A matrix type gravity energy storage system and charge-discharge power response method

Abstract

The application discloses a matrix type gravity energy storage system and a charging and discharging power response method. The mass block is driven to operate by a hydraulic system and a power generation motor. The tension of the steel cable on the mass block is adjusted by the hydraulic system, the stress condition of the mass block during operation is changed, the mechanical torque input by the power generation motor is changed, the output power of the power generation motor is controlled, the purpose of smoothing the system output power is achieved, and the corresponding charging and discharging power accurate response method is used to achieve the purpose of accurately responding to the charging and discharging power.

Description

Technical Field

[0001] This invention relates to a matrix-type gravity energy storage system and a charging and discharging power response method, belonging to the technical field of matrix-type gravity energy storage systems. Background Technology

[0002] Gravity energy storage is a mechanical energy storage method where the storage medium is a solid material. It utilizes the height difference to achieve the mutual conversion between gravitational potential energy and electrical energy in the energy storage system. Currently, domestic and international research on gravity energy storage mainly focuses on two types: vertical and inclined. Among them, there is more research on vertical gravity energy storage, which has the main advantages of high energy conversion efficiency, small footprint, low dependence on geographical environment and natural resources, and high system expansion flexibility.

[0003] A vertical matrix gravity energy storage system mainly consists of a storage yard, mass blocks, a transmission system, a generator motor, a control system, and auxiliary equipment. The generator consumes energy when lifting the mass blocks, storing the input electricity as potential energy. When power needs to be released, the mass blocks fall under gravity, driving the generator to operate and converting the gravitational potential energy back into electrical energy.

[0004] For example, the control method for a matrix-type gravity energy storage system disclosed in patent CN115013266A has a fixed power for each mass block, meaning it exhibits discreteness, with the power depending on its mass and descent height or speed. This discreteness of the mass blocks in a matrix-type gravity energy storage system results in a stepped power response, making it difficult to achieve precise power response. Existing gravity energy storage devices primarily rely on mechanical components to change the speed of the mass blocks and adjust the charging and discharging power. This method places high demands on the mechanical structure, especially the gearbox, and results in low control precision. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a matrix-type gravity energy storage system with smooth output power and a charging and discharging power response method.

[0006] To achieve the above objectives, the technical solution proposed by this invention is as follows: a matrix-type gravity energy storage system, comprising a generator motor, a transmission system, and a mass block, wherein the generator motor is connected to the mass block through the transmission system; the matrix-type gravity energy storage system further comprises a hydraulic system, wherein the hydraulic system comprises an accumulator, an oil tank, a pump, and two symmetrically arranged subsystems; the subsystems comprise a double-acting hydraulic cylinder, a flow divider, a throttle valve, and a pressure regulator; The double-acting hydraulic cylinder is configured as a high-pressure cylinder and a low-pressure cylinder. The oil tank is connected to the high-pressure cylinder and the low-pressure cylinder of the double-acting hydraulic cylinder through high-pressure oil circuit and low-pressure oil circuit respectively. A pump, a pressure regulating valve and a flow divider are sequentially provided on the high-pressure oil circuit. Another flow divider is provided on the low-pressure oil circuit. The two flow dividers are connected by a throttle valve. The accumulator is connected to the high-pressure oil circuit through a branch oil circuit. The two subsystems' double-acting hydraulic cylinders are each connected to a hydraulic transmission system, and the two hydraulic transmission systems are connected to the mass block via a circulating steel cable.

[0007] A further design of the above technical solution is as follows: the transmission system includes a first gearbox and a first electromagnetic clutch, the generator motor is connected to the first gearbox, the first gearbox is connected to the first electromagnetic clutch, and the first electromagnetic clutch is connected to the mass block through a steel cable.

