Impact of new-type synchronous condenser on voltage stability of jarud sending-end system

With the construction and development of UHVDC transmission system, the problem of insufficient dynamic reactive power reserve of the power grid is becoming increasingly prominent. As a typical UHVDC weak sending side, the short-circuit capacity of Jarud sending-end system is small, which causes high pressure on voltage stability in short-term failures. The introduction of new-type synchronous condensers will effectively improve the power system voltage stability. In this paper, Lugu UHVDC system is investigated. Firstly, the general situation of Jarud sending-end system and the demands for dynamic reactive power compensation are introduced. Then, the technical characteristics of the new-type condenser are analyzed starting from the performance improvement on subtransient, transient and steady state. Finally, simulation models of the condenser and Lugu UHVDC transmission system are built in PSCAD/EMTDC and are used to demonstrate. The effects of the new-type condenser on the system voltage are simulated and verified under the AC-side short circuit, the commutation failure and the bipolar blocking. And the impact of condenser on voltage stability of sending-end system is analyzed.