Virtual synchronous generator angular frequency compensation method based on operating point recognition
Patent Information
- Application Number
- CN202611106295.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-24
- Publication Date
- 2026-09-15
Smart Images
Figure CN122763383A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of new energy power generation converter technology, and to a method for angular frequency compensation of a virtual synchronous generator based on operating point identification. Background Technology
[0002] The increasing penetration rate of new energy sources and the growing proportion of power electronic devices in power systems are leading to a weakening of the power grid. Virtual synchronous generators (VSGs) simulate the swing equations of synchronous generators, introducing virtual inertia and damping coefficients to provide frequency and voltage support capabilities, thus exhibiting better adaptability to weak grids. However, VSGs face transient power angle instability issues under large disturbances on the remote grid side. Large disturbance faults are typically accompanied by a drop in remote voltage amplitude and a phase angle jump.
[0003] In existing technologies, the main control strategies for improving the transient stability of virtual synchronous generators include the following: 1) For example, the article "Research on VSG Fault Ride-through Method Based on Flexible Control of Power Angle and Current" published by Li Qinghui, Ge Pingjuan, Xiao Fan, et al. on April 5, 2020, in the *Proceedings of the Chinese Society for Electrical Engineering*, Vol. 40, No. 7, proposes an active power command value adjustment method that comprehensively considers the influence of grid voltage dips and VSG output voltage. By detecting the amplitudes of grid voltage and VSG output voltage before and after a fault occurs, it assumes that the power angle is constant under the proposed control, and adjusts the output active power ratio based on the detected voltage information. However, this method relies on remote grid voltage measurement, which introduces a detection delay, causing the power angle to be inconsistent. Furthermore, the amplitude of the VSG output voltage fluctuates during transient periods, resulting in errors in the output active power ratio.
[0004] 2) For example, the article titled "Control of Grid-Forming VSCs: A Perspective of AdaptiveFast / Slow Internal Voltage Source", Wu H, Wang X. IEEE Transactions on Power Electronics, 2023, 38(8): 10151-10169. ("Control of Grid-Forming Voltage Source Converters: A Perspective of Adaptive Fast / Slow Internal Potential", IEEE Transactions on Power Electronics, 2023). Through hybrid synchronous control that adjusts the active power reference value and modifies the angular frequency using q-axis voltage feedforward, the increase in power angle is suppressed, improving transient stability. However, the article does not study the transient instability mechanism that simultaneously considers grid voltage amplitude drops and phase angle jump faults, nor does it implement targeted control.
[0005] Based on the above literature, the existing technology has the following problems: 1. Existing research on improving the transient stability control of virtual synchronous generators relies on grid-side voltage information, which increases equipment costs and introduces detection delays.
[0006] 2. Existing research on transient stability control of virtual synchronous generators does not conduct transient instability mechanism analysis for different fault types that simultaneously consider voltage amplitude drops and phase angle jumps in the remote grid, nor does it further develop targeted control based on different instability conditions. Summary of the Invention
[0007] The technical problem to be solved by the present invention is the problem existing in the prior art, that is, to identify and perform enhanced control on operating points with instability risk without relying on grid-side voltage parameter detection and line impedance identification.
[0008] The technical solution of the present invention is as follows: A method for angular frequency compensation of a virtual synchronous generator based on operating point identification, the system involved in the method includes a DC power supply, a three-phase grid-connected converter, a three-phase LC filter, a three-phase line impedance, and a three-phase power grid connected in sequence; the method includes the following steps: Step 1: When a voltage amplitude drop and phase angle jump fault occur in the remote power grid, and there is a balance point, the fault is classified according to the positional relationship between the power angle corresponding to the operating point and the power angle corresponding to the balance point at the initial moment after the fault, resulting in four types of faults, among which fault 1, fault 2 and fault 4 have the risk of instability. Step 2: Perform transient analysis on faults with instability risk to obtain the following two transient instability scenarios: After the fault occurs, the transient process of the operating point is to pass through the stable equilibrium point in sequence, cross the unstable equilibrium point, and then enter the acceleration phase; or after the fault occurs, the transient process of the operating point is to directly cross the unstable equilibrium point and enter the acceleration phase. Step 3: Obtain the system output active power in real time through sampling. angular frequency deviation The system active power reference value is recorded as follows: The system output active power at the previous moment was Define active power deviation and changes in active power , , ; Step 4, based on angular frequency deviation Active power deviation Change in active power Given active power threshold and angular frequency threshold This process identifies the location of operating points at risk of transient instability. When the operating point continues to increase its power angle after the fault occurs and it crosses the unstable equilibrium point, the process proceeds to step 5. When the operating point continues to increase its power angle after the fault occurs and it crosses the stable equilibrium point, the process proceeds to step 6. Step 5: When the power angle continues to increase after the operating point crosses the unstable equilibrium point, the first-stage angular frequency compensation control is started. Step 6: When the operating point is detected to have exceeded the stable equilibrium point and the power angle continues to increase, the second-stage angular frequency compensation control is initiated.
