Pumped storage wind power interconnection grid-connected system capacity configuration method and system based on stability domain

Abstract

The invention belongs to the technical field of power system capacity configuration, and discloses a pumped storage wind power interconnection grid-connected system capacity configuration method and system based on a stability domain. The method comprises the following steps: respectively drawing stability domains of alternative capacity configuration schemes of a plurality of pumped storage power stations and wind power stations about speed regulator parameters in the pumped storage power stations and phase-locked loop controller parameters in the wind power stations based on a system model of the pumped storage wind power interconnection grid-connected system; and judging the advantages and disadvantages of each alternative capacity configuration scheme through the boundary of the stability domain so as to obtain the optimal capacity configuration scheme of the pumped storage wind power interconnection grid-connected system. According to the method, advantages and disadvantages of alternative capacity configuration schemes are measured on the basis of the stability domain, and the influence of the power generation capacity configuration of the pumped storage wind power interconnection grid-connected system on the operation stability of the whole system is accurately evaluated, so that the operation stability of the system can be improved by selecting the optimal capacity configuration.

Description

Technical Field

[0001] The present invention belongs to the technical field related to power system capacity configuration, and more specifically, relates to a capacity configuration method and system for a pumped storage wind power interconnected grid-connected system based on a stability domain. Background Art

[0002] Pumped-storage power stations have the advantage of rapid opening and closing, and play an excellent role in ensuring the smooth output of wind power. The use of high-quality pumped storage and wind power resources with huge potential for combined power generation has significant engineering value in ensuring the safe and efficient operation of new power systems. However, due to the frequent switching of unit operating conditions in pumped-storage power stations, the random volatility of wind resources, and the large-scale use of power electronic devices, the frequency oscillation phenomenon in the combined power system has become increasingly prominent, seriously interfering with the safe and stable operation of the power grid. Existing research on improving the overall stability of the power system mainly focuses on the independent grid-connected operation of pumped-storage power stations and wind power stations. Existing research on hybrid renewable energy grid-connected systems focuses more on economic dispatch and performance evaluation, rarely considering the power generation operation of the pumped-storage wind power interconnected grid-connected system, and ignoring the impact of the power generation capacity of both on the overall system stability.

[0003] During their research, the applicant discovered that rational capacity allocation for interconnected pumped-storage and wind power systems is essential for improving the overall stability of the power system. Capacity allocation for interconnected pumped-storage and wind power systems is crucial for maintaining stable power system operation. Currently, there is no relevant theoretical research, and there is also a lack of effective methods for measuring the impact of capacity allocation on grid stability. Therefore, there is an urgent need to develop a capacity allocation method for interconnected pumped-storage and wind power systems to better address the issue of stable power system operation. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a capacity configuration method and system for a pumped-storage wind power interconnected grid-connected system based on a stability domain, which is used to solve the problem that there is a lack of effective methods to measure the impact of capacity configuration on grid stability in existing research on pumped-storage wind power interconnected grid-connected systems, and thus a lack of methods to improve the stability of the power system through capacity configuration. Its purpose is to improve the efficiency of accurately evaluating the impact of the power generation capacity configuration of the pumped-storage wind power interconnected grid-connected system on the overall system operation stability, so as to improve the system operation stability through reasonable capacity configuration.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for capacity configuration of a pumped storage wind power interconnected grid-connected system based on a stability region is provided, comprising: Based on a system model of a pumped storage wind power grid-connected system, the stability domains of several alternative capacity configuration schemes for the pumped storage power station and the wind power station are drawn for the speed regulator parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station; the system model includes a pumped storage power station model, a wind power station model, and a network interface model; The advantages and disadvantages of various alternative capacity configuration schemes are determined by the boundary of the stability region, and then the optimal capacity configuration scheme of the pumped storage wind power interconnected grid-connected system is obtained.

[0006] According to the capacity configuration method of the pumped-storage wind power interconnection grid-connected system based on the stability domain provided by the present invention, the pumped-storage power station model includes a speed regulator model; the speed regulator model adopts a proportional-integral control strategy, corrects and adjusts the speed of the pump turbine through the speed proportional coefficient, and corrects and adjusts the guide vane opening through the permanent slip coefficient to achieve the effect of quickly adjusting the speed of the pump turbine.

