Multi-machine power system operation stability analysis method and system based on pumped storage wind power interconnection

Abstract

The invention belongs to the related technical field of power system stability analysis, and discloses a multi-machine power system operation stability analysis method and system based on pumped storage wind power interconnection. The method comprises the following steps: applying disturbance of electromagnetic power to synchronous generator sets in a multi-machine power system, and then performing time domain simulation to obtain respective electromagnetic power vectors and reference electromagnetic power vectors of the synchronous generator sets, pumped storage sets and wind generating sets in the simulation process; and respectively calculating stability indexes of each synchronous generator set, each pumped storage set and each wind generating set by utilizing the electromagnetic power vector and the reference electromagnetic power vector, and calculating the stability index of the multi-machine electric power system according to the stability indexes of each synchronous generator set, each pumped storage set and each wind generating set. According to the invention, the problem that the stability of the multi-machine power system cannot be analyzed in the prior art is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to the stability analysis of power systems, and more specifically, relates to a method and system for analyzing the operation stability of a multi-machine power system based on the interconnection of pumped-storage power and wind power. Background Art

[0002] As a large-scale and well-regulated flexible energy storage device, pumped-storage power stations play a crucial role in peak shaving and valley filling, and promoting the consumption of new energy. Combining pumped-storage power and wind power can give play to the complementary power advantage and has great application prospects in multi-machine power systems. To alleviate the fluctuations in wind energy output, pumped-storage units often change their operating conditions, leading to risks such as hydraulic vibration, power oscillation, and frequency overrun. The grid connection of large-scale pumped-storage power and wind power is both a threat and a challenge to the safe and stable operation of multi-machine power systems, and it is very necessary to study its operation stability.

[0003] However, existing research on the grid connection of pumped-storage power and wind power mainly focuses on single-machine infinite systems and has not considered the operation of multi-machine power systems. The influence mechanism of the grid connection of pumped-storage power and wind power systems at different node positions on the operation stability of multi-machine power systems has not been explained, and there are defects in small-signal theory and indicators for judging system stability. Currently, there is no reliable comprehensive evaluation stability index to quantitatively judge the operation stability of power systems. Therefore, it is urgent to propose a method for analyzing the operation stability of a multi-machine power system based on the interconnection of pumped-storage power and wind power to solve the above problems. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement requirements of the existing technology, the present invention provides a method and system for analyzing the operation stability of a multi-machine power system based on the interconnection of pumped-storage power and wind power, which solves the problem that the stability of multi-machine power systems cannot be analyzed in the existing technology.

[0005] To achieve the above object, according to one aspect of the present invention, a method for analyzing the operation stability of a multi-machine power system based on the interconnection of pumped-storage power and wind power is provided. The method includes the following steps:

[0006] Apply a disturbance of electromagnetic power to the synchronous generator sets in the multi-machine power system and then perform time-domain simulation to obtain the electromagnetic power vectors and reference electromagnetic power vectors of each synchronous generator set, pumped-storage unit, and wind turbine generator set during the simulation process.

[0007] Calculate the stability indexes of each synchronous generator set, pumped-storage unit, and wind turbine generator set by using the electromagnetic power vectors and reference electromagnetic power vectors, and calculate the stability index of the multi-machine power system based on these.

[0008] Further preferably, the calculation relationship of the stability index of the multi-machine power system is as follows:

[0009]

[0010] Among them, S T is the stability index of the overall multi-machine power system; S ti is the stability index of the i-th area (i = 1 to x) synchronous generator set, and x is the total number of synchronous generator sets in the multi-machine power system; S tPSPS is the stability index of the pumped-storage unit; S tWPS is the stability index of the wind turbine generator set.

[0011] Further preferably, the calculation relationship of the stability index of the synchronous generator set is as follows:

[0012] S ti = ∫P ei - P ei0 dt

[0013] Among them, t is the time-domain simulation time; P ei is the electromagnetic power vector of the synchronous generator set in the i-th area (i = 1 to x) in the time-domain simulation; P ei0 is the reference electromagnetic power vector of the synchronous generator set in the i-th area (i = 1 to x) in the time-domain simulation.

