A SWITCHED RELUCTANCE MOTOR PROVIDING ROTOR POSITION DETECTION AT LOW SPEEDS WITHOUT A SEPERATE ROTOR SHAFT POSITION SENSOR

摘要

A switched reluctance motor includes a rotor mounted forrotation about a rotor shaft axis and a stator surrounding therotor and having at least three electrically independent statorphases. The motor includes an electronic circuit for forselectively energizing the phases in succession with a run currentto generate a torque on the rotor and thereby rotate the rotor.The circuit includes switch operating means for selectivelyoperating switches connecting an energy source to the phases. Thecircuit also includes current sensing means for sensing the amountof current in each of the phases, and timing means for determiningthe amount of time for the current in each phase to reach apredetermined current level threshold. The circuit also includespulse means for periodically selectively operating the switchoperating means for a limited time to energize the unenergizedphases with a seek current without substantially generating torqueon the rotor, and comparing means for comparing the amount of timethat current in each of the unenergized phases took to reach thepredetermined current level threshold. The circuit also includesrun means connected to the comparing means and the switchoperating means for switching on a selected one of the switches torotate the rotor.