[0007] According to the capacity configuration method of the pumped-storage wind power interconnected grid-connected system based on the stability domain provided by the present invention, the wind power station model includes a phase-locked loop controller model; the phase-locked loop controller model projects the AC voltage signal output by the doubly-fed asynchronous wind turbine model onto the direct-axis component of the phase-locked loop coordinate system, and uses a proportional-integral control strategy to solve and obtain the wind power station voltage phase, and the wind power station model and the network interface model are established based on the wind power station voltage phase.

[0008] According to the capacity configuration method of the pumped-storage wind power interconnected grid-connected system based on the stability domain provided by the present invention, the network interface model constructs the voltage and current equations of the pumped-storage power station network interface, the wind power station network interface and the common connection point network interface according to the current flow direction and the principle of voltage and current conservation.

[0009] According to the capacity configuration method of the pumped storage wind power interconnection grid-connected system based on the stability domain provided by the present invention, the speed regulator model in the pumped storage power station model is: ; Where, y is the guide vane opening; t For time; x t The speed of the pumped storage power station unit; b p is the permanent slip coefficient of the pumped storage power station governor; K w is the speed proportional coefficient of the pumped storage power station unit; K P0 is the proportional coefficient of the pumped storage power station governor; K I0is the integral coefficient of the pumped storage power station governor; The phase-locked loop controller model in the wind power station model is: ; Where, δ pll and x pll is the electrical angle and intermediate variable of the phase-locked loop controller; V dsp is the direct axis component of the stator voltage of the doubly fed asynchronous wind turbine generator on the phase-locked loop coordinate axis; ω pll is the speed of the phase-locked loop controller; K Ppll is the proportional coefficient of the phase-locked loop controller; K Ipll is the integral coefficient of the phase-locked loop controller; The network interface model is: ; Where, X TL41 It is the export reactance of the pumped storage power station; X TL42 Export reactor for wind power station; X TL43 is the grid export reactance; I xy41 Export current for pumped storage power stations; I xy42 is the export current of the wind power station; I xy43 is the grid export current; θ is the grid export bus angle; V PCC is the bus voltage amplitude at the grid outlet; V g The outlet voltage of the pumped storage power station; V s is the outlet voltage of the wind power station; V b is the infinite grid voltage; δ is the electrical angle of the synchronous generator; j represents an imaginary number.

[0010] According to the capacity configuration method of the pumped-storage wind power interconnected grid-connected system based on the stability domain provided by the present invention, the alternative capacity configuration scheme is selected and set within a range that meets the requirements based on the actual power generation capacity requirements of the pumped-storage power station and the wind power station. The power generation capacity of the pumped-storage power station and the wind power station in the alternative capacity configuration scheme is a per-unit value in the range of 0-1.

[0011] According to the capacity configuration method of the pumped storage wind power interconnected grid-connected system based on the stability domain provided by the present invention, the stability domain is drawn with respect to the proportional coefficient of the speed regulator in the pumped storage power station and the proportional coefficient of the phase-locked loop controller in the wind power station; wherein the horizontal axis of the stability domain is the proportional coefficient of the speed regulator, and the vertical axis is the proportional coefficient of the phase-locked loop controller.

[0012] According to the capacity configuration method of the pumped storage wind power interconnected grid-connected system based on the stability domain provided by the present invention, the Hopf bifurcation theory is used based on the system model to draw the stability domains of the speed regulator parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station for each alternative capacity configuration scheme.

[0013] According to the capacity configuration method of the pumped storage wind power interconnected grid-connected system based on the stability domain provided by the present invention, the advantages and disadvantages of each alternative capacity configuration scheme are judged by the boundary of the stability domain as follows: Select state points that belong to the stable domains corresponding to various alternative capacity configuration schemes, and determine the sum of the distances between the state points and the boundaries of any stable domain. The alternative capacity configuration scheme corresponding to the stable domain with a larger sum of distances is better than the alternative capacity configuration scheme corresponding to the stable domain with a smaller sum of distances.

[0014] According to another aspect of the present invention, a capacity configuration system for a pumped-storage wind power interconnected grid-connected system based on a stability domain is provided. The system includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, it executes any one of the above-mentioned methods for capacity configuration of a pumped-storage wind power interconnected grid-connected system based on a stability domain.

