5-pole based wye-delta motor starting system and method

Patent metadata

Field	Value
Publication number	US-9748873-B2
Application number	US-201514832628-A
Country	US
Kind code	B2
Filing date	Aug 21, 2015
Priority date	Nov 6, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

One embodiment describes a motor starter, which includes a first single pole switching device that opens to disconnect power from a first winding of a motor; a second single pole switching device that closes after the first switching device opens to connect power to the first winding; a third single pole switching device closes after the second single pole switching device closes to increase power supplied to a second winding of the motor; a fourth single pole switching device that opens after the third single pole switching device closes to disconnect power supplied to a third winding of the motor and to reduce power supplied to the second winding; and a fifth single pole switching device that closes after the fourth switching device opens to connect power to the third winding.

First claim

The invention claimed is:

1. A motor starter comprising:
a first single pole switching device configured to open to disconnect power from a first winding of a motor;
a second single pole switching device configured to close after the first single pole switching device opens to connect power to the first winding;
a third single pole switching device configured to close after the second single pole switching device closes to increase power supplied to a second winding of the motor;
a fourth single pole switching device configured to open after the third single pole switching device closes to disconnect power supplied to a third winding of the motor and to reduce power supplied to the second winding; and
a fifth single pole switching device configured to close after the fourth single pole switching device opens to connect power to the third winding.

2. The motor starter of claim 1 , comprising:
a first mains switching device configured to disconnect a first phase of electric power from the motor starter;
a second mains switching device configured to disconnect a second phase of electric power from the motor starter; and
a third mains switching device configured to disconnect a third phase of electric power from the motor starter.

3. The motor starter of claim 2 , wherein the first single pole switching device, the second single pole switching device, the third single pole switching device, the fourth single pole switching device, the fifth single pole switching device, the first mains switching device, the second mains switching device, and the third mains switching device each comprises a single pole, single current carrying path switching device.

4. The motor starter of claim 1 , wherein the first single pole switching device, the second single pole switching device, the third single pole switching device, the fourth single pole switching device, and the fifth single pole switching device comprise single pole, single current carrying path switching devices.

5. The motor starter of claim 1 , wherein:
the first single pole switching device is configured to selectively connect and disconnect the first winding in a wye configuration;
the second single pole switching device is configured to selectively connect and disconnect the first winding in a delta configuration;
the third single pole switching device is configured to selectively connect and disconnect the second winding in the delta configuration;
the fourth single pole switching device is configured to selectively connect and disconnect the second winding and the third winding in the wye configuration; and
the fifth single pole switching device is configured to selectively connect and disconnect the third winding in the delta configuration.

6. A method for operating a motor starter, comprising:
disconnecting power from a first winding of a motor by opening a first single pole switching device in the motor starter;
after the first single pole switching device is opened, connecting power to the first winding by closing a second single pole switching device in the motor starter;
disconnecting power from a second winding and a third winding of the motor by opening a third single pole switching device in the motor starter;
after the third single pole switching device is opened:
connecting power to the second winding by closing a fourth single pole switching device; and
connecting power to the third winding by closing a fifth single pole switching device, wherein the fourth single pole switching device and the fifth single pole switching device are included in the motor starter.

7. The method of claim 6 , wherein:
disconnecting power from the first winding comprises opening the first single pole switching device based on a first current zero-crossing;
connecting power to the first winding comprises closing the second single pole switching device a first number of electrical degrees after the first current zero-crossing;
disconnecting power from the second winding and the third winding comprises opening the third single pole switching device based on a second current zero-crossing;
connecting power to the second winding comprises closing the fourth single pole switching device a second number of electrical degrees after the second current zero-crossing; and
connecting power to the third winding comprises closing the fifth single pole switching device a third number of electrical degrees after the second current zero-crossing.

8. The method of claim 7 , wherein:
the first current zero-crossing is when current conducted by the first single pole switching device is zero;
the second current zero-crossing is when current conducted by the third single pole switching device is zero;
the first number of electrical degrees is approximately thirty electrical degrees;
the second number of electrical degrees is approximately two hundred and forty electrical degrees; and
the third number of electrical degrees is approximately four hundred and twenty electrical degrees.

9. The method of claim 6 , comprising:
disconnecting power from the third winding by opening the fifth single pole switching device;
disconnecting power from the second winding by opening the fourth single pole switching device;
after opening the fourth single pole switching device and fifth single pole switching device, connecting power to the third winding by closing the third single pole switching device;
disconnecting power from the first winding by opening the second single pole switching device; and
after opening the second single pole switching device, connecting power to the first winding by closing the first single pole switching device.

10. The method of claim 6 , wherein the first single pole switching device, the second single pole switching device, the third single pole switching device, the fourth single pole switching device, and the fifth single pole switching device each comprises a single pole, single current carrying path switching device.

11. A motor starter comprising:
a first single pole switching device configured to open to disconnect power from a first winding of a motor;
a second single pole switching device configured to close after the first single pole switching device opens to connect power to the first winding;
a third single pole switching device configured to open to disconnect power from a second winding and a third winding of the motor;
a fourth single pole switching device configured to close after the third single pole switching device opens to connect power to the second winding;
a fifth single pole switching device configured to close after the third single pole switching device opens to connect power to the third winding;
a first mains switching device configured to disconnect a first phase of electric power from the motor starter;
a second mains switching device configured to disconnect a second phase of electric power from the motor starter; and
a third mains switching device configured to disconnect a third phase of electric power from the motor starter.

12. The motor starter of claim 11 , wherein the first single pole switching device, the second single pole switching device, the third single pole switching device, the fourth single pole switching device, the fifth single pole switching device, the first mains switching device, the second mains switching device, and the third mains switching device each comprises a single pole, single current carrying path switching device.

13. The motor starter of claim 11 , wherein the first single pole switching device, the second single pole switching device, the third single pole switching device, the fourth single pole

Assignees

• Rockwell Automation Tech Inc

Inventors

• Bock Christopher H
• Wieloch Christopher J
• Kinsella James J
• Dziekonski Stefan T

Classifications

• H01H9/56

  for ensuring operation of the switch at a predetermined point in the AC cycle · CPC title

• H02P1/32 Primary

  by star/delta switching · CPC title

• H01H9/563

  for multipolar switches, e.g. different timing for different phases, selecting phase with first zero-crossing · CPC title

• H02P1/26

  for starting an individual polyphase induction motor · CPC title