[0014] Further preferably, the calculation relationship of the stability index of the pumped-storage unit is as follows:

[0015] S tPSPS = ∫P ePSPS - P ePSPS0 dt

[0016] Among them, P ePSPS is the electromagnetic power vector of the pumped-storage unit in the time-domain simulation; P ePSPS0 is the reference electromagnetic power vector of the pumped-storage unit in the time-domain simulation.

[0017] Further preferably, the calculation relationship of the stability index of the wind turbine generator set is as follows:

[0018] S tWPS = ∫P eWPS - P eWPS0 dt

[0019] Among them, P eWPS is the electromagnetic power vector of the wind turbine generator set in the time-domain simulation; P eWPS0 is the reference electromagnetic power vector of the wind turbine generator set in the time-domain simulation.

[0020] According to another aspect of the present invention, there is provided a multi-machine power system based on pumped-storage wind power interconnection, which system includes a synchronous generator set module and a pumped-storage wind power interconnection module, wherein:

[0021] The synchronous generator set module includes a plurality of interconnected synchronous generator sets;

[0022] The pumped-storage wind power interconnection module includes a pumped-storage unit, a wind power generation unit and a transmission line unit. The pumped-storage unit is used for converting the gravitational potential energy of water flow into the kinetic energy of a water turbine for power generation; the wind power generation unit is used for converting wind energy resources into the kinetic energy of a shaft system for power generation, and the transmission line unit is used for connecting the pumped-storage unit and the wind turbine generator set to the common bus of the synchronous generator set module.

[0023] Further preferably, the pumped-storage unit includes an upper reservoir, a penstock, a pumped-storage unit and a lower reservoir connected in sequence; the wind turbine generator unit includes a shaft system, a wind turbine generator set and an inverter connected in sequence.

[0024] According to yet another aspect of the present invention, there is provided a system for analyzing the operating stability of a multi-machine power system based on pumped-storage wind power interconnection, which system includes a simulation module, a monitoring module and a stability analysis module, wherein:

[0025] The simulation module is used for performing time-domain simulation on the multi-machine power system;

[0026] The monitoring module is used for monitoring the electromagnetic power vectors and reference electromagnetic power vectors of each synchronous generator set, pumped-storage unit and wind turbine generator set in the multi-machine power system during the simulation process;

[0027] The stability analysis module is used for respectively calculating the stability indexes of each synchronous generator set, pumped-storage unit and wind turbine generator set and the stability index of the multi-machine power system.

[0028] According to still another aspect of the present invention, there is provided a system for analyzing the operating stability of a multi-machine power system based on pumped-storage wind power interconnection, which system includes an actuator for executing the method for analyzing the operating stability of a multi-machine power system based on pumped-storage wind power interconnection as described above.

[0029] According to still another aspect of the present invention, there is provided a computer-readable storage medium having stored thereon a computer program, which when executed by a processor, implements the method for analyzing the operating stability of a multi-machine power system based on pumped-storage wind power interconnection as described above.

[0030] Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention have the following beneficial effects:

[0031] 1. The operation stability analysis method proposed by the present invention makes up for the defect that the previous power system stability analysis research is limited to the single-machine infinite power system and is difficult to be extended to the multi-machine power system. The stability indexes of the previous single-machine infinite system need to be obtained through frequency-domain calculation, and the operation process is complex and inefficient, making it difficult to be extended to the stability analysis of the multi-machine power system. However, the proposed operation stability index calculation method is obtained through time-domain simulation. It is easy to obtain the electromagnetic power vectors of the units in each power generation area through the power station monitoring system. The calculation of the operation stability index is simple and easy to operate, significantly improving the accuracy and efficiency of the stability assessment of the multi-machine power system with pumped-storage wind power interconnection.

