Method and apparatus for sensing brushless DC motor average current from overcurrent protection circuitry

摘要

A method and an apparatus that permit the measurement of the motor average current directly from the output of the amplifier and filter stage used for instantaneous dc-link overcurrent protection. As such, only one amplifier and filter stage is sufficient to provide both the motor average current and instantaneous dc-link overcurrent protection. The invention permits the suppression of the amplifier and filter stage that is typically used to derive the motor average current directly from the dc-link current.