5 (b) shows the experimental comparison results of the grid frequency stepping from 50Hz to 49.95Hz. In the figure, APFC-VSG represents the grid-connected control method of the energy storage virtual synchronous machine based on active power feedforward compensation proposed in this invention, TVSG represents the traditional grid-connected control method of the energy storage virtual synchronous machine, and FFC-VSG represents the existing grid-connected control method of the virtual synchronous machine based on active power transient feedforward compensation. That is, the curve pointed to by TVSG is the experimental waveform diagram of the traditional grid-connected control method of the energy storage virtual synchronous machine, the curve pointed to by FFC-VSG is the experimental waveform diagram of the existing grid-connected control method of the virtual synchronous machine based on active power transient feedforward compensation, the curve pointed to by FFC-VSG and the curve pointed to by TVSG are both experimental waveform diagrams before the application of this invention, and the curve pointed to by APFC-VSG is the experimental waveform diagram after the application of this invention, specifically the experimental waveform diagram of the grid-connected control method of the energy storage virtual synchronous machine based on active power feedforward compensation proposed in this invention.

[0085] according to Figure 5 (a) Figure 5 (b) It is not difficult to see that the active reference instruction P refThe experimental verification and comparison results under power grid frequency step disturbances are consistent with those of the above. Figure 4 (a) Figure 4 The simulation verification results in (b) are consistent. Specifically, after adding D=284.5 to the TVSG, the grid-connected active power of the energy storage virtual synchronous machine does not have power overshoot under either step disturbance, but there is a steady-state deviation of 28.3kW after the grid frequency step disturbance. Meanwhile, the active power reference command P of FFC-VSG and APFC-VSG are consistent. ref Under grid frequency step disturbances, it can effectively eliminate the dynamic oscillations of grid-connected active power without introducing steady-state deviations. However, the frequency overshoot amplitude of FFC-VSG is within the active power reference command P. ref The frequency change rate under step disturbance is 0.35Hz, which is much higher than the 0.044Hz of the APFC-VSG proposed in this invention. Furthermore, the output frequency of the FFC-VSG has the largest frequency change rate under step disturbance of the grid frequency, while the output frequency of the APFC-VSG has the smallest frequency change rate at this time.

[0086] In summary, the grid-connected control method of the energy storage virtual synchronous machine based on active power feedforward compensation proposed in this invention, compared with existing grid-connected control methods, does not exhibit dynamic oscillation and power overshoot, has a faster dynamic response speed, better frequency dynamic response performance, and no risk of output frequency overshoot. It also takes into account both active power reference commands and grid frequency disturbances. Therefore, the grid-connected control method provided by this invention has better control performance.

[0087] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A method for grid-connected control of energy storage virtual synchronous machine based on active feed-forward compensation, characterized in that, The method comprises the following steps: Step 1, feedforward compensation amount calculation, subtract the grid-connected active power P of the energy storage virtual synchronous machine ref of the energy storage virtual synchronous machine e , and obtain the power difference △P as the input quantity of the feedforward compensation control, pass the power difference △P through the first-order low-pass filter link containing the virtual inertia coefficient J, the primary frequency modulation coefficient k ω , and the feedforward coefficient k d , and obtain the compensation amount δ d of the feedforward compensation control; Step 2, rotor motion equation part, the power difference ΔP obtained in step 1 is passed through a first-order low-pass filter link containing a virtual inertia coefficient J, a primary frequency modulation coefficient k ω , and a virtual damping coefficient D to obtain an angular frequency deviation Δω, and the angular frequency deviation Δω is added to the rated angular frequency ω0 of the power grid to obtain the output angular frequency ω of the energy storage virtual synchronous machine. Step 3, subtract the grid angular frequency ω from the output angular frequency ω of the energy storage virtual synchronous machine obtained in Step 2 g After the integral operation, the power angle δ is obtained g , the power angle δ g is added to the compensation amount δ obtained in Step 1 d to obtain the power factor angle δ of the energy storage virtual synchronous machine; Step 4, multiply the power factor angle δ of the energy storage virtual synchronous machine obtained in step 3 by the synchronous voltage coefficient K to obtain the grid-connected active power P of the energy storage virtual synchronous machine e ; Step 5, the output angular frequency ω of the energy storage virtual synchronous machine obtained in step 2 is integrated and the compensation amount δ obtained in step 1 is added d The output phase θ of the energy storage virtual synchronous machine is obtained, and the output phase θ is used as a phase for dq coordinate transformation, and a voltage reference instruction E in the dq coordinate system is obtained for a reactive power control loop * dq Dq coordinate transformation is performed to obtain a three-phase voltage modulation signal E in the abc coordinate system * abc The three-phase voltage modulation signal E is further used to generate a drive signal of an inverter bridge switch tube of the energy storage converter * abc The drive signal of the inverter bridge switch tube of the energy storage converter is generated through an SVPWM modulation link.

2. The active feed-forward compensation based energy storage virtual synchronous machine grid-connection control method of claim 1, wherein, The calculation formula of the input power difference ΔP of the feedforward compensation control in step 1 is as follows: ΔP = P ref - P e , The compensation amount δ of the feedforward compensation control d The calculation formula used is: In the formula, s is a Laplace operator.

3. The active feed-forward compensation based energy storage virtual synchronous machine grid-connection control method of claim 1, wherein, The calculation formula of the angular frequency deviation Δω in step 2 is as follows: The calculation formula of the output angular frequency ω of the energy storage virtual synchronous machine is as follows: ω = Δω + ω0, In the formula, s is a Laplace operator.

4. The active feed-forward compensation based energy storage virtual synchronous machine grid-connection control method of claim 1, wherein, Power angle delta δ in step 3 g The calculation formula used is: The calculation formula of the power factor angle δ of the energy storage virtual synchronous machine is as follows: δ = δ g + δ d , In the formula, s is a Laplace operator.

5. The active feed-forward compensation based energy storage virtual synchronous machine grid integration control method of claim 1, wherein, The grid-connected active power P of the energy storage virtual synchronous machine in step 4 e The calculation formula used is: In the formula, U g is the grid voltage amplitude, E is the energy storage virtual synchronous machine output voltage amplitude, and X is the line equivalent inductance.

6. The active feed-forward compensation based energy storage virtual synchronous machine grid integration control method of claim 1, wherein, The calculation formula of the output phase θ of the energy storage virtual synchronous machine in step 5 is as follows: In the formula, s is a Laplace operator.

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