4-wire Matrix Converter based voltage sag/swell generator to test LVRT in renewable energy systems

The incorporation of high power rate Wind Energy Conversion Systems (WECS) have significant influence in the stability, power quality and reliability of the electrical grid. Therefore, strict grid codes have been developed during the last years in order to enhance overall stability of the systems. Thereby Low Voltage Ride Through (LVRT) requirements is a key issue for WECS. In order to test the response of WECS under grid-voltage sag conditions, a Voltage Sag Generator (VSG) is needed. This paper presents a novel Matrix Converter based VSG Prototype in order to study the fulfilment of LVRT requirements. Voltage sags/swell of variable magnitude, duration and type can be generated for the proposed VSG without using complex modulation schemes.