Control of active/reactive power and low-voltage ride through for 40 kW three-phase grid-connected single-stage PV system

Abstract

Photovoltaic (PV) grid-connected system becomes one of the most important and promising applications for solar energy, the interfacing of these systems to the grid requires efficient control strategies for operation, control and power quality (PQ) improvement. The operational objectives of PV system are fulfilled by many control modes, during sunlight, the system sends active power to the grid and at the same time compensates some of the load reactive power. In case of lower isolation level, the inverter compensates some of the load reactive power. The advantage of this strategy is to get use of the inverter total capacity all day long. The study presents the maximum real and reactive power control algorithm for 40 kW three-phase single-stage PV system using a fast approximation interpolation algorithm of maximum power-point tracking (MPPT), the controller must fulfil the low-voltage ride through requirements. For this purpose, some modifications need to be applied to make the inverter ride-through compatible with any type of faults according to the grid codes.