Constant power operation of a thyristorized commutatorless series motor

Constant power control of drives in general, like constant torque control, is often required in practical industrial applications. This paper describes the constant power operation of a thyristorized commutatorless series motor (CLSM), which is expected to be competitive for high power (MW ranges), normal speed (1500-3000 r/min) applications. The basic thyristorized CLSM drive, developed in recent past S. SenGupta, et al (2000) is described first along with its simplified analytical model K. Mukherjee, et al (2005). Described next is the system for achieving constant power control of this basic CLSM, where it is operated in conjunction with a front-end thyristorized rectifier. A suitable PI controller controls the front-end rectifier for achieving the constant power operation. The overall drive, including the basic CLSM, the front-end thyristorized rectifier and the respective controller, is modeled and simulated for predicting the performances. The simplified analytical model of the basic CLSM (K. Mukherjee, et al 2005) is utilized to model the overall drive and also for tuning of controller parameters. The discussed scheme is finally implemented in the laboratory and experimental results are validated with the simulation results.