Analysis on Transient Overvoltage Mechanism of Large-scale Renewable Energy Integration System

The transient overvoltage problem on wind farm side is one of the main factors constrained the transmission capacity of large-scale renewable energy integration system and interconnection capacity of renewable energy. In this paper, the sensitivity of the voltage of the wind turbine generators is firstly derived to illustrate the mechanism of the overvoltage problem. Then the simulation is performed on a prototypical system and a practical power grid in north of China respectively. The results show that the constant reactive power control of the dynamic reactive power compensators (RPCs) combined the increasing internal potential of the equivalent system result in the transient overvoltage. Finally, the impact of different control modes of RPCs is analyzed. It is concluded that the constant voltage control of the dynamic reactive power compensators or the small synchronous condensers installing in wind farm can effectively suppress the overvoltage problem.