[0008] The two double-acting hydraulic cylinders are a first double-acting hydraulic cylinder and a second double-acting hydraulic cylinder. The hydraulic transmission system connected to the first double-acting hydraulic cylinder includes a first hydraulic clutch, a second gearbox, and a second electromagnetic clutch. The output end of the first double-acting hydraulic cylinder is connected to the first hydraulic clutch. The first hydraulic clutch is connected to the second gearbox. The second gearbox is connected to the second electromagnetic clutch. The second electromagnetic clutch is connected to the mass block through a circulating steel cable. The hydraulic transmission system connected to the second double-acting hydraulic cylinder includes a second hydraulic clutch, a third gearbox, and a third electromagnetic clutch; the output end of the second double-acting hydraulic cylinder is connected to the second hydraulic clutch, the second hydraulic clutch is connected to the third gearbox, the third gearbox is connected to the third electromagnetic clutch, and the third electromagnetic clutch is connected to the mass block through a circulating steel cable.

[0009] The accumulator is connected between the pump and the pressure regulating valve in the high-pressure oil circuit via a branch oil circuit, and a fifth valve is provided on the branch oil circuit.

[0010] A first valve is provided on the oil line between the distributor and the high-pressure cylinder corresponding to the first double-acting hydraulic cylinder; a third valve is provided between the first pressure regulating valve of the high-pressure oil line and the distributor; a fourth valve is provided between the oil tank and the distributor of the low-pressure oil line; and a second valve is provided on the oil line between the distributor and the low-pressure cylinder. An eighth valve is provided on the oil line between the distributor and the high-pressure cylinder corresponding to the second double-acting hydraulic cylinder. A sixth valve is provided between the second pressure regulating valve of the high-pressure oil line and the distributor. A seventh valve is provided between the oil tank and the distributor of the low-pressure oil line. A ninth valve is provided on the oil line between the distributor and the low-pressure cylinder.

[0011] The matrix-type gravity energy storage system has four operating modes: Mode 1 is system discharge and energy storage device charging; Mode 2 is system discharge and energy storage device releasing energy; Mode 3 is system charging and energy storage device charging; and Mode 4 is system charging and energy storage device releasing energy. In the four working modes, mode 1 is characterized by the first and second electromagnetic clutches being engaged, the third electromagnetic clutch being disengaged, the fourth, sixth, and seventh valves being closed, and the first, second, third, and fifth valves being open. In mode 2, the first and third electromagnetic clutches are engaged, the second electromagnetic clutch is disengaged, the third, fourth, and seventh valves are closed, and the fifth, sixth, eighth, and ninth valves are open. In mode 3, the first and third electromagnetic clutches are engaged, the second electromagnetic clutch is disengaged, the third, fourth, and seventh valves are closed, and the fifth, sixth, eighth, and ninth valves are open. Mode 4 is characterized by the first and second electromagnetic clutches being engaged, the third electromagnetic clutch being disengaged, the fourth, sixth, and seventh valves being closed, and the first, second, third, and fifth valves being open.