[0009] Preferably, the judgment process for the four types of faults in step 1 is as follows: remember The power angle at the stable equilibrium point during normal operation. The power angle at the stable equilibrium point during the fault. The power angle of the unstable equilibrium point during the fault. The operating point power angle at the initial moment of the fault occurrence; The four types of faults are as follows: Fault 1: The power angle undergoes a negative jump, i.e. ; Fault 2: The power angle undergoes a positive jump, and the operating point at the initial moment after the fault does not cross the stable equilibrium point during the fault period, i.e. ; Fault 3: The power angle undergoes a positive jump, and the operating point at the initial moment after the fault lies between the stable equilibrium point and the unstable equilibrium point during the fault period. ; Fault 4: The power angle undergoes a positive jump; initially after the fault, the operating point crosses the unstable equilibrium point during the fault period. ; Among them, fault 1, fault 2, and fault 4 are at risk of instability.
[0010] Preferably, the two transient instability scenarios described in step 2 are as follows: The first type of transient instability: The acceleration area corresponding to fault 1 and fault 2 is greater than the maximum deceleration area. After the fault occurs, the transient process of the running point is in the following order: acceleration phase, deceleration phase after passing the stable equilibrium point, and acceleration phase after passing the unstable equilibrium point. The second type of transient instability: Fault 4. After the fault occurs, the transient process of the operating point is to directly bypass the unstable equilibrium point and enter the acceleration phase.
[0011] Preferably, the process of identifying the location of the operating point with instability risk in step 4 is as follows: definition As a monotonicity indicator, a given angular frequency threshold is used. ; The system outputs active power after D consecutive samplings. and angular frequency deviation And make the following judgment: when all D sampled data satisfy and When, output When all D sampled data satisfy and When, output Otherwise output ; Given an active power threshold Determine the operating point location after the fault occurs: when and When the fault occurs, it is determined that the operating point has crossed the unstable equilibrium point and the power angle continues to increase. when and When the fault occurs, it is determined that the operating point has exceeded the stable equilibrium point and the power angle continues to increase.
[0012] Preferably, step 5 is implemented as follows: Let the angular frequency compensation amount be... Its slope is denoted as ; Define the first-level angular frequency compensation reference value :
[0013] In the formula, This is the angular frequency compensation coefficient. As a reference value for compensation time, This represents the maximum phase distance from the operating point to the stable equilibrium point after a fault occurs. The first-stage angular frequency compensation process is as follows: When compensation is initiated, the angular frequency compensation amount... Starting from 0, the slope is First-level angular frequency compensation reference value With angular frequency deviation Changes are updated in real time; When angular frequency compensation amount Run to = At that time, keep Continue running; when the fault occurs, the running point moves to a stable equilibrium point, i.e. and At that time, angular frequency compensation amount With slope When the change reaches 0, compensation is terminated.
[0014] Preferably, step 6 is implemented as follows: Let the angular frequency compensation amount be... Its slope is denoted as ; Define the second-level angular frequency compensation reference value :
[0015] In the formula, This is the active power droop coefficient. This is the system's rated angular frequency; The second-stage angular frequency compensation process is as follows: When compensation is initiated, the angular frequency compensation amount... Starting from 0, the slope is Second-stage angular frequency compensation reference value With angular frequency deviation and output active power Changes are updated in real time; When angular frequency compensation amount Run to = At that time, keep = Continue running; when the fault occurs, the running point moves to a stable equilibrium point, that is... and At that time, angular frequency compensation amount With slope When the change reaches 0, the compensation is terminated.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Compared with the transient fault scenarios of virtual synchronous generators studied in existing literature, this invention analyzes the transient process under different combinations of voltage amplitude drops and phase angle jumps, and classifies the transient instability conditions; 2. Compared to traditional virtual synchronous generator transient control strategies that require detection of remote grid-side information, this invention can identify operating points at risk of instability under fault conditions using near-end parameters, thus saving costs; 3. The virtual synchronous generator angular frequency compensation method based on operating point identification described in this invention, wherein the first-stage angular frequency compensation enables the operating point to return to the stable equilibrium point after crossing the unstable equilibrium point during a fault, thereby achieving transient stability, and the second-stage angular frequency compensation enables the operating point to quickly achieve transient stability when moving from the acceleration region to the stable equilibrium point during a fault. Attached Figure Description
[0017] Figure 1 This is a system topology diagram involved in an embodiment of the present invention.
