Model-based Vector Control Of IPMSM System For Electric Vehicles

As the only power output of pure electric vehicles, motor and its controlsystem bear very important role. Their performances affect the vehicle’s power,comfort and economy. Interior permanent magnet synchronous motor (IPMSM)with the advantage of high power density, mature control technology and widespeed range, is gradually extended to apply to driven system of electric vehicles.Firstly, d-q axis current command expressions of MTPA control andflux-weakening control has been studied in the speed given mode and the torquegiven mode respectively. Based the Finite Element Analysis, the time-varying selfinductances and mutual inductances of the motor are calculated out in order tocharacterize magnetic saturation and cross-coupling effects. Then the IPMSMmathematical model is established. Under the restriction of current limit circle andvoltage limit circle, the d-q axis MTPA and flux-weakening current instructionsconsidering saturation as well as cross-coupling effect are obtained by means ofoptimization method.On the basis of the above research, the model-based IPMSM vector controlsystem and traditional invariable parameter control system are shaped, thesimulation results show that the IPMSM vector control system consideringsaturation and cross-coupling effect, compare with the traditional control system,can produce greater torque and adapt better to motor real-time operating conditionswhile reaching a wider speed range.At last, the host computer test system for electric vehicle’s IPMSM driver hasbeen built by application of CAN bus technology and the LabVIEW developmentenvironment. Human-computer interaction between host computer and IPMSMdriver is implemented. Actual tests show the instruction is successfully sent whilethat the real-time status successfully feedback.