Loss Modulated Direct Power Control for Single-Phase Grid Connected Multisource Fed Photovoltaic System

In this paper, a loss modulated direct power control method is proposed for a single-phase grid connected photovoltaic system. The proposed method employs the concept of adding the modulated signal corresponding to converter losses with the modulated signal corresponding to power transfer with ideal inverter. The proposed method is explained with the model of grid connected voltage source inverter with and without converter losses. The implementation of the control method does not require phase-locked-loop resulting in improved efficiency and response time. Further, an algorithm is proposed to generate the reference power required to implement the direct power control with maximum power point tracking for multisource photovoltaic system. The proposed control method and algorithm is implemented with switched capacitor based boost multilevel inverter. The simulation results under varying irradiance and reactive power are presented. The results show the good tracking performance of maximum power point along with real and reactive powers.