SENSORLESS CONTROL APPARATUS FOR SYNCHRONOUS RELUCTANCE MOTOR FOR IMPROVING PERFORMANCE OF TRACKING LOOP IN LOW VELOCITY MODE

摘要

PURPOSE: A sensorless control apparatus is provided to control the velocity of a motor in a smooth manner by estimating the velocity through the velocity obtained from the position calculated in accordance with a low velocity mode or a high velocity mode. CONSTITUTION: A sensorless control apparatus comprises a flux estimation unit(21) for taking, as an input, voltage and current of a synchronous reluctance motor, and estimating a flux; a high velocity rotor position estimation unit(22) for taking, as an input, the estimated flux from the flux estimation unit, and estimating the position of a rotor, during high velocity operation; a low velocity rotor position estimation unit(31) for taking, as an input, the estimated flux from the flux estimation unit, and estimating the position of a rotor, during low velocity operation; a switching unit(29) for selecting and switching the output of the low velocity rotor position estimation unit or the high velocity rotor position estimation unit in accordance with a high velocity mode or a low velocity mode; a rotating velocity estimation unit(100) for computing the output of the low velocity rotor position estimation unit or the high velocity rotor position estimation unit, and applying the estimated rotating velocity to the high velocity rotor position estimation unit; and a coordinate converting unit(30) for converting the output of the switching unit into a synchronous or static coordinate system, and outputting the coordinate system to the flux estimation unit.