DEVICE FOR DEFINING COORDINATES OF INDUCTION MOTOR IN VARIABLE-SPEED DRIVE Russian patent published in 2002 - IPC

FIELD: electrical engineering; general-purpose industrial drives. SUBSTANCE: newly introduced in device are control system for polar coordinates of stator current vector and system for computing polar coordinates of rotor flux linkage vector that interacts with control system. Control system for computing polar coordinates of stator current vector functions to trace changes in constant-sign quantities as distinct from prior art where tracer currents are organized to follow up sinusoidally varying quantities. Such novelty makes it possible to avoid use of variable parameters and very high gain factors at the same time maintaining high precision of motor coordinate location thereby essentially reducing requirements to speed of implementing processor unit. Control system is built so that coordinates can be computed throughout entire speed variation range without any uncertainty at it zero value as distinct from prior art. Effect of permanent feedback circuits in system for computing polar coordinates of rotor flux linkage vector causes reduced response of operating device to noise compared with prior art. EFFECT: enhanced reliability of recovering motor coordinates under steady state and transient operating conditions of drive. 2 dwg