A motor heavy-load starting method and system for track-type gravity energy storage

Abstract

The present invention relates to a motor heavy-load starting method and system for rail-type gravity energy storage, and relates to the field of intelligent control technology, including: obtaining the current carrying state of a rail train; combining a flexible electric drive control strategy with the current carrying state of a rail train, monitoring and analyzing the train carrying state in real time, and obtaining the starting torque required by the motor; setting the starting parameters of the motor according to the starting torque required by the motor, the starting parameters include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding, and the angular velocity of the motor; according to the starting parameters of the motor, using a dq rotating coordinate system to transform the voltage equation, magnetic flux equation, and torque equation of the motor to obtain the transformed coordinates. The present invention can perform torque calculation and dynamic adjustment strategies through flexible electric drive control to achieve smooth starting and efficient operation of rail trains under heavy load conditions.

Description

Technical Field

[0001] The invention relates to the field of intelligent control technology, and in particular to a motor heavy-load starting method for track-type gravity energy storage. Background Art

[0002] In rail-based gravity energy storage systems, train starting and operation control is not only a key link, but also an important factor affecting the performance and efficiency of the entire system. However, traditional starting methods often have many limitations and shortcomings.

[0003] First, the traditional starting method relies too much on manual operation and experience judgment. This method is not only difficult to achieve train control and optimized scheduling, but also prone to human errors and judgment bias, leading to instability and safety hazards during train starting and operation.

[0004] Secondly, the train is susceptible to shock and vibration during the starting process. Due to the lack of advanced control strategies and monitoring mechanisms in traditional methods, shock and vibration during the starting process are often difficult to be effectively suppressed, which not only affects the stability of the train, but may also cause damage to the train and track, shortening its service life. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for heavy-load starting of a motor for rail-type gravity energy storage, which can perform torque calculation and dynamic adjustment strategy through flexible electric drive control to achieve smooth starting and efficient operation of rail trains under heavy load conditions.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0007] In a first aspect, a motor heavy-load starting method for rail-type gravity energy storage comprises:

[0008] Get the current transportation status of the rail train;

[0009] Combine the flexible electric drive control strategy with the current transportation status of the rail train, monitor and analyze the train transportation status in real time, and obtain the starting torque required by the motor;

[0010] According to the starting torque required by the motor, set the starting parameters of the motor, which include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor;

[0011] According to the starting parameters of the motor, the dq rotating coordinate system is used to transform the voltage equation, flux equation and torque equation of the motor to obtain the transformed coordinates;

[0012] According to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the motor stator winding current, and the grid-side inverter is adjusted to achieve the starting control of the motor;

[0013] During the motor starting control process, vector control or direct torque control strategy is used to adjust the motor starting current and torque to achieve smooth starting of the motor under heavy load starting conditions;

[0014] After the motor is started, the main control center uses a flexible electric drive control strategy to monitor the motor's current, voltage, and speed in real time, so that the motor can achieve the expected torque output and speed under heavy load conditions.

[0015] Furthermore, the flexible electric drive control strategy is combined with the current transportation status of the rail train to monitor and analyze the train transportation status in real time to obtain the starting torque required by the motor, including:

[0016] Sensors will be installed on rail trains to detect train speed, acceleration and position to obtain operation data;

[0017] The flexible electric drive control strategy is combined with the current carrying state of the rail train to obtain a control strategy;

[0018] According to the control strategy and operation data, through T m =k×(m×a×r×η) to obtain the starting torque corresponding to the motor in the driving mechanical structure, where m represents the total mass of the train, a represents the acceleration value that the train hopes to achieve, r represents the radius of the train wheel, η represents the efficiency of the transmission system in the process of transmitting power, k represents the friction coefficient, T m Indicates the actual torque that the motor needs to output during the starting process.

[0019] Furthermore, the starting parameters of the motor are set according to the starting torque required by the motor. The starting parameters include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor, including:

[0020] According to the motor starting torque, motor design data and actual operating status, the inductance of the stator winding, the magnetic flux of the rotor and the resistance of the stator winding are obtained through test calculation;

[0021] According to the starting torque requirement and load characteristics, the target angular velocity at starting is obtained;

[0022] The calculated inductance, flux linkage, resistance and angular velocity are input into the motor controller to obtain the starting parameters of the motor.

[0023] Furthermore, according to the starting parameters of the motor, the voltage equation, flux equation and torque equation of the motor are transformed using the dq rotating coordinate system to obtain the transformed coordinates, including:

[0024] According to the starting parameters of the motor, the voltage equation of the three-phase stator winding in the three-phase stationary coordinate system is obtained. The voltage equation is specifically:

[0025]

[0026] Among them, R s is the stator winding resistance, L s is the stator winding inductance, L m is the mutual inductance between the stator and the rotor, λ r is the magnetic flux of the rotor, v a 、v b and v c They are the phase a voltage, phase b voltage and phase c voltage of the motor stator winding. and The phase current i a 、i b and i c The time derivative of is the time derivative of the rotor flux;

[0027] According to the voltage equation, Calculate the stator current in the dq coordinate system, where θ is the rotor angle of the motor and i d and i q dq components of stator current;

[0028] According to the voltage equation, Convert the voltage equation of the motor into the form of dq coordinate system, where ω is the electrical angular velocity of the motor, v d and v q is the voltage component in the dq coordinate system;

[0029] In the dq coordinate system, the magnetic flux equation of the rotor is:

[0030] The torque equation in the dq coordinate system is:

[0031] Among them, i r is the rotor current component, λ d and λ q is the flux component in the dq coordinate system, p is the number of pole pairs of the motor, and T is the torque.

