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.