The Characteristic Analysis And Physical Model Design Of Thyristor Controlled Series Compensation

TCSC (Thyristor Controlled Series Compensation) is one kind of FACTS (Flexible AC Transmission System) instrument. It can realize the large-scale smooth regulation of the TCSC impedance through changing the trigger angle of thyristor, which has significant meaning for electric power system. TCSC can be used to improve the transmission capacity and voltage distribution of some transmission aisle. In the netlike power network, TCSC can be used to control power flow based on the system operation condition, so the network loss can be reduced and the distribution of power flow can be optimized. If located on appropriate transmission lines, TCSC can make the transmission line appear electrically shorter which results in increasing the synchronizing torques between the generators and thus improves the transient stability margin of the power system. TCSC can also be used to improve the weak damp or negative damp status between inter-network or local network, accordingly improve the dynamic stability. Through a certain trigger rule, TCSC has the capability to control the energy exchange between the series capacitor and the turbine-generator shaft, restrain the subsynchronous heft, and thus, avoid the risk of potential subsynchronous resonance problems.Firstly, the application and researches of TCSC are overviewed. The importance of developing the TCSC physical model is given, the frame and the operation principle of TCSC are described. Then, using a topological model building method, the TCSC steady state model with the resistance in the reactance branch is formulated. The time domain representations of the voltage across the capacitor and the current in the inductance branch are deduced. The digital simulation and the prototype test investigate the influence of the resistance contained in the reactance branch on the steady state characteristics of TCSC.The physical model of TCSC is a useful tool for investigating the dynamic characteristics for the reason that with such a physical model the detail dynamic of TCSC with the real power system can be precisely simulated. In this paper, system of glyphographes for data recording, system protecting and controlling are designed withsuch DSP chips as TMS320C206 and TMS320F240 according to parameters of dynamic simulation lab. Functions as data recording, system protecting and controlling are realized. Monitoring and controlling system that based on VC++6.0 and NetBIOS is also set up. Functions as communication between the above two systems, good interface, curve drawing and operation of data based on database ACCESS are also realized.This thesis experiments on the developed TCSC experimental setup. Impedance step response under different synchronization signal, transient characteristic when capacitive vernier mode and inductive vernier mode switch each other are investigated. Meanwhile, this thesis discusses the mode switch process deeply.