[0032] Further, according to the transformed coordinates, the machine-side rectifier is controlled, the output voltage is adjusted to achieve the control of the motor stator winding current, and the grid-side inverter is adjusted to achieve the starting control of the motor, including:

[0033] According to the transformed coordinates, the DC side voltage of the machine-side rectifier is controlled to obtain the output voltage of the rectifier;

[0034] According to the output voltage of the grid-side inverter, the target voltage is converted into a voltage component in the dq coordinate system to realize grid-side inverter control;

[0035] According to the grid-side inverter control, the inverter output voltage is adjusted. When starting the motor, the inverter output voltage is gradually increased to achieve the starting control of the motor.

[0036] Furthermore, during the starting control process of the motor, vector control or direct torque control strategy is used to adjust the starting current and torque of the motor to achieve smooth starting of the motor under heavy load starting conditions, including:

[0037] During the motor starting control process, the target torque and flux are set by the PI controller, the current control loop is designed to keep the current within the set value range, and the PI controller is used to adjust the d-axis and q-axis currents to ensure that the motor obtains a smooth torque output during the starting phase;

[0038] The voltage signal in the dq coordinate system is converted into a three-phase voltage signal using pulse width modulation technology to drive the inverter to realize the driving of the motor;

[0039] Depending on the motor drive, the motor current, torque and speed are monitored to achieve smooth starting of the motor under heavy load starting conditions.

[0040] Furthermore, after the motor is started, the main control center uses the flexible electric drive control strategy to monitor the motor's current, voltage, and speed in real time, so that the motor can achieve the expected torque output and speed under heavy load conditions, including:

[0041] After the motor is started, the three-phase current, voltage and speed data of the motor are collected, and the collected data are processed through the flexible electric drive control strategy to obtain actual data;

[0042] The target torque and speed values ​​of the motor are set in the overall control center, and the target parameters are adjusted according to load requirements and application needs to obtain the target data.

[0043] By comparing the actual data with the target data, the motor operating status is monitored in real time, and the motor control parameters are adjusted to enable the motor to achieve the expected torque output and speed under heavy load conditions.

[0044] Secondly, the motor heavy-load starting system of the rail-type gravity energy storage system includes:

[0045] The acquisition module is used to obtain the current carrying state of the rail train; the flexible electric drive control strategy is combined with the current carrying state of the rail train to monitor and analyze the train carrying state in real time to obtain the starting torque required by the motor; according to the starting torque required by the motor, the starting parameters of the motor are set, and the starting parameters include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor;

[0046] A processing module is used to perform coordinate transformation on the voltage equation, flux equation and torque equation of the motor according to the starting parameters of the motor using a dq rotating coordinate system to obtain transformed coordinates; according to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the stator winding current of the motor, and the grid-side inverter is adjusted to achieve the starting control of the motor;

[0047] The adjustment module is used to use vector control or direct torque control strategy to adjust the starting current and torque of the motor during the starting control process of the motor, so as to achieve smooth starting of the motor under heavy-load starting conditions; after the motor is started, the main control center uses a flexible electric drive control strategy to monitor the current, voltage, and speed of the motor in real time, so that the motor can achieve the expected torque output and speed under heavy-load conditions.

[0048] According to a third aspect, a computing device includes:

[0049] one or more processors;

[0050] The storage device is used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method described.

[0051] In a fourth aspect, a computer-readable storage medium stores a program, and when the program is executed by a processor, the method described is implemented.

[0052] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0053] By accurately calculating and controlling the motor starting torque, the motor can start smoothly under heavy load conditions and reduce starting shock; improve motor efficiency, optimize power usage, and reduce system energy consumption; monitor and adjust the motor operating status in real time to ensure stable system operation and reduce the occurrence of faults; combine flexible electric drive control strategies with real-time data analysis to improve the system's response speed to load changes; and improve the overall operating efficiency of the motor and vehicle system through precise control and optimization strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. Some specific embodiments of the present application will be described in detail in an illustrative and non-restrictive manner with reference to the drawings. The same reference numerals in the drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings:

[0055] Figure 1 It is a schematic diagram of the motor heavy-load starting method for track-type gravity energy storage according to the present invention.

[0056] Figure 2 It is a schematic diagram of the motor heavy-load starting system for track-type gravity energy storage of the present invention. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below according to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0058] The following embodiment of the present application takes the motor heavy-load starting method for rail-type gravity energy storage as an example to explain the scheme of the present application in detail, but this embodiment cannot limit the scope of protection of the present application.

[0059] like Figure 1 As shown, the present invention provides a motor heavy-load starting method for track-type gravity energy storage, comprising:

[0060] Step 11, obtaining the current transportation status of the rail train;

[0061] Step 12, combining the flexible electric drive control strategy with the current transportation state of the rail train, monitoring and analyzing the transportation state of the train in real time, and obtaining the starting torque required by the motor;

[0062] Step 13, setting the starting parameters of the motor according to the starting torque required by the motor, the starting parameters including the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor;

[0063] Step 14, according to the starting parameters of the motor, using the dq rotating coordinate system to perform coordinate transformation on the voltage equation, flux equation and torque equation of the motor to obtain transformed coordinates;

[0064] Step 15, according to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the motor stator winding current, and the grid-side inverter is adjusted to achieve the starting control of the motor;

[0065] Step 16, during the starting control process of the motor, a vector control or direct torque control strategy is used to adjust the starting current and torque of the motor to achieve a smooth starting of the motor under heavy load starting conditions;

[0066] Step 17, after the motor is started, the main control center uses a flexible electric drive control strategy to monitor the current, voltage, and speed of the motor in real time, so that the motor can achieve the expected torque output and speed under heavy load conditions.

