Virtual synchronous machine parallel networking control method based on triple fractional order

Abstract

The invention discloses a virtual synchronous machine parallel networking control method based on triple fractional orders, and aims to solve the problem of dynamic oscillation of output active power and output frequency of a traditional virtual synchronous machine parallel networking system under load disturbance. According to the method, a single virtual inertia control link in a traditional virtual synchronous machine parallel networking control method is replaced by a triple fractional order virtual inertia control link, and the response performance of output active power and output frequency of a virtual synchronous machine parallel networking system is optimized by adjusting introduced triple adjustable parameters. The method has the advantages of flexible control parameter selection, no influence on the steady-state equalization effect of the active power, capability of eliminating the dynamic oscillation of the active power and inhibiting the dynamic oscillation of the output frequency, and can be applied to the field of virtual synchronous machine parallel networking control in the power electronic technology.

Description

Technical Field

[0001] The present invention relates to the field of virtual synchronous machine control, and in particular to a virtual synchronous machine parallel networking control method based on triple fractional order, which is suitable for virtual synchronous machine parallel networking operation scenarios in power electronics technology and microgrid scenarios including such virtual synchronous machine parallel networking systems. Background Art

[0002] Virtual Synchronous Generator (VSG) simulates the rotor motion equation of synchronous generator, making VSG have a certain inertia support capacity, but it inevitably introduces the problem of dynamic oscillation of output active power and output frequency, especially in VSG parallel network system. In addition, although increasing the virtual damping parameter of VSG can suppress the dynamic oscillation of output active power and output frequency of VSG parallel network system, it is easy to cause the angular frequency steady-state deviation of VSG parallel network system and the output active power sharing error to increase.

[0003] To this end, people have conducted various studies, such as the article entitled "Active Power Oscillation Damping Control of Multiple Virtual Synchronous Generators in Parallel Operation in Microgrids", "Proceedings of the Chinese Society of Electrical Engineering", Vol. 39, No. 21, 2019, pp. 6247-6254; This article analyzes the reasons for the dynamic oscillation of active power in the traditional virtual synchronous generator (TVSG) parallel networking system, and proposes a mutual damping control strategy based on a distributed communication architecture to achieve effective suppression of the dynamic oscillation of active power in the TVSG parallel networking system, but it requires the introduction of data communication lines, which in turn limits the flexibility of the layout and control of the TVSG parallel networking system.

[0004] An article entitled "Parameter Self-adjusting Optimization Control Strategy for Dual-machine Parallel System of Virtual Synchronous Generators" was published in the Transactions of the Chinese Society of Electrotechnical Engineering, Vol. 34, No. 1, 2019, pp. 128-138. This article introduces an adaptive adjustment method based on virtual inertia and virtual damping parameters into the traditional virtual synchronous generator (TVSG) parallel network system. By changing the virtual inertia parameters and virtual damping parameters in real time, it effectively suppresses the dynamic oscillation of active power in the TVSG parallel network system. However, it has the disadvantages of complex system control parameter design and nonlinear parameter changes.

[0005] An article entitled “Active Power Oscillation Damping Based on Acceleration Control in Paralleled Virtual Synchronous Generators System”, M. Chen, D. Zhou and F. Blaabjerg, IEEE Transactions on Power Electronics, 2021, 36(8), 9501-9510 (“Active Power Oscillation Damping Based on Acceleration Control in Paralleled Virtual Synchronous Generators System”, IEEE Journal of Power Electronics, Vol. 36, No. 8, 2021, pp. 9501-9510); This article introduces a disturbance compensation link based on angular acceleration control and power feedback into the traditional virtual synchronous generator (TVSG) parallel network system, which can suppress the dynamic oscillation of the active power of the TVSG parallel network system. However, it has the disadvantages of increasing the order of the control system and difficulty in ensuring a good suppression effect under large interference.

