Study on the Key Equipment's Insulation Level of ±800kV UHVDC Power Transmission Project

Abstract

China is currently pushing on constructing ±800kV UHVDC power transmission projects. The Yunnan-Guangdong power transmission project to be built in 2009 will be the first UHVDC power transmission project around the world. The paper has presented insulation level and insulation coordination for the key equipment, which would be adopted in the Yunnan-GuangdongUHVDCProject. The research result herein reveals that, compared to 1.6 times insulation level of the key equipments of traditional ±500kV project, it is practical to reduce that of UHVDC project respectively, and the technical measurement would be rational arrangement of arrester and smoothing reactor and reasonable reduction of insulation margin. Furthermore, the test voltage level corresponding to long DC operation voltage has also been discussed in this paper, which is for evaluating internal insulation withstanding capability.

Research on Voltage Mechanism of Power System

“…When 2 eq eq E PX <0.5,the receiving-end system can absorb some reactive power by the system or send some reactive power to the system, depending on the specific voltage level.In any case, receiving-end bus voltage must be higher than the allowable minimum value to cope with the system and disturbance of the load of receiving end, to obtain a stable operation. [2] Figure 3-2 Voltage-reactive power character of receiving end After analyzing equation (3.4), you can further obtain a concise voltage stability criteria as follows:…”