[0067] In an embodiment of the present invention, the starting torque of the motor is accurately calculated and adjusted through a flexible electric drive control strategy to ensure that the motor can start smoothly under heavy load conditions and reduce vibration and impact during the starting process; by real-time monitoring and adjusting the motor parameters, the energy efficiency of the motor is optimized, energy waste is reduced, and the energy efficiency of the overall system is improved; the operating status of the motor is monitored in real time, and the control parameters of the motor are adjusted in time to reduce the occurrence of faults and improve the reliability and safety of the system; the dq rotating coordinate system is used to accurately transform the motor equations to ensure accurate adjustment of the motor stator winding current and starting control and improve the accuracy of the operation; combined with real-time monitoring data and flexible electric drive control strategies, rapid response to load changes is achieved to ensure that the motor maintains optimal performance under different operating conditions; through vector control or direct torque control strategies, the starting current and torque of the motor are optimized to achieve smooth starting and efficient operation of the motor.

[0068] In a preferred embodiment of the present invention, the above step 11 may include:

[0069] Get the current transportation status of the rail train, which includes no-load, empty and full-load status;

[0070] In an embodiment of the present invention, the energy consumption of the motor and other power systems is adjusted according to the transportation status of the train, so as to optimize the overall energy consumption and reduce the operating cost. Under different transportation status, the acceleration and braking strategies of the train are adjusted to improve energy efficiency and operating efficiency. The transportation status is monitored in real time to ensure that the train does not exceed the rated load, so as to avoid failures or accidents caused by overload. Under full load or no-load status, the braking strategy is adjusted in time to ensure the reliability and stability of the braking performance.

[0071] In a preferred embodiment of the present invention, the above step 12 may include:

[0072] Sensors will be installed on rail trains to detect train speed, acceleration and position to obtain operation data;

[0073] The flexible electric drive control strategy is combined with the current carrying state of the rail train to obtain a control strategy;

[0074] According to the control strategy and operation data, through T m =k×(m×a×r×η) to obtain the starting torque corresponding to the motor in the driving mechanical structure, where m represents the total mass of the train, a represents the acceleration value that the train hopes to achieve, r represents the radius of the train wheel, η represents the efficiency of the transmission system in the process of transmitting power, k represents the friction coefficient, T m Indicates the actual torque that the motor needs to output during the starting process.

[0075] In an embodiment of the present invention, by acquiring the speed, acceleration and position data of the train in real time, the required starting torque can be accurately calculated, thereby ensuring the optimization of the performance of the motor during the starting process; according to the real-time operating data and feedback of the control strategy, the starting torque of the motor is dynamically adjusted to adapt to different transport states and operating conditions, thereby ensuring the smoothness and reliability of the train starting process; accurate calculation of the starting torque helps to optimize the energy efficiency of the motor, thereby reducing energy consumption and operating costs; by reasonably setting the starting parameters of the motor, energy loss and system wear caused by excessive starting torque can be reduced; accurate starting torque calculation can reduce the impact on the mechanical system and track during the starting process, and reduce the risk of system failure; combined with flexible electric drive control strategy and operating data, it can ensure stable starting of the motor under various transport states, thereby improving the overall reliability of the system.

[0076] In the specific implementation process of the present invention, a variety of sensors are installed on the rail train to monitor the running status of the train in real time, mainly including: a speed sensor for measuring the real-time speed of the train; an acceleration sensor for obtaining the acceleration of the train, which can reflect the acceleration or deceleration state of the train; a position sensor for determining the current position of the train on the track to assist in judging the state and position change of the train. The sensor will continuously collect the running data of the train and transmit the data to the control system through the communication module. According to the real-time running data (speed, acceleration, position) provided by the sensor and the carrying state of the train (current total mass, whether it is loaded with cargo), the output torque and control parameters of the motor are dynamically adjusted to achieve smooth and efficient starting. The control system will analyze the current state of the train (such as the total mass M of the train) and the running data (speed v, acceleration a), and the starting torque calculated by the above formula is the torque output required by the motor in the current running state. According to the calculated starting torque, the motor controller will adjust the working parameters of the motor in real time, such as current, torque, and angular velocity, to ensure that the motor can provide sufficient torque to overcome the static friction of the train and achieve smooth starting.

[0077] In a preferred embodiment of the present invention, the above step 13 may include:

[0078] According to the motor starting torque, motor design data and actual operating status, the inductance of the stator winding, the magnetic flux of the rotor and the resistance of the stator winding are obtained through test calculation;

[0079] According to the starting torque requirement and load characteristics, the target angular velocity at starting is obtained;

[0080] The calculated inductance, flux linkage, resistance and angular velocity are input into the motor controller to obtain the starting parameters of the motor.

