Gravity energy storage and pumped storage coupled hybrid energy storage system and control method thereof

Abstract

The invention discloses a gravity energy storage and pumped storage coupled hybrid energy storage system and a control method thereof. The hybrid energy storage system comprises a gravity energy storage system, a pumped storage system and a control system, the control system comprises a comprehensive control platform, a power grid frequency modulation controller, a power grid voltage regulation controller, a gravity energy storage control system, a pumped storage control system and an active and reactive output detection device. Active and reactive power required by peak regulation and dynamic active and reactive power required by frequency modulation and voltage regulation are superposed to form final active and reactive power control instructions, and the final active and reactive power control instructions are respectively sent to a gravity energy storage control system and a pumped storage control system to realize active and reactive power response; meanwhile, the active and reactive output detection device adjusts active and reactive output of the gravity energy storage control system and the pumped storage control system by receiving active and reactive measurement signals of the gravity energy storage control system and the pumped storage control system and feeding back the signals to the comprehensive control platform, and accurate tracking of active and reactive instructions is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage systems, and in particular to a hybrid energy storage system coupling gravity energy storage and pumped storage and a control method thereof. Background Art

[0002] Renewable energy sources, mainly wind power and photovoltaic power, are characterized by randomness, intermittency and volatility, and they urgently need energy storage as a regulating power source to support the grid connection and consumption of new energy sources. Pumped storage is the most ideal energy storage technology, which can provide peak regulation, frequency regulation, inertia support, voltage regulation and other support for new power systems with a high proportion of new energy sources. However, the output of new energy sources fluctuates frequently, and frequent frequency regulation and short-time scale power response may cause wear of pumped storage units, reduce the life and reliability of pumped storage units, and endanger the safety of the power grid.

[0003] Therefore, additional energy storage is needed to take on the role of frequent frequency modulation and short-time scale power response. Summary of the invention

[0004] In view of the problems such as the great pressure on absorbing new energy power and the great difficulty in storing power in the medium and long term, the present invention provides a hybrid energy storage system coupling gravity energy storage and pumped storage and a control method thereof. The hybrid energy storage system uses the gravity energy storage system to pull a heavy object block up and down in a vertical shaft, provides frequency modulation power response and short-time scale power response, replaces part of the pumped storage frequency modulation and short-time scale power response functions, so as to improve the reliability and life of the pumped storage unit; the hybrid energy storage system control method is used to improve the operating economy and reliability of the hybrid energy storage system.

[0005] To this end, the present invention adopts the following technical solution.

[0006] In a first aspect, the present invention provides a hybrid energy storage system coupling gravity energy storage and pumped storage, which includes a gravity energy storage system, a pumped storage system and a control system;

[0007] The gravity energy storage system comprises a weight block, a shaft, an electromechanical equipment platform, a first electric generator, a transmission system and a pulley block; the electric generator, the transmission system and the pulley block are placed on the electromechanical equipment platform, the first electric generator controls the weight block to move upward in the shaft through the transmission system and the pulley block to store electricity, and the weight block moves downward in the shaft and drives the first electric generator through the transmission system and the pulley block to generate electricity;

[0008] The pumped storage system comprises a lower energy storage reservoir, an upper energy storage reservoir, a pump turbine, a second motor generator and an underground powerhouse; the pump turbine and the second motor generator are placed in the underground powerhouse, the second motor generator drives the pump turbine to move water from the lower energy storage reservoir to the upper energy storage reservoir to store electricity, and the water drives the pump turbine and the second motor generator to generate electricity during the process of water flowing from the upper energy storage reservoir to the lower energy storage reservoir;

[0009] The control system includes an integrated control platform, a power grid frequency regulation controller, a power grid voltage regulation controller, a gravity energy storage control system, a pumped storage control system and an active and reactive output detection device;

