Flux-weakening Control For Ipmsm Of Electric Vehicles

The electric vehicles gradually obtain application because of energy shortage and environmental pollution.High performance IPMSM is widely applied to the drive system of electric vehicles.The flux-weakening control for IPMSM can improve the electric vehicles' power abilities and extend the range of speed in the case of limited inverter capability,so it obtains widely attention in the field of electric vehicles' driving motor controlling.The flux-weakening control for IPMSM of electric vehicles is studied in this paper.The main research contents include:1.The classification and mathematical model of IPMSM are studied.The hybrid IPMSM is easier to flux-weakening control because it colligates the advantages of the radial IPMSM and the tangential IPMSM,and the mathematical models of IPMSM in static three-phase coordinates and in rotary two-phase coordinates is given.2.The flux-weakening control theories of IPMSM are studied,the theories which the IPMSM are controlled by MTPA control in the constant torque operational area and controlled by flux-weakening control in the constant power operational area are pointed out.The influence of PM flux parameter and the d,q axis inductance parameter on the IPMSM's flux-weakening control performance is analyzed.3.The IPMSM's internal magnetic fields are analyzed by the ANSYS Maxwell 2D finite element analysis software,the analysis results suggest that the IPMSM's internal magnetic fields have the effects of flux saturation and cross-coupling,the motor's inductance parameters change from d-axis current and q-axis current,and the inductance parameters' 3D curves diagrams with d-axis current and q-axis current are given.4.The IPMSM's flux-weakening control plans base on constant inductance parameters and changed inductance parameters.The flux-weakening control plans in both cases are simulated in Matlab/Simulink and the flux-weakening effects are-ared.The conclusion that the flux-weakening control plans base on changed inductance parameters can better realize the IPMSM's flux-weakening control and the system's dynamic and static performance is good when the motor's inductance parameters are changing.