[0081] In the embodiment of the present invention, by calculating the starting torque of the motor, the inductance and resistance of the stator winding and the magnetic flux of the rotor, the starting parameters of the motor can be accurately adjusted, thereby optimizing the starting performance of the motor; setting the starting parameters according to the target angular velocity and load characteristics is conducive to smooth starting and avoiding violent fluctuations during the starting process; accurately calculating the starting parameters of the motor to ensure that the energy efficiency of the motor is optimized during the starting process, thereby reducing unnecessary energy waste, and inputting the inductance, magnetic flux, resistance and angular velocity into the motor controller is conducive to achieving accurate motor control and enhancing the stability and reliability of the system; optimizing the motor starting parameters, reducing electrical and mechanical fluctuations during the starting process, and improving the stable operation of the system. Accurate motor starting parameters can improve the response speed of the system to load changes, thereby improving the overall operating performance of the train or equipment. By adjusting the starting parameters, the motor can be adapted to different load characteristics and improve the adaptability of the system. Real-time monitoring of the starting parameters and operating status of the motor can predict potential faults and abnormalities, perform maintenance in advance, and reduce downtime. Through the test data of inductance, resistance and magnetic flux, the cause of the motor failure can be more accurately diagnosed and the maintenance strategy can be optimized.

[0082] In the specific implementation process of the present invention, the stator winding inductance, rotor flux and stator winding resistance of the motor are obtained. The stator winding inductance reflects the reaction of the magnetic field in the stator winding of the motor to the change of current. In actual operation, the impedance of the stator winding can be measured by using a test device such as an impedance analyzer or a bridge. By measuring the change of impedance at different frequencies, The inductance value can be calculated, where V is the voltage on the stator, ω is the angular frequency, I is the current, and L is the inductance value. The rotor flux reflects the strength of the magnetic field inside the motor, especially the change in magnetic flux during motor starting and rotor operation. During actual operation, the flux can be calculated through external sensors and motor back-EMF tests. Using the waveform data of the stator current and stator voltage, the flux value is reversed by λ=N×Φ, where N is the number of turns of the winding, Φ is the magnetic flux, and λ is the flux. The resistance of the stator winding can be obtained by direct measurement or calculation. The DC resistance of the winding can be directly measured using a multimeter or through a bridge. For AC resistance, it is usually calculated by measuring the impedance of the motor (including inductance and resistance). In order to meet the starting torque requirements and load characteristics, it is necessary to calculate the target angular velocity of the motor during the starting process. The calculation of the angular velocity depends on the load characteristics of the train (i.e., the total mass of the train and the required acceleration), and is related to the torque output of the motor. Infer angular velocity, where ω is the angular velocity, T start is the starting torque of the motor, k t is the torque constant of the motor, k t It can be obtained through design or testing. The motor controller generates a control strategy based on the input inductance, resistance, flux and angular velocity, combined with the current current and voltage signals; input inductance, the motor controller will use the inductance data to calculate the interaction between the stator current and the magnetic field, and optimize the excitation current of the motor; input flux, the rotor flux information is used for the controller's flux regulation to ensure that the flux is synchronized with the current so that the motor can effectively generate torque; input resistance, the stator resistance value affects the accuracy of current control, the controller needs to consider the influence of resistance to ensure the accuracy of voltage and current control; input angular velocity, the target angular velocity is the final starting target of the motor, the controller will dynamically adjust the current and voltage according to the angular velocity requirements to ensure that the motor accelerates as expected. After receiving all the parameters, the controller will output the control signals for starting. These signals include: phase current. According to the calculated starting torque, the controller will adjust the current of each phase winding of the motor stator to ensure that the motor generates sufficient starting torque; phase voltage. The controller will optimize the current path, reduce energy loss and smooth the acceleration process of the motor by adjusting the voltage on the stator; rotor magnetic field. According to the changes in magnetic flux and inductance, the controller will adjust the rotor magnetic field in real time to make the magnetic field consistent with the torque output and avoid torque loss or fluctuation.

[0083] In a preferred embodiment of the present invention, the above step 14 may include:

[0084] According to the starting parameters of the motor, the voltage equation of the three-phase stator winding in the three-phase stationary coordinate system is obtained. The voltage equation is specifically:

[0085]

[0086] Among them, R s is the stator winding resistance, L s is the stator winding inductance, L m is the mutual inductance between the stator and the rotor, λ r is the magnetic flux of the rotor, v a 、v b and v c They are the phase a voltage, phase b voltage and phase c voltage of the motor stator winding. and The phase current i a 、i b and i c The time derivative of is the time derivative of the rotor flux;

[0087] According to the voltage equation, Calculate the stator current in the dq coordinate system, where θ is the rotor angle of the motor and i d and i q dq components of stator current;

[0088] According to the voltage equation, Convert the voltage equation of the motor into the form of dq coordinate system, where ω is the electrical angular velocity of the motor, v d and v q is the voltage component in the dq coordinate system;

[0089] In the dq coordinate system, the magnetic flux equation of the rotor is:

[0090] The torque equation in the dq coordinate system is:

[0091] Among them, i r is the rotor current component, λ d and λ q is the flux component in the dq coordinate system, p is the number of pole pairs of the motor, and T is the torque.

