Method and device for parameter cooperative adaptive control in VSG and combined energy power generation system

Abstract

The invention relates to the technical field of new energy power generation protection control devices, intelligent power grids and the like, in particular to a method and a device for cooperatively and adaptively controlling parameters in a VSG, and a combined energy power generation system. The parameter cooperative adaptive control method in the VSG comprises the following steps: step D, in a virtual synchronous generator, adopting a control strategy of the following virtual rotational inertia J: # imgabs0 #, J0 being a rotational inertia initial value; omega is the real-time angular velocity of the power grid; delta omega is power grid angular velocity deviation; tj is an angular velocity deviation change threshold; e, in the virtual synchronous generator, a control strategy of the following virtual damping coefficient D is adopted: # imgabs 1 #, and kd is a damping correction coefficient; zeta is the damping ratio, omega0 is the standard angular velocity in the power grid, and SE is the per unit value of the synchronous power of the virtual synchronous generator; and Sn is the rated capacity of the virtual synchronous generator. The J and D parameter cooperative adaptive control strategy has better frequency fluctuation suppression performance.

Description

Technical Field

[0001] The present invention relates to the technical fields of renewable energy power generation protection and control devices, smart grids, and more particularly to a method and device for coordinated adaptive control of parameters in a VSG and a combined energy power generation system. Background Art

[0002] New energy systems such as photovoltaics, wind power, and geothermal energy differ significantly from traditional power generation systems. In traditional power generation systems, synchronous generators provide rotational inertia and damping to maintain system stability. However, when new energy generation systems are integrated into the power grid through power electronics, the power system exhibits low inertia and underdamping, resulting in reduced frequency stability.

[0003] To enhance the proactive support capabilities of renewable energy, Virtual Synchronous Generator (VSG) technology has emerged and garnered widespread attention. This technology, based on energy reserves from renewable energy sources or the addition of energy storage, mimics the operating mechanisms of synchronous generators by improving converter control. This enables renewable energy power generation equipment to autonomously establish voltage and frequency, enabling proactive support functions such as inertia response, primary frequency regulation, and rapid voltage regulation.

[0004] However, in the process of implementing the present invention, the applicant discovered that the above-mentioned prior art has the following technical defects:

[0005] (1) The virtual moment of inertia J is set to have only upper and lower limits, and the control is single, which cannot be accurately controlled according to the frequency changes of the power system.

[0006] (2) There is a lack of comprehensive consideration of the relationship between the virtual moment of inertia J and the virtual damping coefficient D. Summary of the Invention

[0007] 1. Technical Problems to be Solved

[0008] The present invention is intended to at least partially solve one of the above technical problems.

[0009] 2. Technical Solution

[0010] A first aspect of the present invention provides a method for collaborative adaptive control of parameters in a VSG. The method for collaborative adaptive control of parameters in a VSG includes:

[0011] Step D: In the virtual synchronous generator, the following control strategy for the virtual moment of inertia J is adopted:

[0012]

[0013] Where J0 is the initial value of the moment of inertia; ω is the real-time angular velocity of the grid; Δω is the angular velocity deviation of the grid; Tj K is the angular velocity deviation change threshold; j1 , K j2 is the adjustment coefficient; Indicates the absolute value of the rate of change of angular velocity;

[0014] Step E: In the virtual synchronous generator, the following control strategy of the virtual damping coefficient D is adopted:

[0015]

[0016]

[0017] Among them, k d is the damping correction coefficient; ζ is the damping ratio, ω0 is the standard angular velocity in the power grid, S E is the per-unit value of the synchronous power of the virtual synchronous generator; S n is the rated capacity of the virtual synchronous generator.

[0018] In some embodiments of the present invention, the method further includes before step D and step E:

[0019] Step C: Establish the relationship between the virtual moment of inertia J and the virtual damping coefficient D of the virtual synchronous generator:

[0020]

[0021] D P =Dω0 2 / S n (14-2)

[0022]

[0023] Where H is the inertia time constant.

[0024] In some embodiments of the present invention, before step C, the method further includes:

[0025] Step A: construct the active regulation equation of VSG to reflect the virtual moment of inertia J and virtual damping coefficient D for the real-time angular velocity ω and active power P of the grid. e the impact of;

[0026] Step B: Based on the active power regulation equation, analyze the changing patterns of the frequency and frequency change rate of the virtual synchronous generator when the load changes / the output of the new energy power generation module changes, and derive the changing patterns of the virtual moment of inertia J and the virtual damping coefficient D.

[0027] In some embodiments of the present invention, the active power regulation equation in step A is:

[0028]

[0029] Where s is a complex variable; P ref is the power instruction of the virtual synchronous generator, k p is the active power-frequency regulation coefficient in the virtual synchronous generator.

[0030] In some embodiments of the present invention, in step B, for the virtual synchronous generator, under the condition that the moment of inertia and the damping coefficient remain unchanged, an oscillation process is divided into four intervals:

[0031] Interval ①: t1 to t2;

[0032] In interval ①, the virtual rotor angular velocity of the virtual synchronous generator is greater than the grid speed and gradually increases. The rate of change of the angular velocity dω / dt suddenly increases and then gradually decreases. When dω / dt is greater than 0, J and D are increased to suppress the deviation between dω / dt and Δω, thereby constraining the increase of the rotor angular velocity.

[0033] Interval ②: t2-t3

[0034] In interval ②, the rate of change of the virtual rotor angular velocity dω / dt is less than 0, entering the deceleration stage. ω gradually decreases from the maximum value, but ω>ω0, that is, the virtual rotor angular velocity is still greater than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

[0035] Interval ③: t3-t4

[0036] In interval ③, the virtual rotor angular velocity of the virtual synchronous generator is less than the grid speed and gradually decreases. The rate of change of the angular velocity dω / dt is negative, but considering its absolute value, it still suddenly increases and then gradually decreases. When dω / dt is less than 0, increasing J and D can suppress the deviation between dω / dt and Δω, thereby constraining the increase of the virtual rotor angular velocity.

[0037] Interval ④: t4-t5

[0038] In interval ④, the rate of change of the virtual rotor angular velocity dω / dt is greater than 0, entering the deceleration stage, and ω gradually increases from the minimum value, but ω<ω0, that is, the virtual rotor angular velocity is still less than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

[0039] In some embodiments of the present invention, the parameter value range is as follows: 0.2<J0<0.8.

