Analysis and simulation of possible bifurcation and subharmonic oscillation in transformer coupled TCR system

Thyristor controlled reactor (TCR), which is typically linked by a coupling transformer to the gird, is widely used as a continuously variable reactive power compensator in electric power systems. This paper focuses on anomalous nonlinear phenomena in a TCR system, called switching time bifurcation, and is showed the possibility of subharmonic and interharmonic oscillations accompanied with the switching time bifurcation and synchronous resonances. Also impact of capacitor banks on occurrence of bifurcation phenomenon has been considered. It has been shown that the correct selection of the shunt capacitor may prevent or reduce bifurcation phenomenon.