Design And Realization Of Three-Phase Current Source Natural-Sampling SPWM Rectifier Based On FPGA

With developing of full-controlled converter technology and expanding of the application field, high power factor PWM rectifier attracts the widespread attention in industrial field gradually. During all the PWM methods, natural-sampling SPWM is a good choice for its flexibleness, good output wave shape and low harmonic. The traditional realization of SPWM control scheme based on DSP is difficult to fulfill natural-sampling SPWM calculation for the sequential control process of DSP, which hamper the performance improving of the PWM rectifier in some special applications. So, this paper introduces a digital scheme to implement natural-sampling SPWM control based on FPGA, and the scheme is validated on a three-phase current source rectifier (CSR) topology. Compared with DSP, FPGA has plenty of programmable logic resources, rich I/O ports and enables the control system to operate at parallel control process. All these excellent advantages make the control circuit working at very faster speed and with minimal time delay. It is proved from simulations and experiments that the proposed natural-sampling SPWM scheme based on FPGA is right and effective.