A method and system for capacity configuration of pumped storage wind power interconnection and grid connection based on stability domain

Abstract

The present application belongs to the technical field of power system capacity configuration, and discloses a pumped storage wind power interconnected grid system capacity configuration method and system based on stability domain, which comprises the following steps: based on the system model of the pumped storage wind power interconnected grid system, drawing the stability domain of the alternative capacity configuration scheme of the pumped storage power station and the wind power station about the governor parameter in the pumped storage power station and the phase-locked loop controller parameter in the wind power station; determining the advantages and disadvantages of each alternative capacity configuration scheme through the boundary of the stability domain, and then obtaining the optimal capacity configuration scheme of the pumped storage wind power interconnected grid system. The present application measures the advantages and disadvantages of the alternative capacity configuration scheme based on the stability domain, realizes the accurate evaluation of the influence of the generation capacity configuration of the pumped storage wind power interconnected grid system on the overall system operation stability, and thus can improve the system operation stability by selecting the optimal capacity configuration.

Description

Technical Field

[0001] This invention belongs to the technical field of power system capacity configuration, and more specifically, relates to a capacity configuration method and system for pumped storage wind power interconnection and grid connection based on a stability domain. Background Technology

[0002] Pumped storage power stations offer the advantage of rapid start-up and shutdown, playing a crucial role in ensuring stable wind power output. The combined power generation of pumped storage in high-quality regulating areas and the vast potential of wind power resources holds significant engineering value for 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 fluctuations of wind power resources, and the large-scale use of power electronic devices, frequency oscillations in the combined power system are becoming 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 considers economic dispatch and performance evaluation more, rarely considering the power generation and operation of pumped storage and wind power interconnected grid-connected systems, and neglecting the impact of the combined power generation capacity on the overall system stability.

[0003] The applicant's research revealed that proper capacity configuration of pumped-storage wind power interconnection systems is essential for improving the overall stability of the power system. Capacity configuration of pumped-storage wind power interconnection systems is a crucial aspect of maintaining stable power system operation. Currently, there is a lack of relevant theoretical research, and effective methods for measuring the impact of capacity configuration on grid stability are also lacking. Therefore, there is an urgent need to propose a capacity configuration method for pumped-storage wind power interconnection systems to better address the issue of stable power system operation. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a capacity configuration method and system for pumped-storage wind power interconnection systems based on the stability domain. This addresses the lack of effective methods for measuring the impact of capacity configuration on grid stability in existing research on pumped-storage wind power interconnection systems, thus lacking methods for improving power system stability through capacity configuration. The aim is to improve the efficiency of accurately assessing the impact of pumped-storage wind power interconnection system capacity configuration on the overall system operational stability, thereby enhancing system operational stability through reasonable capacity configuration.

[0005] To achieve the above objectives, according to one aspect of the present invention, a capacity configuration method for a pumped storage wind power interconnection system based on a stability domain is provided, comprising:

[0006] Based on the system model of the pumped storage and wind power interconnection system, several alternative capacity configuration schemes for pumped storage power stations and wind power stations are plotted, and the stability domains of the governor parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station are plotted. The system model includes a pumped storage power station model, a wind power station model, and a network interface model.

[0007] The advantages and disadvantages of each alternative capacity configuration scheme are determined by the boundary of the stability domain, thereby obtaining the optimal capacity configuration scheme for the pumped storage wind power interconnection and grid connection system.

[0008] According to the capacity configuration method of the pumped storage wind power interconnection system based on the stability domain provided by the present invention, the pumped storage power station model includes a governor model; the governor model adopts a proportional-integral control strategy, which corrects and adjusts the pump-turbine speed through the speed proportional coefficient, and corrects and adjusts the guide vane opening through the permanent slip coefficient, so as to achieve the function of rapidly adjusting the pump-turbine speed.

[0009] According to the capacity configuration method for pumped storage wind power interconnection system based on 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 for the voltage phase of the wind power station, and establishes the wind power station model and the network interface model based on the voltage phase of the wind power station.