[0040] In some embodiments of the present invention, the parameter value range is as follows: ω0 is the standard angular velocity in a 50 Hz power grid.

[0041] In some embodiments of the present invention, the parameter value range is as follows: 0.05≤T j ≤0.2.

[0042] In some embodiments of the present invention, the parameter value range is as follows: 0.1≤K j1 ,K j2 ≤0.5.

[0043] In some embodiments of the present invention, the parameter value range is as follows: 100≤k p ≤500.

[0044] In some embodiments of the present invention, 1≤k d ≤2.

[0045] In some embodiments of the present invention, 5kΩ≤P ref ≤50kΩ.

[0046] In some embodiments of the present invention, 0<D0<ΔP / ωΔω max , where ΔP is the active power mutation, ω is the system angular frequency, Δω max is the maximum value of the system angular frequency change.

[0047] A second aspect of the present invention provides a VSG parameter collaborative adaptive control device. The VSG parameter collaborative adaptive control device includes:

[0048] The virtual moment of inertia control module is used to adopt the following control strategy for the virtual moment of inertia J:

[0049]

[0050] Where J0 is the initial value of the moment of inertia; ω is the real-time angular velocity of the grid; Δω is the angular velocity deviation of the grid; T j is the change threshold; K j1 , K j2 is the adjustment coefficient; Indicates the absolute value of the rate of change of angular velocity;

[0051] The virtual damping coefficient control module is used to adopt the following control strategy of the virtual damping coefficient D:

[0052]

[0053]

[0054] Among them, k dis the damping correction coefficient; ζ is the damping ratio, ω0 is the standard frequency in the power grid, S E is the per-unit value of the synchronous power of the virtual synchronous generator; S n is the rated capacity of the virtual synchronous generator.

[0055] In some embodiments of the present invention, further comprising:

[0056] The parameter coordination module is used to establish the relationship between the virtual moment of inertia J and the virtual damping coefficient D of the virtual synchronous generator:

[0057]

[0058] D P =Dω0 2 / S n (14-2)

[0059]

[0060] Where H is the inertia time constant.

[0061] A third aspect of the present invention provides a combined energy generation system. The combined energy generation system comprises:

[0062] New energy power generation module;

[0063] Energy storage module;

[0064] A three-phase inverter, whose upstream side is connected to the new energy power generation module and the energy storage module, and whose downstream side is connected to the three-phase AC power grid;

[0065] The inverter control system, whose control signal output terminal is connected to the three-phase inverter, includes:

[0066] A parameter collaborative adaptive control module is used to execute the parameter collaborative adaptive control method in the VSG described above to generate a virtual moment of inertia J and a virtual damping coefficient D;

[0067] A virtual exciter is used to adjust the output voltage E of the three-phase inverter in real time by simulating the excitation system of a traditional synchronous generator;

[0068] The VSG mechanical equation module simulates the rotor motion characteristics of a traditional synchronous generator, enabling the inverter to respond to changes in grid frequency like a traditional synchronous generator and providing inertial support to obtain voltage, frequency, and power control instructions;

[0069] The control signal generation module is used to convert the voltage, frequency and power instructions calculated by the VSG mechanical equation into a PWM modulation signal for the three-phase inverter, and use the PWM modulation signal to control the three-phase inverter.

[0070] In some embodiments of the present invention, the new energy power generation module is one or more of the following: a photovoltaic power generation module, a wind power generation module, and a geothermal power generation module.

[0071] 3. Beneficial Effects

[0072] It can be seen from the above technical solutions that the present invention has at least one of the following beneficial effects compared to the prior art:

[0073] (1) Unlike the principles for selecting the moment of inertia and damping coefficient in conventional technology, in the present invention, J and D are increased in interval ①, and J is reduced (smaller than the baseline value) in interval ② to accelerate the frequency back to the standard value, and then D is appropriately increased (an excessively large D value will prolong the recovery time). Furthermore, the appropriate increase in D is controlled by the J value, thereby reducing the number of unknown parameters.

[0074] (2) In the present invention, the inertia time constant H and the setting damping D are used. p Small signal analysis of the VSG system reveals the impact of the moment of inertia and damping coefficient on system stability. The system is then parameterized using an optimal second-order system. This approach achieves an optimal balance between system response speed, overshoot, and stability.

[0075] It should be noted that, in the present invention, the root locus diagram is drawn by small signal analysis of the second-order system, and the mathematical relationship between the virtual moment of inertia J and the virtual damping coefficient D is obtained according to the parameter tuning process, thereby avoiding the segmented control method of the damping coefficient D, so that the virtual moment of inertia J and the virtual damping coefficient D can be coordinated and adaptively controlled.

[0076] (3) In the prior art, the bang-bang control method of the virtual moment of inertia J is single and can only adjust the maximum and minimum parameters.

[0077] In the present invention, in order to avoid the situation where dω / dt tends to infinite value at the initial stage of disturbance, the inverse tangent function arctan is proposed. -1 The moment of inertia J is controlled by the inverse tangent function, which is dynamically adjusted according to the rate of change of the angular frequency, thus improving the accuracy of tracking frequency changes. In addition, the control method of the present invention is more accurate than the bang-bang control method in the prior art.

[0078] (4) The above-mentioned MATLAB / Simulink simulation verification shows that the J and D parameters collaborative adaptive control virtual synchronous generator of the present invention has better frequency fluctuation suppression performance, which can not only reduce the rate of change of frequency fluctuation, but also reduce the frequency offset, ultimately reducing the frequency overshoot, shortening the recovery time, and improving the frequency stability performance. At the same time, it also reflects the flexibility of the virtual synchronous generator in control. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 Flowchart of the parameter collaborative adaptive control method in VSG according to an embodiment of the present invention.

[0080] Figure 2 4 is a structural topology diagram of a virtual synchronous generator in an embodiment of the present invention.

[0081] Figure 3 Schematic diagram of the control principle of the virtual speed regulator of the virtual synchronous generator in an embodiment of the present invention.

