A novel voltage sag generator for low voltage ride-through testing of grid-connected PV system

The capability of Low Voltage Ride-Through (LVRT) is required in China´s standards as more and more photovoltaic (PV) generation system in large scale are connected to the grid. Voltage sag generator (VSG) is the device for LVRT testing. A novel design of VSG for LVRT testing of PV system is proposed in this paper, by which the grid voltage sags to 90%∼0% (10% per degree) can be simulated with good performance. With the SVG, an entire model for LVRT test of PV system is built on real-time digital simulator (RTDS). The results of simulation verify the correction of LVRT platform and the feasibility of VSG design. This paper helps for the research of PV system´ LVRT and the production of real VSG device for LVRT testing.