A control method for a vertical gravity energy storage system based on a doubly-fed motor

Abstract

A control method for a vertical gravity energy storage system based on a doubly-fed motor, the control method comprising: analyzing the physical characteristics and mathematical analytical model of the heavy object block during the rising and falling process of the gravity energy storage system, and establishing a function of the speed set value of the heavy object block; calculating the speed set value of the doubly-fed motor according to the structure of the gravity energy storage system and the speed set value of the heavy object block; outputting a reference voltage on the rotor side to the doubly-fed motor according to the given speed and given reactive power of the doubly-fed motor, wherein the reference voltage is used to adjust the speed and reactive power of the doubly-fed motor. The present invention uses a control algorithm to realize the control of the movement speed and power generation power of the heavy object block, and improves the operation stability of the doubly-fed motor of the gravity energy storage system during frequent switching of various working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of gravity energy storage, and specifically to a control method for a vertical gravity energy storage system based on a doubly-fed motor. Background Art

[0002] Traditional pumped-storage energy storage, as the most widely used large-scale energy storage technology in the current power system, is restricted by the geographical conditions of water resources for large-scale development, and it is difficult to meet the diverse application scenario requirements of the new power system in terms of power response time and efficiency. The gravity energy storage technology based on solid weights, with advantages such as not relying on water resources, flexible siting, and high efficiency, is expected to become one of the important energy storage technologies in water-scarce areas in the future and can well meet the requirements of renewable energy power grid connection for energy storage technology.

[0003] Gravity energy storage is mainly divided into two categories: one is the ramp-type gravity energy storage system, including mountain track vehicle energy storage, mountain gravity energy storage, etc.; the other is the vertical gravity energy storage system, including energy storage tower type, vertical matrix type, underground shaft energy storage, piston water pump energy storage, etc. The ramp-type gravity energy storage system is suitable for energy storage in mountainous areas, with high siting requirements and unsatisfactory conversion efficiency and comprehensive benefits. The energy storage tower type and vertical matrix type in the vertical gravity energy storage system have no geographical restrictions and strong feasibility for large-scale promotion. Although the key technologies such as the technical vertical improvement, horizontal transfer, and automatic connection of the vertical gravity energy storage system, as well as the key technologies of core electromechanical equipment such as the generator motor and grid connection control, have been elaborated and discussed; there are still many technical problems to be solved in aspects such as heavy-load rapid lifting and transfer, control of the start-stop and switching process of heavy objects, grid connection control, and energy efficiency improvement. In particular, the problem of low energy conversion efficiency of the gravity energy storage system when the motor starts and stops frequently and switches frequently between the electric / generation states.

[0004] The technical differences between the present application and the prior art are as follows;

[0005] Technical comparison with the patent CN119010116A "An operation method for a modular gravity energy storage system with economy";

[0006] The patent CN119010116A controls the stator voltage, stator current, excitation current, etc., reduces various losses during the operation of the gravity energy storage system, and realizes the economic operation of the gravity energy storage system. The present invention controls the movement speed of the heavy object block by using a seven-segment s speed curve, establishes the movement curve function of the heavy object block during the movement process, reduces the impact of the acceleration and deceleration of the heavy object block on the gravity energy storage system, and improves the operation stability of the gravity energy storage system.

[0007] Technical comparison with the patent CN116505666A "A direct-drive gravity energy storage system and its optimization method";

[0008] Patent CN116505666A is a direct-drive gravity energy storage system, and the control object of the motor controller is the d-axis current on the stator side of the motor i s_d and the q-axis current on the stator side i s_q However, the present invention is a control method for a gravity energy storage system with a gear drive, and a motion curve function of the heavy object block during the motion process is established. The control object of the motor controller is the d-axis current on the rotor side of the motor i rd and the q-axis current on the rotor side i rq , improving the operation stability of the gravity energy storage system

[0009] Technical comparison with patent CN115653855A "A method for improving the efficiency of a gravity energy storage power generation system";