[0012] A method for charging and discharging power response based on the above-mentioned matrix-type gravity energy storage system includes the following steps: Step S1: Determine the system operating mode and the number of mounted mass blocks; Let the reference value of the system output power be... P ref The overall efficiency of the generator motor and mechanical transmission system is or Then the power input to the mechanical transmission system P 1 is: ; To ensure normal system operation and maintain a certain safety margin, the actual capacity of the energy storage device should be at least greater than the gravitational potential energy stored in the two mass blocks, i.e.: ; In the formula, W max This is the maximum capacity of the energy storage device. m For the mass of the mass block, g It is the acceleration due to gravity. h The height of the mass block; Based on the relationship between mass blocks and power, the number of mass blocks is: ; In the formula, v ref The rated operating speed for the mass block, n Round down; Assume the actual number of mass blocks to be mounted by the system is... n ref ; when At that time, let the energy that the accumulator can currently release be... W 1, 1) If Then determine the number of mounted mass blocks. The system is operating in mode 2; 2) If Then determine the number of mounted mass blocks. The system is operating in mode 1; when At that time, let the energy that the energy storage device can currently store be... W 2, 1) If Then determine the number of mounted mass blocks. The system is operating in mode 4; 2) If Then determine the number of mounted mass blocks. The system is operating in mode 3; Step S2: Set the pressure setting value of the pressure regulating valve; The power provided by the mass block is: ; In the formula, n The number of mass blocks to be mounted. v ref The rated operating speed for the mass block; The hydraulic system should provide the following power: ; The reference value for the output tension of the hydraulic system is: ; In the formula, k This refers to the gear ratio of the gearbox; F ref This is the pressure setting value of the pressure regulating valve; Step S3: Set the throttle valve opening setting value; Hydraulic cylinder internal pressure p for: ; In the formula, A This refers to the effective working area of ​​the piston in a double-acting hydraulic cylinder, specifically the high-pressure cylinder. Liquid flow rate through the throttle valve Q It can be represented as: ; The reference value for the throttle valve opening is: ; In the formula, Cd The flow coefficient for the circular hole is... D This represents the maximum flow area of ​​the throttle valve. r The density of the hydraulic oil; Step S4: Adjust the throttle valve and pressure valve according to the set values; Set the pressure regulating valve to the specified value. F ref The throttle valve opening is adjusted to x ref This allows for the establishment of a reference value for the current output power. P ref A precise response.

[0013] The beneficial effects of this invention are as follows: This invention uses an auxiliary hydraulic system and a generator motor to jointly drive the mass block. By adjusting the tension of the steel cable on the mass block through the hydraulic system, the stress on the mass block during operation is changed, thereby changing the mechanical torque input to the generator motor and controlling the output power of the generator motor to achieve the purpose of smoothing the system output power. Furthermore, a corresponding precise charging and discharging power response method is used to achieve the purpose of precise charging and discharging power response. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the matrix-type gravity energy storage system in this invention; Figure 2 The flowchart of the system's working mode; Figure 3 Flowchart of a method for accurate charge and discharge power response. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Example 1

[0016] like Figure 1 As shown, in this embodiment, the matrix-type gravity energy storage system is divided into four parts: a generator motor, a mechanical transmission system, a hydraulic system, and a mass block.

[0017] The generator motor is connected to the electromagnetic clutch 1 via a gearbox 1. The electromagnetic clutch 1 controls the gearbox shaft to connect with the main shaft carrying the mass block. The mass block and the main shaft are connected by a steel cable. The mass block is fixed to the steel cable by a lifting device, which is responsible for fixing and separating the mass block from the steel cable during loading and unloading.

[0018] The hydraulic system can be divided into two symmetrical subsystems. The upper subsystem provides upward pulling force, and the lower subsystem provides downward pulling force. The upper and lower subsystems are connected to the mass block by a circulating steel cable. Electromagnetic clutch 2 is used to control the connection between the upper subsystem and a main shaft, and electromagnetic clutch 3 is used to control the connection between the lower subsystem and a main shaft. The circulating steel cable is connected to the upper and lower main shafts.

[0019] The two double-acting hydraulic cylinders are double-acting hydraulic cylinder 1 and double-acting hydraulic cylinder 2. The hydraulic transmission system includes a hydraulic clutch, a gearbox and an electromagnetic clutch. The output end of the double-acting hydraulic cylinder 1 is connected to the hydraulic clutch 1, the hydraulic clutch 1 is connected to the gearbox 2, the gearbox 2 is connected to the electromagnetic clutch 2, and the electromagnetic clutch 2 is connected to the mass block through a circulating steel cable. Similarly, the output end of the double-acting hydraulic cylinder 2 is connected to the hydraulic clutch 2, the hydraulic clutch 2 is connected to the gearbox 3, the gearbox 3 is connected to the electromagnetic clutch 3, and the electromagnetic clutch 3 is connected to the mass block through a circulating steel cable.