[0082] Figure 4 Schematic diagram of the potential and voltage control principle of the virtual synchronous generator in an embodiment of the present invention.

[0083] Figure 5 This is a voltage and current dual closed-loop control diagram of the virtual synchronous generator in an embodiment of the present invention.

[0084] Figure 6 Schematic diagram of the overall structure of the integration of various parts of the virtual synchronous generator in an embodiment of the present invention.

[0085] Figure 7 This is the power angle and frequency oscillation curve of the traditional synchronous generator.

[0086] Figure 8 Schematic diagram of the small signal analysis model of the virtual synchronous generator.

[0087] Figure 9 Root locus diagram of the small signal analysis model for the virtual synchronous generator.

[0088] Figure 10 These are the step response curves of the active power output of the virtual synchronous generator under different control strategies.

[0089] Figure 11 Comparison of the output frequency of virtual synchronous generators under different control strategies.

[0090] Figure 12 and Figure 13 They respectively show the changes of the virtual moment of inertia J and the virtual damping coefficient D under the parameter collaborative adaptive control method in the VSG of this embodiment. DETAILED DESCRIPTION

[0091] Aiming at the problem in the prior art that output fluctuations caused by the access of distributed energy to microgrids can lead to grid frequency instability and power fluctuations, the present invention provides a collaborative adaptive control strategy for the virtual moment of inertia J and the virtual damping coefficient D in a virtual synchronous generator (VSG).

[0092] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific implementation methods and with reference to the accompanying drawings.

[0093] A first aspect of the present invention provides a method for collaborative adaptive control of parameters in a VSG. Figure 1 FIG. 1 is a flow chart of a parameter cooperative adaptive control method in a VSG according to an embodiment of the present invention. Figure 1 As shown, the parameter collaborative adaptive control method in the VSG of this embodiment includes:

[0094] Step A: construct the active regulation equation of VSG to reflect the virtual moment of inertia J and virtual damping coefficient D for the real-time angular velocity ω and active power P of the grid. e the impact of;

[0095]

[0096] Where ω0 is the standard angular velocity in the power grid; s is a complex variable; P ref is the active power instruction of the virtual synchronous generator, which is a fixed value; k p is the active power-frequency regulation coefficient in the virtual synchronous generator.

[0097] In this step, 100≤k p ≤500; 5kΩ≤P ref ≤50kΩ.

[0098] In this embodiment, the specific derivation process of step A is as follows:

[0099] In a traditional synchronous generator, the mechanical equation of the synchronous generator can be expressed as:

[0100]

[0101] Where: J represents the moment of inertia of the synchronous generator; ω0 is the synchronous angular velocity in the 50Hz power grid; T m , T e , T d It is divided into mechanical torque, electromagnetic torque and damping torque of the synchronous generator; D represents the damping coefficient; δ is the power angle of the synchronous generator.

[0102] Figure 2 This is a topological diagram of the virtual synchronous generator in the embodiment of the present invention. Figure 2 , in the virtual synchronous generator, the electromagnetic torque T e The electromagnetic power P of the virtual synchronous generator can be e and angular velocity ω, and the generator electromagnetic power can be expressed by the three-phase inverter output voltage e abc , current i abcThe result is formula (2).

[0103]

[0104] Please refer to Figure 2 and Figure 5 , e a 、e b 、e c They are the output voltages of phase a, phase b, and phase c of the three-phase inverter, collectively referred to as e abc ;i a 、i b 、i c They are the output currents of phase a, phase b, and phase c of the three-phase inverter, collectively referred to as i abc ;u a 、u b 、u c They are the terminal voltages of phase a, phase b, and phase c of the virtual synchronous generator, collectively referred to as u abc .

[0105] In the virtual synchronous generator, by introducing the moment of inertia J and the damping coefficient D, the inverter has inertia in the process of power and frequency disturbance changes, so that the inverter device has the ability to damp the grid power oscillation of the traditional synchronous generator during the power generation and grid connection process. This is of great significance to the stability of frequency and power in the operation of the microgrid, and it can also be used to improve the stability of the frequency and power of the microgrid. Figure 1 The equivalent model of the virtual synchronous generator can be obtained as follows:

[0106]

[0107] Where: L is the synchronous inductance of the virtual synchronous generator; R is the synchronous resistance of the virtual synchronous generator; u abc is the terminal voltage of the virtual synchronous generator.

[0108] Traditional generators can adjust their output active power by changing the input power of the prime mover, that is, changing the mechanical power, and stabilize the grid frequency through the frequency regulator. m To adjust the active power of the grid-connected inverter. m =P m / ω,P m is the input mechanical power. The active power regulation equation is:

[0109] P m =P ref +k p (ω0-ω) (4)

[0110] Where: P refis the active power instruction of the virtual synchronous generator, which is a fixed value; k p is the active power-frequency regulation coefficient in the virtual synchronous generator.

[0111] Substituting equation (4) into equation (1) and performing Laplace transform, we can obtain the active power regulation equation in VSG:

[0112]

[0113] The active power regulation equation in VSG of formula (5) is expressed as a graph, as follows: Figure 3 shown.

[0114] Step B: Based on the active power regulation equation, analyze the changing rules of the frequency and frequency change rate of the virtual synchronous generator when the load changes / the output of the new energy power generation module changes, and derive the changing rules of the virtual moment of inertia J and the virtual damping coefficient D, where:

[0115] For a virtual synchronous generator, under the condition that the moment of inertia and damping coefficient remain unchanged, an oscillation process is divided into four intervals:

[0116] Interval ①: t1 to t2;

[0117] In interval ①, the virtual rotor angular velocity of the virtual synchronous generator is greater than the grid speed and gradually increases. The rate of change of the angular velocity dω / dt suddenly increases and then gradually decreases. When dω / dt is greater than 0, J and D are increased to suppress the deviation between dω / dt and Δω, thereby constraining the increase of the rotor angular velocity.

[0118] Interval ②: t2-t3

[0119] In interval ②, the rate of change of the virtual rotor angular velocity dω / dt is less than 0, entering the deceleration stage. ω gradually decreases from the maximum value, but ω>ω0, that is, the virtual rotor angular velocity is still greater than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

[0120] Interval ③: t3-t4

[0121] In interval ③, the virtual rotor angular velocity of the virtual synchronous generator is less than the grid speed and gradually decreases. The rate of change of the angular velocity dω / dt is negative, but considering its absolute value, it still suddenly increases and then gradually decreases. When dω / dt is less than 0, increasing J and D can suppress the deviation between dω / dt and Δω, thereby constraining the increase of the virtual rotor angular velocity.