[0006] An article entitled "Analysis of Active Oscillation Characteristics of Energy Storage VSG Parallel Networking System and Its Improvement Strategy" is published in Electric Power Automation Equipment, Vol. 44, No. 5, 2024, pp. 51-57. This article uses a first-order low-pass filter link containing virtual inertia parameters and primary frequency modulation parameters to construct an active dynamic feedforward term, and introduces the active dynamic feedforward term into the traditional virtual synchronous generator (TVSG) parallel networking system. By adjusting the feedforward parameters, the ability of the TVSG parallel networking system to suppress the dynamic oscillation of active power is improved. However, there are disadvantages that the downward slope of the open-loop gain of the control system is reduced in the high frequency band and the control freedom still needs to be further improved.

[0007] From the above, it can be seen that although the existing technology solves the problem of dynamic oscillation of active power in the traditional virtual synchronous machine parallel networking system, it still has the disadvantages of requiring data communication lines, complex system control parameter design, poor robustness under large disturbances, and the control freedom still needs to be further improved. Summary of the invention

[0008] In order to overcome the limitations of various technical solutions given in the background technology, the present invention aims at the problem that the output active power of the traditional virtual synchronous machine parallel networking system is difficult to take into account both the steady-state balancing effect and the dynamic oscillation due to disturbance. A virtual synchronous machine parallel networking control method based on triple fractional order is provided. The control method can effectively suppress the dynamic oscillation of the output active power and the output frequency of the virtual synchronous machine grid-connected networking system without affecting the steady-state balancing effect. It has the advantages of no need for differential operations, no need for data communication lines, no increase in the control system order, increased control freedom and more flexible control parameter selection.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A triple fractional-order virtual synchronous machine parallel networking control method comprises the following steps:

[0011] Step 1: In the triple fractional order rotor motion equation part, the active reference instruction P of the virtual synchronous machine is ref Subtract the output active power P of the virtual synchronous machine e The power difference ΔP of the virtual synchronous machine is obtained, and the power difference ΔP is converted into a virtual inertia parameter J and a triple fractional integral coefficient λ. i (i=1, 2, 3), triple fractional-order virtual damping parameter D i The angular frequency deviation Δω of the virtual synchronous machine is obtained by using the triple fractional-order rotor motion equation (i=1, 2, 3), and the output angular frequency ω of the virtual synchronous machine is obtained by adding the angular frequency deviation Δω to the rated angular frequency ω0;

[0012] Step 2: Subtract the angular frequency ω of the virtual synchronous machine parallel network system from the output angular frequency ω of the virtual synchronous machine obtained in step 1 bus After the integration operation, the power factor angle δ of the virtual synchronous machine is obtained;

[0013] Step 3: multiply the power factor angle δ of the virtual synchronous machine obtained in step 2 by the synchronous voltage coefficient K to obtain the output active power P of the virtual synchronous machine. e ;

[0014] Step 4: The virtual synchronous machine output angular frequency ω obtained in step 1 is integrated to obtain the output phase angle θ of the virtual synchronous machine, and the output phase angle θ is used as the phase used for dq coordinate transformation to obtain the voltage reference instruction E in the dq coordinate system for the reactive control loop. d With E q Perform dq coordinate transformation to obtain the three-phase voltage modulation signal E in the abc coordinate system a 、E b With E c , and then the three-phase voltage modulation signal E a 、Eb With E c The driving signal of the virtual synchronous machine switch tube is generated through the SVPWM modulation link.

[0015] Preferably, the calculation formula used for the power difference ΔP of the virtual synchronous machine in step 1 is:

[0016] ΔP=P ref -P e ,

[0017] The calculation formula for the angular frequency deviation Δω of the virtual synchronous machine is:

[0018]

[0019] Where s is the Laplace operator.

[0020] The calculation formula for the output angular frequency ω of the virtual synchronous machine is:

[0021] ω=Δω+ω0,

[0022] Preferably, the calculation formula used for the power factor angle δ of the virtual synchronous machine in step 2 is:

[0023]

[0024] Where s is the Laplace operator.

