Unified Control of Photovoltaic Grid-Connection and Power Quality Managements

This paper presents a control system that combines photovoltaic (PV) grid-connected generation and power quality managements. With the proposed structure, the system can not only realize photovoltaic generation, but also suppress current harmonics, compensate reactive power, eliminate voltage sags or swells and mitigate instantly power interruption and other power quality problems. An adaptive predictive maximum power point tracking (MPPT) algorithm is employed to improve the efficiency of PV generation. To simplify the control, the synchronous reference frame method is applied in modeling the inverter. The structure of a faster internal current control loop and a slower external voltage control loop is used in order to obtain a good dynamic response. The simulation results verify the good performance of the proposed controller.