Study of Dynamic Reactive Power Support of Synchronous Condenser on UHV AC/DC Hybrid Power System

Abstract

As the Inner Mongolia Autonomous Region, UHV AC and DC power transmission and transformation projects have been put into operation successively, the Inner Mongolia area power grid has become UHV AC/DC hybrid power system. However, the development of AC and DC projects is not balanced. The characteristics of “strong DC and weak AC” are obvious. Especially, when the sending end auxiliary thermal power unit is connected to the high voltage AC and DC hybrid power grid, it will be bound to affect the safe and stable operation of the UHV power grid, and the stability of the transmission end system is difficult to be guaranteed. The high capacity synchronous condenser can improve the short circuit ratio of DC power transmission system in AC/DC power grid, enhance the dynamic voltage support capacity of the AC power grid and improve the stability of the power grid. This paper takes the regional power grid of the transmission end of the xilinhaote to Taizhou of jiang su ultra-high voltage dc transmission project (hereinafter referred to as the “Xitai DC”) as the research object, using Power System Analysis Software Package simulation software, through simulation to carry out the comparison analysis. From the angle of AC and DC transmission capacity and single end trip of line, it comprehensively evaluates influence of synchronous condenser on the stability level of the power grid. The results show that the synchronous condenser has good dynamic voltage support ability and strong short-time overload ability and can effectively improve the stability level of UHV AC and DC hybrid power grid.