Design Of Electro-hydraulic Coupler Controller

Environmental pollution and global warming have caused countries around the world to gradually raise the exhaust emission standards of cars,which has led to the replacement of a large number of traditional fuel vehicles by various new energy vehicles.As one of the main driving components of many new energy vehicles,electromechanical hydraulic coupler has entered the public field of vision in recent years and has become a new research hotspot due to its advantages of reversibility,infinitely variable,good dynamic characteristics of variables,and high efficiency.As the core component of the entire system,the electromechanical fluid coupler controller is responsible for improving the operating efficiency of the system and ensuring the driving performance under various complex working conditions.This paper proposes a vector control strategy based on the sliding mode speed controller id=0,combined with a 1000-line photoelectric encoder to achieve dual closed-loop control of system current and speed,to ensure that the electromechanical hydraulic coupler has accurate speed regulation in the full speed range and operates under sudden load smooth.The research content of this article includes three parts:The modeling and simulation of the electromechanical-hydraulic coupler control system is carried out through Simulink.Mathematical expression of the electrical structure of the electromechanical hydraulic coupler and the conversion between the coordinates;study the theory and implementation of SVPWM and vector control technology;put forward and elaborate the sliding mode vector control strategy based on id=0;Analysis of the dual power torque source of the fluid coupling.Then the above theory and mathematical formulas are fused in Simulink to build a current and speed double closed-loop control model,and the acceleration and load mutation experiment of the electromechanical hydraulic coupler control system model is carried out.From the output information of speed response,torque,phase current and reactive current,it is determined that the designed control strategy can meet the design requirements.After the control strategy is verified,the controller needs to be designed.The hardware part mainly designs the minimum system and communication circuit based on STM32F407ZGT6,the drive and protection circuit of the power module,the signal detection and protection circuit of the system,and the encoder circuit that completes the speed closed loop.The software part gives the design principle and design flow of the main program,interrupt program,rotor position detection and speed measurement program,SVPWM program,and then combines STM32 CubeMX and Ewarm to write the program.In order to ensure the performance of the designed controller,physical verification is carried out.The double-pulse program is used to verify the dead time and drive waveform of the hardware circuit.After the verification of the basic hardware circuit of the system,the control program was debugged and verified.Through the observation of the speed information of the starting process and the current information of the steady state process,it was found that the system has good acceleration performance;and the current waveform has a high sine degree during the steady state operation.No burr appears,indicating that the system reactive current is very small and the system efficiency is high.