[0010] Patent CN115653855A analyzes the energy conservation equation during the motion of the heavy object block in the gravity energy storage system, and improves the operation efficiency of the gravity energy storage system by adding a cable channel connecting the falling heavy object and the heavy object to be lifted in the system. However, the present invention controls the motion speed of the heavy object block by using a seven-segment s speed curve, establishes a motion curve function of the heavy object block during the motion process, reduces the impact of the acceleration and deceleration of the heavy object block on the gravity energy storage system, and improves the operation stability of the gravity energy storage system

[0011] Technical comparison with patent CN118619055A "A vertical gravity energy storage system based on a doubly-fed motor";

[0012] Patent CN118619055A designs a vertical gravity energy storage system based on a doubly-fed motor, describes the spatial layout structure of each component of the gravity energy storage system, and analyzes the operation process of the gravity energy storage system. However, the present invention focuses on analyzing the operation states of the heavy object block under different working conditions, establishes a motion curve function of the heavy object block during the motion process, thereby reducing the impact of the acceleration and deceleration of the heavy object block on the gravity energy storage system, and improving the operation stability of the gravity energy storage system

[0013] Technical comparison with patent CN117895541A "A gravity energy storage power smoothing control method considering energy storage capacity limitations";

[0014] Patent CN117895541A analogizes the basic mathematical model of the gravity energy storage body to the state of charge of battery energy storage, establishes a mathematical model for measuring the equivalent state of charge of the energy storage body, and further studies the control strategy of the body considering capacity limitations; a first-order inertia link is added to the input torque of the synchronous machine, smoothing the input / output power of the synchronous machine and suppressing the frequency oscillation problem caused by torque jump. In contrast, the present invention analyzes the operating states of the heavy object block under different working conditions, establishes the motion curve function of the heavy object block during the motion process, thereby reducing the impact of the acceleration and deceleration of the heavy object block on the gravity energy storage system, realizing the control of the rotational speed and reactive power of the doubly-fed motor, and improving the operating stability of the gravity energy storage system.

[0015] The present invention proposes a control method for a vertical gravity energy storage system based on a doubly-fed motor. Based on the technical principle of gravity energy storage, this method establishes a mathematical model for the ascending and descending processes of the heavy object block, uses modeling and simulation software to simulate the motion process of the heavy object block, and applies a control algorithm to achieve the control of the motion speed and power generation of the heavy object block, improving the operating stability of the doubly-fed motor of the gravity energy storage system during frequent switching of various working conditions. Summary of the Invention

[0016] Aiming at the problem of poor system stability during frequent start-stop and frequent switching between motor / generator states of the doubly-fed motor in the existing gravity energy storage system, the present invention proposes a control method for a vertical gravity energy storage system based on a doubly-fed motor to improve the operating stability of the gravity energy storage system under various working conditions.

[0017] To achieve the above object, the technical solution adopted by the present invention is:

[0018] A control method for a vertical gravity energy storage system based on a doubly-fed motor, comprising the following steps:

[0019] S1 Analyze the physical characteristics and mathematical analysis model of the ascending and descending processes of the heavy object block in the gravity energy storage system, and establish a function for the given value of the heavy object block speed;

[0020] S2 Calculate the given value of the doubly-fed motor speed according to the structure of the gravity energy storage system and the given value of the heavy object block speed;

[0021] S3 Output the reference voltage on the rotor side to the doubly-fed motor according to the given speed and given reactive power of the doubly-fed motor, wherein the reference voltage is used to adjust the speed and reactive power of the doubly-fed motor.

