Research And Implementation Of Non-Inductive Vector Control Strategy Of Permanent Magnet Synchronous Motor Based On Flux Observe

The development of new energy vehicles is of great importance as most countries focus on ways to reduce carbon emissions and improve energy efficiency due to the increasing pollution of diesel cars and increasing consumption of non-renewable resources.As one of the most important parts of new energy vehicle,electric motor plays a major role in the new energy vehicle driving.Due to the complex operating conditions of the motor of the new energy vehicle,the failure of the resolver caused by it has attracted the attention of scholars at home and abroad.Therefore,the use of non-inductive vector control as a fault-tolerant control strategy for resolver faults has good research value and application prospects.In this paper,the intuition vector control technology of the permanent magnet synchronous machine is further studied:(1)Aiming at the failure of the resolver of the new energy vehicle,a fault-tolerant composite control strategy based on the non-inductive vector control technology is designed.This method is based on the nonlinear flux linkage observer,which is used to estimate the position information and rotational speed of the rotor,and is divided into two stages according to the rotational speed.In the zero-low speed stage,the current-frequency ratio control method is applied.The currentfrequency ratio control has certain anti-interference and load-carrying capabilities,and can effectively avoid the problems of starting overcurrent and starting failure.In the middle and high speed stage,the traditional nonlinear flux linkage observer is used to improve the performance of the nonlinear flux linkage observer by using the closed-loop feedback control idea to solve the problems of large rotor position estimation error and poor robustness when the motor is started with load.The back EMF and observer gain are dynamically compensated by the output angular velocity,thereby producing the effect of compensating the flux linkage.Therefore,an improved flux linkage observer is designed,and an improved simulation model is built.Simulation results show that the improved algorithm improves the rotor position estimation accuracy and startup stability.(2)In view of the problems of overshoot and variable parameters in the traditional PI speed loop adjustment of new energy vehicles,the active disturbance rejection control technology is used in the motor speed loop,and the active disturbance rejection control adopts pure proportional control plus system disturbance observation.Feedforward compensation is used for speed control,and the feedback link of traditional PI is changed to feedforward compensation of disturbance amount.Therefore,the ADRC speed loop is designed and its model is built.It can be seen from the simulation results that the speed loop controller using ADRC has faster response,anti-interference,small overshoot and easy parameter adjustment.Finally,a permanent magnet synchronous machine hardware experimental platform based on inductive vector control is established and the method mentioned above is experimentally validated.The experimental results show that the improved flux linkage observer can effectively improve the starting ability and the precision of the convergence angle.Moreover,the performance of the composite control strategy is very stable under the condition of rated speed and full torque output.The motor does not fail to start or run out of control when the motor is started repeatedly for 20 times,and it also has a good tracking performance for the motor speed.The controller using the ADRC as the speed loop also has faster response,anti-interference,small overshoot and easy parameter adjustment.