[0010] According to the capacity configuration method of the pumped storage and wind power interconnection 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 point of common coupling network interface based on the current flow direction and the principle of voltage and current conservation.

[0011] According to the capacity configuration method for pumped storage wind power interconnection system based on the stability domain provided by the present invention, the governor model in the pumped storage power station model is as follows:

[0012] ;

[0013] In the formula, y For guide vane opening; t For time; x t This refers to the rotational speed of the pumped storage power station unit. b p This refers to the permanent slip coefficient of the governor in a pumped storage power station. K w This refers to the proportional coefficient of the pumped storage power station unit speed; K P0This refers to the proportional coefficient of the governor in a pumped storage power station. K I0 The integral coefficient of the governor of the pumped storage power station;

[0014] The phase-locked loop controller model in the wind power station model is as follows:

[0015] ;

[0016] In the formula, δ pll and x pll For the electrical angle and intermediate variables of the phase-locked loop controller; V dsp This represents the direct-axis component of the stator voltage of a doubly-fed asynchronous wind turbine generator on the phase-locked loop coordinate axis. ω pll The rotational speed of the phase-locked loop controller; K Ppll This refers to the proportional gain of the phase-locked loop controller; K Ipll The integral coefficient of the phase-locked loop controller;

[0017] The network interface model is as follows:

[0018] ;

[0019] In the formula, X TL41 For the output reactance of the pumped storage power station; X TL42 For the output reactance of the wind power station; X TL43 For the power grid output reactance; I xy41 This refers to the outlet current of the pumped storage power station. I xy42 This refers to the output current of the wind power station. I xy43 This refers to the grid output current. θ The angle of the power grid outlet bus; V PCC This refers to the voltage amplitude at the power grid output bus. V g This refers to the outlet voltage of the pumped storage power station. V s This refers to the output voltage of the wind power station. V b The voltage of the power grid is infinite. δ denoted as the electrical angle of the synchronous generator; j represents an imaginary number.

[0020] According to the capacity configuration method of the pumped storage and wind power interconnection system based on the stability domain provided by the present invention, the alternative capacity configuration scheme is selected and set within the range that meets 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, ranging from 0 to 1.

[0021] According to the capacity configuration method of the pumped storage wind power interconnection system based on the stability domain provided by the present invention, the stability domain is plotted with respect to the proportional coefficient of the governor 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 governor and the vertical axis is the proportional coefficient of the phase-locked loop controller.

[0022] According to the stability-domain-based capacity configuration method for pumped storage and wind power interconnection systems provided by the present invention, the stability domains of each alternative capacity configuration scheme with respect to the governor parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station are plotted based on the system model using Hopf bifurcation theory.

[0023] According to the capacity configuration method for pumped storage wind power interconnection system based on stability region provided by the present invention, the merits of each alternative capacity configuration scheme are determined by the boundary of the stability region as follows:

[0024] Select a state point that belongs to the stable domain corresponding to each of the alternative capacity configuration schemes, and determine the sum of the distances between the state point and the boundary 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.

[0025] According to another aspect of the present invention, a capacity configuration system for a pumped-storage wind power interconnection 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 the capacity configuration method for a pumped-storage wind power interconnection system based on a stability domain as described above.

[0026] Overall, compared with the prior art, the capacity configuration method and system for pumped storage wind power interconnection based on the stability domain provided by this invention offer the following advantages:

[0027] 1. A method is proposed that uses a system model to plot a stability domain composed of parameters of the pumped storage unit governor and the phase-locked loop controller of the wind turbine. Based on the stability domain, the advantages and disadvantages of multiple alternative capacity configuration schemes are evaluated to select the optimal capacity configuration. The stability domain can accurately assess the operational stability of the pumped storage wind power interconnection system, thereby accurately evaluating the impact of the power generation capacity configuration of the pumped storage wind power interconnection system on the overall system operational stability. This allows for the selection of the optimal capacity configuration to improve system operational stability. Furthermore, the calculation method of the stability domain is relatively simple and easy to operate, which improves the efficiency of accurately assessing the impact of capacity configuration on the overall system operational stability and also improves the efficiency of capacity configuration.

