Polyphase AC electric motor
View Patent ↗Object: To provide a polyphase AC electric motor whereby partial discharge can be suppressed. Resolution Means: The winding of each phase includes a first partial conductor that is an input side partial conductor; an nth partial conductor connected to a neutral point; and second to n-1th partial conductors. Moreover, a partial conductor disposed within the stator adjacent to the first partial conductor of each phase, or a partial conductor including a coil end portion disposed adjacent to a coil end portion where the first partial conductor extends out of the slot, is any of the following: (1) of the intermediate partial conductors, an ath (where a is a natural number greater than or equal to 2) partial conductor of the same phase or a different phase where voltage takes an extreme value when AC voltage is applied from the inverter; (2) any of an a-3th to a-1th partial conductors of the same phase or a different phase, or any of an a+1th to a+3th partial conductors of the same phase or a different phase connected to the intermediate partial conductor taking the extreme value; (3) any of a n-3th to nth partial conductors of the same phase or a different phase.
1. A polyphase AC electric motor, comprising:
a stator in which windings of different phases are distribution wound and star-connected, the polyphase AC electric motor being driven by an inverter; wherein the winding of each phase includes:
a first partial conductor that is an input side partial conductor connected to an input terminal,
an nth partial conductor that is a final partial conductor connected to a neutral point, where n is a natural number greater than or equal to 2, and
second to n-1th partial conductors that are intermediate partial conductors connected between the first partial conductor and the nth partial conductor;
a partial conductor disposed adjacent to the first partial conductor of each phase within the stator, or a partial conductor including a coil end portion disposed adjacent to a coil end portion where the first partial conductor extends out of a slot, corresponds to a partial conductor described in any of (1) to (2):
(1) of the intermediate partial conductors, an ath partial conductor of the same phase or a different phase where voltage takes an extreme value when AC voltage is applied from the inverter, where a is a natural number greater than or equal to 2;
(2) any of an a−3th to a−1th partial conductors of the same phase or a different phase, or any of an a+1th to a+3th partial conductors of the same phase or a different phase connected to the intermediate partial conductor taking the extreme value; and
wherein the partial conductor that takes the extreme value is a bth partial conductor of the same phase or a different phase adjacent in a circumferential direction of the stator to a slot end in which the first partial conductor of each layer is housed, where n is a natural number greater than or equal to 2, any of a b−3th to b−1th partial conductors connected to the partial conductor, or any of a b+1th to b+3th partial conductors connected to the partial conductor.
2. The polyphase AC electric motor according to claim 1 , wherein:
a partial conductor disposed adjacent within the stator to the second partial conductor or the third partial conductor of each phase, or a partial conductor including a coil end portion disposed adjacent to a coil end portion where the first partial conductor or the third partial conductor extends out of the slot corresponds to a partial conductor described in any of the (1) to (2).
3. The polyphase AC electric motor according to any one of claims 1 to 2 , wherein:
the first partial conductor of at least one phase of the first partial conductors of the plurality of phases is disposed at a first end portion in a radial direction of the stator; and
the first partial conductors of the other phases are disposed at a second end portion in the radial direction of the stator.
4. The polyphase AC electric motor according to any one of claims 1 to 2 , wherein:
winding directions, with respect to the circumferential direction of the stator, of the windings of different phases are all the same direction.
5. The polyphase AC electric motor according to any one of claims 1 to 2 , wherein:
at least one winding direction, with respect to the circumferential direction of the stator, of the windings of different phases is an opposite direction.
6. The polyphase AC electric motor according to claim 1 or 2 , wherein:
the partial conductor including the coil end portion disposed adjacent to the coil end portion where the first partial conductor extends out of the slot corresponds to a partial conductor described in any of (1) to (2):
(1) a b−1th partial conductor or a b+1th partial conductor connected before or after the bth partial conductor;
(2) any of a n−1th to nth partial conductors of the same phase or a different phase.
7. The polyphase AC electric motor according to claim 3 , wherein:
winding directions, with respect to the circumferential direction of the stator, of the windings of different phases are all the same direction.
8. The polyphase AC electric motor according to claim 3 , wherein:
at least one winding direction, with respect to the circumferential direction of the stator, of the windings of different phases is an opposite direction.