[0032] 2. The operation stability index of the present invention can truly reflect the operation stability of the multi-machine power system with pumped-storage wind power interconnection, avoid deriving the complex state matrix of the multi-machine power system with pumped-storage wind power interconnection and solving high-order eigenvalues, effectively saving the computer operation time, and having good migration.

[0033] 3. The operation stability index proposed by the present invention is a comprehensive evaluation stability index, taking into account the stability performance of the units in each power generation area of the multi-machine power system with pumped-storage wind power interconnection, applicable to the research on the grid connection position and capacity configuration law of the pumped-storage wind power interconnection, and can provide reliable suggestions for the safe and stable operation of the actual pumped-storage wind power interconnection grid connection.

[0034] 4. The stability analysis and evaluation method of the multi-machine power system with pumped-storage wind power interconnection proposed by the present invention uses the rule that the smaller the operation stability index, the better to judge the strength of the overall system operation stability, can avoid scenarios with larger operation stability indexes in advance, can effectively improve the damping performance of the pumped-storage wind power interconnection grid connection system, and maximize the solution of the low-frequency oscillation problem existing in the multi-machine power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a flowchart of the operation stability analysis method of the multi-machine power system based on pumped-storage wind power interconnection constructed according to the preferred embodiment of the present invention;

[0036] Figure 2 is a schematic structural diagram of the pumped-storage wind power interconnection system connected to the multi-machine power system at the second common bus 7 constructed according to the preferred embodiment of the present invention;

[0037] Figure 3 is the electromagnetic power vector diagram of the first synchronous generator set in the time-domain simulation of the pumped-storage wind power interconnection system connected to the multi-machine power system at the first common bus 4, the second common bus 7 and the third common bus 9 constructed according to the preferred embodiment of the present invention;

[0038] Figure 4It is the electromagnetic power vector diagram of the second synchronous generator set in the time-domain simulation of the pumped-storage wind power interconnected system constructed according to the preferred embodiment of the present invention when the first common bus 4, the second common bus 7, and the third common bus 9 are incorporated into the multi-machine power system;

[0039] Figure 5 It is the electromagnetic power vector diagram of the third synchronous generator set in the time-domain simulation of the pumped-storage wind power interconnected system constructed according to the preferred embodiment of the present invention when the first common bus 4, the second common bus 7, and the third common bus 9 are incorporated into the multi-machine power system;

[0040] Figure 6 It is the electromagnetic power vector diagram of the pumped-storage unit in the time-domain simulation of the pumped-storage wind power interconnected system constructed according to the preferred embodiment of the present invention when the first common bus 4, the second common bus 7, and the third common bus 9 are incorporated into the multi-machine power system;

[0041] Figure 7 It is the electromagnetic power vector diagram of the wind turbine generator set in the time-domain simulation of the pumped-storage wind power interconnected system constructed according to the preferred embodiment of the present invention when the first common bus 4, the second common bus 7, and the third common bus 9 are incorporated into the multi-machine power system;

[0042] Figure 8 It is the stacked bar chart of the operation stability indexes of each power generation area in the time-domain simulation of the pumped-storage wind power interconnected system constructed according to the preferred embodiment of the present invention when the first common bus 4, the second common bus 7, and the third common bus 9 are incorporated into the multi-machine power system.

[0043] In all the drawings, the same reference numerals are used to represent the same elements or structures, where:

[0044] 1 - First generator bus, 2 - Second generator bus, 3 - Third generator bus, 4 - First common bus, 5 - First load bus, 6 - Second load bus, 7 - Second common bus, 8 - Third load bus, 9 - Third common bus, 10 - Fourth generator bus. Detailed implementation manners

[0045] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present 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 only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] A multi-machine power system based on the interconnection of pumped-storage power generation and wind power. This multi-machine power system includes a synchronous generator set module and a pumped-storage power generation and wind power interconnection module. The synchronous generator set module includes multiple interconnected synchronous generator sets. The pumped-storage unit is used to convert the gravitational potential energy of water flow into the kinetic energy of the turbine rotating for power generation; the wind power generation unit is used to convert wind energy resources into the kinetic energy of the shaft system rotating for power generation, and the transmission line unit is used to connect the pumped-storage unit and the wind turbine generator set to the common bus of the synchronous generator set module. The pumped-storage unit includes an upper reservoir, a penstock, a pumped-storage unit and a lower reservoir connected in sequence; the wind turbine generator unit includes a shaft system, a wind turbine generator set and an inverter connected in sequence.

