Impact of FRT Control Strategies of Photovoltaic Power Generation System on Short-Term Dynamic Voltage Response

In this paper the study of impact of the FRT control strategies of photovoltaic (PV) power plants considering recently amended German grid code on short-term dynamic voltage response (recovery) is presented. For the study, a simplified dynamic PV power plant model, which is validated against measured data and detailed model, suitable for the stability study is developed. Different control strategies during grid fault are compared with FRT capability and comprehensive dynamic grid support for their dynamic performance in terms of improving grid voltage recovery. In addition, the influence of system load and grid strength along with different steady state reactive power control modes are analysed. The results indicated that the FRT capability and comprehensive dynamic grid support of German grid code improves the grid voltage during fault and speed up voltage recovery which helps the PV system from short-term voltage stability problems. Among the reactive power control modes during steady operation, the voltage control performs well. In addition, the voltage of stiff grid with high short circuit ratio recovers rapidly.