[0020] The upper subsystem uses gearbox 2 for speed change, and hydraulic clutch 1 is used to control the connection between gearbox 2 and double-acting hydraulic cylinder 1. The left cylinder of double-acting hydraulic cylinder 1 is usually in a high oil pressure state during operation, and is a high-pressure cylinder; the right cylinder is usually in a low oil pressure state during operation, and is a low-pressure cylinder. The oil tank is connected to the high-pressure and low-pressure cylinders of the double-acting hydraulic cylinder 1 via high-pressure and low-pressure oil lines respectively. A pump, pressure regulating valve 1, and a flow divider are sequentially installed on the high-pressure oil line. Another flow divider is installed on the low-pressure oil line. The two flow dividers are connected by a throttle valve 1. The accumulator is connected to the high-pressure oil line via a branch oil line; this branch oil line is equipped with valve 5. Valve 1 is installed on the oil line between the flow divider and the high-pressure cylinder on the high-pressure oil line, and valve 3 is installed between the pressure regulating valve 1 and the flow divider. Valve 4 is installed between the oil tank and the flow divider in the low-pressure oil line, and valve 2 is installed on the oil line between the flow divider and the low-pressure cylinder. Valve 8 is installed on the oil line between the flow divider corresponding to the double-acting hydraulic cylinder 2 and the high-pressure cylinder. Valve 6 is installed between the pressure regulating valve 2 and the flow divider in the high-pressure oil line, valve 7 is installed between the oil tank and the flow divider in the low-pressure oil line, and valve 9 is installed on the oil line between the flow divider and the low-pressure cylinder.

[0021] Valves 1 and 2 are used to open and close the cylinder body and oil circuit of the double-acting hydraulic cylinder 1. Throttle valve 1 connects the oil circuits on both sides of the double-acting hydraulic cylinder 1. By controlling throttle valve 1, the flow rate passing through throttle valve 1 per unit time can be controlled, thereby adjusting the piston movement speed of the double-acting hydraulic cylinder 1. Valves 3 and pressure regulating valve 1 work together to regulate the high-pressure cylinder pressure of the double-acting hydraulic cylinder 1. Valves 4 are responsible for opening and closing the oil tank and oil circuit. The oil tank is responsible for storing and releasing hydraulic oil to maintain the balance of the hydraulic oil in the system. The pump is responsible for pumping the hydraulic oil in the tank to the oil circuit when the system needs to replenish hydraulic oil, ensuring the stability of the hydraulic system's oil pressure. Valves 5 are responsible for opening and closing the accumulator and oil circuit. The accumulator can convert the energy in the system into compressible energy or potential energy for storage. When the system needs it, it converts the compressible energy or potential energy into hydraulic or pneumatic energy and releases it to replenish the system. The following subsystems are similar and will not be described in detail here.

[0022] Based on the direction of energy flow between the generator motor and the energy storage device, the system in this embodiment has four operating modes: 1) System discharge, energy storage device charging; 2) System discharge, energy storage device discharging; 3) System charging, energy storage device charging; 4) System charging, energy storage device discharging; respectively: Mode 1: System discharges, accumulator charges. Electromagnetic clutches 1 and 2 are engaged, 3 is disengaged. Valves 4, 6, and 7 are closed, valves 1, 2, 3, and 5 are open.

[0023] Mode 2: System discharge, accumulator releases energy. Electromagnetic clutches 1 and 3 are engaged, 2 is disengaged. Valves 3, 4, and 7 are closed, valves 5, 6, 8, and 9 are open.

[0024] Mode 3: System charging, accumulator charging. Electromagnetic clutches 1 and 3 are engaged, 2 is disengaged. Valves 3, 4, and 7 are closed, valves 5, 6, 8, and 9 are open.

[0025] Mode 4: System charging, accumulator releasing energy. Electromagnetic clutches 1 and 2 are engaged, 3 is disengaged. Valves 4, 6, and 7 are closed, valves 1, 2, 3, and 5 are open.