[0010] The grid frequency modulation controller adjusts the active power according to the difference between the set frequency and the measured grid frequency, and the grid voltage regulation controller adjusts the reactive power according to the difference between the set voltage and the measured grid voltage; the integrated control platform receives active and reactive control instructions from the upper-level control center to meet the peak load of active and reactive power, and at the same time receives output instructions from the grid frequency modulation controller and the grid voltage regulation controller for dynamic active and reactive regulation of frequency and voltage regulation. The active and reactive power required for peak load regulation and the dynamic active and reactive power required for frequency and voltage regulation are superimposed to form the final active and reactive control instructions, which are sent to the gravity energy storage control system and the pumped storage control system respectively to realize active and reactive response. At the same time, the active and reactive output detection device adjusts the active and reactive output of the gravity energy storage control system and the pumped storage control system by receiving the active and reactive measurement signals of the gravity energy storage control system and the pumped storage control system and feeding them back to the integrated control platform, so as to realize accurate tracking of active and reactive instructions and achieve effective control of hybrid energy storage.

[0011] The present invention utilizes the coupling complementarity of gravity energy storage and pumped storage in terms of grid frequency regulation and multi-time scale power response, thereby promoting the consumption of new energy and increasing the life of pumped storage units.

[0012] Furthermore, the gravity energy storage control system includes a gravity energy storage inverter reactive controller, a gravity energy storage power controller and a converter; the gravity energy storage inverter reactive controller and the gravity energy storage power controller respectively receive reactive instructions and active instructions from the integrated control platform, and output gravity energy storage active and reactive control signals to control the converter, and the converter drives the first electric motor to drive the weight block to move up and down to provide active response, and the converter provides reactive response.

[0013] Furthermore, the pumped storage control system includes a pump-turbine controller, a guide vane system and a synchronous generator excitation controller; the pump-turbine controller receives active power instructions from the integrated control platform, adjusts the water flow change by controlling the guide vane system to control the mechanical power of the pump-turbine, and then controls the electric power of the second electric generator to achieve active power response; the synchronous generator excitation controller receives reactive power instructions from the integrated control platform, and achieves reactive power response by controlling the excitation current of the second electric generator.

[0014] In a second aspect, the present invention provides a control method for the hybrid energy storage system coupled with the gravity energy storage and pumped storage, which comprises:

[0015] Step 1, determine whether the hybrid energy storage system needs to participate in peak regulation, frequency regulation, voltage regulation or inertia support. If the hybrid energy storage system needs to participate in peak regulation, execute step 2; if the hybrid energy storage system needs to participate in frequency regulation, execute step 3; if the hybrid energy storage system needs to participate in voltage regulation, execute step 4; if the hybrid energy storage system needs to participate in inertia support, execute step 5;

[0016] Step 2: Control the operation of pumped storage according to the peak load regulation equation. Use the electric energy during the low load period to pump water from the lower storage reservoir to the upper storage reservoir. During the peak load period, release water from the upper storage reservoir to the lower storage reservoir to generate electricity. If the target peak load regulation requirement is still not met, gravity energy storage is used to achieve effective peak load regulation.

[0017] Step 3: Control the operation of gravity energy storage according to the frequency modulation equation, and realize the instantaneous response of frequency modulation power by instantaneous up and down movement of the weight block. If the weight block reaches the maximum operating speed but still fails to meet the target frequency modulation value requirement, pumped storage is used at the same time to adjust the speed and power of the pump turbine to achieve rapid adjustment of the grid frequency, thereby supplementing part of the power required for frequency modulation.

[0018] Step 4, control the gravity energy storage operation according to the voltage regulation equation, and use the converter of the gravity energy storage control system to respond to the reactive power required for voltage regulation. If the target voltage regulation value requirement is still not met, the pumped storage method is used at the same time, and the reactive response of voltage regulation is achieved through the pumped storage synchronous generator excitation controller;

[0019] Step 5, control the operation of pumped storage according to the inertia support equation, and achieve inertia support by adjusting its rotational inertia and the response capability of the pumped storage system. If the target inertia support is still not met, gravity energy storage is used at the same time to achieve inertia support.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. By utilizing the coupling complementarity of gravity energy storage and pumped storage, it can help to absorb new energy, promote medium- and long-term storage of electricity, and provide a new idea for hybrid energy storage applications.

