The FC-TCR is supplied from the step down coupling transformer. The variation in reactive power is performed by switching the FC-TCR and controlling the firing angle α, which is in the range of 0–90°. For keeping the system voltage constant, the SVC susceptance B is measured using the voltage regulator as shown in Fig. 7 of the SVC control system. The equivalent susceptance, Beq as mentioned in (3) is determined by the firing angle α of the thyristors that is defined as the delay angle measured from the peak of the capacitor voltage to the firing instant [4], [5], [6], [7], [8] and [9].
equation(3)
Beq=BL(a)+BC