[0122] Interval ④: t4-t5

[0123] In interval ④, the rate of change of the virtual rotor angular velocity dω / dt is greater than 0, entering the deceleration stage, and ω gradually increases from the minimum value, but ω<ω0, that is, the virtual rotor angular velocity is still less than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

[0124] In this embodiment, the derivation process of step B is as follows:

[0125] Traditional synchronous generators adjust the reactive power and terminal voltage of the generator output by adjusting the excitation current. In the inverter of a virtual synchronous generator, the reactive power and terminal voltage of the inverter can be adjusted by the virtual potential, as shown in Equation (6).

[0126] U m =k q (Q ref -Q)+U n (6)

[0127] Where: U n is the reference voltage, usually k q is the reactive power regulation coefficient; Q ref is the inverter reactive power command, Q is the actual output reactive power of the inverter. Then we can get Figure 4 The potential voltage control principle diagram of the virtual synchronous generator is shown.

[0128] Then the potential voltage vector of the virtual synchronous generator is:

[0129]

[0130] In order to make the output voltage more stable and respond faster, a voltage-current dual closed loop can be used to control the output voltage. Figure 5 FIG. 1 is a voltage and current double closed-loop control diagram of a virtual synchronous generator in an embodiment of the present invention. Figure 5 As shown in FIG, the outer loop of the voltage-current dual closed-loop control is the voltage control loop, which is used to control and stabilize the voltage, and the inner loop is the current control loop, which is used to improve the response speed of the system.

[0131] for Figure 5 The voltage and current dual closed-loop control shown in the figure is expressed as follows:

[0132]

[0133]

[0134]

[0135]

[0136] Where K pc is the proportional coefficient of the current inner loop controller PI controller; K ic is the integral coefficient of the current inner loop PI controller; K pv is the proportional coefficient of the voltage outer loop PI controller; K iv is the integral coefficient of the voltage outer loop PI controller. Inverter output voltage, is the capacitor voltage, C is the filter capacitor, L is the filter inductor, i s is the stator current of the virtual synchronous generator, and i is the load current.

[0137] In summary, the overall structure of the virtual synchronous generator obtained by integrating various parts in the embodiment of the present invention can be drawn as follows: Figure 6 The form shown.

[0138] According to the transformation of formula (1), we can get:

[0139]

[0140] In the formula, if T m -T e -Jdω / dt is fixed, then increasing D can reduce the deviation Δω. m -T e -T d If J remains constant, increasing J can reduce the rate of change of angular velocity dω / dt. To ensure frequency stability, Δω and dω / dt are suppressed by varying the virtual moment of inertia J and the virtual damping coefficient D. This is similar to how the moment of inertia of a traditional synchronous generator and the damping characteristics caused by the damping winding, rotor losses, and physical friction maintain grid stability.

[0141] In the present invention, by selecting appropriate virtual moment of inertia J and virtual damping system D, the maximum frequency variation amplitude when facing system load changes can be reduced, the frequency variation amplitude can be suppressed, and the frequency can be restored to stability more quickly.

[0142] Figure 7 The power angle and frequency oscillation curves of a traditional synchronous generator are shown below. (a) shows the power angle oscillation curve, and (b) shows the frequency oscillation curve. When the given active power of the synchronous generator increases from P1 to P2, the power and frequency changes during the switching process are both damped oscillations.

[0143] The oscillation process of a virtual synchronous generator is similar to this. Generally, for ease of analysis, with the moment of inertia and damping coefficient unchanged, an oscillation process is divided into four intervals: ① t1 to t2; ② t2 to t3; ③ t3 to t4; and ④ t4 to t5.

[0144] 1. Interval ①: t1 to t2

[0145] In interval ①, the virtual rotor angular velocity of the virtual synchronous generator is greater than the grid speed and gradually increases. The rate of change of the angular velocity dω / dt suddenly increases and then gradually decreases. When dω / dt is greater than 0, J and D are increased to suppress the deviation between dω / dt and Δω, thereby constraining the increase of the rotor angular velocity.

[0146] 2. Interval ②: t2-t3

[0147] In interval ②, the rate of change of the virtual rotor angular velocity dω / dt is less than 0, entering the deceleration stage, and ω gradually decreases from the maximum value, but ω>ω0, that is, the virtual rotor angular velocity is still greater than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

[0148] 3. Interval ③: t3-t4

[0149] Interval ③ is similar to interval ①.

[0150] In interval ③, the virtual rotor angular velocity of the virtual synchronous generator is less than the grid speed and gradually decreases. The rate of change of the angular velocity dω / dt is negative, but considering its absolute value, it still suddenly increases and then gradually decreases. When dω / dt is less than 0, increasing J and D can suppress the deviation between dω / dt and Δω, thereby constraining the increase of the virtual rotor angular velocity.

[0151] 4. Interval ④: t4-t5

[0152] Interval ④ is similar to interval ②.

[0153] In interval ④, the rate of change of the virtual rotor angular velocity dω / dt is greater than 0, entering the deceleration stage, and ω gradually increases from the minimum value, but ω<ω0, that is, the virtual rotor angular velocity is still less than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

[0154] In the virtual synchronous generator, the selection principles of the moment of inertia and damping coefficient are shown in Table 1.

[0155] Table 1 Selection principles of moment of inertia and damping coefficient under different conditions

[0156] interval Δω dω / dt J changes D changes ① Greater than 0 Greater than 0 Increase Increase ② Greater than 0 Less than 0 Reduce Increase appropriately ③ Less than 0 Less than 0 Increase Increase ④ Less than 0 Greater than 0 Reduce Increase appropriately

[0157] It should be noted that in this embodiment, J and D are increased in interval ①, and J is reduced (smaller than the baseline value) in interval ② to accelerate the frequency recovery to the standard value. Then, D is appropriately increased (an excessively large D value will prolong the recovery time). Furthermore, the appropriate increase in D is controlled by the J value, thereby reducing the number of unknown parameters.

