Design And Research Of Back To Back Permanent Magnet Synchronous Motor Driver With Three Level Topology

Three-level topologies had widely applications in photovoltaic,wind power converters.It has higher efficiency,higher switching frequency comparing with the traditional power topologies.The efficiency improvement can rise the power of the PV converters and increase the power density of electronic equipment.Furthermore,low du/dt of three level topology can also reduce the value of the filter.The volume and cost of the filter will decrease.Based on the research of three-level topology,this paper applies three-level topology to PMSM driver system.The Space Vector PWM procedure,rectifier control,PMSM control and neutral point voltage control are studied in this paper.Also,the software PLL,parameter configuration of PI control,design of LCL filter are analyzed.The simulation of software PLL,neutral point voltage control is given to verify the control system.A 11 kW back-to-back PMSM prototype driver is designed for tests.Finally,this paper test the current THD(Total Harmonic Distortion)at rated power,neutral point voltage in dynamic conditions.The experiment results show that the prototype drive is capable of bi-directional power transmission and the neutral point voltage is suppressed within ±15V.The THD of the current is lower than 5.0%.