[0028] 2. The proposed stability domain considers the controller parameters of both pumped storage power stations and wind power stations, which is more comprehensive than previous studies that only considered the controller parameters of pumped storage power stations or wind power stations. The stability domain drawn can comprehensively reflect the operational stability performance of the pumped storage and wind power interconnection grid system.

[0029] 3. The proposed capacity allocation method is an analysis method with a second-level time scale. Compared with the traditional power plant scheduling capacity allocation method, it considers a shorter time scale and is suitable for the field of small signal stability research. The capacity allocation conclusions obtained can provide guidance for the power generation capacity allocation and safe and stable operation of actual pumped storage wind power interconnection grid-connected systems. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a capacity configuration method for a pumped storage wind power interconnection system based on a stability domain, provided by an embodiment of the present invention.

[0031] Figure 2 The topology diagram of the pumped storage wind power interconnection and grid connection system provided in the embodiment of the present invention.

[0032] Figure 3 The stability domains corresponding to the four alternative capacity configuration schemes for pumped storage wind power interconnection and grid connection systems provided in the embodiments of the present invention.

[0033] Figure 4 The dynamic response of pumped storage unit speed is shown for the four alternative capacity configuration schemes of pumped storage wind power interconnection grid connection system provided in the embodiments of the present invention.

[0034] Figure 5 The dynamic response of wind turbine generator speed is shown for the four alternative capacity configuration schemes of pumped storage wind power interconnection and grid connection systems provided in the embodiments of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be 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 illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Please see Figure 1 This embodiment provides a capacity configuration method for a pumped storage wind power interconnection and grid connection system based on a stability domain. The capacity configuration method includes:

[0037] Several alternative capacity configuration schemes for pumped storage power stations and wind power stations are set up.

[0038] Based on the system model of the pumped storage and wind power interconnection system, several alternative capacity configuration schemes for pumped storage power stations and wind power stations are plotted, and the stability domains of the governor parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station are plotted. The system model includes a pumped storage power station model, a wind power station model, and a network interface model.

[0039] The advantages and disadvantages of each alternative capacity configuration scheme are determined by the boundary of the stability domain, thereby obtaining the optimal capacity configuration scheme for the pumped storage wind power interconnection and grid connection system.

[0040] Further reference Figure 2 The pumped-storage wind power interconnection system includes a pumped-storage power station, a wind power station, and a network interface. The pumped-storage power station consists of an upper reservoir, a water intake pipeline, a pump-turbine unit, and a lower reservoir connected in sequence. The pump-turbine unit is connected to the pumped-storage power station's network interface via a transformer. The wind power station includes a shaft system, a DFIG (Diverterless Generator) wind turbine, an inverter, and a PLL (Phase-Locked Loop Controller) connected in sequence, connected to the wind power station's network interface via a transformer. The wind turbine 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 point of common coupling (PCC) network interface. The PCC network interface is used for grid connection.

[0041] Furthermore, a system model of the pumped-storage wind power interconnection system is constructed, with each system model corresponding one-to-one with its components. The constructed pumped-storage power station model includes a pump-turbine model, a water diversion pipeline model, a synchronous generator model, and a governor model. The constructed wind power station model includes a doubly-fed asynchronous wind turbine model, a shaft system model, and a phase-locked loop controller model.

[0042] Furthermore, the constructed pumped storage power station governor model adopts a proportional-integral control strategy. The pump-turbine speed is corrected and adjusted by the speed proportional coefficient, and the guide vane opening is corrected and adjusted by the permanent slip coefficient. That is, the turbine speed and guide vane opening are corrected and adjusted by feedback through the speed proportional coefficient and the permanent slip coefficient, so as to achieve the function of quickly adjusting the pumped storage unit speed, i.e., the pump-turbine speed.