[0158] Through the above steps, in the VSG control strategy, the increase and decrease rules of the virtual moment of inertia J and the virtual damping coefficient D under the conditions of power angle and frequency oscillation have been mastered. However, in the process of change, how much should they be set to and what is the relationship between the two? These need to be explained in subsequent steps.

[0159] Step C: Establish the relationship between the virtual moment of inertia J and the virtual damping coefficient D of the virtual synchronous generator through parameter setting small signal analysis:

[0160]

[0161] D P =Dω0 2 / S n (14-2)

[0162]

[0163] Where H is the inertia time constant.

[0164] In this embodiment, the derivation process of step C is as follows:

[0165] The moment of inertia of a traditional synchronous generator is a physical quantity related to the size of the generator. Generally, this value increases with the increase of the rated power. In general, the inertia time constant H is used to measure the inertia of generators of different sizes. H is defined as:

[0166]

[0167] Where S n is the rated capacity of the synchronous generator, J is the moment of inertia of the synchronous generator; ω0 is the synchronous angular velocity of the power grid.

[0168]

[0169] T* is the reference value of torque, then the power reference value P*=T*ω*, and the speed per unit value is 1, then P*=T*. Definition:

[0170] ωr ω0=ω-ω0, (14-1)

[0171] D P =Dω0 2 / S n (14-2)

[0172] Substituting both into formula (1) and performing Laplace transform, we can obtain:

[0173]

[0174] Combining the above analysis and formula (15), and drawing on the traditional power system small signal analysis method, the virtual synchronous generator small signal analysis model can be obtained, as follows: Figure 8 As shown, the input and output power of the virtual synchronous generator are a typical second-order transfer function:

[0175]

[0176] Where S E is the per-unit value of the synchronous power of the virtual synchronous generator:

[0177]

[0178] Where, E s and δ s is the virtual synchronous generator P ref and Q ref The relevant steady-state operating equilibrium point. When the inductance parameters of the LC filter circuit are known and the grid voltage U is constant, the solution can be obtained from equation (18):

[0179]

[0180] It can be seen that when the active and reactive power instructions are given, S E is a constant, then the second-order model of the virtual synchronous generator and its natural oscillation angular frequency ω n and the damping coefficient ζ are:

[0181]

[0182] Figure 9 The root locus diagram of the small signal analysis model of the virtual synchronous generator. Among them, (a) is the root locus diagram of the model with constant virtual damping and gradually increasing virtual inertia; (b) is the root locus diagram of the model with constant virtual inertia and gradually increasing virtual damping. Figure 9 As we know, the poles are all on the left side of the complex plane, and the system is stable. As the moment of inertia increases, the poles move closer to the imaginary axis to the right, and the dynamic performance of the system deteriorates. Therefore, the value of the moment of inertia should not be too large. Figure 9It can be seen that when the damping coefficient increases, a set of conjugate poles gradually becomes smaller, converges at the real axis, and then separates to the left and right directions, and the system changes from underdamping to overdamping.

[0183] Generally speaking, for traditional generators, the natural oscillation angular frequency is between 0.628 and 15.7 rad / s. p If it is not large enough, it will cause low-frequency oscillation of the power grid, which is a major hidden danger of the power system. However, for the virtual synchronous generator, inertia and damping can be considered as set. When the damping is large enough, G(s) is an underdamped second-order system, 0<ζ<1, and its dynamic response time is

[0184]

[0185] The concept of optimal second-order system is used to obtain fast response speed and small overshoot, and the damping ratio of the system is controlled at ζ = 0.707, that is,

[0186]

[0187] This example can provide some quantitative analysis results, L = 0.001H, R = 0.24Ω, S n =50KVA, active power instruction P ref is 10kΩ, the reactive power Q ref The instruction is 0var, then (δ s , Es)=(0.03166rad, 225.6V), then we can get S E =1.946. Generally speaking, 0.2 <J0<0.8,0<D0<ΔP / (ωΔω max ), where ΔP is the active power mutation, ω is the system angular velocity, and Δω is max It is the maximum value of the system angular frequency change. If J0 = 0.2, then D0 after tuning = 11.13.

[0188] It should be noted that, in this embodiment, the inertia time constant H and the setting damping D are used. p Small signal analysis of the VSG system reveals the impact of the moment of inertia and damping coefficient on system stability. The system is then parameterized using an optimal second-order system. This approach achieves an optimal balance between system response speed, overshoot, and stability.

[0189] It should be noted that, in this embodiment, the root locus diagram is drawn through the small signal analysis of the second-order system, and the mathematical relationship between the virtual moment of inertia J and the virtual damping coefficient D is derived according to the parameter tuning process, thereby avoiding the segmented control method of the damping coefficient D, so that the virtual moment of inertia J and the virtual damping coefficient D can be coordinated and adaptively controlled.

[0190] In step D, in order to avoid the situation where dω / dt tends to infinite value at the initial stage of disturbance, the arctan function is used. -1 To design the control strategy of the virtual moment of inertia J, the adaptive control strategy of the virtual moment of inertia J designed according to Table 1 is as follows:

[0191]

[0192] Where J0 is the initial value of the moment of inertia; ω is the real-time angular velocity of the grid; Δω is the angular velocity deviation of the grid; T j K is the angular velocity deviation change threshold; j1 , K j2 is the adjustment coefficient; Indicates the absolute value of the rate of change of angular velocity.

[0193] In this step, 0.2<J0<0.8; 0.05≤T j ≤0.2; 0.1≤K j1 ,K j2 ≤0.5.

[0194] It should be noted that in traditional technology, the bang-bang control method of the virtual moment of inertia J is single and can only adjust the maximum and minimum parameters. In this embodiment, in order to avoid the situation where dω / dt tends to infinite value at the initial stage of disturbance, the arctan function is proposed. -1 The moment of inertia J is controlled by the inverse tangent function, which is dynamically adjusted according to the rate of change of the angular frequency, thereby improving the accuracy of tracking frequency changes. The control method of this embodiment is more accurate than the bang-bang control method in the prior art.

