LOSS MINIMIZATION OF A DC MOTOR DRIVE

ABSTRACT

This paper presents a practical method for operation of a semi-converter-fed DC motor drive at the point of maximum efficiency while maintaining any particular torque-speed load point. Design and operation of an economical, microprocessor-based adaptive controller used to retrofit a commercially available SCR drive for minimum loss operation of a DC motor is described. Experimental and simulation results are presented in graphical forms, giving comparison of overall drive system efficiencies between loss minimization adaptive control and conventional constant field current operation for a standard-efficiency DC motor with a 7½ hp rating for both separately excited and shunt connected configurations. The greatest potential for energy savings is found to exist for the case of light load at low speeds.