[0043] The constructed wind power station phase-locked loop (PLL) controller model projects the AC voltage signal output from the doubly-fed asynchronous wind turbine model onto the direct-axis component of the PLL coordinate system. A proportional-integral (PII) control strategy is used to solve for the wind power station voltage phase, i.e., the PLL electrical angle, providing a phase reference for system power flow calculation. Specifically, the wind power station model and the network interface model are established based on the wind power station voltage phase. The network interface model, according to the current flow direction, utilizes the voltage and current conservation principle to construct the voltage and current equations for the pumped-storage power station network interface, the wind power station network interface, and the point of common coupling (PCC) network interface.

[0044] Furthermore, the pump-turbine model can be represented as follows:

[0045] ;

[0046] In the formula, q t The flow rate of the water pump and turbine; m t The mechanical torque of the water pump turbine; y For guide vane opening; x t The speed of the water pump turbine is the same as the speed of the pumped storage power station unit. h For the turbine head; e qy , e qx and e qh This is the partial derivative of the pump-turbine flow rate with respect to the guide vane opening, rotational speed, and head. e y , e x and e h This is the partial derivative of the mechanical torque of the pump-turbine with respect to the guide vane opening, rotational speed, and head.

[0047] Furthermore, the water diversion pipeline model can be represented as follows:

[0048] ;

[0049] In the formula, t For time; Twt0 The inertial time constant of the water flow; h t0 This refers to the head loss in the water diversion pipeline; H 0 represents the initial head of the water pump and turbine.

[0050] Furthermore, the synchronous generator model can be represented as follows:

[0051] ;

[0052] In the formula, δ For the electrical angle of the synchronous generator; ω b This is the reference value for rotational speed; m t and m t0 The mechanical torque and initial value of the pumped storage power station; m e Electromagnetic power for pumped storage power stations; D The damping coefficient; T J The inertial time constant of the pumped storage power station unit; This refers to the transient electromotive force of the generator. E fd0 This is the initial value of the excitation voltage; The direct-axis open-circuit transient time constant; X d and Synchronization and transient reactance of a direct-axis pumped storage power station; I dg The current component of a pumped-storage power station is a direct-axis component.

[0053] Furthermore, the speed governor model can be represented as:

[0054] ;

[0055] In the formula, b p This refers to the permanent slip coefficient of the governor in a pumped storage power station. K w This refers to the proportional coefficient of the pumped storage power station unit speed; K P0 This refers to the proportional coefficient of the governor in a pumped storage power station. K I0 This is the integral coefficient of the governor of the pumped storage power station.

[0056] Furthermore, the doubly-fed asynchronous wind turbine model can be represented as:

[0057] ;

[0058] In the formula, E d and E q This refers to the transient electromotive force of a doubly-fed asynchronous wind turbine. L m Mutual inductance between rotor and stator; L rr For rotor self-inductance; I ds and I qs These are the direct-axis and quadrature-axis components of the stator current of a doubly-fed asynchronous wind turbine generator. V dr and V qr These are the direct-axis and quadrature-axis components of the rotor voltage of a doubly-fed asynchronous wind turbine generator. R r Rotor resistance; ω pll The rotational speed of the phase-locked loop controller; ω r This refers to the rotor speed of the wind power station.

[0059] Furthermore, the aforementioned shaft system model can be represented as:

[0060] ;

[0061] In the formula, m mw0 This represents the initial mechanical power value of the doubly-fed asynchronous wind turbine generator; m ew Electromagnetic power for doubly-fed asynchronous wind turbine generators; T j Let be the inertial time constant of the wind turbine.