[0026] The accurate charge / discharge power response method in this embodiment, such as Figure 3 The steps shown are as follows: Step 1: Determine the system operating mode and the number of mounted mass blocks; Let the reference value of the system output power be... P ref The overall efficiency of the generator motor and mechanical transmission system is or Then the power input to the mechanical transmission system P 1 is: ; To ensure normal system operation and maintain a certain safety margin, the actual capacity of the accumulator must be at least greater than the gravitational potential energy stored in the two mass blocks, i.e. ; In the formula, W max This is the maximum capacity of the energy storage device. m For the mass of the mass block, g It is the acceleration due to gravity. h The height of the mass block; Since the number of mass blocks must be an integer, and the energy of the accumulator has upper and lower limits, the actual number of mass blocks to be mounted needs to be determined based on the accumulator's specifications. This is based on the relationship between mass blocks and power: ; n Round down; Assume the actual number of mass blocks to be mounted by the system is... n ref ， Combination Figure 2 The flowchart shown; when At that time, let the energy that the accumulator can currently release be... W 1 1) If Then determine the number of mounted mass blocks. The system is operating in mode 2; 2) If Then determine the number of mounted mass blocks. The system is operating in mode 1.

[0027] when Let the energy that the energy storage device can currently store be... W 2 1) If Then determine the number of mounted mass blocks. The system is operating in mode 4; 2) If Then determine the number of mounted mass blocks. The system is operating in mode 3.

[0028] Step 2: Set the pressure setting value of the pressure regulating valve; The power provided by the mass block is: ; In the formula, n The number of mass blocks to be mounted. v ref The rated operating speed for the mass block.

[0029] The hydraulic system should provide the following power: ; The reference value for the output tension of the hydraulic system is: ; In the formula, k This refers to the gear ratios of gearboxes 2 and 3; F ref This is the pressure setting value of the pressure regulating valve.

[0030] Step 3: Set the throttle valve opening setting value; Hydraulic cylinder internal pressure p for: ; In the formula, A This refers to the effective working area of ​​the piston in a double-acting hydraulic cylinder, specifically the high-pressure cylinder.

[0031] Liquid flow rate through the throttle valve Q It can be represented as: ; The reference value for the throttle valve opening can be obtained through calculation: ; In the formula, C d The flow coefficient for the circular hole is... D This represents the maximum flow area of ​​the throttle valve. r This refers to the density of the hydraulic oil.

[0032] Step 4: Adjust the throttle valve and pressure valve according to the set values; Set the pressure regulating valve to the specified value. F ref The throttle valve opening is adjusted to x ref This allows for the establishment of a reference value for the current output power. P ref A precise response.

[0033] Example 2 In this embodiment, the generator motor has a rated power of 6.5MW and can support a maximum of 12 mass blocks. The average lifting speed of the mass blocks is set as follows: v ref =2m / s, mass weight m=27.64t, work done height h=108m, time t Take 54 seconds. Efficiency of the steel cable and drive shaft section. or 1 = 0.98, the efficiency of the gearbox or 2 = 0.96, the efficiency of a double-acting hydraulic cylinder or 3 = 0.9, the efficiency of the pressure regulating valve or 4 = 0.95. The gear ratios of gearboxes 2 and 3. k=20. The acceleration due to gravity, g, is taken as 9.8 m / s². 2 Energy storage capacity W max Take 25 kWh (approximately 3 mgh). Throttling valve orifice flow coefficient. C d Take 0.62 as the effective working area of ​​the piston in a double-acting hydraulic cylinder. A Take 314.16m 2 (Radius 10m), Maximum flow channel area of ​​the throttle valve D Take 0.314m 2 Hydraulic oil density r Take 0.8 g / cm³.