[0025] Preferably, the output active power P of the virtual synchronous machine in step 3 is e The calculation formula used is:

[0026]

[0027] Where U bus is the voltage amplitude of the virtual synchronous machine parallel network system, E is the output voltage amplitude of the virtual synchronous machine, and X is the equivalent inductive reactance of the line.

[0028] Preferably, the calculation formula used for the output phase angle θ of the virtual synchronous machine in step 4 is:

[0029]

[0030] Voltage reference command E in dq coordinate system d With E q The calculation formulas used are:

[0031]

[0032] In the formula, Q ref is the reactive power reference instruction of the virtual synchronous machine, Q e is the output reactive power of the virtual synchronous machine, k qis the primary voltage regulation parameter, E0 is the voltage reference instruction of the virtual synchronous machine, and s is the Laplace operator.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention provides a virtual synchronous machine parallel networking control method based on triple fractional order. The control method replaces the first-order virtual inertia control link in the traditional virtual synchronous machine parallel networking control method with a triple fractional order virtual inertia control link, and optimizes the dynamic response performance of the output active power and output frequency of the virtual synchronous machine parallel networking system by adjusting the triple adjustable parameters. The method has the advantages of not affecting the steady-state balancing effect of active power, flexible control parameter selection, elimination of active power dynamic oscillation and suppression of output frequency dynamic oscillation, and can be applied to the field of virtual synchronous machine parallel networking control in power electronics technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 4 is a control structure diagram of a virtual synchronous machine according to an embodiment of the present invention.

[0036] Figure 2 It is a closed-loop equivalent control structure diagram of the virtual synchronous machine output active power according to an embodiment of the present invention.

[0037] Figure 3 It is a schematic diagram of coordinate transformation and modulation according to an embodiment of the present invention.

[0038] Figure 4 It is a circuit topology diagram of a virtual synchronous machine parallel networking system according to an embodiment of the present invention.

[0039] Figure 5 It is a closed-loop equivalent control structure diagram of the output active power of the virtual synchronous machine parallel networking system according to an embodiment of the present invention.

[0040] Figure 6 It is a comparison diagram of simulation waveforms before and after the virtual synchronous machine parallel networking system adopts the present invention.

[0041] Figure 7 The diagram is a comparison of experimental waveforms before and after the virtual synchronous machine parallel networking system adopts the present invention. DETAILED DESCRIPTION

[0042] The following specific implementation will be further described in conjunction with the above drawings, as follows:

[0043] See also Figure 1 The present invention proposes a triple fractional-order virtual synchronous machine parallel networking control method, comprising the following steps:

[0044] Step 1: In the triple fractional order rotor motion equation part, the active reference instruction P of the virtual synchronous machine isref Subtract the output active power P of the virtual synchronous machine e The power difference ΔP of the virtual synchronous machine is obtained, and the power difference ΔP is converted into a virtual inertia parameter J and a triple fractional integral coefficient λ. i (i=1, 2, 3), triple fractional-order virtual damping parameter D i The angular frequency deviation Δω of the virtual synchronous machine is obtained by using the triple fractional-order rotor motion equation (i=1, 2, 3), and the output angular frequency ω of the virtual synchronous machine is obtained by adding the angular frequency deviation Δω to the rated angular frequency ω0;

[0045] The calculation formula for the power difference ΔP of the virtual synchronous machine in step 1 is:

[0046] ΔP=P ref -P e ,

[0047] The calculation formula for the angular frequency deviation Δω of the virtual synchronous machine is:

[0048]

[0049] In the formula, λ i (i=1, 2, 3) is the integral coefficient and 0<λ i <1 and 0<λ1+λ2+λ3<1, s is the Laplace operator.