[0015] In general, compared with the prior art, the above technical solutions conceived by the present invention provide a method and system for capacity configuration of a pumped storage wind power interconnected grid-connected system based on a stability domain: 1. A method is proposed to draw a stability domain based on the system model, consisting of the pumped-storage unit speed governor parameters and the wind turbine phase-locked loop controller parameters. Multiple alternative capacity configuration options are then evaluated based on the stability domain to select the optimal capacity configuration. This stability domain allows for accurate assessment of the operational stability of the pumped-storage wind power grid-connected system, and thus accurately assesses the impact of the generation capacity configuration of the pumped-storage wind power grid-connected system on the overall system operational stability. This allows for improved system operational stability by selecting the optimal capacity configuration. The stability domain calculation method is relatively simple and easy to use, improving the efficiency of accurately assessing the impact of capacity configuration on overall system operational stability and capacity configuration efficiency. 2. The proposed stability domain considers the controller parameters of both the pumped storage power station and the wind power station simultaneously. Compared with previous studies that only considered the controller parameters of the pumped storage power station or the wind power station separately, it is more comprehensive. The resulting stability domain can comprehensively reflect the operational stability performance of the interconnected pumped storage wind power system. 3. The proposed capacity allocation method is an analytical method with a time scale of seconds, which is shorter than the time scale considered by traditional power station scheduling capacity allocation methods. It is suitable for the field of small-signal stability research. The obtained capacity allocation conclusions can provide guidance for the power generation capacity allocation and safe and stable operation of actual pumped storage wind power interconnected grid-connected systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a capacity configuration method for a pumped storage wind power interconnected grid-connected system based on a stability domain provided by an embodiment of the present invention.

[0017] Figure 2 This is a topology diagram of the pumped storage wind power interconnected grid-connected system provided by an embodiment of the present invention.

[0018] Figure 3 These are the stability domains corresponding to the four alternative capacity configuration schemes for the pumped storage wind power interconnected grid-connected system provided in the embodiments of the present invention.

[0019] Figure 4 The dynamic response of the pumped storage unit speed corresponding to the four alternative capacity configuration schemes of the pumped storage wind power interconnection grid-connected system provided in the embodiments of the present invention.

[0020] Figure 5 The dynamic response of wind turbine speed corresponding to the four alternative capacity configuration schemes for the pumped storage wind power interconnection grid-connected system provided in the embodiments of the present invention. DETAILED DESCRIPTION

[0021] 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 with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0022] See also Figure 1 This embodiment provides a capacity configuration method for a pumped storage wind power interconnected grid-connected system based on a stability domain. The capacity configuration method includes: Set up several alternative capacity configuration plans for pumped storage power stations and wind power stations; Based on a system model of a pumped storage wind power grid-connected system, the stability domains of several alternative capacity configuration schemes for the pumped storage power station and the wind power station are drawn for the speed regulator parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station; the system model includes a pumped storage power station model, a wind power station model, and a network interface model; The advantages and disadvantages of various alternative capacity configuration schemes are determined by the boundary of the stability region, and then the optimal capacity configuration scheme of the pumped storage wind power interconnected grid-connected system is obtained.

[0023] For further reference, Figure 2 The pumped-storage wind power grid-connected system includes a pumped-storage power station, a wind power station, and a network interface. The pumped-storage power station includes an upper reservoir, a water diversion pipeline, a pump-turbine, and a lower reservoir, all connected in sequence. The pump-turbine is connected to the pumped-storage power station network interface via a transformer. The wind power station includes a shaft system, a wind turbine generator (DFIG), an inverter, and a phase-locked loop (PLL) controller, all connected in sequence, connected to the wind power station network interface via a transformer. The wind turbine generator can be, for example, a doubly-fed asynchronous wind turbine. The network interface includes a pumped-storage power station network interface, a wind power station network interface, and a common connection point network interface. The common connection point network interface is used for grid connection.

[0024] Furthermore, a system model for the interconnected pumped-storage wind power system was constructed, with each system model corresponding to its components. The constructed pumped-storage power station model included a pump-turbine model, a water diversion pipeline model, a synchronous generator model, and a speed regulator model. The constructed wind power station model included a doubly-fed asynchronous wind turbine generator model, a shaft system model, and a phase-locked loop controller model.

[0025] Furthermore, the constructed pumped storage power station speed regulator model adopts a proportional-integral control strategy, which corrects and adjusts the speed of the pump turbine through the speed proportional coefficient, and corrects and adjusts the guide vane opening through the permanent slip coefficient. That is, the turbine speed and guide vane opening feedback are corrected and adjusted at the same time through the speed proportional coefficient and the permanent slip coefficient, so as to achieve the effect of quickly adjusting the speed of the pumped storage unit, that is, the speed of the pump turbine.