[0022] 2. By replacing part of the pumped storage frequency regulation and short-time scale power response functions with a gravity energy storage system, the reliability and life of the pumped storage unit can be improved.

[0023] 3. The control logic of the hybrid energy storage system control method is clear. The peak regulation equation and inertia support equation are used to control the priority operation of pumped storage and the gravity energy storage is used for supplementation. The frequency regulation equation and pressure regulation equation are used to control the priority operation of gravity energy storage and the pumped storage is used for supplementation, thereby effectively realizing the economical, efficient and safe operation of the hybrid energy storage system.

[0024] 4. The hybrid energy storage system has a unique design and a novel and effective control method. Each part can be used according to the design ideas and can also be adjusted appropriately to improve the peak and frequency regulation of the power grid, promote the safe and stable operation of the power grid, and improve the operating economy and reliability of the hybrid energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a hybrid energy storage system coupling gravity energy storage and pumped storage according to the present invention;

[0026] In the figure, 101-energy storage lower reservoir; 102-energy storage upper reservoir; 103-second electric generator; 104-water pump turbine; 105-underground plant; 106-vertical shaft; 107-weight block; 108-electromechanical equipment platform; 109-first electric generator; 110-transmission system and pulley block.

[0027] Figure 2 is a control block diagram of a control system in a hybrid energy storage system of the present invention;

[0028] In the figure, 201-integrated control platform; 202-grid frequency regulation controller; 203-grid voltage regulation controller; 204-gravity energy storage control system; 205-pumped storage control system; 206-gravity energy storage converter reactive power controller; 207-gravity energy storage power controller; 208-converter; 211-pump turbine controller; 212-synchronous generator excitation controller; 213-guide vane system; 216-active and reactive output detection device.

[0029] Figure 3 It is a logic diagram of the hybrid energy storage system control method of the present invention. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0031] Example 1

[0032] This embodiment provides a hybrid energy storage system that couples gravity energy storage with pumped storage. Figure 1 As shown, it consists of a gravity energy storage system, a pumped storage system and a control system.

[0033] The gravity energy storage system includes a weight block 107, a shaft 106, an electromechanical equipment platform 108, a first electric generator 109 and a transmission system and a pulley block 110; the first electric generator 109 and the transmission system and the pulley block 110 are placed on the electromechanical equipment platform 108, and the first electric generator 109 controls the weight block 107 to move upward in the shaft 106 through the transmission system and the pulley block 110 to achieve electricity storage, and the weight block 107 moves downward in the shaft 106 and drives the first electric generator 109 through the transmission system and the pulley block 110 to achieve power generation.

[0034] The pumped storage system includes a lower energy storage reservoir 101, an upper energy storage reservoir 102, a pump-turbine 104, a second electric generator 103 and an underground plant 105; the pump-turbine 104 and the second electric generator 103 are placed in the underground plant 105, and the second electric generator 103 stores electricity by driving the pump-turbine 104 to move water from the lower energy storage reservoir 101 to the upper energy storage reservoir 102. In the process of water flowing from the upper energy storage reservoir 102 to the lower energy storage reservoir 101, the pump-turbine 104 and the second electric generator 103 are driven to generate electricity.

[0035] like Figure 2 As shown, the control system includes an integrated control platform 201, a power grid frequency regulation controller 202, a power grid voltage regulation controller 203, a gravity energy storage control system 204, a pumped storage control system 205 and an active and reactive output detection device 216.

[0036] The grid frequency modulation controller 202 adjusts the active power according to the difference between the set frequency and the measured grid frequency, and the grid voltage regulation controller 203 adjusts the reactive power according to the difference between the set voltage and the measured grid voltage; the integrated control platform 201 receives active and reactive power control instructions from the upper-level control center to meet the peak load of active and reactive power, and at the same time receives output instructions from the grid frequency modulation controller and the grid voltage regulation controller for dynamic active and reactive power regulation of frequency modulation and voltage regulation, the active and reactive power required for peak load regulation, and the dynamic active power required for frequency modulation and voltage regulation. The active and reactive power are superimposed on each other to form the final active and reactive control instructions, which are sent to the gravity energy storage control system 204 and the pumped storage control system 205 to realize the active and reactive response. At the same time, the active and reactive output detection device 216 adjusts the active and reactive output of the gravity energy storage control system 204 and the pumped storage control system 205 by receiving the active and reactive measurement signals of the gravity energy storage control system 204 and the pumped storage control system 205 and feeding them back to the integrated control platform 201, so as to realize the accurate tracking of the active and reactive power instructions and achieve the effective control of the hybrid energy storage.

