Research On The Inverter Topology For Dual Motor Independent Drive

In this thesis,several traditional dual-motor topologies are analyzed and two topologies are studied in detail,which are the four-leg topology and five-leg topology.Aiming at the existing problems in five-leg topology,this thesis puts forward an improved inverter topology,which makes up the problem,e.g.,DC bus voltage utilization is low.The simulation model of PMSM Vector Control in Matlab /Simulink environment is established.The simulation results show that with the improved inverter topology two motors can be controlled independently and the control strategy is simple.Based on the analysis of the principle of an SPWM for the four-leg inverter,the effect of the DC-link voltage unbalance on the motors is pointed out and an effective compensation method is proposed.The mathematical model of two permanent magnet synchronous motors(PMSMs)is established and a simulation model of two vector control systems with speed and current loops are built.The simulation results verify that the two PMSMs can be effectively controlled with the proposed SPWM control algorithm,and the system has good dynamic and static performance.Then the experimental platform is set up to verify the theory.Besides,for the four-leg inverter,some problems such as the large input current harmonic and low DC bus voltage utilization are pointed out and an improved topology is put forward.The simulation results show that two motors can run stately under the rated state and the input current harmonic is small.