[0195] In step E, based on the relationship between J and D in step C, the virtual damping coefficient D is controlled by the virtual moment of inertia J. At the same time, the virtual damping coefficient D satisfies the variation rule of J and D established in step B. That is, the following control strategy for the virtual damping coefficient D is adopted:

[0196]

[0197]

[0198] Among them, k d is the damping correction coefficient; ζ is the damping ratio, ω0 is the standard angular velocity in the power grid, S E is the per-unit value of the synchronous power of the virtual synchronous generator; S n is the rated capacity of the virtual synchronous generator.

[0199] In this step, 1≤k d ≤2.

[0200] In this embodiment, the derivation process of step E is as follows:

[0201] In the prior art, there is no description of the analytical control of the damping coefficient D. In this embodiment, the setting principle of the virtual damping coefficient D can be expressed according to formula (23) based on the relationship between the damping coefficient and the moment of inertia of the virtual synchronous generator, thereby avoiding the traditional segmented damping coefficient control:

[0202]

[0203] Since the damping coefficient D can only increase, and the difference between the absolute value of J and the reference value J0 can be used to suppress the damping D from becoming too large, the formula becomes:

[0204]

[0205] Where k d is the damping correction coefficient, J0 is the initial value of the moment of inertia, T d is a fixed value.

[0206]

[0207] It should be noted that steps A through C in this embodiment merely constitute the process of constructing a VSG mathematical model. In practical scenarios, these steps may be omitted, and the implementation may proceed directly from step C or step D. This still implements the present invention and falls within the scope of protection of the present invention.

[0208] In order to verify the effectiveness of the theoretical analysis of the above embodiment and the proposed improved cooperative adaptive control strategy, a single-machine virtual synchronous generator model was built in MATLAB / Simulink software and simulation analysis was performed. The simulation parameters are shown in Table 2. In the table, C is the filter capacitor; U is the filter capacitor; dc is the DC bus voltage; U N is the AC rated voltage.

[0209] Table 2 Simulation parameters

[0210] Parameter Type parameter Parameter value Main circuit parameters L / mH 1 Main circuit parameters C / μF 20 Main circuit parameters R / Ω 0.24 Main circuit parameters Udc / V 800 Main circuit parameters <![CDATA[J0 / (kg·m2)]]> 0.2 Main circuit parameters <![CDATA[D0 / (N·m·s·rad-1)]]> 11.13 Control parameters (active power-frequency adjustment coefficient) <![CDATA[k p ]]> 200 Control parameters (adjustment coefficients) <![CDATA[K j1 ]]> 0.2 Control parameters (adjustment coefficients) <![CDATA[K j2 ]]> 0.1 Control parameters (angular velocity deviation change threshold) <![CDATA[T j ]]> 0.1 Control parameters (damping correction coefficient) <![CDATA[k d ]]> 1.3 Control parameters (intermediate parameters) <![CDATA[T d ]]> 24.89

[0211] A single virtual synchronous generator is connected to the power grid. The simulation time is 2s. The load active power is 10kΩ and the reactive power is 0kvar. Initially, the given output active power of the virtual synchronous generator is 10kΩ. At 0.5s, the active power suddenly increases to 20kΩ and then suddenly drops to 10kΩ at 1.3s. The reactive power remains constant at 0kvar.

[0212] Figure 10The following curves show the step response of the active power output of the virtual synchronous generator under different control strategies. The green line shows the active power response under the control strategy with fixed J and fixed D; the brown line shows the active power response under the control strategy with varying J and fixed D; and the orange line shows the active power response under the control strategy of this embodiment with coordinated changes in J and D. As can be seen from the figure, when the input power suddenly increases, the active power overshoot for the constant-parameter virtual synchronous generator control, the moment of inertia adaptive control, and the coordinated moment of inertia and damping coefficient adaptive control are 10%, 2.75%, and 2.5%, respectively, with adjustment times of approximately 0.8s, 0.7s, and 0.7s, respectively.

[0213] Figure 11 Figure 1 compares the output frequency of a virtual synchronous generator under different control strategies. The green line shows the active power response under the control strategy with fixed J and fixed D; the brown line shows the active power response under the control strategy with varying J and fixed D; and the orange line shows the active power response under the control strategy of this embodiment with coordinated changes in J and D. The figure shows that the adaptive change in the moment of inertia significantly impacts the frequency change rate. When the input power suddenly increases, the frequency deviation of the output frequency of the virtual synchronous generator under fixed control parameters approaches 0.3 Hz, and the oscillation duration is approximately 0.2 s. Using the adaptive moment of inertia control strategy, the maximum frequency deviation is reduced to 0.225 Hz, and the adjustment time is reduced somewhat, but not significantly. Using the coordinated adaptive control strategy, the frequency deviation is reduced to 0.15 Hz, indicating that the addition of adaptive damping coefficient control reduces the frequency deviation range. The simulation conditions are as follows: the VSG power command increases from 10 kΩ to 20 kΩ in 0.5 seconds and returns to 10 kΩ in 1.3 seconds.

[0214] Figure 12 and Figure 13 They are respectively the changes of the virtual moment of inertia J and the virtual damping coefficient D under the parameter cooperative adaptive control method in the VSG of this embodiment. Figure 12 As shown in the figure, at the moment when the VSG power command rises at 0.5 seconds, the system active power overshoot and system frequency deviation are suppressed by increasing the moment of inertia J. After the system frequency deviation reaches the maximum value, the system frequency recovery speed is accelerated by reducing the moment of inertia J. The analysis after the VSG active power is restored at 1.3 seconds is similar, and the simulation experiment is consistent with the theoretical analysis. Figure 13 As shown in the figure, at the moment when the VSG power rises at 0.5 seconds, the system active power overshoot and the system frequency deviation are suppressed by increasing the damping coefficient D. After the system frequency deviation reaches the maximum value, a faster recovery time is obtained by appropriately increasing the damping coefficient. The simulation experiment is consistent with the theoretical analysis.

[0215] The above-mentioned MATLAB / Simulink simulation verification shows that the J and D collaborative adaptive control virtual synchronous generator of the present invention has better frequency fluctuation suppression performance, which can not only reduce the rate of change of frequency fluctuations, but also reduce the frequency offset, ultimately reducing the frequency overshoot, shortening the recovery time, and improving the frequency stability performance. At the same time, it also reflects the flexibility of the virtual synchronous generator in control.

