Efficiency-Optimized Speed Control System Synthesis Method Based on Improved Optimal Regulator Theory---pplication to Separately Excited DC Motor System

A new synthesis method for the efficiency-optimized speed control system for the separately excited dc motor system is proposed on the basis of an improved optimal regulator theory. The optimal ratio of the armature current and the field current that gives the maximum efficiency is analytically derived, and the error term of the current ratio is included in a performance index. Then, the control system which realizes both the satisfactory response and the optimal current ratio giving the optimal efficiency is constructed in the systematic design procedure. In simulational and experimental results, close agreement between them is obtained. Also, considerable improvement on the efficiency of the motor system at the steady state is obtained.