All-mode phase shifting transformer model in electric power system

Abstract

The phase shifting transformer in the electric power system (EPS) provides more efficient control of EPS modes by voltage and active power flow regulation. However, nowadays quasi-steady and transient processes in the EPS become more complicated. As a result, the commonly used simulation tools apply decomposition of EPS processes to quasi-steady and transient, simplification of mathematical models of EPS elements, limitation of the simulation time interval. Mentioned simplifications and limitations in general lead to an uncertain loss of completeness of EPS modeling. The concept of software and hardware tools of phase shifting transformer simulation, presented in the article, allows to solve this problem. The software and hardware of phase shifting transformer simulation are the tools of hybrid simulation, which include analog, digital, and physical approaches of the simulation. The analog approach is the solution of the differential equations system, describing the phase shifting transformer processes by continuous implicit integration. The digital approach provides the control of the electronic switches, the phase shifting transformer parameters, such as leakage inductance, active resistance etc. The physical approach is the connection and switching in the EPS elements as in real EPS. The article presents the all-mode thyristor-controlled phase shifting transformer model, developed by hybrid simulation approach and adapted for use in the Hybrid Real Time Power System Simulator developed in Tomsk polytechnic university. The appropriate research of phase shifting transformer in the EPS was carried out by Hybrid Real Time Power System Simulator, in which the Tomsk EPS (region of Russia where there is a problem of non-synchronous operation of the northern and southern parts) is implemented. By means of the Tomsk EPS model and developed phase shifting transformer model, the purpose of which was to interconnect two asynchronously operating parts of the Tomsk EPS and experimental research were carried out.