Development of a SOPC for PMSM drives

A system-on-a-programmable-chip (SOPC) using an Altera FPGA (Stratix EP1S10) and a Nios embedded processor to develop drive system for permanent magnet synchronous motor (PMSM) is presented in this paper. In this SOPC, it has two modules to construct a fully digital drive controller. One module performs the function of the speed/position loop control and motion trajectory control of PMSM drives. The other module performs the function of the current loop control for PMSM drives, which includes vector control, SVPWM generation, coordinate transformation, PI controller and the pulse detection of the quadrature encoder. The former is implemented by software using Nios embedded processor due to the need of complicated control algorithm and low sampling frequency control (motion trajectory control & position control: less than 1kHz). The latter is implemented by hardware due to the need of high sampling frequency control (current loop: 16 kHz, PWM circuit: 4∼8 MHz) but simple computation. To confirm the effectiveness of the proposed SOPC, an experimental system with a PMSM, a FPGA experimental board, an inverter and a rectifier has been set up and some experimental results have been validated with the theoretical ones.