FPGA电流型PMSM变频驱动器及开路故障保护

电流源逆变器(CSI)随着反阻断IGBT器件的成功开发,在电动汽车等大功率变频调速领域前景广大。FPGA作为控制器,其时序控制能力强大,适合用来实现基于电流型空间矢量脉宽调制(SVPWM)技术的永磁同步电机(PMSM)变频驱动器。该系统通过采用最小直流链电流命令产生法和合理的死区开关状态设置,有效减小直流和开关损耗。系统为应对开路故障引起直流链电感产生瞬间高压打坏开关器件的现象,设置由双向TVS管和功率电阻构成的电感电压箝位环节,并监测直流链电流值,一旦低于限值则实现保护性停机。实际系统使用Xilinx公司FPGA开发板,基于电流源逆变器转子参考框下交流侧的理论模型,建立了一套数字化闭环调速策略,实测定子电流THD值及功率因数均达到良好效果。

FPGA current PMSM variable frequency drive and open-phase-fault protection

With the successful development of RB-IGBT device,Current-source-inverter（CSI）has a broad prospect in the field of electric vehicles and other high power variable frequency speed adjusting areas. FPGA as a controller with powerful time-sequence control ling ability is suitable for PMSM variable frequency driver based on current type SVPWM technology. The sys-tem can reduce DC and switching loss by generating method of minimum DC link current command and rational dead zone on-off state setup. In the system,Bi-directional TVS and inductor voltage clamp link constructed by power resistor is set up to counter the phenomenon of switch device damage caused by transient high voltage produced by DC link inductance generated by open-circuit fault and to monitor the DC link current value. That is,if the DC link current is below the limit,the system protectively shuts off. The actual system is realized by using Xilinx FPGA board to build a close-loop control,which is based on the equiva-lent model of CSI’s AC side under rotor reference frame. The measured stator current THD value and power factor reached a good result.