[0026] The constructed wind power station phase-locked loop controller model projects the AC voltage signal output by the doubly-fed asynchronous wind turbine model onto the direct-axis component of the phase-locked loop coordinate system. It then uses a proportional-integral control strategy to solve for the wind power station voltage phase, or the phase-locked loop electrical angle, providing a phase reference for system power flow calculations. The wind power station model and network interface model are established based on this wind power station voltage phase. The network interface model uses the principle of voltage and current conservation based on the current flow direction to construct the voltage and current equations for the pumped-storage power station network interface, the wind power station network interface, and the common connection point network interface.

[0027] Furthermore, the pump-turbine model can be expressed as: ; Where, q t is the pump turbine flow rate; m t is the mechanical torque of the pump turbine; y is the guide vane opening; x t is the speed of the pump turbine, i.e. the speed of the pumped storage power station unit; h is the turbine head; e qy 、 e qx and e qh is the partial derivative of the pump-turbine flow with respect to the guide vane opening, speed and head; e y 、 e x and e h It is the partial derivative of the mechanical torque of the pump-turbine with respect to the guide vane opening, speed and water head.

[0028] Furthermore, the water diversion pipeline model can be expressed as: ; Where, t For time; T wt0 is the water flow inertia time constant; h t0 is the head loss of the water diversion pipeline; H 0 is the initial value of the pump-turbine head.

[0029] Furthermore, the synchronous generator model can be expressed as: ; Where, δ is the electrical angle of the synchronous generator; ω b is the speed reference value; m t and m t0 is the mechanical torque of the pumped storage power station and its initial value; m e It is the electromagnetic power of pumped storage power station; D is the damping coefficient; T J is the inertia time constant of the pumped storage power station unit; is the transient potential of the generator; Efd0 is the initial value of the excitation voltage; is the direct-axis open-circuit transient time constant; X d and Synchronous and transient reactance of a direct-axis pumped storage power station; I dg is the direct axis current component of the pumped storage power station.

[0030] Furthermore, the speed regulator model can be expressed as: ; Where, b p is the permanent slip coefficient of the pumped storage power station governor; K w is the speed proportional coefficient of the pumped storage power station unit; K P0 is the proportional coefficient of the pumped storage power station governor; K I0 is the integral coefficient of the pumped storage power station governor.

[0031] Furthermore, the doubly-fed asynchronous wind turbine model can be expressed as: ; Where, E d and E q is the transient potential of the doubly-fed asynchronous wind turbine generator; L m is the mutual inductance between the rotor and the stator; L rr is the rotor self-inductance; I ds and I qs are the direct-axis and quadrature-axis components of the stator current of the doubly-fed asynchronous wind turbine generator; V dr and V qr are the direct-axis and quadrature-axis components of the rotor voltage of the doubly-fed asynchronous wind turbine generator; R r is the rotor resistance; ω pll is the speed of the phase-locked loop controller; ω r is the rotor speed of the wind power station.

[0032] Furthermore, the shafting model can be expressed as: ; Where, m mw0is the initial value of the mechanical power of the doubly fed asynchronous wind turbine generator; m ew is the electromagnetic power of the doubly-fed asynchronous wind turbine generator; T j is the inertia time constant of the wind turbine.

[0033] Furthermore, the phase-locked loop model can be expressed as: ; Where, δ pll and x pll is the phase-locked loop electrical angle and intermediate variable; V dsp is the direct-axis component of the stator voltage of the doubly-fed asynchronous wind turbine generator in the phase-locked loop coordinate system; K Ppll is the phase-locked loop proportional coefficient; K Ipll is the phase-locked loop integral coefficient.

[0034] Furthermore, the network interface model can be expressed as: ; Where, X TL41 It is the export reactance of the pumped storage power station; X TL42 Export reactor for wind power station; X TL43 is the grid export reactance; I xy41 Export current for pumped storage power stations; I xy42 is the export current of the wind power station; I xy43 is the grid export current; θ is the grid export bus angle; V PCC is the bus voltage amplitude at the grid outlet; V g The outlet voltage of the pumped storage power station; V s is the outlet voltage of the wind power station; V b is the infinite grid voltage; j represents an imaginary number.

