Systems and methods for braking an electric motor
AssigneeNidec Motor Corporation
InventorsDarko Marcetic, Thomas J. Sheahan
Life of this patent
Estimating the term…
Abstract
A motor controller for an electric motor having a stator and a rotor. The motor controller includes a power input for receiving AC power from a power source; a control input for receiving a control signal from a control; and circuitry for switching power from the power source to the electric motor in response to the control signal. The circuitry is operable to: apply a braking waveform to the stator while the rotor is rotating; monitor a reactive power of the stator; detect an increase in the reactive power of the stator to determine the rotor has substantially stopped rotating; and remove the braking waveform from the stator in response to detecting the increase in the reactive power.
Claims31
A motor controller for an electric motor having a stator and a rotor, the motor controller comprising:
- a power input for receiving power from a power source;
- and
- circuitry for switching power from the power source to the electric motor, wherein the circuitry is operable to:
- apply a braking waveform to the stator while the rotor is rotating;
- monitor a reactive power of the stator;
- detect an increase in the reactive power of the stator to determine the rotor has substantially stopped rotating;
- and
- remove the braking waveform from the stator in response to detecting the increase in the reactive power.
A motor controller for an electric motor having a stator and a rotor, the motor controller comprising:
- a power input for receiving AC power from a power source;
- a control input for receiving a control signal from a control;
- circuitry for switching power from the power source to the electric motor in response to the control signal, wherein the circuitry is operable to:
- apply a controlled current braking waveform to the stator while the rotor is rotating;
- determine when the rotor has substantially stopped rotating;
- and
- remove the controlled current braking waveform from the stator in response to determining the rotor has substantially stopped rotating.
A motor controller for an electric motor having a stator and a rotor, the motor controller comprising:
- a power input for receiving AC power from a power source;
- a control input for receiving a control signal from a control;
- circuitry for switching power from the power source to the electric motor in response to the control signal, wherein the circuitry is operable to:
- apply a braking waveform to the stator while the rotor is rotating;
- monitor a current through a current shunt while the braking waveform is applied to the stator;
- determine whether the rotor has substantially stopped rotating using the monitored current through the current shunt;
- and
- remove the applied braking waveform from the stator in response to determining the rotor has substantially stopped rotating.
A motor assembly comprising:
- an electric motor having a stator and a rotor;
- and
- a motor controller for driving and controlling the electric motor, the motor controller comprising:
- a power input for receiving AC power from a power source;
- a control input for receiving a control signal from a control;
- circuitry for switching power from the power source to the electric motor in response to the control signal, wherein the circuitry is operable to:
- apply a braking waveform to the stator while the rotor is rotating;
- monitor a reactive power of the stator;
- detect an increase in the reactive power of the stator to determine the rotor has substantially stopped rotating;
- and
- remove the braking waveform from the stator in response to detecting the increase in the reactive power.
A method of braking an electric motor having a stator and a rotor, the method comprising:
- applying a braking waveform to the stator while the rotor is rotating;
- monitoring a reactive power of the stator;
- detecting an increase in the reactive power of the stator indicating the rotor has substantially stopped rotating;
- and
- removing the applied braking waveform from the stator in response to detecting said increase.
A method of braking an electric motor having a stator and a rotor, the method comprising:
- applying a controlled current braking waveform to the stator while the rotor is rotating;
- determining when the rotor has substantially stopped rotating;
- and
- removing the applied controlled current braking waveform from the stator in response to determining the rotor has substantially stopped rotating.
A method of braking an electric motor assembly having an electric motor and a motor controller, the electric motor including a stator and a rotor, the motor controller including one or more current shunts, the method comprising:
- applying a braking waveform to the stator while the rotor is rotating;
- monitoring a current through one of said one or more current shunts while the braking waveform is applied to the stator;
- determining whether the rotor has substantially stopped rotating using the monitored current through only one of said one or more current shunts;
- and
- removing the applied braking waveform from the stator in response to determining the rotor has substantially stopped rotating.
Dependencies are inferred from the claim text.