A Novel High Step-Up DC-DC Converter with Improved P&O MPPT for Photovoltaic Applications

In this research work, a Maximum Power Point Tracking (MPPT) algorithm is proposed that improves the tracking accuracy and efficiency of the conventional Perturb and Observe (P&O) algorithm. Due to steady-state oscillations and passive dynamics, the efficiency of conventional P&O algorithm is significantly affected in varying climatic conditions. Therefore, to improve its efficiency and tracking accuracy, a reference voltage is defined as a function of irradiance and temperature in the proposed Improved Perturb and Observe (IP&O) algorithm. Moreover, the solar irradiance and temperature of the PV panel are estimated that results in low steady-state oscillations and fast dynamic response. Furthermore, to step-up a low generated PV voltage to a high voltage level, a non-isolated DC-DC converter suitable for large voltage conversion ratios is also designed. The proposed converter uses only one switch that makes its circuitry and control simple and makes it very feasible for PV applications. This converter attains a high voltage gain with relatively low voltage stress on a switch compared with the conventional or other newly developed topologies that have the same or lesser components count. To validate the theoretical concepts of the DC-DC converter and the IP&O algorithm, simulations are carried out in MATLAB/Simulink environment at varying operating climatic conditions. The simulation results and the comparative examination with the conventional P&O algorithm validate the proposed algorithm's adequate performance.