Development Of PMSM Drive System For Hydrogen Fuel Cell Based On Sensorless Control Algorithm

With the increasingly strict of laws on energy saving and emission reduction,hydrogen fuel cell vehicles,as one of the new energy vehicles,have received more and more attention.Hydrogen fuel cells for vehicles are required to work stably in various harsh environments,which puts higher requirements on the control of the air compressor,the core component of the whole system.Real-time acquisition of motor rotor’s position information is a prerequisite for precise motor control.Traditional position sensors are extremely vulnerable to damage in harsh environments.Therefore,the research and development of the sensorless motor drive system for hydrogen fuel cell vehicle’s air compressor is of great significanceWe discussed the limitations of traditional mechanical position sensors in the field of automotive air compressors,drive systems for common motor and algorithms for sensorless motor control.For the working characteristics of hydrogen fuel cell’s air compressors,we take the model reference adaptive algorithm as the rotor position estimation algorithm to research and develop the motor drive system.We analyzed the vector control algorithm of the permanent magnet synchronous motor and the motor math model in three types of coordinate systems.We designed a position estimation algorithm based on model reference adaptive algorithm.Considering all aspects,we designed a control strategy that satisfies the position sensorless motor from startup status to normal operation status.The rotor is pre-positioned by twice pre-setting to avoid the problem that the rotor cannot be positioned at an angle of π to the A-phase axis.Then the motor accelerates to 1000r/min and switches to sensorless double closed-loop vector control.The two algorithms have different principles adopt two-stage PI adjustment.In order to reduce the pulsation of the motor when switching,a smooth switching method from open loop to closed loop is designed.Based on the Simulink,simulation models were built respectively,and the actual parameters of the motor were used to verify the effectiveness and feasibility of the model and control algorithm.The simulation results show that the speed,output torque and three-phase current of the developed control system can quickly stabilize to the target value when the target speed and load torque step signals are applied.The developed control algorithm changes stably more than the process of direct switching,and the position estimation algorithm can also achieve smoother control than when directly starting with MRAS.According to the software and hardware requirements of the motor drive system for vehicles,taking into account the stability and safety,the motor drive system is designed based on DSP and IGBT,and a variety of hardware protection circuits are provided.The PCB circuit is isolated according to the module layout,and measures such as opening windows,increasing the line width and copper thickness can meet the requirements of high voltage and large currentBased on the single-ended flyback transformer and PWM control chip,a multi-output isolated voltage module is designed.The designed hardware circuit was partially debugged.Debugging experiments showed that the designed flyback transformer and its surrounding circuits can effectively output the target voltage under load and input undervoltage.