[0037] Specifically, the gravity energy storage control system 204 includes a gravity energy storage inverter reactive controller 206, a gravity energy storage power controller 207 and an inverter 208; the gravity energy storage inverter reactive controller 206 and the gravity energy storage power controller 207 respectively receive reactive instructions and active instructions from the integrated control platform 201, and output gravity energy storage active and reactive control signals to control the inverter 208, and the inverter 208 drives the first electric motor 109 to drive the weight block 107 to move up and down to provide active response, and the inverter 208 provides reactive response.

[0038] Specifically, the pumped storage control system includes a pump-turbine controller 211, a guide vane system 213 and a synchronous generator excitation controller 212; the pump-turbine controller 211 receives active power instructions from the integrated control platform 201, and adjusts the water flow change by controlling the guide vane system 213 to control the mechanical power of the pump-turbine 104, and then controls the electric power of the second electric generator 103 to achieve active power response; the synchronous generator excitation controller 212 receives reactive power instructions from the integrated control platform 201, and achieves reactive power response by controlling the excitation current of the second electric generator 103.

[0039] Example 2

[0040] This embodiment provides a control method for a hybrid energy storage system that couples gravity energy storage and pumped storage as described in Embodiment 1, such as Figure 3 As shown, the steps are as follows:

[0041] Step 1, determine whether the hybrid energy storage system needs to participate in peak regulation, frequency regulation, voltage regulation or inertia support. If the hybrid energy storage system needs to participate in peak regulation, execute step 2; if the hybrid energy storage system needs to participate in frequency regulation, execute step 3; if the hybrid energy storage system needs to participate in voltage regulation, execute step 4; if the hybrid energy storage system needs to participate in inertia support, execute step 5;

[0042] Step 2: Control the operation of pumped storage according to the peak load regulation equation. Use the electric energy during the low load period to pump water from the lower storage reservoir to the upper storage reservoir. During the peak load period, release water from the upper storage reservoir to the lower storage reservoir to generate electricity. If the target peak load regulation requirement is still not met, gravity energy storage is used to achieve effective peak load regulation.

[0043] Step 3: Control the operation of gravity energy storage according to the frequency modulation equation, and realize the instantaneous response of frequency modulation power by instantaneous up and down movement of the weight block. If the weight block reaches the maximum operating speed but still fails to meet the target frequency modulation value requirement, pumped storage is used at the same time to adjust the speed and power of the pump turbine to achieve rapid adjustment of the grid frequency, thereby supplementing part of the power required for frequency modulation.

[0044] Step 4, control the gravity energy storage operation according to the voltage regulation equation, and use the converter of the gravity energy storage control system to respond to the reactive power required for voltage regulation. If the target voltage regulation value requirement is still not met, the pumped storage method is used at the same time, and the reactive response of voltage regulation is achieved through the pumped storage synchronous generator excitation controller;

[0045] Step 5, control the operation of pumped storage according to the inertia support equation, and achieve inertia support by adjusting its rotational inertia and the response capability of the pumped storage system. If the target inertia support is still not met, gravity energy storage is used at the same time to achieve inertia support.

[0046] Furthermore, in step 2, the peak load regulation equation is composed of a peak power generation equation for peak power load control and a valley power storage equation for valley power load control.

