Permanent magnet motor harmonic filter

Abstract

Architectures or techniques are presented that can improve operation of permanent magnet (PM) motors, which can be part of a compressor or other heating, ventilation, and air conditioning (HVAC) device. Such improvements can be achieved by integration of inductive filtering into the motor assembly. A higher overall inductance can reduce current ripple and can further result in a lower total harmonic distortion, reduced power loss, and reduced heat generated. For example a first architecture can include a ferromagnetic core element in the PM motor that can cause a non-torque-producing reluctance path to the shaft. A second architecture can integrate a signal filter, which is customarily external, into a housing of the PM motor. Such can significant reduce costs and provide other advantages. A third architecture can couple an inductor (e.g., of the signal filter) to the shaft. Rotation of the shaft can thus serve to provide additional cooling for the inductor.