[0047] Specifically, the constructed pumped-storage power generation and wind power interconnection system is planned to be incorporated into the multi-machine power system at the second common bus 7.

[0048] In an embodiment of the present invention, the multi-machine power system with pumped-storage power generation and wind power interconnection includes synchronous generator sets in three regions, namely the first synchronous generator set, the second synchronous generator set and the third synchronous generator set, and a pumped-storage unit and a wind turbine generator set in one region. The buses for the power system to be connected to the grid include the first generator bus 1, the second generator bus 2, the third generator bus 3, the first common bus 4, the first load bus 5, the second load bus 6, the second common bus 7, the third load bus 8, the third common bus 9, and the fourth generator bus 10. The topology of the multi-machine power system with pumped-storage power generation and wind power interconnection is as Figure 2 shown.

[0049] A method for analyzing the operation stability of a multi-machine power system based on the interconnection of pumped-storage power generation and wind power provided by an embodiment of the present invention is as Figure 1 shown.

[0050] (1) Apply a small disturbance fault to the multi-machine power system with pumped-storage power generation and wind power interconnection, and conduct a time-domain simulation for a period of time after the fault is removed.

[0051] In an embodiment of the present invention, the position where the small disturbance fault is applied is the first synchronous generator set (any one of the synchronous generator sets), the type is a 0.1 p.u. step-down disturbance of electromagnetic power, the fault is removed after 0.1 s, and the time-domain simulation of the multi-machine power system is conducted until 10 s.

[0052] In an embodiment of the present invention, the time-domain simulation solves the state variable equation of the multi-machine power system with pumped-storage power generation and wind power interconnection through the ode15s function of MATLAB.

[0053] (2) Obtain the electromagnetic power vectors and reference electromagnetic power vectors of each generator set in the multi-machine power system with pumped-storage power generation and wind power interconnection in the time-domain simulation.

[0054] In one embodiment of the present invention, the electromagnetic power vectors and reference electromagnetic power vectors of each generating unit in the multi-machine power system of pumped-storage wind power interconnection in the obtained time-domain simulation are defined as follows. Define the electromagnetic power vector and reference electromagnetic power vector of the synchronous generating unit in the i-th region (i = 1 to x) in the time-domain simulation as P ei and P ei0 , define the electromagnetic power vector and reference electromagnetic power vector of the pumped-storage unit in the time-domain simulation as P ePSPS and P ePSPS0 , define the electromagnetic power vector and reference electromagnetic power vector of the wind turbine generating unit in the time-domain simulation as P eWPS and P eWPS0 .

[0055] In one embodiment of the present invention, the grid connection position of the pumped-storage wind power interconnection system is changed so that it is connected to the multi-machine power system at the first common bus 4, the second common bus 7, and the third common bus 9 respectively. The electromagnetic power vectors of each power generation area in the time-domain simulation when the pumped-storage wind power interconnection system is connected to the multi-machine power system at the first common bus 4, the second common bus 7, and the third common bus 9 are as Figures 3 - 7 shown.

[0056] Referring to Figures 3 - 7 , it can be seen that after a small disturbance fault is applied to the first synchronous generating unit, through the adjustment of the internal controller of the multi-machine power system of pumped-storage wind power interconnection, the oscillation amplitudes of the electromagnetic power vectors in each power generation area gradually decrease and quickly converge to a stable state. It shows that the pumped-storage wind power interconnection system connected to the multi-machine power system at the second common bus 7 is small-signal stable and can quickly return to the equilibrium state after a small disturbance fault, and has good damping performance for low-frequency oscillations.