[0092] In an embodiment of the present invention, by calculating the stator current in the dq coordinate system, the operating state of the motor can be more accurately controlled, thereby improving the response speed and stability of the motor; the voltage equation of the motor is converted into the form of the dq coordinate system, so that the voltage control is more accurate, thereby improving the operating performance of the motor; in the dq coordinate system, the torque equation can more intuitively describe the torque generation of the motor, thereby realizing precise control of the torque and improving the efficiency and performance of the motor; by accurately controlling the current and voltage of the motor, power loss can be reduced and the overall energy efficiency of the system can be improved; the control method in the dq coordinate system can effectively improve the response speed of the motor to load changes, so that the motor can adapt to different working conditions more quickly; by optimizing current and voltage control, the motor can remain stable during startup, acceleration and operation, and reduce vibration and noise; using the dq coordinate system for current and voltage calculations supports more flexible control strategies, such as vector control or direct torque control.

[0093] In the specific implementation process of the present invention, first, the three-phase voltage and phase current of the motor are obtained through sensors. Next, these three-phase quantities are converted into voltage and current in the dq coordinate system using Clarke transformation and Park transformation. The magnetic flux equation of the rotor is used to calculate the magnetic flux component in the dq coordinate system; the voltage, current and magnetic flux component in the dq coordinate system are substituted into the torque equation to calculate the output torque of the motor. In actual motor control, the controller will dynamically adjust the q-axis current of the motor according to the required torque, thereby accurately controlling the torque output.

[0094] In a preferred embodiment of the present invention, the above step 15 may include:

[0095] According to the transformed coordinates, the DC side voltage of the machine-side rectifier is controlled to obtain the output voltage of the rectifier;

[0096] According to the output voltage of the grid-side inverter, the target voltage is converted into a voltage component in the dq coordinate system to realize grid-side inverter control;

[0097] According to the grid-side inverter control, the inverter output voltage is adjusted. When starting the motor, the inverter output voltage is gradually increased to achieve the starting control of the motor.

[0098] In an embodiment of the present invention, the output voltage of the inverter is gradually increased to achieve smooth motor starting and avoid excessive impact and overload during motor starting; by controlling the voltage of the rectifier and the inverter, the starting process and operating state of the motor can be accurately controlled to ensure that the motor starts and runs according to the set requirements; the DC side voltage of the rectifier is adjusted to ensure the voltage balance in the motor control system, thereby improving the stability and performance of the system; by optimizing the control of the rectifier and the inverter, the efficient transmission of electric energy from the power grid to the motor is ensured, and energy loss is reduced; the target voltage is converted into a voltage component in the dq coordinate system, so that the inverter can more accurately control the current and voltage of the motor and improve the control accuracy; voltage control is performed in the dq coordinate system, which can respond to motor load changes more quickly and improve the dynamic performance of the system; the output voltage of the inverter is steadily increased to reduce the current fluctuation during the motor starting process, thereby reducing the impact and vibration on the system. By gradually increasing the voltage, the motor is prevented from overloading during the starting process, and the stable operation of the motor and its drive system is protected. By accurately controlling the voltage of the rectifier and the inverter, the overall energy efficiency of the system is improved and energy waste is reduced. Effectively control voltage and current, reduce energy loss caused by improper control, and improve the overall energy utilization of the system. Gradually increasing the output voltage can make the motor accelerate smoothly, improve user experience, and reduce suddenness and discomfort during startup. Smooth motor starting reduces mechanical noise and vibration, and improves the comfort and quietness of operation.

[0099] In the specific implementation process of the present invention, the rectifier usually uses pulse width modulation technology to adjust the DC side voltage. By controlling the input voltage of the rectifier on the machine side, the rectified DC voltage can be adjusted; the function of the grid-side inverter is to invert the voltage on the DC bus into AC power and synchronize it to the grid. The output voltage of the inverter usually needs to be synchronized with the grid voltage, so it is necessary to set the target output voltage of the grid-side inverter. The target voltage can be a three-phase AC voltage, and the voltage is converted into a voltage component in the dq coordinate system after transformation; by setting the target voltage component in the dq coordinate system, the pulse width modulation controller of the inverter will adjust the output voltage to make it close to the set target voltage component to ensure that the output voltage of the inverter is consistent with the voltage phase of the grid. When the motor is started, it is usually necessary to gradually increase the output voltage of the inverter to smooth the starting process of the motor and avoid impact current and excessive motor torque. In the initial stage of motor starting, the motor speed is very low, the q-axis current will be relatively small, and therefore the output torque is low. In order to achieve smooth starting, the output voltage of the inverter cannot reach the full value immediately, but should be gradually increased over time. The output voltage component of the inverter can be gradually increased by setting a reference value at startup; this can be achieved through a ramp function, that is, setting the target voltage to gradually increase from an initial value to a rated value. Normally, the target voltage increases in direct proportion to the speed of the motor, and the voltage gradually increases as the motor speed increases. During the starting process of the motor, the torque control is mainly achieved by controlling the q-axis current. The controller dynamically adjusts the q-axis current according to the torque demand at startup to gradually accelerate the motor. At the same time, the controller synchronously adjusts the dq-axis voltage components to keep the motor starting in a safe and stable working state.

[0100] In a preferred embodiment of the present invention, the above step 16 may include:

[0101] During the motor starting control process, the target torque and flux are set by the PI controller, the current control loop is designed to keep the current within the set value range, and the PI controller is used to adjust the d-axis and q-axis currents to ensure that the motor obtains a smooth torque output during the starting phase;

[0102] The voltage signal in the dq coordinate system is converted into a three-phase voltage signal using pulse width modulation technology to drive the inverter to realize the driving of the motor;

[0103] Depending on the motor drive, the motor current, torque and speed are monitored to achieve smooth starting of the motor under heavy load starting conditions.