[0047] Specifically, the peak power generation equation is:

[0048]

[0049] Where W0 is the power generation, W 0threshold is the power generation threshold, when W0≤W 0threshold When only pumped storage is involved in power generation, m c1 is the mass of water used for power generation, g is the acceleration of gravity, h1 is the height difference of pumped storage, η c1 is the one-way power generation efficiency of pumped storage; when W0>W 0threshold When the pumped storage and gravity storage jointly participate in power generation, m c1maxis the maximum water mass used for power generation, m z1 is the mass of the gravity energy storage block used for power generation, h z1 is the height difference of gravity energy storage, η z1 It is the one-way power generation efficiency of pumped storage.

[0050] Specifically, the low-valley period electricity storage equation is:

[0051]

[0052] Where W1 is the storage capacity, W 1threshold is the power storage threshold, when W1≤W 1threshold When , only pumped storage participates in power storage, where m c2 is the mass of water used for electricity storage, η c2 is the one-way storage efficiency of pumped storage; when W1>W 1threshold When the pumped storage and gravity storage are used to store electricity, m c2max is the maximum water mass used for electricity storage, m z2 is the mass of the gravity energy storage block used for electricity storage, h z1 is the height difference of gravity energy storage, η z2 It is the one-way storage efficiency of gravity energy storage.

[0053] Specifically, in step 3, the frequency modulation equation is:

[0054]

[0055] Where, P is the frequency modulation power, P threshold is the frequency modulation power threshold, when P≤P threshold When , only the gravity energy storage system participates in frequency modulation, where R gra is the frequency droop coefficient of gravity energy storage, Δf is the frequency offset, P gra is the gravity energy storage power; when P>P threshold When the gravity energy storage and pumped storage jointly participate in frequency regulation, the weight coefficients of the two are a1 and a2 respectively, R pump is the pumped storage frequency regulation droop coefficient, P pump It is the pumped storage power.

[0056] Specifically, in step 4, the voltage regulation equation is:

[0057]

[0058] In the formula, Q is the voltage regulation reactive power, Q threshold is the reactive voltage threshold, when Q≤Q threshold When , only the gravity energy storage system participates in the voltage regulation, where K greis the gravity energy storage voltage regulation droop coefficient, ΔV is the voltage offset, Q gra is the gravity energy storage reactive power; when Q>Q threshold When the gravity energy storage and pumped storage jointly participate in the pressure regulation, the weight coefficients of the two are b1 and b2 respectively, K pump is the pumped storage voltage droop coefficient, Q pump It is the reactive power of pumped storage.

[0059] Specifically, in step 5, the inertia support equation is:

[0060]

[0061] Where P inertia is the inertia support power, P inertia_threshold is the inertia support power threshold, when P inertia ≤P inrrtia_threshold When the pumped storage unit responds autonomously and provides pumped storage inertia support power P inertia_pump , when P inertia >P inertia_threshold When the pumped storage and gravity energy storage systems jointly respond to the inertia support power, K inertia_grav is the virtual inertia coefficient of gravity energy storage.

