Second Order Ripple Reduction in Switched Boost Inverter For Standalone Nanogrid Applications

The switched boost inverters are single stage topologies that boost dc voltage and convert it to required ac voltage. It requires lesser number of components and is more efficient compared to conventional two stage dc-dc-ac methods. The dc-ac conversion results in second order harmonic currents (SHCs) to be reflected at the source end. It causes various problems such as heating or failure of sources, oscillations in maximum power point tracking. The active or passive filters for SHCs may increase component count as well as increase overall cost of the system. In this paper, a sliding mode control based voltage and current control method method is proposed so as to reduce the SHCs in Switched Boost Inverter (SBI). Also, the transients during dc or ac load variations are kept within allowed range. This results in excellent voltage regulation during load changes. The proposed controller is validated through simulation for different types of load and upto 50 % load variations.