Effects of Source Impedance on the Steady-State Performance of Thyristor Controlled Circuits

General mathematical relations are developed for the power factor and harmonic contents of the currents and metering voltages of thyristor controlled inductive loads fed from a source having significant impedance. This impedance has previously been neglected; it could be that of the supply feeder or transformer. The general relations developed cover the special cases described in the literature. Numerical solutions and the results obtained by an analogue computer study agree with those of actual tests. The voltage regulation caused when feeding a thyristor controlled load is slightly less than when feeding an uncontrolled load of the same power and equal power factor. The voltage regulation decreases with decrease of power factor for the same thyristor controlled load.