End Ring and Rotor Bar for Line Start Permanent Magnet Motor

摘要

A rotor for an LSIPM comprises a plurality of permanent magnets defining a number of poles (“P”) of the LSIPM, and a plurality of rotor bars spaced about the rotor defining a rotor bar area (“BA”). The rotor bars are formed of a conductive material having an associated conductivity (“σRB”). End members are disposed on axial opposite ends of the rotor core. The end members are in electrical contact with the rotor bars. The end members are formed from a material having an associated conductivity (“σEM”). Each end ring member has a minimum geometric cross sectional area (“ERA”) and outer diameter that generally corresponds to the rotor core outer diameter. The ERA is greater than 0.5 times the rotor bar area per the number of poles (BA/P) times a ratio of the rotor bar material conductivity to the end member material conductivity (σRB/σEM).

主权项

1. An electrical machine comprising:
a stator; a rotor core having an outer diameter disposed within the stator, the rotor core comprising a plurality of permanent magnet defining a number of poles (P) of the machine, the rotor core further comprising a plurality of rotor bars spaced about the rotor core center axis, the rotor bars defining a rotor bar area (“BA”), the rotor bars being formed of a conductive material having a conductivity (σRB); and end members disposed on axial opposite ends of the rotor core, the end members being in electrical contact with the rotor bars, the end members being formed from a material having an associated conductivity (σEM), each end ring member having a minimum geometric cross sectional area (“ERA”), wherein the end members have an outer diameter that is generally equal to the rotor core outer diameter, and wherein the ERA is greater than about 0.5 times the rotor bar area per the number of poles (BA/P) times a ratio of the rotor bar material conductivity to the end member material conductivity (σRB/σEM).