[0062] The present invention utilizes the coupling complementarity of gravity energy storage and pumped storage systems to achieve hybrid energy storage control. Combined with a unique control method, it can effectively adapt to the frequent fluctuations of new energy, assist in peak and frequency regulation of the power grid, promote safe and stable operation of the power grid, and increase the life of the pumped storage unit, thereby improving the operating economy and reliability of hybrid energy storage.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A hybrid energy storage system coupling gravity energy storage and pumped storage, characterized in that: Including gravity energy storage system, pumped storage system and control system; The gravity energy storage system comprises a weight block (107), a shaft (106), an electromechanical equipment platform (108), a first electric generator (109), a transmission system and a pulley block (110); the first electric generator (109), the transmission system and the pulley block (110) are placed on the electromechanical equipment platform (108); the first electric generator (109) controls the weight block (107) to move upward in the shaft (106) through the transmission system and the pulley block (110) to store electricity; the weight block (107) moves downward in the shaft (106) and drives the first electric generator (109) through the transmission system and the pulley block (110) to generate electricity; The pumped storage system comprises a lower energy storage reservoir (101), an upper energy storage reservoir (102), a water pump turbine (104), a second electric generator (103) and an underground powerhouse (105); the water pump turbine (104) and the second electric generator (103) are placed in the underground powerhouse (105); the second electric generator (103) drives the water pump turbine (104) to move water from the lower energy storage reservoir (101) to the upper energy storage reservoir (102) to achieve electricity storage; and in the process of water flowing from the upper energy storage reservoir (102) to the lower energy storage reservoir (101), the water pump turbine (104) and the second electric generator (103) are driven to achieve electricity generation; The control system comprises an integrated control platform (201), a power grid frequency regulation controller (202), a power grid voltage regulation controller (203), a gravity energy storage control system (204), a pumped storage control system (205) and an active and reactive output detection device (216); The grid frequency modulation controller (202) adjusts active power according to the difference between the set frequency and the measured grid frequency, and the grid voltage regulation controller (203) adjusts reactive power according to the difference between the set voltage and the measured grid voltage; the integrated control platform (201) receives active and reactive power control instructions from the upper-level control center to meet the peak regulation of active and reactive power, and at the same time receives output instructions from the grid frequency modulation controller and the grid voltage regulation controller for dynamic active and reactive power regulation of frequency modulation and voltage regulation, and the active and reactive power required for peak regulation and the dynamic active and reactive power required for frequency modulation and voltage regulation. Active power and reactive power are superimposed to form final active power and reactive power control instructions, which are respectively sent to the gravity energy storage control system (204) and the pumped storage control system (205) to realize active power and reactive power response. Meanwhile, the active power and reactive power output detection device (216) receives active power and reactive power measurement signals of the gravity energy storage control system (204) and the pumped storage control system (205) and feeds them back to the integrated control platform (201), thereby adjusting the active power and reactive power output of the gravity energy storage control system (204) and the pumped storage control system (205), thereby realizing accurate tracking of active power and reactive power instructions.

2. A hybrid energy storage system combining gravity energy storage and pumped storage according to claim 1, characterized in that: The gravity energy storage control system (204) comprises a gravity energy storage inverter reactive controller (206), a gravity energy storage power controller (207) and a converter (208); the gravity energy storage inverter reactive controller (206) and the gravity energy storage power controller (207) respectively receive reactive instructions and active instructions from the integrated control platform (201), and output gravity energy storage active and reactive control signals to control the converter (208); the converter (208) drives the first electric motor (109) to drive the weight block (107) to move up and down to provide active response, and the converter (208) provides reactive response.

3. A hybrid energy storage system combining gravity energy storage and pumped storage according to claim 1, characterized in that: The pumped storage control system comprises a pump-turbine controller (211), a guide vane system (213) and a synchronous generator excitation controller (212); the pump-turbine controller (211) receives an active power instruction from an integrated control platform (201), controls the guide vane system (213) to adjust the water flow change, thereby controlling the mechanical power of the pump-turbine (104), and further controls the electric power of the second electric generator (103) to achieve active power response; the synchronous generator excitation controller (212) receives a reactive power instruction from the integrated control platform (201), and achieves reactive power response by controlling the excitation current of the second electric generator (103).

4. The control method of the hybrid energy storage system of gravity energy storage coupled with pumped storage as claimed in any one of claims 1 to 3, characterized in that: include: Step 1, determine whether the hybrid energy storage system needs to participate in peak regulation, frequency regulation, voltage regulation or inertia support. If the hybrid energy storage system needs to participate in peak regulation, execute step 2; if the hybrid energy storage system needs to participate in frequency regulation, execute step 3; if the hybrid energy storage system needs to participate in voltage regulation, execute step 4; if the hybrid energy storage system needs to participate in inertia support, execute step 5; Step 2: Control the operation of pumped storage according to the peak load regulation equation. Use the electric energy during the low load period to pump water from the lower storage reservoir to the upper storage reservoir. During the peak load period, release water from the upper storage reservoir to the lower storage reservoir to generate electricity. If the target peak load regulation requirement is still not met, gravity energy storage is used to achieve effective peak load regulation. Step 3: Control the operation of gravity energy storage according to the frequency modulation equation, and realize the instantaneous response of frequency modulation power by instantaneous up and down movement of the weight block. If the weight block reaches the maximum operating speed but still fails to meet the target frequency modulation value requirement, pumped storage is used at the same time to adjust the speed and power of the pump turbine to achieve rapid adjustment of the grid frequency, thereby supplementing part of the power required for frequency modulation. Step 4, control the gravity energy storage operation according to the voltage regulation equation, and use the converter of the gravity energy storage control system to respond to the reactive power required for voltage regulation. If the target voltage regulation value requirement is still not met, the pumped storage method is used at the same time, and the reactive response of voltage regulation is achieved through the pumped storage synchronous generator excitation controller; Step 5, control the operation of pumped storage according to the inertia support equation, and achieve inertia support by adjusting its rotational inertia and the response capability of the pumped storage system. If the target inertia support is still not met, gravity energy storage is used at the same time to achieve inertia support.

