Grid-connected PV system modeling and control based on the variable step size of MPPT algorithm

Abstract

Based on two kinds of maximum power point tracking (MPPT), this paper proposed an improved variable step size incremental conductance algorithm which combined with constant voltage tracking. The operating point of PV array is located near the maximum power point (MPP) rapidly by using the fixed voltage method, and the PV array is controlled to run at the MPP quickly and accurately adopting different disturbance step. Grid-connected inverter adopts the double closed-loop control strategy of based on feed-forward decoupling to realize the decoupling control of active and reactive power. In PSCAD/EMTDC, the model of grid-connected photovoltaic system (GCPS) has been implemented and verified the effectiveness of the improved MPPT algorithm.