[0035] Furthermore, the alternative capacity configuration scheme is selected and set based on the actual power generation capacity requirements of the pumped-storage power station and the wind power station within a range that meets the requirements. The power generation capacity of the pumped-storage power station and the wind power station in the alternative capacity configuration scheme is a per-unit value in the range of 0-1. The capacity configuration scheme includes capacity parameters for the pumped-storage power station and the wind power station, and the capacity parameters are the ratios of the actual capacity to the theoretical maximum capacity.

[0036] In some specific embodiments, the aforementioned several capacity configuration schemes for pumped storage units and wind turbine generator sets are preset in advance according to actual power generation capacity requirements of the power station units, and are divided into four capacity configuration schemes (Case 1 to Case 4).

[0037] Furthermore, the capacity configuration scheme of Case 1 is m t0 =0.2, m mw0 =0.2; the capacity configuration scheme for Case 2 is m t0 =0.4, m mw0 =0.4; the capacity configuration scheme for Case 3 is m t0 =0.6, m mw0 =0.6; the capacity configuration scheme of Case 4 is m t0 =0.8, m mw0 =0.8. The specific values ​​of the alternative capacity configuration schemes are not limited thereto, and any combination can be selected while meeting the capacity requirements. The capacities of the pumped storage power station and the wind power station may also be unequal, and the number of alternative capacity configuration schemes may be greater than 4, without specific limitation.

[0038] Furthermore, the stability region is plotted based on the governor scaling coefficient in the pumped-storage power station and the phase-locked loop controller scaling coefficient in the wind power station; the horizontal axis of the stability region is the governor scaling coefficient, and the vertical axis is the phase-locked loop controller scaling coefficient. The stability region of each alternative capacity configuration scheme is plotted using the pumped-storage unit governor scaling coefficient and the wind turbine unit phase-locked loop controller scaling coefficient to simultaneously reflect the stable operating performance of power stations within the pumped-storage wind power interconnection system.

[0039] Furthermore, the stability domain of the pumped storage unit speed regulator parameters and wind turbine phase-locked loop controller parameters is determined based on the Hopf bifurcation theory. The range of the stability domain is determined by the cross-sectional coefficient of the Hopf bifurcation theory. The stability domains corresponding to the capacity allocation schemes of the four pumped storage wind power interconnection grid-connected systems are as follows: Figure 3 shown.

[0040] See Figure 3 It can be seen that the stability domain is bounded by the upper bifurcation boundary of the wind power station phase-locked loop controller parameters, the bifurcation boundary of the pumped-storage power station speed regulator parameters, the lower bifurcation boundary of the wind power station phase-locked loop controller parameters, and the ordinate axis. Case 1 has the largest stability domain area, the smallest bifurcation boundary of the pumped-storage unit speed regulator parameters, but the largest bifurcation boundary of the wind turbine phase-locked loop controller parameters. This indicates that Case 1 has the widest stable operating range, and the wind turbine phase-locked loop controller parameters can be set within a wide range to ensure stable system operation. Similarly, Case 2 and Case 3 have the second largest stability domain areas, and Case 4 has the smallest stability domain. The parameter stability operating ranges of the four pumped-storage wind power interconnection system capacity allocation schemes decrease in order.

[0041] Furthermore, the advantages and disadvantages of each alternative capacity configuration solution are determined by the boundary of the stability region as follows: Select state points that belong to the stable domains corresponding to various alternative capacity configuration schemes, and determine the sum of the distances between the state points and the boundaries of any stable domain. The alternative capacity configuration scheme corresponding to the stable domain with a larger sum of distances is better than the alternative capacity configuration scheme corresponding to the stable domain with a smaller sum of distances.

[0042] Specifically, the method for determining the pros and cons of each alternative capacity configuration scheme at the boundary of the stability domain is to arbitrarily give a state point composed of a speed regulator and a phase-locked loop controller. In this embodiment, the state point in the stability domain is selected. S 1=( K P0 , K Ppll )=(0.3,2) as the speed regulator and phase-locked loop controller parameters. If the state point S The greater the sum of the distances from the four boundaries of the stability region, the better the speed regulation quality of the pumped storage power station and wind power station after a small disturbance fault. The resulting capacity configuration is the optimal capacity configuration for the interconnected pumped storage and wind power system. Small disturbance faults are short-lived (less than 0.1 seconds) and can be quickly cleared and restored to their original state.