[0022] As a further improvement of the present invention, the control method for a vertical gravity energy storage system based on a doubly-fed motor is characterized in that: in the step S1 of establishing the function for the given value of the heavy object block speed, the specific process is as follows:

[0023] The motion speed of the heavy object block is controlled by using a seven-segment s speed curve, and the physical quantities involved include a constant jerkJ , Constant reverse jerk - J、 Maximum acceleration a max , Maximum reverse acceleration - a max , Maximum speed v max , Number of times of recording the position information of the heavy object per second d , Total distance of the heavy object movement h , Movement time of the heavy object t , Speed of the heavy object v ;

[0024] The first stage: At , move with a constant jerk J , and the speed v of the heavy object is expressed as:

[0025] ;

[0026] Among them, the time of the first stage;

[0027] The second stage: At , move with the maximum acceleration a max , and the speed v of the heavy object is expressed as;

[0028] ;

[0029] Among them, the speed at the time of the first stage, and the time of the second stage;

[0030] The third stage: At , move with a constant reverse jerk - J , and the speed v of the heavy object is expressed as:

[0031] ;

[0032] Among them, the speed at the time of the second stage, and the time of the third stage;

[0033] The fourth stage: At , move at the maximum speed v max , where h is the total distance of the heavy object movement, and the speed v of the heavy object is expressed as:

[0034] ;

[0035] Among them, the speed at the third stage of time , the fourth stage of time ;

[0036] Stage 5: At time, with a constant reverse jerk - J movement, the velocity of the heavy block v The expression is:

[0037] ;

[0038] Among them, the speed at the fourth stage of time , the fifth stage of time ;

[0039] ;

[0040] Stage 6: At time, with the maximum reverse acceleration - a max movement, the velocity of the heavy block v The expression is:

[0041] ;

[0042] Among them, the speed at the fifth stage of time , the sixth stage of time ;

[0043] Stage 7: At time, with a constant jerk J movement, the velocity of the heavy block v The expression is:

[0044] ;

[0045] Among them, the speed at the sixth stage of time , the seventh stage of time .

[0046] As a further improvement of the present invention, the calculated speed set value of the doubly-fed motor in step S2 includes:

[0047] According to the speed set value of the heavy block and the radius of the transmission shaft r , the angular velocity of the transmission shaft is obtained. From the transmission ratio of the gearbox k , the mechanical angular velocity of the motor is obtained, and finally the speed set value of the motor is obtained. The expression is as follows:

[0048] ;

[0049] Among them, the gearbox transmission ratio .

[0050] As a further improvement of the present invention, step S3 outputs a reference voltage on the rotor side to the doubly-fed motor according to the given speed and given reactive power of the doubly-fed motor, including the following steps:

[0051] Step 1, calculate the given value of the reactive power of the doubly-fed motor and the given value of the motor speed ;

[0052] Step 2, obtain the three-phase grid voltage u sabc 、current i sabc connected to the stator of the doubly-fed motor, the three-phase rotor current i rabc connected to the converter, and the mechanical angular velocity of the motor. Obtain the stator voltage angular velocity through the phase-locked loop PLL, and then integrate to obtain the stator flux angle . Multiply the mechanical angular velocity of the motor by the number of pole pairs n p to obtain the rotor electrical angular velocity , and then integrate to obtain the rotor flux angle . Multiply the mechanical angular velocity of the motor by the coefficient to obtain the motor speed n ; The three-phase grid voltage u sabc 、current i sabc are subjected to coordinate transformation to obtain the stator voltage u sdq 、current i sdq in the dq coordinate system. Among them, the stator voltage u sdq includes the d-axis component u sd 、q-axis component u sq . The stator current i sdq includes the d-axis component i sd 、q-axis component i sq . According to the power calculation formula, calculate the stator active power P s 、stator reactive power Q s ; The three-phase rotor current of the doubly-fed motori rabc The actual value of the rotor current in the dq coordinate system is obtained through coordinate transformation i rdq , where the actual value of the rotor current i rdq includes the d-axis component i rd and the q-axis component i rq ;

[0053] Step 3: Take the difference between the reactive power reference value , the motor speed reference value of the doubly-fed motor, the stator reactive power Q s , and the motor speed n , input them into a PI regulator, and output the reference value of the rotor current in the dq coordinate system ;

