Research On Simulation And Application Of Thyristor Controlled Transformer Controlled Shunt Reactor

With the development of EHV and UHV in our country, research on controllable shunt reactor (CSR) becomes more and more important. It shows that, as a FACTS device, CSR has wide range of uses in reactive compensation, voltage stability, controlling secondary arc current and power frequency overvoltage, and system stability. Meanwhile, it is one of the most useful method to resolve the contradiction between reactive compensation and controlling overvoltage.This paper analysed the advantages of Thyristor Controlled Transformer (TCT) Controlled Shunt Reactor, simulated types of TCTCSR, and researched on the application of the TCTCSR in EHV system. The main work of this paper is as follows:Firstly, this paper introduced structures and theories of three types of controllable shunt reactor. The three types are Stepped Controlled Shunt Reactor, Magnetically Controlled Shunt Reactor and Thyristor Controlled Transformer (TCT) Controlled Shunt Reactor. This paper also concluded the advantages and disadvantages of these three types, from response speed, control characteristic, harmonic characteristic economics, technology maturity and other respects.Secondly, using theory analysis, simulation and other methods, from control characteristic and harmonic characteristic respects, this paper compared three typical types of CTCSR. The three types are 12 pulse structure,6 pulse with Y connection on control winding and △ connection on valve block winding structure and 6 pulse with Y connection on control winding and Y connection on valve block winding structure. According to the simulation result, this paper recommended the 6 pulse with Y connection on control winding and Y connection on valve block winding structure as the best structure of TCTCSR.Finally, based on parameters of one certain 750kV transmission line, this paper designed a simulation model and applied TCTCSR into it. According to the simulation result, the TCTCSR was proved to have significant influence on inhibition of secondary arc current and power frequency overvoltage caused by capacity effect, unbalanced short circuit and load rejection.