Independent Real and Reactive Power Control for Single Stage H8 Transformer-less Solar PV Inverter
The rapid development in power electronics technologies and solar photovoltaic (PV) cell, the interest towards solar PV cell based electric power generation and other applications are increasing with a greater pace. For low power grid or direct load applications, single stage solar PV inverters without transformers are advantageous. Based on this concept solar single stage eight switch H8 based transformerless solar PV inverter is proposed. The objective of the work is to propose a control scheme for H8 inverter to have better power handling capability and for independent real and reactive power control. For this, the test system is studied using MATLAB/ SIMULINK software under three cases (i) constant real power and varying reactive power, (ii) varying real power and constant reactive power and (iii) varying both real and reactive power. The proposed inverter is compared with single-stage solar PV with two switches boost and six switches inverter topology. It is found that power flow ripples and surges are lesser for proposed H8 than with single-stage topology.