Study On 15-Phase PMSM Control System Based On FPGA

On the background of the research for the fifteen-phase Permanent Magnetic Synchronous Motor (PMSM) system using for ship propulsion, this study researched the FPGA based all digital vector control method for 2MW fifteen-phase PMSM. Multi-phase motors have several advantages over traditional three-phase motors. The characteristic of high availability, fault tolerant makes the multi-phase motors very suitable for low voltage high power drive situation. The ship electrical propulsion is an advanced propulsion mode, which takes the comprehensive interest of the researchers all over the world, the control system of propulsion motor is one of the key technologies. Therefore, the results obtained in this paper demonstrate the feasibility and practical significance of the fifteen-phase permanent magnet motor drives.Firstly, a literature survey on the work accomplished in this area is presented, and the detailed analysis is given. A novel five unit parallel drive fifteen-phase PMSM control system is proposed. The stator winding of fifteen-phase PMSM investigated in this paper is composed of five stand-alone three-phase star connect winding sets, each of them takes the poles solely, all of the five windings distribute alternately . In this way, the windings can decouple essentially, and the fifteen-phase PMSM can be equivalent to five three-phase PMSM units. The mathematic model of fifteen-phase PMSM is reduced too. The control system of fifteen-phase PMSM driven by five drive unit in parallel is proposed and simulated in Simulink. The simulation results are given to support validity of the theoretical findings.Secondly, some key arithmetic of all digital drive and control system is written, and the hardware logical circuit in FPGA is given. The IP cores of multiplier, divider, CORDIC trigonometric function resolver, SVPWM modulation, PID regulator and Sinc3 filter have been developed using the Verilog-HDL. After synthetized, mapped and routed in ISE 9.1, the IP cores are used to implement Rotor Field Oriented Control (RFOC) of PMSM unit dual close-loop controller on a single Xilinx XC3S400 FPGA chip. Also, a high power density, high integration, high reliable 11kW drive unit pattern is designed. The experimental results show the excellent dynamic and static performance.Thirdly, the high performance CAN node based on MCP2515 is designed to realize the parallel operation of drive units. A CAN communication management module is designed in FPGA using micro-program method to simply the communication. The five drive units compose a CAN LAN, master drive unit carries out the calculation of speed close-loop, and broadcasts the current reference through CAN Bus, each slave drive unit carries out the calculation of current close-loop, then a dual close-loop control system of fifteen PMSM is implemented.At last, the CAN Bus based five units parallel drive system is systematically tested. Experimental results shows the drive units can work harmoniously and share the load equally. Experiments have been conducted under the fault situation with the failure of one even more drive units, the results demonstrate the fifteen-phase PMSM drive system can operates continuously and steadily without additional hardware and control algorithm adjusting, which further demonstrate the feasibility and practical significance of the fault tolerant fifteen-phase PMSM drive system.