Electronically controlled switch for an electric motor

Patent metadata

Field	Value
Publication number	US-10686389-B2
Application number	US-201916262123-A
Country	US
Kind code	B2
Filing date	Jan 30, 2019
Priority date	Jun 30, 2014
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A system in which the operation of an electric motor is controlled by electronically controlled switches. The system includes the motor having a run winding and a start winding, a heating component, and a motor control subsystem. A control unit closes a first switch to energize the run winding, closes a second switch to energize the start winding, determines based on an amplitude and a lag time of a current flowing through the motor whether the motor has started and is running normally, and if so, opens the second switch to de-energize the start winding and closes a third switch to activate the heating component. The control unit determines whether the motor has started and is running normally by comparing the real time amplitude and lag time of the current to a plurality of stored amplitudes and lag times associated with different operating conditions.

First claim

Having thus described one or more embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:

1. A motor control subsystem for an electric motor system including an electric motor having a run winding and a start winding and further including a user interface configured to receive a user input from a user, the motor control subsystem being configured to control operation of the electric motor, the motor control subsystem comprising:
a control unit in electrical communication with the user interface and configured to receive the user input from the user interface;
a first electronically controlled switch electrically connected in series between the control unit and the run winding of the electric motor and configured to control a flow of electric current to the run winding in response to a first control signal from the control unit;
a second electronically controlled switch electrically connected in series between the control unit and the start winding of the electric motor and configured to control the flow of electric current to the start winding in response to a second control signal from the control unit; and
a sensor in electrical communication with the control unit and configured to sense a voltage or a current to the electric motor and to provide an input signal to the control unit regarding the sensed voltage or current,
wherein the control unit sends a first control signal to close the first electronically controlled switch and thereby energize the run winding of the electric motor, sends a second control signal to close the second electronically controlled switch and thereby energize the start winding of the electric motor, determines based on the input signal whether the electric motor has started, and if the electric motor has started, sends a third control signal to open the second electronically controlled switch and thereby de-energize the start winding of the electric motor.

2. The motor control subsystem as set forth in claim 1 , wherein the electric motor is part of a machine, and the machine is a residential or commercial appliance.

3. The motor control subsystem as set forth in claim 2 , wherein the motor control subsystem is further configured to control operation of an operationally associated additional component which is also part of the machine, and wherein if the electric motor has started, the control unit activates the operationally associated additional component.

4. The motor control subsystem as set forth in claim 3 , wherein the machine is a clothes dryer and the operationally associated additional component is a heater component.

5. The motor control subsystem as set forth in claim 1 , wherein the electric motor is an electric induction or a permanent magnet motor.

6. The motor control subsystem as set forth in claim 1 , wherein the control unit is a microprocessor.

7. The motor control subsystem as set forth in claim 1 , wherein the sensor is selected from the group consisting of a resistor, a transformer, a Hall effect sensor.

8. The motor control subsystem as set forth in claim 1 , wherein the control unit is located on a printed circuit board and receives power from a first power supply, and the electric motor receives power from a second power supply, and the first and second electronically controlled switches are located on the printed circuit board and receive power from the first power supply.

9. The motor control subsystem as set forth in claim 1 , wherein the control unit receives power from a first power supply, and the electric motor receives power from a second power supply, and the first and second electronically controlled switches are located on the electric motor and receive power from the second power supply.

10. A method of controlling an electric motor system, the electric motor system including an electric motor having a run winding and a start winding and a motor control subsystem, the motor control subsystem including a control unit, first and second electronically controlled switches, and a sensor, the method comprising the steps of:
(1) sending by the control unit a first control signal to close the first electronically controlled switch and thereby energize the run winding of the electric motor;
(2) sending by the control unit a second control signal to close the second electronically controlled switch and thereby energize the start winding of the electric motor;
(3) receiving at the control unit an input signal from the sensor regarding a voltage or a current to the electric motor;
(4) determining by the control unit based on the input signals whether the electric motor has started; and
(5) if the electric motor has started, sending by the control unit a third control signal to open the second electronically controlled switch and thereby de-energize the start winding of the electric motor.

11. The method as set forth in claim 10 , wherein the electric motor is part of a machine, and the machine is a residential or commercial appliance.

12. The method as set forth in claim 11 , wherein the method further includes controlling an operationally associated additional component which is also part of the machine, and the method further includes the step of (6) if the electric motor has started, activating the operationally associated additional component.

13. The method as set forth in claim 12 , wherein the machine is a clothes dryer and the operationally associated additional component is a heater component.

14. The method as set forth in claim 10 , wherein the electric motor is an electric induction or a permanent magnet motor.

15. The method as set forth in claim 10 , wherein the control unit is a microprocessor.

16. A motor control subsystem for an electric motor system including an electric motor having a run winding and a start winding and further including a user interface configured to receive a user input from a user, the motor control subsystem being configured to control operation of the electric motor and an operationally associated additional component which are both part of a machine, the motor control subsystem comprising:
a control unit in electrical communication with the user interface and configured to receive the user input from the user interface;
a first electronically controlled switch electrically connected in series between the control unit and the run winding of the electric motor and configured to control a flow of electric current to the run winding in response to a first control signal from the control unit;
a second electronically controlled switch electrically connected in series between the control unit and the start winding of the electric motor and configured to control the flow of electric current to the start winding in response to a second control signal from the control unit; and
a sensor in electrical communication with the control unit and configured to sense a voltage or a current to the electric motor and to provide an input signal to the control unit regarding the sensed voltage or current,
wherein the control unit—
sends a first control signal to close the first electronically controlled switch and thereby energize the run winding of the electric motor,
sends a second control signal to close the second electronically controlled switch and thereby energize the start winding of the electric motor,
determines based on the input signal whether the electric motor has started, and
if the electric motor has started, sends a third control signal to open the second electronically controlled switch and thereby de-energize the start winding of

Assignees

• Nidec Motor Corp

Inventors

• Peterson Gregory A
• Lass David E

Classifications

• H02P1/44 Primary

  by phase-splitting with a capacitor · CPC title

• D06F58/50 Primary

  Responding to irregular working conditions, e.g. malfunctioning of blowers · CPC title

• D06F2105/28

  Electric heating · CPC title

• D06F2105/46

  Drum speed; Actuation of motors, e.g. starting or interrupting · CPC title

• H02P1/42

  for starting an individual single-phase induction motor {(H02P27/04 takes precedence)} · CPC title