[0034] The hydraulic pressure of the high-pressure cylinder in this example p Calculate using the formula, according to the formula Substituting the above data, we can calculate... p =16844.96N / m 2 Let the reference value of the system output power at this time be... P ref =3.75MW, the energy that the accumulator can currently release. W 1 = 15 kWh. The system operates in mode 2, with electromagnetic clutches 1 and 3 engaged, clutch 2 disengaged, valves 3, 4, and 7 closed, and valves 5, 6, 8, and 9 open. The generator motor carries 8 mass blocks, and the hydraulic system requires a compensation power of 98.672 kW. Based on the compensation power value, the calculated pressure setting value of the pressure regulating valve is approximately 986.72 kN, and the throttle valve opening is 58.14%. Adjusting the throttle valve and pressure valve according to the set values, the accumulator releases energy to push the double-acting hydraulic cylinder 2 to apply a downward pulling force to the mass blocks, thus achieving power regulation.

[0035] The technical solutions of the present invention are not limited to the above embodiments. All technical solutions obtained by equivalent substitution fall within the scope of protection claimed by the present invention.

Claims

1. A matrix-type gravity energy storage system, comprising a generator motor, a transmission system, and a mass block, wherein the generator motor is connected to the mass block via the transmission system; characterized in that: The matrix-type gravity energy storage system also includes a hydraulic system, which comprises an accumulator, an oil tank, a pump, and two symmetrically arranged subsystems; the subsystems include a double-acting hydraulic cylinder, a flow divider, a throttle valve, and a pressure regulator; The double-acting hydraulic cylinder is configured as a high-pressure cylinder and a low-pressure cylinder. The oil tank is connected to the high-pressure cylinder and the low-pressure cylinder of the double-acting hydraulic cylinder through high-pressure oil circuit and low-pressure oil circuit respectively. A pump, a pressure regulating valve and a flow divider are sequentially provided on the high-pressure oil circuit. Another flow divider is provided on the low-pressure oil circuit. The two flow dividers are connected by a throttle valve. The accumulator is connected to the high-pressure oil circuit through a branch oil circuit. The two subsystems' double-acting hydraulic cylinders are each connected to a hydraulic transmission system, and the two hydraulic transmission systems are connected to the mass block via a circulating steel cable.

2. The matrix-type gravity energy storage system according to claim 1, characterized in that: The transmission system includes a first gearbox and a first electromagnetic clutch. The generator motor is connected to the first gearbox, the first gearbox is connected to the first electromagnetic clutch, and the first electromagnetic clutch is connected to the mass block via a steel cable.

3. The matrix-type gravity energy storage system according to claim 2, characterized in that: The two double-acting hydraulic cylinders are a first double-acting hydraulic cylinder and a second double-acting hydraulic cylinder. The hydraulic transmission system connected to the first double-acting hydraulic cylinder includes a first hydraulic clutch, a second gearbox, and a second electromagnetic clutch. The output end of the first double-acting hydraulic cylinder is connected to the first hydraulic clutch. The first hydraulic clutch is connected to the second gearbox. The second gearbox is connected to the second electromagnetic clutch. The second electromagnetic clutch is connected to the mass block through a circulating steel cable. The hydraulic transmission system connected to the second double-acting hydraulic cylinder includes a second hydraulic clutch, a third gearbox, and a third electromagnetic clutch; the output end of the second double-acting hydraulic cylinder is connected to the second hydraulic clutch, the second hydraulic clutch is connected to the third gearbox, the third gearbox is connected to the third electromagnetic clutch, and the third electromagnetic clutch is connected to the mass block through a circulating steel cable.

4. The matrix-type gravity energy storage system according to claim 3, characterized in that: The accumulator is connected between the pump and the pressure regulating valve in the high-pressure oil circuit via a branch oil circuit, and a fifth valve is provided on the branch oil circuit.

