Field Oriented Control of Synchronous Machines using a Novel Feedback System

Abstract

Field orientation method of speed control has emerged as a powerful tool for ac machines. The dynamic performance of such a drive is comparable to that of a converter fed four quadrant dc drive. An over view of various control strategies to implement the principle of field orientation in synchronous motors is presented. In addition, a novel scheme of hysteresis current control with field orientation for a salient pole synchronous motor is illustrated. In view of the significant reduction in cost and simplification of the circuit complexity of the scheme, it can very well replace the commonly favoured separately excited dc motor drive.