[0062] Furthermore, the phase-locked loop model can be expressed as:

[0063] ;

[0064] In the formula, δ pll and x pll For phase-locked loop electrical angle and intermediate variables; V dsp This represents the direct-axis component of the stator voltage of a doubly-fed asynchronous wind turbine in the phase-locked loop coordinate system. K Ppll This refers to the proportional gain of the phase-locked loop; K Ipll represents the integral coefficient of the phase-locked loop.

[0065] Furthermore, the network interface model can be represented as:

[0066] ;

[0067] In the formula, X TL41 For the output reactance of the pumped storage power station; X TL42 For the output reactance of the wind power station; X TL43 For the power grid output reactance; I xy41 This refers to the outlet current of the pumped storage power station. I xy42 This refers to the output current of the wind power station. I xy43 This refers to the grid output current. θ The angle of the power grid outlet bus; V PCC This refers to the voltage amplitude at the power grid output bus. V g This refers to the outlet voltage of the pumped storage power station. V s This refers to the output voltage of the wind power station. V b The voltage of the infinite power grid is represented by ; j represents an imaginary number.

[0068] Furthermore, the alternative capacity configuration scheme is selected and set within the required range 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, ranging from 0 to 1. The capacity configuration scheme includes capacity parameters for the pumped storage power station and the wind power station, where the capacity parameter is the ratio of the actual capacity to the theoretical maximum capacity.

[0069] In some specific embodiments, the various capacity configuration schemes for pumped storage units and wind turbine generators are preset in advance according to the actual power generation capacity requirements of the power station units, and are divided into four capacity configuration schemes (Case 1 to Case 4).

[0070] Furthermore, the capacity configuration scheme for Case 1 is as follows: m t0 =0.2, m mw0 =0.2; The capacity configuration scheme for Case 2 is as follows: m t0 =0.4, m mw0 =0.4; The capacity configuration scheme for Case 3 is as follows: m t0 =0.6, m mw0 =0.6; The capacity configuration scheme for Case 4 is as follows: mt0 =0.8, m mw0 =0.8. The specific values ​​of the alternative capacity configuration schemes are not limited to this. Any combination can be selected as long as the capacity requirements are met. The capacities of pumped storage power stations and wind power stations can also be different, and the number of alternative capacity configuration schemes can be greater than 4. There is no specific limitation.

[0071] Furthermore, the stability region is plotted with respect to the proportional coefficient of the governor 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 region represents the proportional coefficient of the governor, and the vertical axis represents the proportional coefficient of the phase-locked loop controller. The stability regions of various alternative capacity configuration schemes are plotted using the proportional coefficients of the governor of the pumped storage unit and the proportional coefficients of the phase-locked loop controller of the wind turbine unit to simultaneously reflect the stable operating performance of the power stations within the pumped storage and wind power interconnection system.

[0072] Furthermore, the stability regions plotted for the pumped-storage unit governor parameters and the wind turbine phase-locked loop controller parameters are determined based on Hopf bifurcation theory. The range of the stability region is determined by the cross-section coefficient of Hopf bifurcation theory. The stability regions corresponding to the four capacity allocation schemes for pumped-storage wind power interconnection systems are as follows: Figure 3 As shown.

[0073] See Figure 3 It can be seen that the stability region 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 governor parameters, the lower bifurcation boundary of the wind power station phase-locked loop controller parameters, and the vertical axis. Case 1 has the largest stability region area, the pumped storage unit governor parameter bifurcation boundary is the smallest, but the wind power generator phase-locked loop controller parameter bifurcation boundary is the largest, indicating that Case 1 has the widest stable operating range, and the wind power generator phase-locked loop controller parameters can ensure stable system operation within a relatively large range. Similarly, Case 2 and Case 3 have the next largest stability region areas, and Case 4 has the smallest stability region. The stable operating range of the parameters for the four pumped storage wind power interconnection grid-connected system capacity allocation schemes decreases in that order.

[0074] Furthermore, determining the merits of each alternative capacity configuration scheme based on the boundary of the stability region specifically involves:

[0075] Select a state point that belongs to the stable domain corresponding to each of the alternative capacity configuration schemes, and determine the sum of the distances between the state point and the boundary 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.

