Programmable Thyristor Power Supply for Large Capacitor Banks

While charging large capacitor banks from a constant-voltage source the initial charging current can be excessively large. Various methods are available to overcome this difficulty such as the use of a series resistor, motorized auto-transformers, induction regulators, etc., which have certain disadvantages. This paper discusses a thyristor phase controlled capacitor charging system which enables programmable constant current charging. Further, ample standby power is available at the end of the charging cycle which helps in sustaining the voltage across the electrolytic capacitor banks which have comparatively high leakage.