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

Patent metadata

Field	Value
Publication number	US-9746521-B2
Application number	US-201514832829-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 including 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 that opens to disconnect power from a second winding of the motor; a fourth single pole switching device that closes after the third single pole switching device opens to connect power to the second winding; a fifth single pole switching device that opens to disconnect power form a third winding of the motor; and a sixth single pole switching device closes after the fifth single pole 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 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 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 open to disconnect power form a third winding of the motor; and
a sixth single pole switching device configured to close after the fifth 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, second, third, fourth, fifth, and sixth single pole switching devices and the first, second, and third mains switching devices each comprise a single pole, single current carrying path switching device.

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

5. The motor starter of claim 1 , wherein the first, second, third, fourth, fifth and sixth single pole switching devices each comprises a power electronic switching device or a single pole, single current carrying path switching device.

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

7. A method for operating a motor starter, comprising:
breaking a first multi-pole phase switching device such that:
at a first time, a first pole of the first multi-pole switching device disconnects a first winding of a motor from a wye configuration;
at a second time, a second pole of the first multi-pole switching device disconnects a second winding of the motor from the wye configuration; and
at a third time, a third pole of the first multi-pole switching device disconnects a third winding of the motor from the wye configuration; and

making a second multi-pole switching device such that:
at a fourth time after the first time, a first pole of the second multi-pole switching device connects the first winding in a delta configuration;
at a fifth time after the second time, a second pole of the second multi-pole switching device connects the second winding in the delta configuration; and
at a sixth time after the third time, a third pole of the second multi-pole switching device connects the third winding in the delta configuration.

8. The method of claim 7 , comprising:
making the first multi-pole switching device such that:
at a seventh time before the first time, the first pole of the first multi-pole switching device connects the first winding in the wye configuration;
at an eighth time before the first time, the second pole of the first multi-pole switching device connect the second winding in the wye configuration; and
at a ninth time before the first time, the third pole of the first multi-pole switching device connects the third winding in the wye configuration.

9. The method of claim 8 , wherein:
the fourth time, the fifth time, and the sixth time occur substantially simultaneously;
the fourth time and the fifth time occur substantially simultaneously before the sixth time;
the fourth time and the fifth time occur substantially simultaneously after the sixth time; or
the fourth time occurs before the fifth time and the fifth time occurs before the sixth time.

10. The method of claim 7 , where the first and the second multi-pole switching devices each comprises a three phase switching device.

11. The method of claim 7 , wherein:
the first time, the second time, and the third time occur substantially simultaneously;
the first time and the second time occur substantially simultaneously before the third time;
the first time and the second time occur substantially simultaneously after the third time; or
the first time occurs before the second time and the second time occurs before the third time.

12. The method of claim 7 , wherein:
the first time corresponds with a first current zero-crossing;
the second time corresponds with a second current zero-crossing;
the third time corresponds with a third current zero-crossing;
the fourth time corresponds with a first predicted current zero-crossing;
the fifth time corresponds with a second predicted current zero-crossing; and
the sixth time corresponds with a third predicted current zero-crossing;
wherein each current zero-crossing occurs when current conducted by a respective pole is zero and each predicted current crossing occurs at a line-to-line voltage maximum.

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

• H01H47/02

  for modifying the operation of the relay · CPC title

• H01H47/002

  Monitoring or fail-safe circuits · CPC title

• H01H71/082

  Connections between juxtaposed circuit breakers · CPC title

• H01H9/26

  for interlocking two or more switches ({H01H13/568 takes precedence;} by a detachable member H01H9/28 {; for electromagnetic relays H01H50/323}) · CPC title