[0050] The calculation formula for the output angular frequency ω of the virtual synchronous machine is:

[0051] ω=Δω+ω0,

[0052] Step 2: Subtract the angular frequency ω of the virtual synchronous machine parallel network system from the output angular frequency ω of the virtual synchronous machine obtained in step 1 bus After the integration operation, the power factor angle δ of the virtual synchronous machine is obtained;

[0053] Among them, the calculation formula used for the power factor angle δ of the virtual synchronous machine in step 2 is:

[0054]

[0055] Where s is the Laplace operator.

[0056] Step 3: multiply the power factor angle δ of the virtual synchronous machine obtained in step 2 by the synchronous voltage coefficient K to obtain the output active power P of the virtual synchronous machine. e ;

[0057] Among them, the output active power P of the virtual synchronous machine in step 3 is e The calculation formula used is:

[0058]

[0059] Where U bus is the voltage amplitude of the virtual synchronous machine parallel network system, E is the output voltage amplitude of the virtual synchronous machine, and X is the equivalent inductive reactance of the line.

[0060] Based on the above control and combined Figure 1 The power transfer model can be obtained as follows Figure 2 The output active power closed-loop equivalent control structure diagram when the triple fractional-order virtual synchronous machine is connected to the AC bus is shown.

[0061] Step 4, such as Figure 3 As shown, the virtual synchronous machine output angular frequency ω obtained in step 1 is integrated to obtain the output phase θ of the virtual synchronous machine, and the output phase θ is used as the phase used for dq coordinate transformation to obtain the voltage reference instruction E in the dq coordinate system for the reactive control loop. d With E q Perform dq coordinate transformation to obtain the three-phase voltage modulation signal E in the abc coordinate system a 、E b With E c , and then the three-phase voltage modulation signal E a 、E b With E c The driving signal of the virtual synchronous machine switch tube is generated through the SVPWM modulation link.

[0062] Among them, the calculation formula used for the output phase angle θ of the virtual synchronous machine in step 4 is:

[0063]

[0064] Voltage reference command E in dq coordinate system d With E q The calculation formulas used are:

[0065]

[0066] In the formula, Q ref is the reactive power reference instruction of the virtual synchronous machine, Q e is the output reactive power of the virtual synchronous machine, k q is the primary voltage regulation parameter, E0 is the voltage reference instruction of the virtual synchronous machine, and s is the Laplace operator.

[0067] The circuit topology structure of the virtual synchronous machine parallel network system is shown in the figure below: Figure 4 shown. Figure 4 Middle,U dc1 with U dc2are the DC side voltage amplitudes of the first and second virtual synchronous machines in the virtual synchronous machine parallel networking system, L1 and L2 are the filter inductors of the first and second virtual synchronous machines in the virtual synchronous machine parallel networking system, C1 and C2 are the filter capacitors of the first and second virtual synchronous machines in the virtual synchronous machine parallel networking system, L line1 With L line2 They are the line inductances of the first virtual synchronous machine and the second virtual synchronous machine in the virtual synchronous machine parallel networking system, and S is the common load switching switch of the virtual synchronous machine parallel networking system.

[0068] Combination Figure 4 The circuit topology diagram of the virtual synchronous machine parallel network system Figure 2 The output active power closed-loop equivalent control structure diagram when the triple fractional-order virtual synchronous machine is connected to the AC bus can be obtained as follows: Figure 5 The output active power closed-loop equivalent control structure diagram of the triple fractional-order virtual synchronous machine parallel network system is shown. Figure 5 In, D 11 , D 21 , D 31 are the virtual damping parameters of the first triple fractional-order virtual synchronous machine in the triple fractional-order virtual synchronous machine parallel network system, D 12 , D 22 , D 32 are the virtual damping parameters of the second triple fractional-order virtual synchronous machine in the triple fractional-order virtual synchronous machine parallel network system. λ1, λ2, λ3 are the fractional-order integral coefficients of the triple fractional-order virtual synchronous machine parallel network system, P load is the active power consumed by the system load. The subscripts "1" and "2" are used to distinguish the first triple fractional-order virtual synchronous machine and the second triple fractional-order virtual synchronous machine in the triple fractional-order virtual synchronous machine parallel network system.

