VSG Based on Spatial Phase Analysis of PV for Unbalanced Voltage Grid Fault

Photovoltaic power (PV) generation systems connected to distribution network are able to effectively absorb local solar energy and improve the reliability of power supply. The virtual synchronous generation (VSG) technology used in inverter of the PV can help it improve the ability of connecting to power system by increasing system inertia and damping. This paper proposes an optimized VSG control strategy which is based on spatial phase analysis to solve the fault problem of PV system facing unbalanced voltage fault in grid so that the reliability of PV system can be improved. In details, the proposed strategy is able to control the fault current and reduce second harmonic component of power of PV system connected to grid by analyzing different vectors affecting different electrical parameters. The simulation carried on PSCAD/EMTDC proves the effectiveness and superiority of proposed improved VSG strategy compared with P/Q and normal VSG strategy.