[0076] Specifically, the method for determining the merits of each alternative capacity configuration scheme at the stability domain boundary is as follows: given any state point composed of a speed controller and a phase-locked loop controller, this embodiment selects a state point within the stability domain. S 1=( K P0 , K Ppll The parameters ) = (0.3, 2) are used as parameters for the speed governor and phase-locked loop controller. If the state point... S The greater the sum of the distances from the four boundaries of the stable domain, the better the unit speed regulation quality of pumped storage power stations and wind power stations after being subjected to small disturbance faults. The resulting capacity configuration scheme is the optimal capacity configuration scheme for the pumped storage wind power interconnection grid system. The small disturbance fault refers to a fault with a short duration (less than 0.1s) that can be quickly cleared and restored to the original state.

[0077] See Figure 3 It can be seen that, under Case 1, the state points within the stability region S Case 1 has the furthest distance from the bifurcation boundary of the phase-locked loop controller parameters in wind power plants and the bifurcation boundary of the governor parameters in pumped-storage power plants. Cases 2 and 3 are next, while Case 4 has a relatively close distance to the bifurcation boundary. This indicates that under Case 1, the speed regulation quality of pumped-storage and wind power plants is better after experiencing minor disturbances or faults. This capacity configuration scheme is the optimal capacity configuration scheme for the pumped-storage wind power interconnection system.

[0078] Furthermore, to verify the accuracy of the assessment of the impact of alternative capacity configuration schemes on the overall system stability of the pumped storage wind power interconnection system, state points within the stability domain were selected. S 1. As parameters for the speed governor and phase-locked loop controller, a three-phase short-circuit ground fault is applied to the power grid, lasting for 0.05 seconds before being cleared. The dynamic speed response of the pumped storage unit is as follows: Figure 4 As shown, the dynamic response of the wind turbine generator speed is as follows: Figure 5 As shown.

[0079] See Figure 4 and Figure 5 It can be seen that as the generating capacity of pumped storage power stations and wind power stations increases synchronously, after a three-phase short-circuit ground fault, the pumped storage and wind power interconnection system, through internal controller regulation, causes the speed oscillation amplitude of the pumped storage units and wind turbine units to gradually increase. This is due to the state point... SSince the system is within the stable region, the oscillation amplitudes of both the pumped-storage turbine (PSH) and wind turbine speeds gradually decrease after the disturbance and quickly converge to a stable state. Dynamic process performance analysis shows that the settling time and overshoot of both the PSH and wind turbine speeds are significantly increased. In Case 1, the PSH settling time is 15.75 s with an overshoot of 0.009, while the wind turbine settling time is 0.58 s with an overshoot of 1.0021. In Case 2, the PSH settling time is 21.19 s with an overshoot of 0.019, while the wind turbine settling time is 6.94 s with an overshoot of 1.0041. In Case 3, the PSH settling time is... The overshoot was 0.029, while the wind turbine's speed settling time was 13.54s with an overshoot of 1.0063. In Case 4, the pumped storage turbine's speed settling time was 25.52s with an overshoot of 0.039, while the wind turbine's speed settling time was 47.41s with an overshoot of 1.0107. This indicates that the synchronous increase in power generation capacity in a pumped storage wind power grid interconnection system has a significant impact on the speed of the corresponding power station units. When synchronously increasing the power generation capacity, more attention should be paid to the dynamic adjustment performance of the corresponding power station controllers.

[0080] 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 indicates that the capacity configuration scheme of Case 1 is the optimal capacity configuration scheme for pumped storage wind power interconnection and grid connection system.

[0081] In another embodiment, a capacity configuration system for a pumped-storage wind power interconnection system based on a stability 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 the capacity configuration method for a pumped-storage wind power interconnection system based on a stability domain as described above.