[0069] Example

[0070] In order to verify the control effect of the parallel networking control method of a virtual synchronous machine (TFO-VSG) based on triple fractional order proposed in the present invention, the TFO-VSG parallel networking control method proposed in the present invention is compared with the existing traditional virtual synchronous machine (TVSG) parallel networking control method (the TVSG parallel networking control method is mentioned in the background technology and is given in the article entitled "Analysis of active oscillation characteristics of energy storage VSG parallel networking system and its improvement strategy", "Electric Power Automation Equipment" Vol. 44, No. 05, pp. 51-57, 2024) under two conditions of whether or not the proposed triple fractional order virtual inertia link is introduced. The comparison is mainly in terms of the active power P consumed by the system load. loadUnder the condition of step disturbance, the output frequency f1 and f2 of the virtual synchronous machine parallel network system and the output active power P e1 With P e2 , and the response performance of the system frequency f. The details are as follows:

[0071] First, relevant parameters are set. In this embodiment, the relevant parameters in the control method of the virtual synchronous machine parallel network based on triple fractional order of the present invention are set as follows:

[0072] The virtual synchronous machine (VSG) parallel networking system mainly includes a VSG1 with a rated capacity of 100kVA and a VSG2 with a rated capacity of 50kVA. ref1 The active reference command P of VSG2 is 40kW. ref2 The rated angular frequency ω0 is 314.16 rad / s, and the virtual inertia parameter J1 of VSG1 is 6 kg·m 2 , the virtual inertia parameter J2 of VSG2 is 3kg·m 2 , the voltage amplitude U of the virtual synchronous machine parallel network system bus is 311V, the output voltage amplitudes E1 and E2 of the virtual synchronous machine are 311V, the line equivalent inductance X1 of VSG1 is 0.2Ω, the line equivalent inductance X2 of VSG2 is 0.1Ω, and the synchronous voltage coefficient K1 of VSG1 is 1.5U bus E1 / X1=725407.5, VSG2 synchronous voltage coefficient K2=1.5U bus E2 / X2=1450815, here the fractional-order integral coefficient λ1 of the TFO-VSG parallel network system is set to 0.2, λ2 is set to 0.1, and λ3 is set to 0.3. The virtual damping parameter D of TFO-VSG1 is 11 Set to 5J / rad, virtual damping parameter D 21 Set to 5J / rad, virtual damping parameter D 31 The virtual damping parameter D of TFO-VSG2 is set to 50.66 J / rad. 12 Set to 5J / rad, virtual damping parameter D 22 Set to 5J / rad, virtual damping parameter D 32 Set to 25.33 J / rad.

[0073] Based on the above parameter settings, simulation and experimental comparison tests were carried out, as follows:

[0074] Set the simulation conditions as follows: Set the active power P consumed by the system load load At the initial moment, the step is from 60kW to 90kW.

[0075] The experimental working conditions are set as follows: at the initial moment, the VSG1 and VSG2 parallel network system jointly drag a 60kW resistive load to maintain stable operation, a 60kW resistive step load is added at 1s, and the 60kW resistive step load is removed at 1.6s.

[0076] According to the above simulation conditions, we can get Figure 6 The virtual synchronous machine parallel networking system shown is a comparison diagram of the output frequency simulation waveforms before and after the present invention is adopted. Among them, TVSG represents the existing traditional virtual synchronous machine parallel networking control method, TFO-VSG represents a virtual synchronous machine parallel networking control method based on triple fractional order proposed in the present invention, that is, the curves pointed to by TVSG1 and TVSG2 respectively represent the simulation waveforms of the output frequency f1 of TVSG1 and the output frequency f2 of TVSG2 under the existing traditional virtual synchronous machine parallel networking control method, and the curves pointed to by TFO-VSG1 and TFO-VSG2 respectively represent the simulation waveforms of the output frequency f1 of TFO-VSG1 and the output frequency f2 of TFO-VSG2 under the virtual synchronous machine parallel networking control method based on triple fractional order proposed in the present invention.

