Multiple-speed electric machine and method of operating the same
AssigneeA. O. Smith Corporation
InventorsWilliam Louis Mehlhorn, William James Watkins, Jevon Darvell Reynolds
Life of this patent
Estimating the term…
Abstract
An electric machine assembly having an electric machine. The electric machine can include a first speed circuit and a second speed circuit. In some constructions, both speed circuits can be of a permanent split capacitor design. At least one of the speed circuits can include a switch that is controlled by the controller to limit current through an auxiliary circuit of the unused speed circuit when certain conditions exist.
Claims20
A method of controlling an electric machine, the electric machine comprising a rotor and a stator, the method comprising:
- providing an electric machine comprising
- a first speed circuit comprising a first main winding, an auxiliary winding, and a switch connected in series with the auxiliary winding, and
- a second speed circuit comprising a second main winding;
- providing an operational power to one of the first speed circuit and the second speed circuit;
- and
- controlling the switch to limit current through the auxiliary winding based at least in part on the provision of the operational power to the second speed circuit.
An electric machine assembly comprising:
- a shaft;
- a rotor connected to the shaft for rotation with the shaft;
- a first speed circuit comprising a first main circuit, a first auxiliary circuit, and a switch connected in series with the first auxiliary circuit, the first speed circuit being configured to cause the rotor and shaft to rotate at a first speed when an operational power is provided to the first speed circuit;
- a second speed circuit comprising a second main circuit and a second auxiliary circuit, the second speed circuit being configured to cause the rotor and shaft to rotate at a second speed when an operational power is provided to the second speed circuit;
- and
- a controller configured to control operation of the switch based at least in part on whether an operational power is provided to the first speed circuit or the second speed circuit, the controller controlling the switch to limit current through the switch when the second speed circuit receives the operational power.
A method of controlling an electric machine, the electric machine comprising a rotor and a stator, the method comprising:
- providing an electric machine comprising
- a first speed circuit of a permanent split capacitor design, the first speed circuit comprising
- a first main circuit comprising a first main winding,
- a first auxiliary circuit comprising a first phase winding and a first capacitor connected in series with the first phase winding, and
- a solid-state switch connected in series with the auxiliary circuit,
- a second speed circuit of a permanent split capacitor design, the second speed circuit comprising
- a second main circuit comprising a second main winding, and
- a second auxiliary circuit comprising a second phase winding and a second capacitor connected in series with the second phase winding,
- providing an operational power to one of the first speed circuit and the second speed circuit;
- and
- controlling the solid-state switch to allow current through the auxiliary winding based at least in part on the provision of the operational power to the first speed circuit.
Dependencies are inferred from the claim text.