[0082] The capacity configuration method provided by this invention can accurately analyze and evaluate the operational stability of pumped storage-wind power interconnection and grid connection systems, providing guidance for the production design and optimized operation of actual power plants.

[0083] Those skilled in the art will readily understand 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 within the scope of protection of the present invention.

Claims

1. A stable domain-based pumped storage wind power interconnected grid system capacity configuration method, characterized in that, include: Based on the system model of the pumped storage and wind power interconnection system, several alternative capacity configuration schemes for pumped storage power stations and wind power stations are plotted, and the stability domains of the governor parameters in the pumped storage power station and the phase-locked loop controller parameters in the wind power station are plotted. 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 each alternative capacity configuration scheme are determined by the boundary of the stability domain, thereby obtaining the optimal capacity configuration scheme for the pumped storage wind power interconnection and grid connection system. The pumped storage power station model includes a governor model; the governor model adopts a proportional-integral control strategy, which corrects and adjusts the pump-turbine speed through the speed proportional coefficient, and corrects and adjusts the guide vane opening through the permanent slip coefficient, so as to achieve the function of quickly adjusting the pump-turbine speed. 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 for the voltage phase of the wind power station, and establishes the wind power station model and the network interface model based on the voltage phase of the wind power station. The network interface model constructs voltage and current equations for the pumped storage power station network interface, wind power station network interface, and point of common coupling network interface based on the current flow direction and the principle of voltage and current conservation. The specific method for determining the merits of each alternative capacity configuration scheme by using the boundary of the stability region is as follows: Select a state point that belongs to the stable domain corresponding to each of the alternative capacity configuration schemes, and determine the sum of the distances between the state point and the boundary 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.

2. The method of claim 1, wherein, The governor model in the pumped storage power station model is: ； In the formula, y is the guide vane opening; t is the time; x t is the pumped storage power station unit speed; b p is the pumped storage power station governor steady-state slip coefficient; K w is the pumped storage power station unit speed proportional coefficient; K P0 is the pumped storage power station governor proportional coefficient; K I0 is the pumped storage power station governor integral coefficient; The phase-locked loop controller model in the wind power station model is as follows: ； wherein δ pll and x pll is the phase locked loop controller electrical angle and intermediate variable; V dsp is the direct axis component of the stator voltage of the doubly-fed induction wind generator in the phase locked loop coordinate axis; ω pll is the phase locked loop controller rotational speed; K Ppll is the phase locked loop controller proportional coefficient; K Ipll is the phase locked loop controller integral coefficient; The network interface model is as follows: ； wherein X TL41 is the pumped storage plant export reactance; X TL42 is the wind power plant export reactance; X TL43 is the grid export reactance; I xy41 is the pumped storage plant export current; I xy42 is the wind power plant export current; I xy43 is the grid export current; θ is the grid export bus angle; V PCC is the grid export bus voltage magnitude; V g is the pumped storage plant export voltage; V s is the wind power plant export voltage; V b is the infinite grid voltage; δ is the synchronous generator electrical angle; j denotes the imaginary number.

3. The method of claim 1 or 2, wherein, The alternative capacity configuration scheme is selected and set within the range that meets 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, ranging from 0 to 1.

4. The method of claim 1 or 2, wherein, The stability region is plotted with respect to the proportional coefficient of the governor in a pumped storage power station and the proportional coefficient of the phase-locked loop controller in a wind power station; wherein the horizontal axis of the stability region is the proportional coefficient of the governor and the vertical axis is the proportional coefficient of the phase-locked loop controller.

5. The method of claim 1 or 2, wherein, Based on the system model, the stability domains of each alternative capacity configuration scheme with respect to the governor parameters in pumped storage power stations and the phase-locked loop controller parameters in wind power stations are plotted using Hopf bifurcation theory.

6. A stable domain based pumped storage wind power interconnection grid system capacity configuration system, characterized in that, The system includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it performs the capacity configuration method for a pumped storage wind power interconnection system based on the stability domain, as described in any one of claims 1-5.

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