[0216] This concludes the introduction to the parameter collaborative adaptive control method in the VSG of this embodiment.

[0217] Based on the parameter cooperative adaptive control method in the VSG in the above embodiment, the second aspect of the present invention provides a parameter cooperative adaptive control device in the VSG. The parameter cooperative adaptive control device in the VSG in the embodiment of the present invention includes: a parameter cooperation module, a virtual rotation inertia control module, and a virtual damping coefficient control module.

[0218] In this embodiment, the parameter coordination module is used to establish the relationship between the virtual moment of inertia J and the virtual damping coefficient D of the virtual synchronous generator:

[0219]

[0220] D P =Dω0 2 / S n (14-2)

[0221]

[0222] Where H is the inertia time constant.

[0223] In this embodiment, the virtual moment of inertia control module is used to adopt the following control strategy for the virtual moment of inertia J:

[0224]

[0225] Where J0 is the initial value of the moment of inertia; ω is the real-time angular velocity of the grid; Δω is the angular velocity deviation of the grid; T j is the change threshold; K j1 , K j2 is the adjustment coefficient; Indicates the absolute value of the rate of change of angular velocity;

[0226] In this embodiment, the virtual damping coefficient control module is used to adopt the following control strategy for the virtual damping coefficient D:

[0227]

[0228]

[0229] Among them, kd is the damping correction coefficient; ζ is the damping ratio, ω0 is the standard frequency in the power grid, S E is the per-unit value of the synchronous power of the virtual synchronous generator; S n is the rated capacity of the virtual synchronous generator.

[0230] Based on the parameter cooperative adaptive control method in the VSG in the above embodiment, the third aspect of the present invention provides a combined power generation system. Figure 6 , the combined power generation system according to the embodiment of the present invention includes:

[0231] New energy power generation module; energy storage module;

[0232] A three-phase inverter, whose upstream side is connected to the new energy power generation module and the energy storage module, and whose downstream side is connected to the three-phase AC power grid;

[0233] An inverter control system, whose control signal output terminal is connected to the three-phase inverter, comprises:

[0234] A parameter collaborative adaptive control module, configured to execute the parameter collaborative adaptive control method in the VSG of the above embodiment to generate the virtual moment of inertia J and the virtual damping coefficient D;

[0235] A virtual exciter is used to adjust the output voltage E of the three-phase inverter in real time by simulating the excitation system of a traditional synchronous generator;

[0236] The VSG mechanical equation module simulates the rotor motion characteristics of a traditional synchronous generator, enabling the inverter to respond to changes in grid frequency like a traditional synchronous generator and providing inertial support to obtain voltage, frequency, and power control instructions;

[0237] The control signal generation module is used to convert the voltage, frequency and power instructions calculated by the VSG mechanical equation into a PWM modulation signal for the three-phase inverter, and use the PWM modulation signal to control the three-phase inverter.

[0238] Wherein, the new energy power generation module is one or more of the following: photovoltaic power generation module, wind power generation module, geothermal power generation module.

[0239] Thus, the various embodiments of the present invention have been introduced. According to the above description, those skilled in the art should have a clear understanding of the present invention.

[0240] It should be noted that for certain implementation methods, if they are not the key content of the present invention and are well known to ordinary technicians in the relevant technical field, due to space limitations, they are not described in detail in the drawings or text of the specification. In this case, reference can be made to relevant existing technologies for understanding.

[0241] For the numerical values ​​and numerical ranges mentioned in the present invention, unless expressly indicated to the contrary, the numerical parameters in the description and claims of the present invention may be approximate values ​​and may vary according to the content of the present invention. Specifically, all numbers representing the content of compositions, reaction conditions, etc. recorded in the description and claims should be understood to be modified by the term "about" in all cases, and the meaning of the expression is to include a variation of ±10% from the specific quantity in some embodiments.

[0242] Regarding the steps in the present invention, unless specifically described or steps must occur in sequence, the order of the steps is not limited to the above list and can be changed or rearranged according to desired designs.

[0243] Those skilled in the art will appreciate that the modules or steps of the present invention described above can be implemented using a general-purpose computing device. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they can be implemented using program code executable by a computing device, which can then be stored in a storage device and executed by the computing device. Alternatively, they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

[0244] The present invention may also be implemented as an apparatus or device program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium or may be in the form of one or more signals. Such signals may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0245] The present invention can be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. The various component embodiments of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The physical implementation of the hardware structure includes, but is not limited to, physical devices, which include, but are not limited to, transistors, memristors, DNA computers, single-chip microcomputers, microprocessors, or digital signal processors (DSPs). In addition, the present invention is not directed to any particular programming language. It should be understood that the content of the present invention can be implemented using various programming languages, and the description of specific languages ​​herein is intended to disclose the best mode of implementation of the present invention.

[0246] Those skilled in the art will understand that, in the claims and description of the present invention, the word "comprising" does not exclude the presence of elements (or steps) not listed in the claims. The word "a" or "an" preceding an element (or step) does not exclude the presence of a plurality of such elements (or steps).

[0247] Furthermore, the above embodiments are provided solely to enable the present invention to satisfy legal requirements. The present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0248] Similarly, it should be understood that in order to streamline the present invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the invention should not be interpreted as reflecting the intention that the claimed invention requires more features than those explicitly stated in each claim. More precisely, as reflected in the claims, each inventive aspect consists in less than all the features of the preceding single embodiment. Moreover, the embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, the technical features in different embodiments can be freely combined to form more embodiments. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0249] The above specific embodiments provide a detailed description of the objectives, technical means and beneficial effects of the present invention. It should be understood that the purpose of the detailed description is to enable those skilled in the art to understand the present invention more clearly, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for cooperative adaptive control of parameters in VSG, characterized in that: include: Step D: In the virtual synchronous generator, the following control strategy for the virtual moment of inertia J is adopted: Where J0 is the initial value of the moment of inertia; ω is the real-time angular velocity of the grid; Δω is the angular velocity deviation of the grid; T j K is the angular velocity deviation change threshold; j1 , K j2 is the adjustment coefficient; Indicates the absolute value of the rate of change of angular velocity; Step E: In the virtual synchronous generator, the following control strategy of the virtual damping coefficient D is adopted: Among them, k d is the damping correction coefficient; ζ is the damping ratio, ω0 is the standard angular velocity in the power grid, S E is the per-unit value of the synchronous power of the virtual synchronous generator; S n is the rated capacity of the virtual synchronous generator.