[0104] In an embodiment of the present invention, the PI controller is used to adjust the d-axis and q-axis currents to keep the current within the set range, so as to avoid the instantaneous current shock generated by the motor at startup, thereby preventing the sharp fluctuation of the torque; the PI controller can adjust the d-axis current (control magnetic flux) and q-axis current (control torque) of the motor in real time according to the actual operation conditions, so as to ensure that the torque and magnetic flux remain within the ideal range, improve the accuracy and stability of the motor operation, and control the d-axis and q-axis currents to ensure that the required current matches the actual load of the motor during the startup and operation of the motor, reduce the invalid current and energy consumption, and improve the efficiency of the motor. The voltage signal in the dq coordinate system is converted into a three-phase voltage signal to drive the inverter through PWM technology, so as to ensure that the inverter can control the operation of the motor more accurately. The precise adjustment of the PWM signal frequency and duty cycle makes the motor run more smoothly and reduces harmonic interference and current pulsation. PWM modulation can reduce high-order harmonic components and reduce electromagnetic interference during the operation of the motor, thereby improving the overall stability and reliability of the system.

[0105] In the specific implementation process of the present invention, it is necessary to set the target torque and flux through the PI controller. The torque depends on the motor load condition. The PI controller is adjusted to a suitable target value according to the actual working condition to ensure that the motor can generate sufficient driving force. The flux is to optimize the starting efficiency. The flux of the motor needs to remain stable during the starting process. The goal of flux control is to make the magnetic flux inside the motor within a stable range, so as to avoid excessive or too small flux causing unstable torque output. The current of the motor is divided into d-axis current and q-axis current in the dq coordinate system. The target torque and flux generate q-axis current reference value and d-axis current reference value through the PI controller to control the current of the motor. The purpose of the current control loop is to ensure that the actual current of the motor is within the set range and maintain the stability of the torque output. To this end, the PI controller is designed to control the d-axis current and q-axis current respectively; in order to ensure the accuracy of the current control, the actual current of the motor needs to be sampled in real time and fed back to the PI controller. The three-phase current is measured by the current sensor and converted into the dq coordinate system, which is used as the input signal of the PI controller for closed-loop control. The closed-loop controller generates a correction signal by comparing the target current and the actual current. Through the current control loop, the PI controller outputs the voltage reference value in the dq coordinate system and controls the output voltage of the inverter. Since the inverter is a three-phase AC system, the voltage signal of the dq coordinate system needs to be converted into a three-phase voltage signal. And the pulse width modulation technology is used to convert the three-phase voltage reference signal generated above into a switch signal that can actually be applied to the inverter. PWM modulates the voltage to the required output voltage value by controlling the on and off time of the switch to drive the three-phase winding of the motor. In order to ensure the smooth start of the motor under heavy load starting conditions, it is necessary to monitor the key parameters of the motor in real time. Under heavy load starting conditions, the starting torque required by the motor is large, so special attention should be paid to the control of torque and current. In order to avoid current shock or excessive torque causing motor overload, the current should be dynamically adjusted through the PI controller. Specific measures include: limiting the current increase: during the motor starting process, limit the increase of the q-axis current to ensure that the torque increases gradually, and avoid sudden increase in current to cause motor overheating or damage; adjusting the PI controller parameters: under heavy load conditions, appropriately adjust the gain of the PI controller to ensure that the current control response is fast and there is no overshoot, so as to maintain the smooth start of the motor.

[0106] In another specific implementation process of the present invention, during the startup process, the acceleration of the motor should be smooth and robust. According to the feedback of current and torque, by adjusting the reference value of the dq axis current, the speed of the motor is gradually increased to avoid excessive current shock or current fluctuation in the startup phase; the target torque and magnetic flux are set by the PI controller, the dq axis current reference value is generated, the current control loop is designed, and the PI controller is used to adjust the d axis current and the q axis current respectively to keep the current within the set range to ensure that the motor outputs a stable torque, and the dq voltage signal is converted into a three-phase voltage signal by transformation, and the inverter is driven by PWM technology to control the three-phase voltage of the motor to drive the motor.

[0107] In a preferred embodiment of the present invention, the above step 17 may include:

[0108] After the motor is started, the three-phase current, voltage and speed data of the motor are collected, and the collected data are processed through the flexible electric drive control strategy to obtain actual data;

[0109] The target torque and speed values ​​of the motor are set in the overall control center, and the target parameters are adjusted according to load requirements and application needs to obtain the target data.

[0110] By comparing the actual data with the target data, the motor operating status is monitored in real time, and the motor control parameters are adjusted to enable the motor to achieve the expected torque output and speed under heavy load conditions.

