Symmetrical and Extinction Angle Control of Solid-State Series Motor Drive

In this paper, two control schemes are proposed and investigated for solid-state dc series motor drive. Performance characteristics such as torque speed, input harmonic content, power factor variation, and peak motor current are obtained for both control schemes and compared with the commonly used phase-angle control scheme under identical operating conditions. The input power factor is always lagging in the phase and symmetrical angle control schemes, while it is leading in extinction angle control scheme over a wide range of speed and power. Each control scheme appears to have certain merits over the other schemes. Experimental results verify the basic principles of operation and demonstrate the feasibility of these control schemes.