Voltage Control Of A 3-Ø Self – Excited Induction Generators Using TSC (Thyristor Switched Capacitance)

A. Kumar, A. Chaubey
Infosys Limited, IN

Keywords: thyristor, induction generator, wind energy


An induction generator requires reactive power to set up and sustain magnetization and hence generates power. In grid connected induction generators this requirement is met by the grid, which unnecessarily burdens the grid and in some cases the amount of reactive power consumed might even exceed the amount of active power generated.Our work is based on the Thyristor Switched Capacitance scheme using TRIAC, since it minimizes the number of power components required. We developed the voltage regulator using TRIAC as a power switch. Firing scheme for the TRIAC is developed in such a way that the external capacitor is injected to the existing power system when the current across the capacitor is minimum to ensure lower surge losses compared to normal condition without VAr compensation. We found that when monostable pulse generated at the negative edge of the rectangular wave using IC-74121is amplified, it triggers the TRIAC and when this pulse is aligned with the peak value of the input signal the capacitor is successfully injected using TSC scheme, which regulates the terminal voltage of the induction generator. By increasing the value of external capacitor, rate of decrease in terminal voltage of the Induction generator can be controlled.