Series-commutated SCR controllers for variable-speed reluctance motor drives

A series of electronic controllers using power SCR1s has been developed and tested for use in controlling variable-speed reluctance motors from a fixed-voltage direct-current source. The series commutated SCR1s are operated in a pulse mode compatable with the restrictions of the reluctance machine. The motor-controller system is capable of both motoring and regenerating operation. The controllers have been designed to control both the magnitude and the pulse width of the output current pulse over a wide range of pulse frequency. The controllers have been tested at power levels up to 20 H.P. and controller efficiency has been accurately measured using electronic-multiplier wattmeters. The theory of the power circuit has been, developed including the derivation of current wave forms with time-varying inductance loads.