A microprocessor-based suboptimal speed controller for an SCR-DC motor drive

The authors present the implementation of a suboptimal speed control algorithm for an SCR-DC motor drive. The algorithm is based on look-up tables that provide steady-state open-loop control. The nominal firing angle correction is based on constraints on the execution time and the maximum average armature current. The performance of the algorithm is compared to that of the two-step look-ahead controller. The algorithm is also verified through bench model testing. The algorithm considerably reduces the number of look-up tables and hence can be implemented on a single off-the-shelf microprocessor instead of two microprocessors in a master-slave configuration