Digital sinusoidal PWM generation using a low-cost micro-controller based single-phase inverter

This paper presents the implementation of two digital sinusoidal PWMs (DSPWMs) using a low-cost 8-bit micro-controller. Each DSPWM is implemented using two different PWM hardware modes on the micro-controller. The benefits and limitations of each DSPWM are investigated in relation to the switching frequency and micro-controller performance from experimental verification using a 2 kVA single-phase inverter. The standard left aligned PWM module found on low-cost micro-controllers is shown to provide performance benefits similar to a DSPWM requiring a higher-cost micro-controller for its implementation. The main benefit being the reduction in microcontroller resources, allowing more time for features such as protection, monitoring, interfacing, variable switching frequency and grid synchronization