Control for multi-phase induction motor

• US 9,450,530 B2
• Filed: 01/23/2014
• Issued: 09/20/2016
• Est. Priority Date: 08/11/2010
• Status: Active Grant

• Current Assignee: Dayton-Phoenix Group, Inc.
• Original Assignee: Dayton-Phoenix Group, Inc.
• Inventors: Zahora, Joseph A., Bui, Xung T., Bryant, Brad S.
• Primary Examiner(s): Chan, Kawing
• Application Number:
  US14/162,323
• Publication Number:
  US 20140132198A1
• Time in Patent Office: 971 Days
• Field of Search: 318/727, 318/767, 318/771, 318/778, 318/779
• US Class Current: 1/1
• CPC Class Codes: H02P 2207/01 Asynchronous machines
• CPC Class Codes: H02P 23/03 specially adapted for very low speeds
• CPC Class Codes: H02P 25/184 wherein the motor speed is changed by switching from a delta to a star, e.g. wye, connection of its windings, or vice versa
• CPC Class Codes: H02P 29/60 Controlling or determining the temperature of the motor or of the drive H02P29/02 takes precedence

Abstract

A method of controlling operation of a multi-phase induction motor may include transmitting a low-speed operation signal by a master computer to a control signal board for low-speed operation of the motor; the control signal board receiving the low-speed operation signal, and in response to the low-speed operation signal, the control signal board sensing that the master computer is not simultaneously transmitting a high-speed operation signal, and in response to receiving the low-speed operation signal and not simultaneously receiving the high-speed operation signal, closing contactors in a power section to transmit power to the motor for low-speed operation, whereby the motor is connected to a source of multi-phase power and operates at low-speed; and the control signal board transmitting a first feedback signal to the master computer that the motor is connected to the source of multi-phase power and is running at low speed.

Claims

1. A method of controlling operation of a multi-phase induction motor, the method comprising:

transmitting a low-speed operation signal by a master computer to a control signal board for low-speed operation of the motor;

receiving the low-speed operation signal by the control signal board, and in response to the low-speed operation signal, the control signal board

sensing that the master computer is not simultaneously transmitting a high-speed operation signal, and

in response to receiving the low-speed operation signal and not simultaneously receiving the high-speed operation signal, closing contactors in a power section to transmit power to the motor for low-speed operation, whereby the motor is connected to a source of multi-phase power and operates at low-speed; and

the control signal board transmitting a first feedback signal to the master computer that the motor is connected to the source of multi-phase power and is running at low-speed.

2. The method of claim 1, further comprising the control signal board receiving a first fault condition signal from a first sensor indicating a first fault condition, and in response to the first fault condition signal, the control signal board transmitting a second feedback signal to the master computer indicating existence of the first fault condition.

3. The method of claim 2, further comprising the control signal board opening the contactors in the power section in response to receiving the first fault condition signal, whereby the motor is disconnected from the source of multi-phase power.

4. The method of claim 3, wherein the fault condition includes one or both of an over-temperature condition of the contactors in the power section and an over-current supplied to the motor.

5. The method of claim 4, wherein the control signal board opening the contactors in the power section includes the control signal board transmitting a signal to the power section.

6. The method of claim 1, further comprising the control signal board receiving signals from a first sensor representative of a current to the motor, and in response to the current to the motor exceeding a predetermined value, the control signal board transmitting a second feedback signal to the master computer that a fault condition exists.

7. The method of claim 6, further comprising the power section opening the contactors in response to receiving the second feedback signal from the control signal board.

8. The method of claim 7, further comprising the control signal board receiving signals from a second sensor representative of a temperature of the contactors in the power section, and in response to the temperature exceeding a predetermined value, the control signal board transmitting a second feedback signal to the master computer that a fault condition exists.

9. The method of claim 1, further comprising the control signal board performing a standby loop;

and the control signal board transmitting a signal to a power section to close the contactors if a fault condition does not exist.

