Single-Phase Inverter with Common Grounded Feature and Connected into Grid

Transformer-less inverters are widely used in grid-tied photovoltaic (PV) applications due to their characteristics such as higher efficiency and lower price. In common-ground transformer-less PV inverters, the neutral point of grid is connected to the negative polarity of the PV panel directly to bypass the parasitic capacitances and to mitigate the leakage current. In this study, a single phase transformer-less grid-tied inverter is proposed and to obtain the unique characteristics of the recommended grid-connected topology, the series-parallel switching technique of the switched capacitor module in a packed unit is applied. Also, by utilizing the common grounding method, the leakage current is eliminated. The provided inverter can generate three-level output voltage waveform. To generate the switching gate pulses of utilized power switches, the peak current controller method is applied. The injected power flows (active and reactive powers) are adjusted using peak current control (PCC) method. Finally, a completely adjusted sinusoidal current can be delivered to power grid. In the next section, the operation procedure, comparison results are presented. Finally, to verify the accurate operation and the theoretical equations of the proposed inverter, simulation results are presented.