Multi-IPMSM Sensorless Speed Synchronous Control Of 4WID/S All-electric Vechicle

The Four-Wheels Independent Drive/Steering All-Electric Vehicle(4WID/S AEV),driven by four in-wheel motors respectively,so that the torque and drive/braking mode of each wheel can be independently controlled,and makes four in-wheel motors synchronous control becomes a challenge.Interior Permanent Magnet Synchronous Motor(IPMSM),as the in-wheel motor,needs accurate rotor position obtained by mechanical sensor,and under the complex condition of 4WID/S AEV,the mechanical sensor is easy to fail,which causes synchronous failure of multiIPMSM system,and causes dragging between the wheels of the 4WID/S AEV,making 4WID/S AEV in dangerous.Therefore,in this paper,to improve the stability and safety of 4WID/S AEV,the multi-IPMSM sensorless speed synchronous control is studied.Firstly,based on the relative-coupling control and Sliding Mode Observer(SMO)sensorless algorithm,the multi-IPMSM sensorless speed synchronous control is constructed.Based on this,the relationship between estimation accuracy of sensorless and synchronous performance of multi-motor system is analyzed.To solve the shortcomings of the traditional relative-coupling control,a simplified relative-coupling control is designed to improve the synchronization performance of multi-IPMSM sensorless traction systems.Secondly,under middle and high speed range,to improve the anti-disturbance ability of system,based on the Nonlinear Active Disturbance Rejection Controller(NADRC)and Improved Phase Locked Loop(IPLL),a multi-IPMSM sensorless speed synchronous control dynamic improvement strategy is proposed.The NADRC is used to reduce the effect of load disturbance.Under acceleration and deceleration,in order to reduce the estimation error of conventional PLL and synchronization error,using IPLL to replace the traditional PLL.In order to verify the dynamic improvement of multi-IPMSM sensorless traction system with this method,simulation and experimental verification are carried out.Lastly,because the temperature rises and magnetic circuit saturation of IPMSM results the parameter mismatch.This paper designs a multi-IPMSM sensorless speed synchronous control parameter modification strategy.Based on the structure of multi-IPMSM sensorless speed synchronous control,the impact caused by the parameter deviation is analyzed,and the inductance with greater influence is selected for real-time correction.Then,the steady-state performance,robustness and synchronization performance of the multi-IPMSM sensorless traction system are improved,and the proposed strategy is verified by experiments.