Unity Efficiency and Low-Cost MPPT Method for Single-Stage Grid-Connected PV System

This paper presents a new maximum power point tracking (MPPT) algorithm based on the adaptive linear neuron concept. This algorithm is designed to extract the maximum power in single-stage grid-connected photovoltaic (PV) system configuration. In the considered system, a PV panel is directly connected to a grid through a three-phase pulse-width modulation inverter. The control is achieved in the synchronous dq frame, and the proposed MPPT estimates directly the optimal d-axis duty cycle component. Furthermore, in order to achieve a unity power factor operation, the q-axis reference current is set to zero. In this work, only one proportional-integral controller is used to maintain the reactive power to zero value. To verify the effectiveness of the proposed algorithm, the grid-connected system is implemented and simulated under MATLAB-Simulink software. The obtained results are compared to those achieved by the conventional perturb and observe based MPPT technique under fast and slow irradiance changes. The simulation results show that the proposed method leads to achieve incomparable performances such as unity efficiency and zero oscillations in the PV panel in both transient and steady-state operations.