Direct control method for a PV system integrated in an Indirect Matrix Converter-based UPQC

This paper proposes a direct control method for a three-phase Photovoltaic (PV) system integrated on the Low-Voltage grid, using an Indirect Matrix Converter (IMC)-based Unified Power Quality Conditioner topology. This topology adds enhanced Power Quality functionality to the PV inverter when connected to a sensitive non-linear load, such as load current harmonics mitigation and voltage sags, swells and harmonics compensation. The PV array is inserted in the DC link of the IMC, which is controlled with a direct sliding mode control method. This direct control allows using a specific modulation method for the shunt converter that guarantees the DC link voltage is adequate for the operation of the IMC. Simulation results are presented to confirm the proper operation of the system under a variety of operating conditions.