[0018] Figure 2 This is a control block diagram of the compensation method of the present invention.
[0019] Figure 3 These are the power angle characteristic curves corresponding to different voltage amplitude drops and phase angle jump fault types described in this invention.
[0020] Figure 4 The simulation diagram shows the first transient instability condition without the angular frequency compensation control of this invention.
[0021] Figure 5 This is a simulation diagram of the first transient instability condition when only the first-stage angular frequency compensation control proposed in this invention is activated.
[0022] Figure 6 Simulation diagram of the first transient instability condition when the complete angular frequency compensation control proposed in this invention is activated.
[0023] Figure 7 The simulation diagram shows the second transient instability condition without the angular frequency compensation control of this invention.
[0024] Figure 8 Simulation diagram of the second transient instability condition when the complete angular frequency compensation control proposed in this invention is activated. Detailed Implementation
[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0026] Figure 1 This is a system topology diagram involved in an embodiment of the present invention. As can be seen from the diagram, the system involved in this method includes a DC power supply, a three-phase grid-connected converter, a three-phase LC filter, a three-phase line impedance, and a three-phase power grid connected in sequence.
[0027] exist Figure 1 middle, The voltage of the DC power supply. and These are the filter inductor and the filter capacitor, respectively. For line impedance, For the filter inductor current, and These are the output voltage and output current of a three-phase grid-connected converter, respectively. This refers to the grid-side voltage. The connection point between the output side of the three-phase grid-connected converter and the three-phase line impedance is the point of common coupling, i.e., PCC.
[0028] In this embodiment, take , , , , .
[0029] Figure 2 This is a control block diagram of the compensation method of the present invention. Figure 2 In this context, s is the Laplace operator. The system's rated angular frequency, This is the reference value for the phase angle of the system output voltage. This represents the equivalent angular frequency deviation.
[0030] Depend on Figure 2 As can be seen, the compensation method of the present invention includes a first-level angular frequency compensation and a second-level angular frequency compensation. The first-level angular frequency compensation can effectively control both transient instability scenarios: in the second transient instability scenario, the fault is detected and controlled immediately after it occurs, resulting in a shorter transient process; in the first transient instability scenario, the fault occurs after an acceleration phase, a deceleration phase, and a re-entry into the acceleration phase after crossing the unstable equilibrium point before detection and control, resulting in a longer transient process. To shorten this transient process, a second-level angular frequency compensation strategy with a lower priority than the first-level angular frequency compensation is further proposed; specifically, it includes the following steps: Step 1: When a voltage amplitude drop and phase angle jump fault occur in the remote power grid, and there is an equilibrium point, the fault is classified according to the positional relationship between the power angle corresponding to the operating point and the power angle corresponding to the equilibrium point at the initial moment after the fault, resulting in four types of faults, among which fault 1, fault 2 and fault 4 have the risk of instability.
[0031] In this embodiment, the process for determining the four types of faults in step 1 is as follows: The phase angle of the grid voltage is The phase angle of the system output voltage is In the parameter design of this invention, the bandwidth of the voltage-current inner loop is much higher than that of the power outer loop; in the transient stability analysis, it can be assumed that the system output voltage can ideally follow the voltage reference value, i.e. The phase difference between the system output voltage and the grid voltage is defined as the power angle. ,Right now .
[0032] remember The power angle at the stable equilibrium point during normal operation. The power angle at the stable equilibrium point during the fault. The power angle of the unstable equilibrium point during the fault. The operating point power angle at the initial moment of the fault occurrence; The four types of faults are as follows: Fault 1: The power angle undergoes a negative jump, i.e. ; Fault 2: The power angle undergoes a positive jump, and the operating point at the initial moment after the fault does not cross the stable equilibrium point during the fault period, i.e. ; Fault 3: The power angle undergoes a positive jump, and the operating point at the initial moment after the fault lies between the stable equilibrium point and the unstable equilibrium point during the fault period. ; Fault 4: The power angle undergoes a positive jump; initially after the fault, the operating point crosses the unstable equilibrium point during the fault period. ; Among them, fault 1, fault 2, and fault 4 are at risk of instability.
