Simulation Research On The Fault And Protection Of Thysistor Controlled Series Compensators And Ultra-High-Voltage Transmission Lines

With the development of huge electric power grid in China, the scale and structure of power grid construction, especially the planning on sending power from west to east, North-South supplementation and nationwide interconnection are coming into being, and more and more new types of transmission technology and modes in the power grid in China are applied. This paper presents the research on the fault and protection of Thysistor Controlled Series Compensators (TCSC) and ultra-high-voltage transmission lines.Thysistor Controlled Series Compensator (TCSC) is one of the important members of Flexible AC Transmission System (FACTS), having a lot of advantages in improving performances of power systems. Now, in the research on the simulation of protection and control schemes of series compensation system, the models of nonlinear component and compensation device protection are ivory-towered, the inner taches of line protective relay are neglected, and the simulation system is different from the engineering practice. This paper improves the TCSC simulation model, takes the YiFeng series compensation project as the prototype , builts the simulation model according with the engineering practice(including Common-Tower Double-Transmission Line and three circuit line), and simulates the actual forms of fault (including inter-line fault). So it establishes the transient simulation platform of the TCSC network,further analyzes the characteristics of the protective relay, gets the engineering results and presents some operation advices.Nowadays ultra-high-voltage (UHV) transmission technology has been developing to the demand of long-distance, large-capacity transmission grid and the construction of large power grids in China. Under construction now,the 1000kV UHVAC transmission testing project from Jindongnan to Jingmen via Nanyang is the world's highest voltage grade, the most challenging of network engineering, the safety and protection issues have been receiving researchers' attention. This paper takes this UHVAC transmission testing project as the prototype, studies the line fault transient process, mainly researches on the influence of the sending-end equivalent power source's Operation Mode (parameters), condition of the electric equipments(high-voltage shunt reactor, low-voltage reactor and low-voltage capacitor) and the fault moment on electromagnetic transient, and presents some operation advices.In addition, the paper also studies on the problem whether chose using PI-type or T-type network model in transmission line model of UHV dynamic simulation test, establishes simulation model, Compares characteristic differences of PI-type and the T-type circuit transmission line model. According the simulation results, it presents the advice about the form of line's model in dynamic simulation test, which is helpful for the establishment of the physical network model of UHV.At last, the paper gives the summaries and points out the further work.