[0054] Step 4: Take the difference between the output reference value of the rotor current in the dq coordinate system and the actual value of the rotor current in the dq coordinate system i rdq , perform an operation on the result obtained by inputting them into a PI regulator and the coupling quantity , and output the reference value of the rotor voltage ;

[0055] Step 5: The reference value of the rotor voltage is obtained through coordinate transformation to get the reference value of the rotor voltage in the coordinate system, input it into the space vector pulse width modulation SVPWM module, and output the three-phase PWM wave for driving the converter, where the bus voltage u dc of the converter is a constant

[0056] As a further improvement of the present invention, in the said step 1, it is stipulated that when the heavy object of the gravity energy storage system based on the doubly-fed motor rises, the motor speed is positive, and when the heavy object descends, the motor speed is negative, and the reactive power reference value and the motor speed reference value of the doubly-fed motor are calculated, where when the heavy object rises, the motor speed reference value ; when the heavy object descends, the motor speed reference value

[0057] As a further improvement of the present invention, in the said step 4, through the actual value of the rotor current in the dq coordinate system i rdq , the stator voltage angular velocity , the rotor electrical angular velocity , the stator voltage amplitude​ , calculate the coupling amount , where the coefficient matrix A and the compensation term B are respectively

[0058] ;

[0059] Among them, the leakage inductance , the slip speed , L r is the rotor self-inductance, L s is the stator self-inductance, L m is the maximum mutual inductance linking the stator and rotor windings in the two-phase rotating coordinate system.

[0060] The advantages of the present invention are as follows:

[0061] The present invention analyzes the motion process of the heavy object block and establishes the relationship between the motion speed of the heavy object block and the motor speed; adopts a seven-segment s speed curve control method to reduce the impact of speed mutation on the gravity energy storage system and enhance the stability of the system; the gravity energy storage system adopts a double closed-loop control of speed current and reactive power to achieve precise control of the speed and reactive power of the doubly-fed motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is the implementation flowchart of the control method of the vertical gravity energy storage system based on the doubly-fed motor of the present invention;

[0063] Figure 2 is the motion curve diagram of the heavy object block of the present invention;

[0064] Figure 3 is the schematic connection diagram of each component of the vertical gravity energy storage system based on the doubly-fed motor of the present invention;

[0065] Figure 4 is the structural block diagram of the control method of the vertical gravity energy storage system based on the doubly-fed motor of the present invention;

[0066] Figure 5 is the schematic diagram of the calculation process of the given reactive power and speed of the doubly-fed motor of the gravity energy storage system of the present invention;

[0067] Figure 6 is the schematic diagram of the calculation process of the active power and reactive power of the doubly-fed motor of the gravity energy storage system of the present invention;

[0068] Figure 7 is the schematic diagram of the calculation process of the rotor dq voltage coupling amount of the doubly-fed motor of the gravity energy storage system of the present invention;

[0069] Figure 8Simulation waveform diagram of the motor speed of the vertical gravity energy storage system based on a doubly-fed motor in the energy storage mode of the present invention;

[0070] Figure 9 Simulation waveform diagram of the reactive power of the vertical gravity energy storage system based on a doubly-fed motor in the energy storage mode of the present invention;

[0071] Figure 10 Simulation waveform diagram of the motor speed of the vertical gravity energy storage system based on a doubly-fed motor in the energy release mode of the present invention;

[0072] Figure 11 Simulation waveform diagram of the reactive power of the vertical gravity energy storage system based on a doubly-fed motor in the energy release mode of the present invention. Specific embodiments

[0073] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0074] Flowchart of the control method for the vertical gravity energy storage system based on a doubly-fed motor, as Figure 1 shown. The method includes: analyzing the physical characteristics and mathematical analysis models of the heavy object block rising and falling processes in the gravity energy storage system, and establishing a given value function for the speed of the heavy object block; calculating the given value of the doubly-fed motor speed according to the structure of the gravity energy storage system and the given value of the heavy object block speed; and outputting the reference voltage on the rotor side to the doubly-fed motor according to the given speed and given reactive power of the doubly-fed motor, where the reference voltage is used to adjust the speed and reactive power of the doubly-fed motor.