[0033] Figure 3 These are the power angle characteristic curves corresponding to the four types of faults in the method of this invention. Figure 3 In the diagram, curve I represents the power angle characteristic curve under normal operation, and curve II represents the power angle characteristic curve under fault conditions. a The stable equilibrium point of the system during normal operation corresponds to the power angle as follows: ;point b This is the unstable equilibrium point of the system during normal operation, and the corresponding power angle is... ;point c This is the stable equilibrium point of the system during the fault, and the corresponding power angle is... ;point d This is the unstable equilibrium point of the system during the fault, corresponding to the power angle as follows: ;point j The operating point at the initial moment after the fault occurs, corresponding to the power angle is .
[0034] exist Figure 3 In the diagram, (a) represents fault 1, (b) represents fault 2, (c) represents fault 3, and (d) represents fault 4.
[0035] After fault 1 occurs, the running point is from point... j Accelerate to point c Then it begins to decelerate. If the angular frequency deviation corresponding to the running point is within the range before reaching the point... d If the time has dropped to 0, the system operating point can move in the opposite direction to the steady-state equilibrium point, i.e., point [missing information]. c The system achieves transient stability; otherwise, the running point will exceed the specified point. d The system continues to accelerate, leading to transient instability; the transient process of fault 2 is consistent with that of fault 1; after fault 3 occurs, the operating point changes from point... j Accelerate to point c Then, it decelerates through the deceleration zone, eventually stabilizing at the stable equilibrium point, i.e., point [missing information]. c The system can achieve transient stability; after fault 4 occurs, the operating point changes from point... j As the system accelerates to the right, the power angle continues to increase, leading to transient instability.
[0036] Under the same voltage drop across the grid, for fault 1, the larger the power angle jump amplitude, the larger the acceleration area, and the higher the risk of transient instability; for fault 2, the larger the power angle jump amplitude, the smaller the acceleration area, and the lower the risk of transient instability. For fault 3, the operating point moves towards the stable equilibrium point, and the acceleration area is smaller than the maximum deceleration area, so there is no risk of transient instability. For fault 4, the operating point has already crossed the unstable equilibrium point at the initial moment after the fault, and then continues to accelerate, with the deceleration area becoming zero, inevitably leading to transient instability.
[0037] Step 2: Perform transient analysis on faults with instability risk to obtain the following two instability scenarios: After the fault occurs, the transient process of the operating point successively passes through the stable equilibrium point and then crosses the unstable equilibrium point to enter the acceleration phase; or the transient process of the operating point after the fault occurs directly crosses the unstable equilibrium point to enter the acceleration phase.
[0038] In this embodiment, the two instability scenarios described in step 2 are as follows: The first type of transient instability: The acceleration area corresponding to fault 1 and fault 2 is greater than the maximum deceleration area. After the fault occurs, the transient process of the running point is in the following order: acceleration phase, deceleration phase after passing the stable equilibrium point, and acceleration phase after passing the unstable equilibrium point. The second type of transient instability: Fault 4. After the fault occurs, the transient process of the operating point is to directly bypass the unstable equilibrium point and enter the acceleration phase.
[0039] Step 3: Obtain the system output active power in real time through sampling. angular frequency deviation The system active power reference value is recorded as follows: The system output active power at the previous moment was Define active power deviation and changes in active power , , .
[0040] Step 4, based on angular frequency deviation Active power deviation Change in active power Given active power threshold and angular frequency threshold This process identifies the location of operating points at risk of instability. When the operating point passes the unstable equilibrium point after a fault occurs and the power angle continues to increase, the process proceeds to step 5. When the operating point passes the stable equilibrium point after a fault occurs and the power angle continues to increase, the process proceeds to step 6.
[0041] In this embodiment, the process of identifying the location of the operating point with instability risk in step 4 is as follows: definition As a monotonicity indicator, a given angular frequency threshold is used. ; The system outputs active power after D consecutive samplings. and angular frequency deviation And make the following judgment: when all D sampled data satisfy and When, output When all D sampled data satisfy and When, output Otherwise output ; Given an active power threshold Determine the operating point location after the fault occurs: when and When the fault occurs, it is determined that the operating point has crossed the unstable equilibrium point and the power angle continues to increase. when and When the fault occurs, it is determined that the operating point has exceeded the stable equilibrium point and the power angle continues to increase.
[0042] Step 5: When the power angle continues to increase after the operating point crosses the unstable equilibrium point, the first-stage angular frequency compensation control is started.