[0111] In the embodiment of the present invention, the PI controller can accurately adjust the d-axis and q-axis currents to ensure that the motor obtains a smooth torque output during the startup phase and reduce torque fluctuations and jitters; by setting the target torque and magnetic flux, the torque output during the motor startup process can be effectively controlled to ensure stable performance of the motor during the startup process; by finely controlling the current and torque, the motor can be started smoothly to reduce mechanical and electrical shocks during startup; under heavy-load starting conditions, through effective current control and PWM drive, the motor can start smoothly under high load conditions to reduce system failures caused by overload; the current control loop design can ensure that the current is within the set value range, reduce current fluctuations, and improve the stability and reliability of the system; the PI controller can adjust the d-axis and q-axis currents in real time to cope with changes in motor load, Maintain current stability to optimize motor performance; use PWM technology to convert the voltage signal in the dq coordinate system into a three-phase voltage signal, which can efficiently drive the inverter and ensure the accuracy and response speed of the motor drive; PWM technology can effectively control the output of the inverter, improve the overall efficiency of the motor drive, and reduce energy loss; by monitoring the motor's current, torque and speed, it can grasp the motor's operating status in real time, and promptly discover and solve potential problems; system monitoring can prevent the motor from overloading during startup and protect the safety and stability of the motor and its drive system; by precisely controlling current and torque, the energy efficiency of the motor during startup is optimized to reduce energy waste; precise PWM control and current management can reduce energy loss caused by improper control and improve the energy utilization efficiency of the system.

[0112] In the specific implementation process of the present invention, a current sensor is used to collect three-phase current data in the operation of the motor, and then coordinate transformation is used to analyze the electromagnetic state and torque output of the motor; the three-phase voltage signal of the motor is collected by a voltage sensor, and the collected current and voltage signals are three-phase AC signals, and these three-phase signals must be converted into dq axis signals through coordinate transformation. And according to the actual data of current, voltage, and speed collected, combined with load conditions and application requirements, the control strategy is adjusted in real time, and multiple goals of torque, speed, and efficiency are considered at the same time. According to the actual load and working conditions of the motor operation, the parameters of the PI controller are adjusted; after the motor is started, the control center sets the target torque and target speed of the motor according to the load requirements and application requirements of the system; the total control center can dynamically adjust the target torque and target speed according to the changes in load, application requirements, and changes in the working environment. After data collection and processing, the actual operating state parameters of the motor are obtained, the actual torque of the motor is compared with the target torque, and the torque error and speed error are calculated; according to the errors of torque and speed, the control parameters of the motor are adjusted using a PI controller to ensure that the motor reaches the target torque and target speed. According to the flexible electric drive control strategy, when the load changes, for example, when the motor encounters a larger load, the torque output needs to be increased. At this time, the PI controller will automatically increase the reference value of the q-axis current to generate more torque. On the contrary, when the load decreases, the PI controller will reduce the current reference value and reduce the torque output to save energy. In addition, in some complex situations, it is necessary to adjust the gain parameters of the PI controller to obtain better dynamic response performance, and through the adaptive control algorithm, the parameters of the PI controller are dynamically optimized according to the current load and operating status.

[0113] like Figure 2 As shown, the motor heavy-load starting system 20 of the rail-type gravity energy storage system includes:

[0114] The acquisition module 21 is used to acquire the current carrying state of the rail train; the flexible electric drive control strategy is combined with the current carrying state of the rail train to monitor and analyze the train carrying state in real time to obtain the starting torque required by the motor; according to the starting torque required by the motor, the starting parameters of the motor are set, and the starting parameters include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor;

[0115] The processing module 22 is used to transform the voltage equation, flux equation and torque equation of the motor according to the starting parameters of the motor using the dq rotating coordinate system to obtain the transformed coordinates; according to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the motor stator winding current, and the grid-side inverter is adjusted to achieve the starting control of the motor; in the starting control process of the motor, the starting current and torque of the motor are adjusted by using vector control or direct torque control strategy to achieve smooth starting of the motor under heavy load starting conditions; after the motor is started, the main control center uses a flexible electric drive control strategy to monitor the current, voltage and speed of the motor in real time, so that the motor can achieve the expected torque output and speed under heavy load conditions.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for starting a motor with heavy load for track-type gravity energy storage, comprising: Get the current transportation status of the rail train; Combine the flexible electric drive control strategy with the current transportation status of the rail train, monitor and analyze the train transportation status in real time, and obtain the starting torque required by the motor; According to the starting torque required by the motor, set the starting parameters of the motor, which include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor; According to the starting parameters of the motor, the dq rotating coordinate system is used to transform the voltage equation, flux equation and torque equation of the motor to obtain the transformed coordinates; According to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the motor stator winding current, and the grid-side inverter is adjusted to achieve the starting control of the motor; During the motor starting control process, vector control or direct torque control strategy is used to adjust the motor starting current and torque to achieve smooth starting of the motor under heavy load starting conditions; After the motor is started, the main control center uses a flexible electric drive control strategy to monitor the motor's current, voltage, and speed in real time, so that the motor can achieve the expected torque output and speed under heavy load conditions.

2. The motor heavy-load starting method for rail-type gravity energy storage according to claim 1, characterized in that: The flexible electric drive control strategy is combined with the current transportation status of the rail train to monitor and analyze the train transportation status in real time to obtain the starting torque required by the motor, including: Sensors will be installed on rail trains to detect train speed, acceleration and position to obtain operation data; The flexible electric drive control strategy is combined with the current carrying state of the rail train to obtain a control strategy; According to the control strategy and operation data, through T m =k×(m×a×r×η) to obtain the starting torque corresponding to the motor in the driving mechanical structure, where m represents the total mass of the train, a represents the acceleration value that the train hopes to achieve, r represents the radius of the train wheel, η represents the efficiency of the transmission system in the process of transmitting power, k represents the friction coefficient, T m Indicates the actual torque that the motor needs to output during the starting process.

