Three-phase asynchronous motor squirrel-cage rotor structure capable of reducing starting current and motor

A three-phase asynchronous motor squirrel-cage rotor structure capable of reducing starting current, comprising:

• a rotating shaft;
• a rotor core fixedly provided on the rotating shaft;
• a plurality of conducting bars respectively provided in rotor slots of the rotor core;
• two end rings that are fixedly provided at two ends of the rotor core respectively and integrally connects the plurality of conducting bars on the rotor core to form a short circuit;
• and
• two starting rings that are respectively provided at outer ends of the two end rings, wherein the starting rings are fixedly connected with the end rings, and a gap between the starting rings and the end rings is controlled to be greater than 0 and less than 3 mm, wherein the starting rings are configured for reducing a magnetic resistance at the end rings, improving a magnetic circuit conduction efficiency, improving an eddy current effect of the starting rings and reducing a starting current of the motor;
• wherein a cross section of the starting rings is any one of ├-shaped, └-shaped, ∪-shaped or rectangular;
• wherein an end face of an end of the starting ring far from the end ring is a plane, an inclined plane or a curved surface;
• wherein the end rings, the rotor core and the conducting bars are configured as an integral structure by casting, integral processing or machining;
• wherein the magnetic fields between the starting ring and the rotating shaft, the rotor core, the conducting bars, the end rings are mutually conducted, and the starting current satisfies the following equation:
• 1
• ⁢
• st
• =
• U
• 1
• X
• m
• ×
• 1
• c
• +
• X
• 1
• ⁢
• σ
• X
• 2
• ⁢
• σ
• ′
• +
• U
• 1
• (
• R
• 1
• +
• cR
• 2
• ′
• )
• 2
• +
• (
• X
• 1
• ⁢
• σ
• +
• cX
• 2
• ⁢
• σ
• ′
• )
• 2
• wherein, Ist represents a motor starting current, U1 represents a motor rated voltage, Xm represents a motor magnetizing reactance,
• c
• =
• 1
• +
• X
• 1
• ⁢
• σ
• X
• m
• ,
• X
• 1
• ⁢
• σ
• represents a motor stator leakage reactance, R1 represents a motor stator winding resistance, R2′ represents motor rotor winding resistance, X2σ′ represents a motor rotor leakage reactance;
• and,
• X
• 2
• ⁢
• σ
• ′
• =
• 2
• ⁢
• π
• ⁢
• f
• ⁢
• w
• 2
• R
• m
• ,
• π
• ≈
• 3.14
• ,
• w is the number of turns of rotor winding, Rm is a reluctance at the end ring, and f is a current alternate frequency.