[0075] Optionally, the analyzing the physical characteristics and mathematical analysis models of the heavy object block rising and falling processes in the gravity energy storage system, and establishing a given value function for the speed of the heavy object block includes:

[0076] During the operation of the gravity energy storage system, in order to reduce the impact of the acceleration and deceleration of the heavy object block on the gravity energy storage system, a seven-segment s speed curve is used to control the movement speed of the heavy object block. The physical quantities involved include a constant jerk J with a magnitude of 4, a maximum acceleration a max with a magnitude of 2, a maximum speed v max with a magnitude of 4, the number of times of recording the position information of the heavy object block per second d with a magnitude of 1000, and the total movement distance h of the heavy object block is 68; the movement state of the heavy object block is obtained, as shown in Table 1; the movement curve diagram of the heavy object block is as Figure 2 shown.

[0077] Table 1 Movement state of the heavy object block

[0078]

[0079] Optionally, according to the structure of the gravity energy storage system and the given value of the heavy object block speed, the given value of the doubly-fed motor speed is calculated, including:

[0080] Based on the schematic diagram of the connection of each component of the vertical gravity energy storage system of the doubly-fed motor, as Figure 3 shown, according to the given value of the heavy object block speed and the radius of the transmission shaft r , the angular velocity of the transmission shaft is obtained. From the transmission ratio k of the gearbox, the mechanical angular velocity of the motor is obtained, and finally the given value of the motor speed is obtained. The expression is as follows:

[0081] ;

[0082] Among them, the transmission ratio of the gearbox .

[0083] Optionally, based on the structural block diagram of the control method of the vertical gravity energy storage system of the doubly-fed motor, as Figure 4 shown, according to the given speed and given reactive power of the doubly-fed motor, the reference voltage on the rotor side is output to the said doubly-fed motor, including the following steps:

[0084] Step 1, calculate the given value of the reactive power of the doubly-fed motor and the given value of the motor speed ;

[0085] Step 2, obtain the three-phase grid voltage u sabc connected to the stator of the doubly-fed motor, the current i sabc , the three-phase rotor current i rabc connected to the rotor of the doubly-fed motor through the converter, and the mechanical angular velocity of the motor. The angular velocity of the stator voltage is obtained through the phase-locked loop PLL and then integrated to obtain the stator flux angle . The mechanical angular velocity of the motor is multiplied by the number of pole pairs n p to obtain the electrical angular velocity of the rotor, and then integrated to obtain the rotor flux angle . The mechanical angular velocity of the motor is multiplied by the coefficient to obtain the motor speed n ; The three-phase grid voltage u sabc, current i sabc After coordinate transformation, the stator voltage in the dq coordinate system is obtained u sdq , current i sdq , where the stator voltage u sdq includes the d-axis component u sd , q-axis component u sq , and the stator current i sdq includes the d-axis component i sd , q-axis component i sq , schematic diagram of the active power calculation and reactive power calculation process of the doubly-fed motor in the gravity energy storage system, as Figure 6 shown, according to the power calculation formula, the stator active power P s , stator reactive power Q s are calculated; the three-phase rotor current of the doubly-fed motor i rabc is transformed through coordinates to obtain the actual value of the rotor current in the dq coordinate system i rdq , where the actual value of the rotor current i rdq includes the d-axis component i rd , q-axis component i rq ;

[0086] Step 3, take the difference between the reactive power set value , motor speed set value of the doubly-fed motor and the stator reactive power Q s , motor speed n , input them into the PI regulator, and output the rotor current set value in the dq coordinate system;

[0087] Step 4, take the difference between the output rotor current set value in the dq coordinate system and the actual value of the rotor current i rdq in the dq coordinate system, perform an operation on the result obtained by inputting it into the PI regulator and the coupling quantity , and output the rotor voltage set value ;

[0088] Step 5, transform the rotor voltage set value through coordinates to obtain Rotor voltage reference value in the coordinate system , input the space vector pulse width modulation SVPWM module, and output the three-phase PWM wave for driving the converter. Among them, the bus voltage of the converter u dc = 1200V.

