Voltage Sensorless MPPT in a Differential Power Processing Photovoltaic System

Abstract

A differential power processing (DPP)-based high-efficiency photovoltaic system that uses an effective duty technique in place of voltage sensors is presented in this paper. The DPP fourth-generation photovoltaic system structure is adopted to reduce the power conversion loss. However, there is a disadvantage that the number of devices increases. Therefore, this paper proposes the effective duty technique that can reduce the number of devices while using the DPP structure. In the effective duty technique, the voltage sensor for maximal power point tracking (MPPT) is eliminated, and the voltage for implementing the P&O algorithm calculated using only measurements from the current sensor. A small-capacity photovoltaic system was constructed for the simulation and experiment. The simulation results confirm that the effective duty technique has the same performance as the conventional MPPT technique. The experimental results confirm that the MPP corresponding to each irradiance amount under changing irradiance conditions was tracked successfully with almost the same performance as MPPT control using voltage and current sensors. The experimental results confirm that the MPP corresponding to each irradiance amount under changing irradiance conditions was tracked successfully with almost the same performance as MPPT control using voltage and current sensors.