Current control apparatus

Patent metadata

Field	Value
Publication number	US-11747841-B2
Application number	US-202017116522-A
Country	US
Kind code	B2
Filing date	Dec 9, 2020
Priority date	Aug 20, 2018
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.

First claim

What is claimed is:

1. A voltage regulator comprising:
a main magnetic core;
a main winding comprising a plurality of taps, the main winding configured to magnetically couple to the main magnetic core;
a first contact configured to electrically connect to one of the plurality of taps;
a second contact configured to electrically connect to one of the plurality of taps;
an auxiliary winding configured to magnetically couple to the main magnetic core; and
an electrical network electrically connected to the auxiliary winding, the electrical network comprising one or more controllable power electronic components, wherein the electrical network is configured to receive reactive power from the auxiliary winding and to provide reactive power to the auxiliary winding.

2. The voltage regulator of claim 1 , wherein the electrical network further comprises a first power converter.

3. The voltage regulator of claim 2 , wherein the electrical network further comprises a direct current (DC) link electrically connected to the first power converter.

4. The voltage regulator of claim 3 , wherein the electrical network further comprises a second power converter electrically connected to the DC link and the first power converter, and wherein the DC link is between the first power converter and the second power converter.

5. The voltage regulator of claim 4 , wherein the first power converter comprises a rectifier, and the second power converter comprises an inverter.

6. The voltage regulator of claim 1 , wherein the one or more controllable power electronic components comprises a plurality of transistors.

7. The voltage regulator of claim 1 , further comprising:
a second magnetic core; and
a current control winding, wherein
the first contact is electrically connected to a first winding,
the second contact is electrically connected to a second winding,
the first winding and the second winding are configured to magnetically couple to the second magnetic core,
the current control winding is electrically connected to the electrical network and is configured to magnetically couple to the second magnetic core, and
the electrical network is further configured to control current in one or more of the first electrical contact and the second electrical contact.

8. The voltage regulator of claim 7 , wherein the electrical network is configured to prevent saturation of the second magnetic core.

9. The voltage regulator of claim 8 , wherein the second magnetic core is a gapped magnetic core.

10. The voltage regulator of claim 7 , wherein the electrical network is configured to control the current in the first contact such that the current in the first contact is zero during a switching operation.

11. The voltage regulator of claim 10 , wherein the electrical network comprises a rectifier electrically connected to the auxiliary winding.

12. The voltage regulator of claim 11 , wherein the one or more controllable power electronics comprise a plurality of transistors, and the rectifier comprises at least some of the plurality of transistors.

13. The voltage regulator of claim 11 , further comprising:
a direct current (DC) link electrically connected to the rectifier; and
an inverter electrically connected to the DC link and the current control winding.

14. The voltage regulator of claim 1 , wherein the electrical network is configured to compensate for reactive power.

15. The voltage regulator of claim 14 , wherein the electrical network is configured to receive reactive power from the auxiliary winding and to provide reactive power to the auxiliary winding to thereby compensate for reactive power.

16. A controller for a voltage regulator, the controller configured to:
receive data from a sensor that measures an electrical quantity in a current path of the voltage regulator, the current path being configured to conduct electrical current between a first switchable contact and a load of the voltage regulator; and
control electrical current in an electrical network based on the data received from the sensor; wherein
the electrical network and a second switchable contact are configured to be magnetically coupled by a magnetic core of the voltage regulator, and controlling the electrical current in the electrical network controls magnetic saturation of the magnetic core.

17. The controller of claim 16 , wherein the controller is configured to control electrical current in the electrical network by controlling a state of at least one electronic switch in the electrical network.

18. The controller of claim 16 , wherein the first and second switchable contacts comprise first and second moveable contacts.

19. A method comprising:
electrically coupling a main winding of a voltage regulator to an alternating current (AC) electrical power distribution system;
magnetically coupling the main winding to a first magnetic core;
electrically connecting an electrical contact to a tap of the main winding;
magnetically coupling an electrical network to a second magnetic core;
magnetically coupling a first secondary winding to the second magnetic core; and
controlling the electrical network to compensate for reactive power from the AC electrical power distribution system, wherein the first secondary winding is electrically connected to the electrical contact, and controlling the electrical network further comprises controlling an electrical current in the electrical contact.

20. The method of claim 19 , further comprising controlling a state of a switch in the electrical network; and wherein
controlling the state of the switch controls the electrical current in the electrical network to thereby control the electrical current in the electrical contact.

21. The method of claim 19 , wherein controlling the electrical network to compensate for reactive power comprises controlling one or more power converters in the electrical network.

22. A voltage regulator comprising:
a main magnetic core;
a main winding comprising a plurality of taps, the main winding configured to magnetically couple to the main magnetic core;
a first contact configured to electrically connect to one of the plurality of taps;
a second contact configured to electrically connect to one of the plurality of taps;
an auxiliary winding configured to magnetically couple to the main magnetic core; and
an electrical network electrically connected to the auxiliary winding, the electrical network comprising one or more controllable power electronic components, wherein the one or more controllable power electronic components comprises a plurality of transistors.

23. The voltage regulator of claim 22 , wherein the electrical network further comprises a power converter configured to compensate for reactive power, and the power converter comprises at least some of the plurality of transistors.

24. A voltage regulator comprising:
a main magnetic core;
a main winding comprising a plurality of taps, the main winding configured to magnetically couple to the main magnetic core;
a first contact configured to electrically connect to one of the plurality of taps;
a second contact configured to electrically connect to one of the plurality of taps;
an auxiliary winding configured to magnetically couple to the main magnetic core; and
an electrical network electrically connected to the auxiliary winding, the electrical network comprising:
one or more controllable power electronic components, a first

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Schaar Jonathan Michael
• Zhao Tiefu

Classifications

• H01H2009/0061

  Monitoring tap change switching devices · CPC title

• G05F1/20 Primary

  semiconductor devices only · CPC title

• H02J3/1878

  using tap changing or phase shifting transformers · CPC title

• H02J4/00

  Circuit arrangements for mains or distribution networks not specified as AC or DC; Circuit arrangements for mains or distribution networks combining AC and DC sections or sub-networks (arrangements using intermediate DC-AC-DC conversion H02J1/002; arrangements using high-voltage DC [HVDC] links H02J3/36) · CPC title

• H01H9/0005 Primary

  Tap change devices · CPC title