Analysis and Improvement of Maximum Power Point Tracking Algorithm Based on Incremental Conductance Method for Photovoltaic Array

Photovoltaic (PV) array in the photovoltaic power system (PVPS) has the nonlinear current-voltage characteristic which is affected by the panels temperature and irradiance conditions. To improve the energy converter efficiency of the PVPS, the maximum power point tracking algorithm should be adopted to maximize the yield of the PV array. The incremental conductance (INC) method is widely used in the PVPS due to its succinctness and high tracking efficiency. The conventional INC algorithm using a fixed iteration step-size is impossible to achieve rapid dynamic response and good steady tracking accuracy simultaneously, because if the step-size is increased for rapid dynamic response, the tracking accuracy is decreased and vice versa. An improved algorithm with variable step- size is proposed to solve the problem in this paper. The contrastive experimental results between the improved and the conventional INC algorithm are presented to demonstrate its effectiveness.