[0057] For the dynamic response of each power generation area, the connection of the pumped-storage wind power interconnection system to the first common bus 4 makes the oscillation amplitude of the first synchronous generator set, pumped-storage unit and wind generator set the lowest, while the connection to the second common bus 7 shows a more violent low-frequency oscillation phenomenon, indicating that the connection of the pumped-storage wind power interconnection system to the first common bus 4 can significantly increase the damping low-frequency oscillation performance of the first synchronous generator set, pumped-storage unit and wind generator set. The dynamic response of the second synchronous generator set and the third synchronous generator set shows a complex change law. Overall, the connection of the pumped-storage wind power interconnection system to the first common bus 4 makes the oscillation amplitude of the second synchronous generator set larger in the early stage, but it can converge quickly to the equilibrium state in the later stage, while the oscillation attenuation rate is lower when it is connected to the second common bus 7. The connection of the pumped-storage wind power interconnection system to the first common bus 4 makes the oscillation amplitude of the third synchronous generator set the largest, and the damping performance gradually decreases, indicating that the connection of the pumped-storage wind power interconnection to the multi-machine power system will weaken the stability of some power generation areas. After comprehensive consideration, it can be seen that the best location for the interconnection of pumped storage wind power into the multi-machine power system is the first common bus 4, and the operating stability and damping characteristics of each power generation area and the overall system are significantly improved.

[0058] (3) Carry out calculation of operational stability indicators for each power generation area and the whole multi-machine power system interconnected by pumped storage and wind power.

[0059] Furthermore, the calculation method of the operation stability index of each power generation area is as follows:

[0060] The operating stability index S of the synchronous generator set in the i-th region (i=1~x) ti The calculation method is

[0061] S ti =∫P ei -P ei0 dt

[0062] Where t is the time domain simulation time in seconds.

[0063] Operation stability index S of pumped storage unit tPSPS The calculation method is

[0064] S tPSPS =∫P ePSPS -P ePSPS0 dt

[0065] Wind turbine operation stability index S tWPS The calculation method is

[0066] S tWPS =∫P eWPS -P eWPS0 dt

[0067] Furthermore, the overall operation stability index S of the multi-machine power system with pumped-storage and wind power interconnection T The calculation method is as follows:

[0068]

[0069] In an embodiment of the present invention, according to the calculation method of the operation stability index of each power generation area, when the pumped-storage and wind power interconnection system is incorporated into the multi-machine power system at the first common bus 4 of the generator, the operation stability index S of the first synchronous generator set t1 is 34.7535, the operation stability index S of the second synchronous generator set t2 is 22.7632, the operation stability index S of the third synchronous generator set t3 is 6.9927, the operation stability index S of the pumped-storage unit tPSPS is 21.1091, and the operation stability index S of the wind turbine generator set tWPS is 2.3674.

[0070] According to the calculation method of the operation stability index of each power generation area, when the pumped-storage and wind power interconnection system is incorporated into the multi-machine power system at the second common bus 7 of the generator, the operation stability index S of the first synchronous generator set t1 is 56.5711, the operation stability index S of the second synchronous generator set t2 is 17.8042, the operation stability index S of the third synchronous generator set t3 is 5.5270, the operation stability index S of the pumped-storage unit tPSPS is 36.2178, and the operation stability index S of the wind turbine generator set tWPS is 4.9994.

[0071] According to the calculation method of the operation stability index of each power generation area, when the pumped-storage and wind power interconnection system is incorporated into the multi-machine power system at the third common bus 9 of the generator, the operation stability index S of the first synchronous generator set t1 is 47.3777, the operation stability index S of the second synchronous generator set t2 is 18.0915, the operation stability index S of the third synchronous generator set t3 is 6.0126, the operation stability index S of the pumped-storage unit tPSPS is 32.2763, and the operation stability index S of the wind turbine generator set tWPS is 4.1081.

[0072] According to the overall operation stability index S of the multi-machine power system with pumped-storage and wind power interconnection TAccording to the calculation method, when the pumped-storage wind power interconnected system is connected to the multi-machine power system at the first common bus 4, the second common bus 7, and the third common bus 9 of the generator, S T are 87.9859, 121.1194, and 107.8662 respectively.