3. The motor heavy-load starting method for rail-type gravity energy storage according to claim 2 is characterized in that: According to the starting torque required by the motor, set the starting parameters of the motor. The starting parameters include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor, including: According to the motor starting torque, motor design data and actual operating status, the inductance of the stator winding, the magnetic flux of the rotor and the resistance of the stator winding are obtained through test calculation; According to the starting torque requirement and load characteristics, the target angular velocity at starting is obtained; The calculated inductance, flux linkage, resistance and angular velocity are input into the motor controller to obtain the starting parameters of the motor.

4. The motor heavy-load starting method for rail-type gravity energy storage according to claim 3 is characterized in that: According to the starting parameters of the motor, the dq rotating coordinate system is used to transform the voltage equation, flux equation and torque equation of the motor to obtain the transformed coordinates, including: According to the starting parameters of the motor, the voltage equation of the three-phase stator winding in the three-phase stationary coordinate system is obtained. The voltage equation is specifically: Among them, R s is the stator winding resistance, L s is the stator winding inductance, L m is the mutual inductance between the stator and the rotor, λ r is the magnetic flux of the rotor, v a 、v b and v c They are the phase a voltage, phase b voltage and phase c voltage of the motor stator winding. and The phase current i a 、i b and i c The time derivative of is the time derivative of the rotor flux; According to the voltage equation, Calculate the stator current in the dq coordinate system, where θ is the rotor angle of the motor and i d and i q dq components of stator current; According to the voltage equation, Convert the voltage equation of the motor into the form of dq coordinate system, where ω is the electrical angular velocity of the motor, v d and v q is the voltage component in the dq coordinate system; In the dq coordinate system, the magnetic flux equation of the rotor is: The torque equation in the dq coordinate system is: Among them, i r is the rotor current component, λ d and λ q is the flux component in the dq coordinate system, p is the number of pole pairs of the motor, and T is the torque.

5. The motor heavy-load starting method for rail-type gravity energy storage according to claim 4, characterized in that: According to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the motor stator winding current, and the grid-side inverter is adjusted to achieve the starting control of the motor, including: According to the transformed coordinates, the DC side voltage of the machine-side rectifier is controlled to obtain the output voltage of the rectifier; According to the output voltage of the grid-side inverter, the target voltage is converted into a voltage component in the dq coordinate system to realize grid-side inverter control; According to the grid-side inverter control, the inverter output voltage is adjusted. When starting the motor, the inverter output voltage is gradually increased to achieve the starting control of the motor.

6. The motor heavy-load starting method for rail-type gravity energy storage according to claim 5, characterized in that: During the motor starting control process, vector control or direct torque control strategy is used to adjust the motor starting current and torque to achieve smooth starting of the motor under heavy load starting conditions, including: During the motor starting control process, the target torque and flux are set by the PI controller, the current control loop is designed to keep the current within the set value range, and the PI controller is used to adjust the d-axis and q-axis currents to ensure that the motor obtains a smooth torque output during the starting phase; The voltage signal in the dq coordinate system is converted into a three-phase voltage signal using pulse width modulation technology to drive the inverter to realize the driving of the motor; Depending on the motor drive, the motor current, torque and speed are monitored to achieve smooth starting of the motor under heavy load starting conditions.

7. The motor heavy-load starting method for rail-type gravity energy storage according to claim 6, characterized in that: After the motor is started, the main control center uses the flexible electric drive control strategy to monitor the motor's current, voltage, and speed in real time, so that the motor can achieve the expected torque output and speed under heavy load conditions, including: After the motor is started, the three-phase current, voltage and speed data of the motor are collected, and the collected data are processed through the flexible electric drive control strategy to obtain actual data; The target torque and speed values ​​of the motor are set in the overall control center, and the target parameters are adjusted according to load requirements and application needs to obtain the target data. By comparing the actual data with the target data, the motor operating status is monitored in real time, and the motor control parameters are adjusted to enable the motor to achieve the expected torque output and speed under heavy load conditions.

8. The motor heavy-load starting system of the rail-type gravity energy storage system is characterized in that: Applied to the method according to any one of claims 1 to 7, comprising: The acquisition module is used to obtain the current carrying state of the rail train; the flexible electric drive control strategy is combined with the current carrying state of the rail train to monitor and analyze the train carrying state in real time to obtain the starting torque required by the motor; according to the starting torque required by the motor, the starting parameters of the motor are set, and the starting parameters include the inductance of the stator winding, the magnetic flux of the rotor, the resistance of the stator winding and the angular velocity of the motor; A processing module is used to perform coordinate transformation on the voltage equation, flux equation and torque equation of the motor according to the starting parameters of the motor using a dq rotating coordinate system to obtain transformed coordinates; according to the transformed coordinates, the machine-side rectifier is controlled to adjust the output voltage to achieve the control of the stator winding current of the motor, and the grid-side inverter is adjusted to achieve the starting control of the motor; The adjustment module is used to use vector control or direct torque control strategy to adjust the starting current and torque of the motor during the starting control process of the motor, so as to achieve smooth starting of the motor under heavy-load starting conditions; after the motor is started, the main control center uses a flexible electric drive control strategy to monitor the current, voltage, and speed of the motor in real time, so that the motor can achieve the expected torque output and speed under heavy-load conditions.

9. A computing device, characterized in that include: one or more processors; A storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the method as claimed in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program, which, when executed by a processor, implements the method according to any one of claims 1 to 7.

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