Design and implementation of DSP based high-frequency SPWM generator

Abstract

Nowadays power electronic DC/AC inverters are widely used in energy conversion and motor control application. Higher-frequency SPWM (Sinusoidal Pulse Width Modulation) waves can decrease the size of passive component in the inverter, achieving a low volume and a lightweight as needed. This paper presents a DSP based SPWM generator, which can operate at switching frequencies up to 1 MHz, thus it can meet the high switching frequency demands of modern DC/AC inverters. The proposed design is based on the HRPWM (High Resolution Pulse Width Modulation) block which is available in the TI DSP, and it is verified using the TMS320F28335 controller and a DC/AC power inverter prototype. The experimental results confirm that this SPWM generator achieves much faster switching frequency, less harmonic interference, and higher resolution of SPWM waveforms, showing a better performance compared to past design.