Time ratio control (TRC) scheme for a DC series motor Part I: Performance

Describes a detailed study of time ratio control (TRC) scheme for a solid state dc series motor drive. The performance characteristics such as torque-speed, supply power factor, supply harmonic content, peak armature current variations are obtained and compared with those obtainable with phase angle control (PAC) scheme under identical operating conditions. The comparative study has revealed that certain performances are improved in the TRC scheme. The drive systems with PAC and TRC schemes simulated on a digital computer. Oscillograms obtained from the experimental setup using a 3 HP dc series motor are presented to demonstrate the feasibility of the schemes and to verify the basic principles of operation.