Grid connected PV system with load power compensation capability using sliding mode control

This paper presents the modelling and design steps for a grid connected Photovoltaic System using a single-stage three-phase Voltage Sourced Converter. As the PV array is directly connected to the DC bus, a Maximum Power Point Tracking algorithm provides the reference voltage for an outer DC voltage control loop. The interface converter is controlled using a direct power sliding mode control without any synchronization circuit. This is possible because the converter´s control is done in the stationary reference frame. Besides the active power injection, this system is able to compensate the reactive and harmonics power consumed by the loads. For the pattern switching, space vector modulation is used to generate constant switching frequency. Simulation results are presented to validate the proposed system during the active power injection and load compensation.