[0073] (4) Analyze and evaluate the operation stability of each power generation area and the whole of the multi-machine power system with pumped-storage wind power interconnection.

[0074] Furthermore, the method for analyzing and evaluating the operation stability of each power generation area of the multi-machine power system with pumped-storage wind power interconnection is as follows: According to S ti Analyze and evaluate the operation stability of the synchronous generator sets in the i-th area (i = 1 to x). The smaller S ti is, the stronger the operation stability of the synchronous generator sets in the i-th area. According to S tPSPS Analyze and evaluate the operation stability of the pumped-storage units. The smaller S tPSPS is, the stronger the operation stability of the pumped-storage units. According to S tWPS Analyze and evaluate the operation stability of the wind turbine generator sets. The smaller S tWPS is, the stronger the operation stability of the wind turbine generator sets.

[0075] In an embodiment of the present invention, a stacked bar chart is drawn according to the operation stability indexes of each power generation area of the multi-machine power system with pumped-storage wind power interconnection, as Figure 8 shown.

[0076] Referring to Figure 8 it can be seen that the height of the stacked bar chart of the operation stability indexes of each power generation area of the multi-machine power system with pumped-storage wind power interconnection exactly corresponds to the value of the overall operation stability index, and the operation stability of each power generation area and the whole can be clearly analyzed and evaluated. Among them, the stacked bar height of the first common bus 4 is the smallest, the third common bus 9 is the second, and the second common bus 7 is the highest, indicating that the best grid connection position for the pumped-storage wind power interconnection to the multi-machine power system is the first common bus 4. The calculation results of the operation stability indexes of each power generation area are consistent with the time-domain simulation results, verifying the accuracy of the proposed operation stability indexes. Comparing the electromagnetic power oscillations of each power generation area, the area of the first synchronous generator set is the largest. The main reason is that the small-signal disturbance is applied to the first synchronous generator set, so the electromagnetic power of the first synchronous generator set near the fault point is greatly affected after the disturbance. In addition, the pumped-storage units are significantly affected by the fault disturbance, showing a large column area. The main reason is that the pumped-storage power station acts as a regulator and performs fast feedback control on the load disturbance of the grid-connected system, thereby suppressing the propagation of low-frequency oscillations.

[0077] Furthermore, the method for analyzing and evaluating the operation stability of the whole of the multi-machine power system with pumped-storage wind power interconnection is according to ST Analyze and evaluate the overall operation stability of a multi-machine power system interconnected with pumped-storage wind power, S T The smaller S is, the stronger the overall operation stability of the pumped-storage wind power interconnected into the multi-machine power system.

[0078] Furthermore, compare the S values when the pumped-storage wind power interconnected system is integrated into the multi-machine power system at the first common bus 4, the second common bus 7, and the third common bus 9 T It can be seen that the S value when interconnected at the first common bus 4 T is the smallest, indicating that the pumped-storage wind power interconnected system has the strongest operation stability when integrated into the multi-machine power system at the first common bus 4. In actual grid-connected operation, it is recommended that the pumped-storage wind power interconnected system be grid-connected at the first common bus 4, which can significantly improve the low-frequency oscillation phenomenon existing in the multi-machine power system, enhance the damping performance of the overall system, and improve the dynamic regulation quality of the units in each power generation area.

[0079] Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for analyzing the operation stability of a multi-machine power system based on pumped storage wind power interconnection, characterized in that: The method comprises the following steps: After applying electromagnetic power disturbance to the synchronous generator set in the multi-machine power system, a time domain simulation is performed to obtain the electromagnetic power vector and reference electromagnetic power vector of each synchronous generator set, pumped storage unit and wind turbine generator set during the simulation process; The electromagnetic power vector and the reference electromagnetic power vector are used to calculate the stability index of each synchronous generator set, pumped storage unit and wind generator set respectively, and the stability index of the multi-machine power system is calculated based on them.