10. The method of claim 9, wherein the control signal board performing a standby loop includes the control signal board

detecting whether the low-speed operation signal is being transmitted by the master computer;

detecting whether a high-speed operation signal is being transmitted by the master computer simultaneously;

receiving a first signal from a first sensor representative of a temperature of the contactors in the power section; and

receiving a second signal from a second sensor representative of a current to the motor.

11. The method of claim 10, wherein transmitting the signal to the power section to close the contactors is performed by the control signal board in response to detecting a low-speed operation signal being transmitted by the master computer, detecting no high-speed operation signal being transmitted by the master computer, the signal from the first sensor indicating that the contactor temperature is below a predetermined value, and the signal from the second sensor indicating that the current to the motor is not in an overload condition.

12. The method of claim 1, further comprising the control signal board performing a running loop;

and if no fault conditions exist, the control signal board transmitting a low-speed operation feedback signal to the master computer.

13. The method of claim 12, wherein the control signal board performing the running loop includes the steps of the control signal board

detecting whether the low-speed signal is being transmitted by the master computer;

receiving a first signal from a first sensor representative of a temperature of the contactors in the power section; and

receiving a second signal from a second sensor representative of a current to the motor.

14. The method of claim 13, wherein transmitting the low-speed operation feedback signal to the master computer is performed by the control signal board in response to detecting a low-speed signal being transmitted by the master computer, the signal from the first sensor indicating that the temperature of the contactors in the power section is below a predetermined value, and the signal from the second sensor indicating that the current to the motor is not in an overload condition.

15. The method of claim 14, further comprising the control signal board transmitting a second signal to the master computer that a fault condition exists in the event that a fault condition is detected by the control signal board.

16. The method of claim 15, wherein transmitting the second signal to the master computer is performed by the control signal board in response to detecting at least one of an absence of a low-speed operation signal being transmitted by the master computer, the signal from the first sensor indicates that a temperature of the contactors in the power section is above a predetermined value, and the signal from the second sensor indicating that the current to the motor is in an overload condition.

17. The method of claim 16, further comprising the control signal board transmitting a third signal to the power section to open the contactors in response to detecting at least one of the signal from the first sensor indicating that the temperature of the contactors in the power section is above a predetermined value and the signal from the second sensor indicating that the current to the motor is in an overload condition.

18. The method of claim 1, wherein closing contactors in a power section includes controlling three silicon-controlled rectifiers.

19. A method of controlling a three-phase AC induction motor, the method comprising:

transmitting a low-speed operation signal by a master computer to a control signal board for low-speed operation of the motor;

receiving the low-speed operation signal by the control signal board, and in response to the low-speed operation signal, the control signal board

sensing that the master computer is not simultaneously transmitting a high-speed operation signal, and

in response to receiving the low-speed operation signal and not simultaneously receiving the high-speed operation signal, closing contactors in a power section to transmit power to the motor for low-speed operation, whereby the motor is connected in a delta configuration to a source of three-phase power from a diesel-electric generator in a locomotive environment and operates at low speed; and

the control signal board transmitting a first feedback signal to the master computer that the motor is connected to the source of three-phase power and is running at low speed.

20. A system for controlling operation of a multi-phase induction motor, the system comprising:

a power section having a plurality of contactors connected to a source of multi-phase power;

a control signal board;

a master computer configured to transmit a low-speed operation signal to the control signal board for low-speed operation of the multi-phase induction motor, and a high-speed operation signal to the control signal board for high-speed operation of the multi-phase induction motor;

the control signal board configured to receive the low-speed operation signal from the master computer, and in response to the low-speed operation signal, the control signal board is configured to sense that the master computer is not simultaneously transmitting the high-speed operation signal, and in response to receiving the low-speed operation signal and not simultaneously receiving the high-speed operation signal, closing the plurality of contactors in the power section to transmit power to the multi-phase induction motor for low-speed operation, whereby the multi-phase induction motor is connected to the source of multi-phase power and operates at low speed; and

the control signal board is further configured to transmit a first feedback signal to the master computer that the multi-phase induction motor is connected to the source of multi-phase power and is running at low speed.