Modeling of Photovoltaic Grid-connected Inverter and Low Voltage Ride-Through Control

Abstract

Low voltage ride through (LVRT) requires distributed photovoltaic power generation to continue grid-connected operation in the event of a grid drop, and to provide active or reactive power support for the grid, which can help the grid voltage and grid frequency to remain stable. Aiming at the high-precision test of the control system of grid-connected photovoltaic inverter with LCL filter, especially in the simulation environment from real-time historical data of irradiation, weather and grid condition, this paper proposes a cyber-physical system (CPS) based on hardware-in-the-loop (HIL) method for LVRT test. This paper firstly analyzes the requirements of LVRT, gives the selection range of LCL filter parameters, the design of phase-locked loop design, and the control strategies of low voltage ride through. Then it establishes and simulates the grid-connected inverter model and uses a HIL simulator device to build a CPS control system test platform. Finally, The HIL test results are compared with similar software simulation research results to verify the effect.