Dual-mode controller for MPPT in single-stage grid-connected photovoltaic inverters

This paper presents a dual-mode controller to improve the performance of maximum power point tracking in grid-connected photovoltaic inverters. Most of grid-connected PV applications require a controllable active/reactive power generation. The proposed method employs both of the load angle and the inverter modulation index into two control modes: Active power mode, and reactive power mode. Such technique enables an efficient and flexible active/reactive power control beside MPPT function using a single-stage VSI. A simulation model is developed for the overall system to investigate the performance of the proposed dual-mode controller. Furthermore, the controller is designed and implemented using a digital signal processor (DSP). Algorithms are configured on a fixed point DSP TMS320F2812. Moreover, the controller is simulated in MATLAB/Simulink environment and is experimentally investigated using a breadboard built especially for the case study. The results show good dynamic and steady-state performances.