2. The VSG parameter cooperative adaptive control method according to claim 1, characterized in that: The step D and step E also include: Step C: Establish the relationship between the virtual moment of inertia J and the virtual damping coefficient D of the virtual synchronous generator: D P =Dω0 2 / S n (14-2) Where H is the inertia time constant.

3. The VSG parameter cooperative adaptive control method according to claim 2, characterized in that: The step C also includes: Step A: construct the active regulation equation of VSG to reflect the virtual moment of inertia J and virtual damping coefficient D for the real-time angular velocity ω and active power P of the grid. e the impact of; Step B: Based on the active power regulation equation, analyze the changing rules of the frequency and frequency change rate of the virtual synchronous generator when the load changes / the output of the new energy power generation module changes, and derive the changing rules of the virtual moment of inertia J and the virtual damping coefficient D.

4. The VSG parameter cooperative adaptive control method according to claim 3, characterized in that: The active power regulation equation in step A is: Where s is a complex variable; P ref is the power instruction of the virtual synchronous generator, k p is the active power-frequency regulation coefficient in the virtual synchronous generator.

5. The method for cooperative adaptive control of parameters in VSG according to claim 4, characterized in that: In step B, for the virtual synchronous generator, under the condition that the moment of inertia and the damping coefficient remain unchanged, an oscillation process is divided into four intervals: Interval ①: t1 to t2; In interval ①, the virtual rotor angular velocity of the virtual synchronous generator is greater than the grid speed and gradually increases. The rate of change of the angular velocity dω / dt suddenly increases and then gradually decreases. When dω / dt is greater than 0, J and D are increased to suppress the deviation between dω / dt and Δω, thereby constraining the increase of the rotor angular velocity. Interval ②: t2-t3 In interval ②, the rate of change of the virtual rotor angular velocity dω / dt is less than 0, entering the deceleration stage. ω gradually decreases from the maximum value, but ω>ω0, that is, the virtual rotor angular velocity is still greater than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged. Interval ③: t3-t4 In interval ③, the virtual rotor angular velocity of the virtual synchronous generator is less than the grid speed and gradually decreases. The rate of change of the angular velocity dω / dt is negative, but considering its absolute value, it still suddenly increases and then gradually decreases. When dω / dt is less than 0, increasing J and D can suppress the deviation between dω / dt and Δω, thereby constraining the increase of the virtual rotor angular velocity. Interval ④: t4-t5 In interval ④, the rate of change of the virtual rotor angular velocity dω / dt is greater than 0, entering the deceleration stage, and ω gradually increases from the minimum value, but ω<ω0, that is, the virtual rotor angular velocity is still less than the grid angular velocity. A smaller moment of inertia should be used to speed up the process of angular velocity returning to the rated value. At the same time, increasing the damping coefficient can further suppress the deviation of the angular velocity. However, the increase in the damping coefficient cannot be too large, otherwise the recovery time will be prolonged.

6. The method for cooperative adaptive control of parameters in VSG according to claim 5, characterized in that: The parameter value range is as follows: 0.2＜J0＜0.8； and / or, ω0 is the standard angular velocity in a 50 Hz power grid; and / or, 0.05≤T j ≤0.2; and / or, 0.1≤K j1 ,K j2 ≤0.5; and / or, 100 ≤ k p ≤500; and / or, 1≤k d ≤2; and / or, 5kΩ≤P ref ≤50kΩ; and / or, 0<D0<ΔP / ωΔω max , where ΔP is the active power mutation, ω is the system angular frequency, Δω max is the maximum value of the system angular frequency change.

7. A parameter cooperative adaptive control device in VSG, characterized in that: include: The virtual moment of inertia control module is used to adopt the following control strategy for the virtual moment of inertia J: Where J0 is the initial value of the moment of inertia; ω is the real-time angular velocity of the grid; Δω is the angular velocity deviation of the grid; T j is the change threshold; K j1 , K j2 is the adjustment coefficient; Indicates the absolute value of the rate of change of angular velocity; The virtual damping coefficient control module is used to adopt the following control strategy of the virtual damping coefficient D: Among them, k d is the damping correction coefficient; ζ is the damping ratio, ω0 is the standard frequency in the power grid, S E is the per-unit value of the synchronous power of the virtual synchronous generator; S n is the rated capacity of the virtual synchronous generator.

8. The VSG parameter cooperative adaptive control device according to claim 7, characterized in that: Also includes: The parameter coordination module is used to establish the relationship between the virtual moment of inertia J and the virtual damping coefficient D of the virtual synchronous generator: D P =Dω0 2 / S n (14-2) Where H is the inertia time constant.

9. A combined energy power generation system, characterized in that: include: New energy power generation module; Energy storage module; A three-phase inverter, whose upstream side is connected to the new energy power generation module and the energy storage module, and whose downstream side is connected to the three-phase AC power grid; An inverter control system, whose control signal output terminal is connected to the three-phase inverter, comprises: A parameter collaborative adaptive control module, configured to execute the parameter collaborative adaptive control method in the VSG according to any one of claims 1 to 6, and generate the virtual moment of inertia J and the virtual damping coefficient D; A virtual exciter is used to adjust the output voltage E of the three-phase inverter in real time by simulating the excitation system of a traditional synchronous generator; The VSG mechanical equation module simulates the rotor motion characteristics of a traditional synchronous generator, enabling the inverter to respond to grid frequency changes like a traditional synchronous generator and providing inertial support to obtain voltage, frequency, and power control instructions. The control signal generation module is used to convert the voltage, frequency and power instructions calculated by the VSG mechanical equation into a PWM modulation signal for the three-phase inverter, and use the PWM modulation signal to control the three-phase inverter.

10. The combined energy generation system according to claim 9, characterized in that: The new energy power generation module is one or more of the following: a photovoltaic power generation module, a wind power generation module, and a geothermal power generation module.

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