5. The matrix-type gravity energy storage system according to claim 4, characterized in that: A first valve is provided on the oil line between the distributor and the high-pressure cylinder corresponding to the first double-acting hydraulic cylinder; a third valve is provided between the first pressure regulating valve of the high-pressure oil line and the distributor; a fourth valve is provided between the oil tank and the distributor of the low-pressure oil line; and a second valve is provided on the oil line between the distributor and the low-pressure cylinder. An eighth valve is provided on the oil line between the distributor and the high-pressure cylinder corresponding to the second double-acting hydraulic cylinder. A sixth valve is provided between the second pressure regulating valve of the high-pressure oil line and the distributor. A seventh valve is provided between the oil tank and the distributor of the low-pressure oil line. A ninth valve is provided on the oil line between the distributor and the low-pressure cylinder.

6. The matrix-type gravity energy storage system according to claim 5, characterized in that: The matrix-type gravity energy storage system has four operating modes: Mode 1 is system discharge and energy storage device charging; Mode 2 is system discharge and energy storage device releasing energy; Mode 3 is system charging and energy storage device charging; and Mode 4 is system charging and energy storage device releasing energy. In the four working modes, mode 1 is that the first and second electromagnetic clutches are closed, the third electromagnetic clutch is open, the fourth, sixth and seventh valves are closed, and the first, second, third and fifth valves are open. In mode 2, the first and third electromagnetic clutches are engaged, while the second electromagnetic clutch is disengaged; The third, fourth, and seventh valves are closed, while the fifth, sixth, eighth, and ninth valves are open. In mode 3, the first and third electromagnetic clutches are engaged, while the second electromagnetic clutch is disengaged; The third, fourth, and seventh valves are closed, while the fifth, sixth, eighth, and ninth valves are open. Mode 4 is characterized by the first and second electromagnetic clutches being engaged, the third electromagnetic clutch being disengaged, the fourth, sixth, and seventh valves being closed, and the first, second, third, and fifth valves being open.

7. A method for charging and discharging power response based on the matrix-type gravity energy storage system of claim 6, characterized in that: Includes the following steps: Step S1: Determine the system operating mode and the number of mounted mass blocks; Let the reference value of the system output power be... P ref The overall efficiency of the generator motor and mechanical transmission system is η The power input to the mechanical transmission system P 1 is: ； The capacity of the energy storage device is set to be greater than the gravitational potential energy stored in the two mass blocks, that is: ； In the formula, W max This is the maximum capacity of the energy storage device. m The mass of the mass block. g It is the acceleration due to gravity. h The height of the mass block; Based on the relationship between mass blocks and power, the number of mass blocks is: ； In the formula, v ref The rated operating speed for the mass block, n Round down; Let the actual number of mass blocks to be mounted by the system be... n ref ; when At that time, let the energy that the accumulator can currently release be... W 1, 1) If Then determine the number of mounted mass blocks. The system is operating in mode 2; 2) If Then determine the number of mounted mass blocks. The system operates in mode 1; when At that time, let the energy that the energy storage device can currently store be... W 2, 1) If Then determine the number of mounted mass blocks. The system is operating in mode 4; 2) If Then determine the number of mounted mass blocks. The system is operating in mode 3; Step S2: Set the pressure setting value of the pressure regulating valve; The power provided by the mass block is: ； In the formula, n The number of mass blocks to be mounted. v ref The rated operating speed for the mass block; The hydraulic system should provide the following power: ； The reference value for the output tension of the hydraulic system is: ； In the formula, k This refers to the gear ratio of the gearbox; F ref This is the pressure setting value of the pressure regulating valve; Step S3: Set the throttle valve opening setting value; Hydraulic cylinder internal pressure p for: ； In the formula, A This refers to the effective working area of ​​the piston in a double-acting hydraulic high-pressure cylinder. Liquid flow rate through the throttle valve Q Represented as: ； The reference value for the throttle valve opening is: ； In the formula, C d The flow coefficient for the circular hole is... D This represents the maximum flow area of ​​the throttle valve. ρ The density of the hydraulic oil; Step S4: Adjust the throttle valve and pressure valve according to the set values; Set the pressure regulating valve to the specified value. F ref The throttle valve opening is adjusted to x ref This allows for the establishment of a reference value for the current output power. P ref A precise response.

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