[0043] See Figure 3 It can be seen that in Case 1, the state point in the stable domain is SCase 1 is farthest from the upper and lower bifurcation boundaries of the wind power station's phase-locked loop controller parameters and the pumped-storage power station's speed regulator parameters. Cases 2 and 3 are next, while Case 4 is closer to the bifurcation boundaries. This indicates that Case 1 provides better speed regulation quality for the pumped-storage power station and wind power station after a small disturbance fault. This capacity configuration is the optimal capacity configuration for the pumped-storage wind power grid-connected system.

[0044] Furthermore, in order to verify the accuracy of the evaluation of the impact of the alternative capacity configuration scheme of the pumped storage wind power interconnection grid-connected system on the overall system stability, the state point in the stable domain is selected. S 1 is used as the speed regulator and phase-locked loop controller parameter. A three-phase short-circuit grounding fault is applied to the power grid and removed after 0.05s. The dynamic response of the pumped storage unit speed is as follows: Figure 4 As shown, the dynamic response of wind turbine speed is as follows: Figure 5 shown.

[0045] See Figure 4 and Figure 5 It can be seen that as the power generation capacity of the pumped storage power station and the wind power station increases synchronously, after the three-phase short circuit grounding fault, the pumped storage wind power interconnection grid system is adjusted by the internal controller, and the speed oscillation amplitude of the pumped storage unit and the wind turbine unit gradually increases. S 1 is in the stable domain. Therefore, the oscillation amplitude of the pumped storage unit speed and the wind turbine speed gradually decreases after the disturbance, and quickly converges into a stable state. Through the analysis of dynamic process performance indicators, it can be seen that the adjustment time and overshoot of the pumped storage unit speed and the wind turbine speed are significantly increased. Under Case 1, the speed adjustment time of the pumped storage unit is 15.75s, and the overshoot is 0.009; while the speed adjustment time of the wind turbine is 0.58s, and the overshoot is 1.0021; under Case 2, the speed adjustment time of the pumped storage unit is 21.19s, and the overshoot is 0.019; while the speed adjustment time of the wind turbine is 6.94s, and the overshoot is 1.0041; under Case 3, the speed adjustment time of the pumped storage unit is The speed regulation time for the pumped-storage generator set is 23.84 seconds, with an overshoot of 0.029; the wind turbine speed regulation time is 13.54 seconds, with an overshoot of 1.0063. In Case 4, the pumped-storage generator set speed regulation time is 25.52 seconds, with an overshoot of 0.039; the wind turbine speed regulation time is 47.41 seconds, with an overshoot of 1.0107. This indicates that the simultaneous increase in generating capacity of power stations in a pumped-storage wind power interconnection system has a significant impact on the speed of the corresponding power station units. When simultaneously increasing the generating capacity of power stations, more attention should be paid to the dynamic regulation performance of the corresponding power station controllers.

[0046] In summary, since the capacity configuration scheme of Case 1 has the smallest generator speed oscillation amplitude and the fastest convergence speed among all capacity configuration schemes, it can be shown that the capacity configuration scheme of Case 1 is the optimal capacity configuration scheme for the pumped storage wind power interconnection grid-connected system.

[0047] In another embodiment, a capacity configuration system for a pumped-storage wind power interconnected grid-connected system based on a stable domain is also provided. The system includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, it executes any one of the above-mentioned methods for capacity configuration of a pumped-storage wind power interconnected grid-connected system based on a stable domain.

[0048] The capacity configuration method provided by the present invention can accurately analyze and evaluate the operational stability of a pumped storage-wind power interconnected grid-connected system, and provide guidance for the actual production design and optimized operation of power stations.

[0049] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements 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 capacity configuration method for a pumped storage wind power interconnected grid-connected system based on a stability domain, characterized in that: include: Based on a system model of a pumped storage wind power grid-connected system, the stability domains of several alternative capacity configuration schemes for the pumped storage power station and the wind power station are drawn for the speed regulator parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station; the system model includes a pumped storage power station model, a wind power station model, and a network interface model; The advantages and disadvantages of various alternative capacity configuration schemes are determined by the boundary of the stability region, and then the optimal capacity configuration scheme of the pumped storage wind power interconnected grid-connected system is obtained.

2. The method for capacity configuration of a pumped storage wind power interconnected grid-connected system based on a stability region according to claim 1, characterized in that: The pumped storage power station model includes a governor model; the governor model adopts a proportional-integral control strategy, corrects and adjusts the speed of the pump turbine through the speed proportional coefficient, and corrects and adjusts the guide vane opening through the permanent slip coefficient, so as to achieve the effect of quickly adjusting the speed of the pump turbine.

