Instability risk and control strategy of receiving-end power grid integrated with UHVDC and HVAC lines

There are many receiving-end provincial grids in North China-Central China synchronous power grid. They get power through UHVDC transmission channel and interprovincial HVAC transmission channel. This paper analyzes two important instability risks faced by this type of provincial power grid, including power angle instability after DC blocking fault and voltage instability after AC system fault. The typical engineering control measures for the instability risk are given, and their applicable conditions, characteristics and application strategies are analyzed. Finally, the application prospect of battery energy storage technology to improve the safety and stability of power grid is discussed.