Magnetic integrated hybrid distribution transformer

Patent metadata

Field	Value
Publication number	US-11587719-B2
Application number	US-201716758403-A
Country	US
Kind code	B2
Filing date	Dec 5, 2017
Priority date	Nov 1, 2017
Publication date	Feb 21, 2023
Grant date	Feb 21, 2023

Abstract

A magnetic integrated hybrid distribution transformer includes a main transformer, a series isolation transformer and a converter, wherein: an iron core includes an iron beam unit, an iron yoke unit and a leakage magnetic core unit. The main transformer includes secondary windings, primary windings and control windings all of which are layer-windings and wound around main transformer iron beams. The series isolation transformer includes converter side windings and grid side windings all of which are pancake-windings and wound around isolation transformer iron beams. The converter side windings and the control windings are respectively connected with the converter by the star connection with neutral point. Leakage magnetic cores are respectively inserted between the primary windings and the control windings or between the converter side windings and the grid side windings, so as to achieve magnetic integration design of the transformer and output connection inductor of the converter.

First claim

What is claimed is:

1. A magnetic integrated hybrid distribution transformer, comprising an iron core, windings and a converter ( 22 ), wherein: the iron core comprises an iron beam unit, an iron yoke unit and a leakage magnetic core unit; the iron beam unit comprises three main transformer iron beams and three isolation transformer iron beams that connect with each other sequentially; the iron yoke unit comprises a bottom iron yoke ( 17 ), a middle iron yoke ( 16 ) and four connection iron yokes; the leakage magnetic core unit comprises four control winding leakage magnetic cores and three converter side winding leakage magnetic cores; the windings comprise main transformer windings and series isolation transformer windings; in each phase, the main transformer windings are a control winding, a primary winding and a secondary winding all of which are wrapped around a corresponding main transformer iron beam; in each phase, the series isolation transformer windings are a grid side winding and a converter winding both of which are wrapped around a corresponding isolation transformer iron beam; each main transformer iron beam connects to the bottom iron yoke ( 17 ) and the middle iron yoke ( 16 ); each connection iron yoke connects to the middle iron yoke ( 16 ) and an end of the corresponding series isolation transformer iron beam; the main transformer iron beams and the isolation transformer iron beams form two main transformer windows and three series isolation transformer windows by sharing the middle iron yoke ( 16 ); the control winding leakage magnetic cores are respectively inserted between primary windings and control windings within two main transformer windows; the converter side winding leakage magnetic cores are respectively inserted between converter side windings and grid side windings within the three series isolation transformer windows; the converter ( 22 ) connects to the control windings and converter side windings.

2. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: in each phase, the primary winding connects with the grid side winding in series, grid side windings connect to a power network by a star connection with neutral point; secondary windings supply load by a three-phase four-wire methods; in each phase, the control winding and the converter side winding connect to the converter ( 22 ) by the star connection with neutral point.

3. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: the converter ( 22 ) comprises current bridge arms, voltage bridge arms, a zero sequence bridge arm and a DC-link (direct current-link) capacitor all of which connect with each other in parallel, the control windings are respectively connected with middle points of the current bridge arms, the converter side windings are respectively connected with middle points of the voltage bridge arms, end points of control windings and converter side windings connect to a middle point of the zero sequence bridge arm.

4. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: the secondary winding, the primary winding and the control winding in each phase are layer-windings all of which are concentrically wound around the corresponding main transformer iron beam from inside to outside; the converter side winding and the grid side winding in each phase are pancake windings both of which are concentrically wound around the corresponding phase isolation transformer iron beam from left to right.

5. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: a bottom end of the main transformer iron beams connects to the bottom iron yoke ( 17 ), an upper end of the main transformer iron beams connects to the middle iron yoke ( 16 ); ends of the isolation transformer iron beams connect to an upper end of the four connection iron yokes in sequence, two adjacent isolation transformer iron beams share a common connection iron yoke, and a bottom end of the four connection iron yokes connects to the middle iron yoke ( 16 ).

6. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: a phase shift arrangement is adopted in the main transformer windings and the series isolation transformer windings.

7. The magnetic integrated hybrid distribution transformer, as recited in claim 6 , wherein: the main transformer windings are respectively arranged on three main transformer iron beams as an order of Phase-A, Phase-B and Phase-C from left to right, the series isolation transformer windings are respectively arranged on three isolation transformer iron beams as an order of Phase-C, Phase-B and Phase-A from left to right.

8. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: each iron yoke is in 45-degree connection with a corresponding iron beam, lamination of the main transformer iron beams is larger than that of the isolation transformer iron beams, and lamination of the bottom iron yoke ( 17 ) and the middle iron yoke ( 16 ) is larger than that of the connection iron yokes.

9. The magnetic integrated hybrid distribution transformer, as recited in claim 8 , wherein: the lamination of the iron core is a silicon steel sheet.

10. The magnetic integrated hybrid distribution transformer, as recited in claim 1 , wherein: air gaps between the control winding leakage magnetic core and one of the middle iron yoke ( 16 ) and the bottom iron yoke ( 17 ) or between the converter side winding leakage magnetic core and one of the middle iron yoke ( 16 ) and the isolation transformer iron beam are adjustable; the control windings are elliptic or semi-elliptic.

11. The magnetic integrated hybrid distribution transformer, as recited in claim 2 , wherein: the converter ( 22 ) comprises current bridge arms, voltage bridge arms, a zero sequence bridge arm and a DC-link (direct current-link) capacitor all of which connect with each other in parallel, the control windings are respectively connected with middle points of the current bridge arms, the converter side windings are respectively connected with middle points of the voltage bridge arms, end points of control windings and converter side windings connect to a middle point of the zero sequence bridge arm.

Assignees

• Univ Xi An Jiaotong

Inventors

• Liang Deliang
• Liu Yibin
• Liang Yang
• Zhang Mingkang
• Chen Qixu
• Sun Guanhua
• Jia Peixin

Classifications

• H01F27/38

  Auxiliary core members; Auxiliary coils or windings · CPC title

• H01F27/24 Primary

  Magnetic cores · CPC title

• H01F27/40

  Structural association with built-in electric component, e.g. fuse · CPC title

• H01F30/12 Primary

  Two-phase, three-phase or polyphase transformers · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title