3. The method for capacity configuration of a pumped storage wind power interconnected grid-connected system based on a stability domain according to claim 2, characterized in that: The wind power station model includes a phase-locked loop controller model; the phase-locked loop controller model projects the AC voltage signal output by the doubly-fed asynchronous wind turbine model onto the direct-axis component of the phase-locked loop coordinate system, and uses a proportional-integral control strategy to solve and obtain the voltage phase of the wind power station. The wind power station model and the network interface model are established based on the wind power station voltage phase.

4. The method for capacity configuration of a pumped storage wind power interconnected grid-connected system based on a stability region according to claim 3, characterized in that: The network interface model constructs voltage and current equations of the pumped storage power station network interface, the wind power station network interface and the common connection point network interface according to the current flow direction and the voltage and current conservation principle.

5. The method for capacity configuration of a pumped storage wind power interconnected grid-connected system based on a stability region according to claim 4, characterized in that: The speed regulator model in the pumped storage power station model is: ； Where, y is the guide vane opening; t For time; x t The speed of the pumped storage power station unit; b p is the permanent slip coefficient of the pumped storage power station governor; K w is the speed proportional coefficient of the pumped storage power station unit; K P0 is the proportional coefficient of the pumped storage power station governor; K I0 is the integral coefficient of the pumped storage power station governor; The phase-locked loop controller model in the wind power station model is: ； Where, δ pll and x pll is the electrical angle and intermediate variable of the phase-locked loop controller; V dsp is the direct axis component of the stator voltage of the doubly fed asynchronous wind turbine generator on the phase-locked loop coordinate axis; ω pll is the speed of the phase-locked loop controller; K Ppll is the proportional coefficient of the phase-locked loop controller; K Ipll is the integral coefficient of the phase-locked loop controller; The network interface model is: ； Where, X TL41 It is the export reactance of the pumped storage power station; X TL42 Export reactor for wind power station; X TL43 is the grid export reactance; I xy41 Export current for pumped storage power stations; I xy42 is the export current of the wind power station; I xy43 is the grid export current; θ is the grid export bus angle; V PCC is the bus voltage amplitude at the grid outlet; V g The outlet voltage of the pumped storage power station; V s is the outlet voltage of the wind power station; V b is the infinite grid voltage; δ is the electrical angle of the synchronous generator; j represents an imaginary number.

6. The method for configuring capacity of a pumped storage wind power interconnected grid-connected system based on a stability domain according to any one of claims 1 to 5, characterized in that: The alternative capacity configuration scheme is selected and set according to the actual power generation capacity requirements of the pumped storage power station and the wind power station within the range that meets the requirements. The power generation capacity of the pumped storage power station and the wind power station in the alternative capacity configuration scheme is a per-unit value in the range of 0-1.

7. The method for configuring capacity of a pumped storage wind power interconnected grid-connected system based on a stability domain according to any one of claims 1 to 5, characterized in that: The stability domain is drawn with respect to the governor proportional coefficient in the pumped storage power station and the phase-locked loop controller proportional coefficient in the wind power station; wherein the abscissa of the stability domain is the governor proportional coefficient, and the ordinate is the phase-locked loop controller proportional coefficient.

8. The method for configuring capacity of a pumped storage wind power interconnected grid-connected system based on a stability domain according to any one of claims 1 to 5, characterized in that: Based on the system model, the Hopf bifurcation theory is used to draw the stability domains of various alternative capacity configuration schemes with respect to the speed regulator parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station.

9. The method for configuring capacity of a pumped storage wind power interconnected grid-connected system based on a stability domain according to any one of claims 1 to 5, characterized in that: The advantages and disadvantages of each alternative capacity configuration scheme are determined by the boundary of the stability region as follows: Select state points that belong to the stable domains corresponding to various alternative capacity configuration schemes, and determine the sum of the distances between the state points and the boundaries of any stable domain. The alternative capacity configuration scheme corresponding to the stable domain with a larger sum of distances is better than the alternative capacity configuration scheme corresponding to the stable domain with a smaller sum of distances.

10. A capacity configuration system for a pumped storage wind power interconnected grid-connected system based on a stability domain, characterized in that: The system includes a memory and a processor, the memory stores a computer program, and the processor executes the capacity configuration method of the pumped storage wind power interconnected grid-connected system based on the stability domain as described in any one of claims 1 to 9 when executing the computer program.

Images