[0077] according to Figure 6 (a) It can be seen that the parallel network system corresponding to the existing TVSG parallel network control method consumes active power P in the system load. load In the process of stepping from 60kW to 90kW, both the output frequency f1 of TVSG1 and the output frequency f2 of TVSG2 have large dynamic oscillations; Figure 6 (b) It can be seen that the parallel network system corresponding to the TFO-VSG parallel network control method proposed in the present invention consumes active power P of the system load. load In the process of stepping from 60kW to 90kW, there is no dynamic oscillation in the output frequency f1 of TFO-VSG1 and the output frequency f2 of TFO-VSG2. Therefore, it can be seen that the TFO-VSG parallel networking control method proposed in the present invention can effectively solve the dynamic oscillation problem of the output frequency of the parallel networking system corresponding to the existing TVSG parallel networking control method under the system load step disturbance.

[0078] According to the above experimental conditions, we can get Figure 7 The virtual synchronous machine parallel networking system shown in the figure shows the output active power and system frequency experimental waveform comparison diagram before and after the present invention is adopted. Among them, TVSG represents the existing traditional virtual synchronous machine parallel networking control method, TFO-VSG represents the virtual synchronous machine parallel networking control method based on triple fractional order proposed by the present invention, that is, the curves pointed to by TVSG1 and TVSG2 respectively represent the output active power P of TVSG1 under the existing traditional virtual synchronous machine parallel networking control method. e1 The TVSG2 output active power P e2The experimental waveforms of TFO-VSG1 and TFO-VSG2 respectively represent the output active power P of TFO-VSG1 under the control method of triple fractional-order virtual synchronous machine parallel networking proposed in the present invention. e1 With TFO-VSG2 output active power P e2 The curve pointed by TVSG represents the experimental waveform of the system frequency f under the conventional virtual synchronous machine parallel networking control method, and the curve pointed by TFO-VSG represents the experimental waveform of the system frequency f under the virtual synchronous machine parallel networking control method based on triple fractional order proposed by the present invention.

[0079] according to Figure 7 (a) It can be seen that the active power P consumed by the system load in the parallel network system corresponding to the existing TVSG parallel network control method is load During the 60kW step, TVSG1 outputs active power P e1 The TVSG2 output active power P e2 There are large dynamic oscillations; Second, the parallel network system corresponding to the TFO-VSG parallel network control method proposed in the present invention consumes active power P of the system load load During the 60kW step, the TFO-VSG1 outputs active power P e1 With TFO-VSG2 output active power P e2 It can be seen that the TFO-VSG parallel networking control method proposed in the present invention can effectively solve the dynamic oscillation problem of the output active power of the parallel networking system corresponding to the existing TVSG parallel networking control method under the system load step disturbance.

[0080] According to Figure 7 (b) It can be seen that the active power P consumed by the system load in the parallel network system corresponding to the existing TVSG parallel network control method is load During the 60kW step, the system frequency f has a large dynamic oscillation; 2. The parallel network system corresponding to the TFO-VSG parallel network control method proposed in the present invention consumes active power P of the system load load There is no dynamic oscillation in the system frequency f during the 60kW step. It can be seen that the TFO-VSG parallel networking control method proposed in the present invention can effectively solve the dynamic oscillation problem of the parallel networking system frequency corresponding to the existing TVSG parallel networking control method under the system load step disturbance.