[0043] In this embodiment, step 5 is implemented as follows: Let the angular frequency compensation amount be... Its slope is denoted as ; Define the first-level angular frequency compensation reference value :
[0044] In the formula, This is the angular frequency compensation coefficient. As a reference value for compensation time, This represents the maximum phase distance from the operating point to the stable equilibrium point after a fault occurs. The first-stage angular frequency compensation process is as follows: When compensation is initiated, the angular frequency compensation amount... Starting from 0, the slope is First-level angular frequency compensation reference value With angular frequency deviation Changes are updated in real time; When angular frequency compensation amount Run to = At that time, keep Continue running; when the fault occurs, the running point moves to a stable equilibrium point, i.e. and At that time, angular frequency compensation amount With slope When the change reaches 0, compensation is terminated.
[0045] Step 6: When the operating point is detected to have exceeded the stable equilibrium point and the power angle continues to increase, the second-stage angular frequency compensation control is initiated.
[0046] In this embodiment, step 6 is implemented as follows: Let the angular frequency compensation amount be... Its slope is denoted as ; Define the second-level angular frequency compensation reference value :
[0047] In the formula, This is the active power droop coefficient. This is the system's rated angular frequency; The second-stage angular frequency compensation process is as follows: When compensation is initiated, the angular frequency compensation amount... Starting from 0, the slope is Second-stage angular frequency compensation reference value With angular frequency deviation and output active power Changes are updated in real time; When angular frequency compensation amount Run to = At that time, keep = Continue running; when the fault occurs, the running point moves to a stable equilibrium point, that is... and At that time, angular frequency compensation amount With slope When the change reaches 0, the compensation is terminated.
[0048] To verify the technical effect of the present invention, a simulation model was established and simulated in the MATLAB / Simulink platform; the VSG was running normally in grid connection at the initial moment, and at time t=2 seconds, a voltage amplitude drop and phase angle jump fault occurred on the remote grid side.
[0049] Figure 4 This is a simulation diagram of the first transient instability condition without the angular frequency compensation control of this invention. Figure 4 As can be seen, the fault is that the voltage amplitude drops to 0.45 pu and the phase angle jumps by +60°. Because the acceleration area is larger than the maximum deceleration area, the system becomes transiently unstable.
[0050] Figure 5This is a simulation diagram of the first transient instability condition when only the first-stage angular frequency compensation control proposed in this invention is activated. Figure 5 It is evident that this compensation can enable the system to achieve transient stability, but the transient process takes a long time.
[0051] Figure 6 This is a simulation diagram showing the first transient instability condition when the complete angular frequency compensation control proposed in this invention is activated. Figure 6 It is evident that this compensation can enable the system to quickly achieve transient stability.
[0052] Figure 7 This is a simulation diagram of the second transient instability condition without the angular frequency compensation control of this invention. Figure 7 As can be seen, the fault is a voltage amplitude drop to 0.45 pu and a phase angle jump of -100°. Since the operating point immediately after the fault crosses the unstable equilibrium point, the system becomes transiently unstable.
[0053] Figure 8 Simulation diagram of the second transient instability condition when the complete angular frequency compensation control proposed in this invention is activated. Figure 8 It is evident that this compensation can enable the system to achieve transient stability.
Claims
1. A virtual synchronous generator angular frequency compensation method based on operating point recognition, the system involved in the method comprising a DC power source, a three-phase grid-connected converter, a three-phase LC filter, a three-phase line impedance and a three-phase power grid connected in sequence; characterized in that, Includes the following steps: Step 1: When a voltage amplitude drop and phase angle jump fault occur in the remote power grid, and there is a balance point, the fault is classified according to the positional relationship between the power angle corresponding to the operating point and the power angle corresponding to the balance point at the initial moment after the fault, resulting in four types of faults, among which fault 1, fault 2 and fault 4 have the risk of instability. Step 2: Perform transient analysis on faults with instability risk to obtain the following two transient instability situations: After the fault occurs, the transient process of the operating point is to pass through the stable equilibrium point in sequence, cross the unstable equilibrium point, and then enter the acceleration phase. After the fault occurs, the transient process at the operating point is to directly bypass the unstable equilibrium point and enter the acceleration phase; Step 3, real-time acquisition of system output active power by sampling angular frequency deviation ; Record the system active power reference value as follows: The system output active power at the previous moment was Define active power deviation and changes in active power , , ; Step 4, based on angular frequency deviation Active power deviation Change in active power Given active power threshold and angular frequency threshold This process identifies the location of operating points at risk of transient instability. When the operating point continues to increase its power angle after the fault occurs and it crosses the unstable equilibrium point, the process proceeds to step 5. When the operating point continues to increase its power angle after the fault occurs and it crosses the stable equilibrium point, the process proceeds to step 6. Step 5: When the power angle continues to increase after the operating point crosses the unstable equilibrium point, the first-stage angular frequency compensation control is started. Step 6: When the operating point is detected to have exceeded the stable equilibrium point and the power angle continues to increase, the second-stage angular frequency compensation control is initiated.
