A Low Cost MCU Based Single Phase Sinusoidal Pulse-Width-Modulated Inverter

Sinusoidal pulse width modulation (SPWM) technique has been widely used in inverters and motor driver ciruits. In this paper, SPWM was generated by a low cost HT66F50 single-chip, wherein the reduced sampling points of a sine wave, and the fewer sampling points were then used to produce SPWM singals. The full-bridge inverter was modulated by the high switching frequency SPWM for the high side switches and the 60Hz control signals for the low side switches. Thus, it not only reduces the required memory spacein MCU, but also reduces the switching power losses. When the SPWM frequency is 19.53 kHz or 11.72 kHz, the total harmonic distortion (THD) of the inverter’s output is less than 0.6% under the load resistance 50, which is in compliance with the specification of IEEE STD. 519-1992.