[0089] In the above step 1, the schematic diagram of the calculation process of the given reactive power and speed of the doubly-fed motor in the gravity energy storage system is as shown in Figure 5 . It is stipulated that the motor speed is positive when the heavy object of the gravity energy storage system based on the doubly-fed motor rises, and the motor speed is negative when the heavy object descends. The given value of the reactive power of the doubly-fed motor and the given value of the motor speed are calculated. Among them, when the heavy object rises, the given value of the motor speed ; when the heavy object descends, the given value of the motor speed .

[0090] In the above step 4, through the actual value of the rotor current i rdq in the dq coordinate system, the angular velocity of the stator voltage , the angular velocity of the rotor electrical , the amplitude of the stator voltage , calculate the coupling quantity , where the coefficient matrix A and the compensation term B are respectively:

[0091] ;

[0092] Among them, the leakage inductance , the slip speed , L r is the rotor self-inductance, L s is the stator self-inductance, L m is the maximum mutual inductance between the stator and rotor windings in the two-phase rotating coordinate system.

[0093] Figure 8 is the simulation waveform diagram of the motor speed of the vertical gravity energy storage system based on the doubly-fed motor working in the energy storage mode, Figure 9 is the simulation waveform diagram of the reactive power of the vertical gravity energy storage system based on the doubly-fed motor working in the energy storage mode; Figure 10 is the simulation waveform diagram of the motor speed of the vertical gravity energy storage system based on the doubly-fed motor working in the energy release mode, Figure 11It is a simulation waveform diagram of the reactive power when the vertical gravity energy storage system based on a doubly-fed motor operates in the energy release mode; the experimental results show that: the control method of the vertical gravity energy storage system based on a doubly-fed motor in this application can achieve precise control of the rotational speed of the doubly-fed motor (the moving speed of the heavy object block) and reactive power when the gravity energy storage system operates in the energy storage and energy release modes.

[0094] The above are only the preferred embodiments of the present invention, and are not any other form of limitation to the present invention. Any modification or equivalent change made according to the technical essence of the present invention still belongs to the scope protected by the present invention.

