Study on the Steady State Characteristic and Transient Stability of UHV AC Half-wave-length Transmission System Based on Quasi-steady Model

Abstract

Ultra high voltage(UHV) half-wave-length alternating current(AC) transmission technology is an attractive and promised technology for long-distance bulk power transmission.And the study on its steady state characteristic and transient stability is the foundation of its feasibility study.Firstly,the quasi-steady model of a half-wave-length AC transmission line which can be adopted in power flow and transient stability engineering calculation was deduced according to transmission line theory and two-port network theory.Secondly,on the foundation of power flow calculation,the steady state operation characteristic of UHV half-wave-length transmission lines was obtained,and the voltage distribution characteristic was analyzed thoroughly from the aspects of incident,reflected wave composition and reactive power demand.Thirdly,on the foundation of a great deal of transient stability calculation,the transient stability limit and transmission capability of UHV half-wave-length transmission lines was proposed,and the impact of the severest contingency point and the frequency variation on transient stability was investigated.The achievements of the paper provide the powerful technical supports for the feasibility research and the implementation of future testing project of UHV half-wave-length transmission system.