2. The method for analyzing the operation stability of a multi-machine power system based on pumped storage wind power interconnection according to claim 1, characterized in that: The calculation relationship of the stability index of the multi-machine power system is as follows: Among them, S T is the overall stability index of the multi-machine power system; S ti is the stability index of the synchronous generator set in the i-th region (i=1~x), x is the total number of synchronous generator sets in the multi-machine power system; S tPSPS is the stability index of the pumped storage unit; S tWPS It is the stability index of wind turbine.

3. The method for analyzing the operation stability of a multi-machine power system based on pumped storage wind power interconnection according to claim 2, characterized in that: The calculation relationship of the stability index of the synchronous generator set is as follows: S ti =∫|P ei -P ei0 |dt Where t is the time domain simulation time; P ei is the electromagnetic power vector of the synchronous generator set in the i-th region (i=1~x) in the time domain simulation; P ei0 It is the reference electromagnetic power vector of the synchronous generator set in the i-th region (i=1~x) in the time domain simulation.

4. A method for analyzing the operation stability of a multi-machine power system based on pumped storage wind power interconnection as claimed in claim 2 or 3, characterized in that: The calculation relationship of the stability index of the pumped storage unit is as follows: S tPSPS =∫|P ePSPS -P ePSPS0 |dt Among them, P ePSPS is the electromagnetic power vector of the pumped storage unit in time domain simulation; P ePSPS0 It is the reference electromagnetic power vector of the pumped storage unit in time domain simulation.

5. The method for analyzing the operation stability of a multi-machine power system based on pumped storage wind power interconnection according to claim 4, characterized in that: The calculation relationship of the stability index of the wind turbine generator set is as follows: S tWPS =∫|P eWPS -P eWPS0 |dt Among them, P eWPS is the electromagnetic power vector of the wind turbine generator in the time domain simulation; P eWPS0 It is the reference electromagnetic power vector of the wind turbine in the time domain simulation.

6. A multi-machine power system based on pumped storage wind power interconnection, characterized in that: The system includes a synchronous generator module and a pumped storage wind power interconnection module, where: The synchronous generator set module comprises a plurality of synchronous generator sets connected to each other; The pumped storage wind power interconnection module includes a pumped storage unit, a wind power generation unit and a transmission line unit. The pumped storage unit is used to convert the gravitational potential energy of the water flow into kinetic energy for the turbine to rotate and generate electricity; the wind power generation unit is used to convert wind resources into kinetic energy for the shaft system to rotate and generate electricity, and the transmission line unit is used to connect the pumped storage unit and the wind generator set to the common bus of the synchronous generator set module.

7. A method for analyzing the operation stability of a multi-machine power system based on pumped storage wind power interconnection as claimed in claim 6, characterized in that: The pumped storage unit comprises an upper reservoir, a pressure steel pipe, a pumped storage unit and a lower reservoir which are connected in sequence; the wind turbine generator unit comprises a shaft system, a wind turbine generator set and an inverter which are connected in sequence.

8. A multi-machine power system operation stability analysis system based on pumped storage wind power interconnection, characterized in that: The system includes simulation module, monitoring module and stability analysis module, among which: The simulation module is used to perform time domain simulation on a multi-machine power system; The monitoring module is used to monitor the electromagnetic power vector and the reference electromagnetic power vector of each synchronous generator set, pumped storage generator set and wind generator set in the multi-machine power system during the simulation process; The stability analysis module is used to calculate the stability index of each synchronous generator set, pumped storage unit and wind generator set and the stability index of the multi-machine power system respectively.

9. A multi-machine power system operation stability analysis system based on pumped storage wind power interconnection, characterized in that: The system includes an actuator, which is used to execute the method for analyzing the operating stability of a multi-machine power system based on pumped storage wind power interconnection as described in any one of claims 1 to 5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the method for analyzing the operating stability of a multi-machine power system based on the interconnection of pumped storage and wind power as described in any one of claims 1 to 5.

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