2. The virtual synchronous generator angular frequency compensation method based on operating point identification according to claim 1, characterized in that, The process for determining the four types of faults mentioned in step 1 is as follows: remember The power angle at the stable equilibrium point during normal operation. The power angle at the stable equilibrium point during the fault. The power angle of the unstable equilibrium point during the fault. The operating point power angle at the initial moment of the fault occurrence; The four types of faults are as follows: Fault 1: The power angle undergoes a negative jump, i.e. ; Fault 2: The power angle undergoes a positive jump, and the operating point at the initial moment after the fault does not cross the stable equilibrium point during the fault period, i.e. ; Fault 3: The power angle undergoes a positive jump, and the operating point at the initial moment after the fault lies between the stable equilibrium point and the unstable equilibrium point during the fault period. ; Fault 4: The power angle undergoes a positive jump; initially after the fault, the operating point crosses the unstable equilibrium point during the fault period. ; Among them, fault 1, fault 2, and fault 4 are at risk of instability.
3. The virtual synchronous generator angular frequency compensation method based on operating point identification according to claim 1, characterized in that, The two transient instability scenarios described in step 2 are as follows: The first type of transient instability: The acceleration area corresponding to fault 1 and fault 2 is greater than the maximum deceleration area. After the fault occurs, the transient process of the running point is in the following order: acceleration phase, deceleration phase after passing the stable equilibrium point, and acceleration phase after passing the unstable equilibrium point. The second type of transient instability: Fault 4. After the fault occurs, the transient process of the operating point is to directly bypass the unstable equilibrium point and enter the acceleration phase.
4. The virtual synchronous generator angular frequency compensation method based on operating point identification according to claim 1, characterized in that, Step 4 describes the process of identifying the location of operating points with instability risks as follows: definition As a monotonicity indicator, a given angular frequency threshold is used. ; The system outputs active power after continuous sampling D times. and angular frequency deviation And make the following judgment: when all D sampled data satisfy and When, output When all D sampled data satisfy and When, output Otherwise output ; Given an active power threshold Determine the operating point location after the fault occurs: when and When the fault occurs, it is determined that the operating point has crossed the unstable equilibrium point and the power angle continues to increase. when and When the fault occurs, it is determined that the operating point has exceeded the stable equilibrium point and the power angle continues to increase.
5. The virtual synchronous generator angular frequency compensation method based on operating point identification according to claim 1, characterized in that, The implementation process of step 5 is as follows: Let the angular frequency compensation amount be... Its slope is denoted as ; Define the first-level angular frequency compensation reference value : In the formula, This is the angular frequency compensation coefficient. As a reference value for compensation time, This represents the maximum phase distance from the operating point to the stable equilibrium point after a fault occurs. The first-stage angular frequency compensation process is as follows: When compensation is initiated, the angular frequency compensation amount... Starting from 0, the slope is First-level angular frequency compensation reference value With angular frequency deviation Changes are updated in real time; When angular frequency compensation amount Run to = At that time, keep Continue running; when the fault occurs, the running point moves to a stable equilibrium point, i.e. and At that time, angular frequency compensation amount With slope When the change reaches 0, compensation is terminated.
6. The virtual synchronous generator angular frequency compensation method based on operating point identification according to claim 1, characterized in that, The implementation process of step 6 is as follows: Let the angular frequency compensation amount be... Its slope is denoted as ; Define the second-level angular frequency compensation reference value : In the formula, This is the active power droop coefficient. This is the system's rated angular frequency; The second-stage angular frequency compensation process is as follows: When compensation is initiated, the angular frequency compensation amount... Starting from 0, the slope is Second-stage angular frequency compensation reference value With angular frequency deviation and output active power Changes are updated in real time; When angular frequency compensation amount Run to = At that time, keep = Continue running; when the fault occurs, the running point moves to a stable equilibrium point, that is... and At that time, angular frequency compensation amount With slope When the change reaches 0, the compensation is terminated.