Claims

1. A control method for a vertical gravity energy storage system based on a doubly-fed motor, characterized in that: The following steps are involved: S1: Analyze the physical characteristics and mathematical analytical model of the rising and falling process of the heavy object in the gravity energy storage system, and establish the given value function of the speed of the heavy object; The step S1 establishes a given value function of the speed of the weight block, and the specific process is as follows: A seven-segment s-speed curve is used to control the speed of the weight, which involves physical quantities including constant acceleration. J , constant reverse jerk - J、 Maximum acceleration a max , Maximum reverse acceleration - a max , Maximum speed v max , the number of times the weight position information is recorded per second d , the total distance the weight moves h , Heavy object movement time t , weight speed v ; The first paragraph: At constant acceleration J Movement, weight speed v The expression is: ； Among them, the first period ; Second paragraph: In At maximum acceleration a max Movement, weight speed v The expression is; ； Among them, the speed of the first period of time , the second period ; The third paragraph: When the reverse acceleration is constant - J Movement, weight speed v The expression is: ； Among them, the speed of the second period , the third period ; The fourth paragraph: At maximum speed v max Sports, including h is the total distance the weight moves, and the speed of the weight v The expression is: ； Among them, the speed of the third period , the fourth period ; Paragraph 5: In When the reverse acceleration is constant - J Movement, weight speed v The expression is: ； Among them, the speed of the fourth period , the fifth period ; ； Paragraph 6: In When the maximum reverse acceleration - a max Movement, weight speed v The expression is: ； Among them, the speed of the fifth period , the sixth period ; Paragraph 7: In At constant acceleration J Movement, weight speed v The expression is: ； Among them, the speed of the sixth period , the seventh period ; In the step S1, it is stipulated that the motor speed of the gravity energy storage system based on the doubly fed motor is positive when the weight block rises, and the motor speed is negative when the weight block falls, and the reactive power given value of the doubly fed motor is calculated. and motor speed given value , where when the weight rises, the motor speed is set to ;When the weight is lowered, the motor speed is set to ,in is the given speed of the weight block; S2: According to the structure of the gravity energy storage system and the given value of the speed of the weight block, the given value of the speed of the doubly-fed generator is calculated; S3: outputting a rotor-side reference voltage to the doubly-fed motor according to a given speed and a given reactive power of the doubly-fed motor, wherein the reference voltage is used to adjust the speed and reactive power of the doubly-fed motor; Step S3 outputs a rotor-side reference voltage to the doubly-fed motor according to a given speed and a given reactive power of the doubly-fed motor, and includes the following steps: Step 1: Calculate the reactive power setting value of the doubly-fed generator and motor speed given value ; Step 2: Obtain the three-phase voltage of the power grid connected to the stator of the doubly-fed generator u sabc , Current i sabc , the three-phase current of the doubly-fed machine rotor connected to the converter i rabc And the motor mechanical angular velocity , obtain the stator voltage angular velocity through the phase-locked loop PLL Then integrate to get the stator flux angle , motor mechanical angular velocity Multiply by the number of pole pairs n p Get the rotor electrical angular velocity Then integrate to get the rotor flux angle , motor mechanical angular velocity Multiply by coefficient Get the motor speed n ; Three-phase voltage of power grid u sabc , Current i sabc After coordinate transformation, the stator voltage in the dq coordinate system is obtained u sdq , Current i sdq , where the stator voltage u sdq Including d-axis component u sd , q-axis component u sq , stator current i sdq Including d-axis component i sd , q-axis component i sq , according to the power calculation formula, the stator active power is calculated P s , stator reactive power Q s ; Doubly-fed machine rotor three-phase current i rabc After coordinate transformation, the actual value of the rotor current in the dq coordinate system is obtained i rdq , where the actual value of the rotor current is i rdq Including d-axis component i rd , q-axis component i rq ; Step 3: Set the reactive power setting value of the doubly-fed generator , Motor speed given value and stator reactive power Q s , Motor speed n Make a difference, input the PI regulator, and output the rotor current given value in the dq coordinate system ; Step 4: Output the rotor current given value in the dq coordinate system The actual value of the rotor current in the dq coordinate system i rdq The result and coupling amount obtained by inputting the PI regulator Perform calculation and output the rotor voltage given value ; In step 4, the actual value of the rotor current in the dq coordinate system is i rdq 、Stator voltage angular velocity , rotor electrical angular velocity , stator voltage amplitude , calculate the coupling , where the coefficient matrix A and compensation term B are: ； Among them, leakage inductance , slip speed , L r is the rotor self-inductance, L s is the stator self-inductance, L m is the maximum mutual inductance of the stator and rotor windings in the two-phase rotating coordinate system; Step 5: Set the rotor voltage to a given value After coordinate transformation, we get Rotor voltage reference value in coordinate system , input space vector pulse width modulation SVPWM module, output three-phase PWM wave driving converter, where the converter bus voltage u dc is a constant.

2. According to claim 1, a control method for a vertical gravity energy storage system based on a doubly-fed motor is characterized in that: Step S2 calculates and obtains the given value of the speed of the doubly-fed generator, including: According to the given value of the speed of the weight block and the drive shaft radius r , get the angular velocity of the transmission shaft , determined by the gearbox ratio k , get the motor mechanical angular velocity , and finally get the motor speed given value , the expression is as follows: ； Among them, the gearbox transmission ratio .

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