Digital implementation of peak current mode control for single-phase H-Bridge inverter with slope compensation

In this paper, digital peak current mode control for single phase H-bridge inverters is developed and implemented. Peak current mode control is achieved by directly controlling the PWM signals by cycle-by-cycle current limitation. Unlike the dc/dc converter where the output voltage always remains in the positive region, the output of H-Bridge inverter flips from positive to negative region continuously. Therefore, a novel control logic circuit is designed and implemented in the hardware to track the reference in both regions. The problem of sub-harmonics which is inherent with peak current mode control is also addressed with the introduction of digital slope compensation.