[0081] Will Figure 7 and Figure 6 After comparing the results of Figure 7 The experimental test results can be compared with Figure 6 The simulation test comparison results in the embodiment are kept in one-to-one correspondence, and both fully demonstrate that the TFO-VSG parallel networking control method proposed in the present invention can effectively solve the output active power, output frequency and system frequency of the parallel networking system corresponding to the existing TVSG parallel networking control method in the system load consumption of active power P load The dynamic oscillation problem under step disturbance exists. Therefore, compared with the existing TVSG parallel networking control method, the TFO-VSG parallel networking control method proposed in the present invention has better control effect.

[0082] The above description is a detailed description of the preferred feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modified changes completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A virtual synchronous machine parallel networking control method based on triple fractional order, characterized in that: The steps include: Step 1: In the triple fractional order rotor motion equation part, the active reference instruction P of the virtual synchronous machine is ref Subtract the output active power P of the virtual synchronous machine e The power difference ΔP of the virtual synchronous machine is obtained, and the power difference ΔP is converted into a virtual inertia parameter J and a triple fractional integral coefficient λ. i (i=1, 2, 3), triple fractional-order virtual damping parameter D i The angular frequency deviation Δω of the virtual synchronous machine is obtained by using the triple fractional-order rotor motion equation (i=1, 2, 3), and the output angular frequency ω of the virtual synchronous machine is obtained by adding the angular frequency deviation Δω to the rated angular frequency ω0; Step 2: Subtract the angular frequency ω of the virtual synchronous machine parallel network system from the output angular frequency ω of the virtual synchronous machine obtained in step 1 bus After the integration operation, the power factor angle δ of the virtual synchronous machine is obtained; Step 3: multiply the power factor angle δ of the virtual synchronous machine obtained in step 2 by the synchronous voltage coefficient K to obtain the output active power P of the virtual synchronous machine. e ; Step 4: The virtual synchronous machine output angular frequency ω obtained in step 1 is integrated to obtain the output phase angle θ of the virtual synchronous machine, and the output phase angle θ is used as the phase used for dq coordinate transformation to obtain the voltage reference instruction E in the dq coordinate system for the reactive control loop. d With E q Perform dq coordinate transformation to obtain the three-phase voltage modulation signal E in the abc coordinate system a 、E b With E c , and then the three-phase voltage modulation signal E a 、E b With E c The driving signal of the virtual synchronous machine switch tube is generated through the SVPWM modulation link.

2. The triple fractional-order virtual synchronous machine parallel networking control method according to claim 1 is characterized in that: The calculation formula used for the power difference AP of the virtual synchronous machine in step 1 is: ΔP=P ref -P e , The calculation formula for the angular frequency deviation Δω of the virtual synchronous machine is: The calculation formula for the output angular frequency ω of the virtual synchronous machine is: ω=Δω+ω0, Where s is the Laplace operator.

3. The triple fractional-order virtual synchronous machine parallel networking control method according to claim 1 is characterized in that: The calculation formula used for the power factor angle δ of the virtual synchronous machine in step 2 is: Where s is the Laplace operator.

4. The triple fractional-order virtual synchronous machine parallel networking control method according to claim 1 is characterized in that: The output active power P of the virtual synchronous machine in step 3 e The calculation formula used is: Where U bus is the voltage amplitude of the virtual synchronous machine parallel network system, E is the output voltage amplitude of the virtual synchronous machine, and X is the equivalent inductive reactance of the line.

5. The triple fractional-order virtual synchronous machine parallel networking control method according to claim 1, characterized in that: The calculation formula used for the output phase angle θ of the virtual synchronous machine in step 4 is: Voltage reference command E in dq coordinate system d With E q The calculation formulas used are: In the formula, Q ref is the reactive power reference instruction of the virtual synchronous machine, Q e is the output reactive power of the virtual synchronous machine, k q is the primary voltage regulation parameter, E0 is the voltage reference instruction of the virtual synchronous machine, and s is the Laplace operator.

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