5. The control method according to claim 4, characterized in that: In step 2, the peak load regulation equation includes a peak power generation equation for peak power load control and a valley power storage equation for valley power load control.

6. The control method according to claim 5, characterized in that: The peak power generation equation is: Where W0 is the power generation, W 0threshold is the power generation threshold, when W0≤W 0threshold When only pumped storage is involved in power generation, m c1 is the mass of water used for power generation, g is the acceleration of gravity, h1 is the height difference of pumped storage, η c1 is the one-way power generation efficiency of pumped storage; when W0>W 0threshold When the pumped storage and gravity storage jointly participate in power generation, m c1max is the maximum water mass used for power generation, m z1 is the mass of the gravity energy storage block used for power generation, h z1 is the height difference of gravity energy storage, η z1 It is the one-way power generation efficiency of pumped storage.

7. The control method according to claim 5, characterized in that: The low-valley period electricity storage equation is: Where W1 is the storage capacity, W 1threshold is the power storage threshold, when W1≤W 1threshold When , only pumped storage participates in power storage, where m c2 is the mass of water used for electricity storage, g is the acceleration of gravity, h1 is the height difference of pumped storage, η c2 is the one-way storage efficiency of pumped storage; when W1>W 1threshold When the pumped storage and gravity storage are used to store electricity, m c2max is the maximum water mass used for electricity storage, m z2 is the mass of the gravity energy storage block used for electricity storage, h z1 is the height difference of gravity energy storage, η z2 It is the one-way storage efficiency of gravity energy storage.

8. The control method according to claim 4, characterized in that: In step 3, the frequency modulation equation is: Where, P is the frequency modulation power, P threshold is the frequency modulation power threshold, when P≤P threshold When , only the gravity energy storage system participates in frequency modulation, where R gra is the frequency droop coefficient of gravity energy storage, Δf is the frequency offset, P gra is the gravity energy storage power; when P>P threshold When the gravity energy storage and pumped storage jointly participate in frequency regulation, the weight coefficients of the two are a1 and a2 respectively, R pump is the pumped storage frequency regulation droop coefficient, P pump It is the pumped storage power.

9. The control method according to claim 4, characterized in that: In step 4, the voltage regulation equation is: In the formula, Q is the voltage regulation reactive power, Q threshold is the reactive voltage threshold, when Q≤Q threshold When , only the gravity energy storage system participates in the voltage regulation, where K gra is the gravity energy storage voltage regulation droop coefficient, ΔV is the voltage offset, Q gra is the gravity energy storage reactive power; when Q>Q threshold When the gravity energy storage and pumped storage jointly participate in the pressure regulation, the weight coefficients of the two are b1 and b2 respectively, K pump is the pumped storage voltage droop coefficient, Q pump It is the reactive power of pumped storage.

10. The control method according to claim 4, characterized in that: In step 5, the inertia support equation is: Where P inertia is the inertia support power, P in e rtia_threshold is the inertia support power threshold, when P inertia ≤P inertia_threshold When the pumped storage unit responds autonomously and provides pumped storage inertia support power P inertia_pump , when P inertia >P inertia_threshold When the pumped storage and gravity energy storage systems jointly respond to the inertia support power, K inertia_grav is the virtual inertia coefficient of gravity energy storage, Δf is the frequency offset, P gra is the gravity energy storage power.

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