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AC & DC FED POWER SUPPLY WITH COMMON COUPLED TRANSFORMER

IP.com Disclosure Number: IPCOM000249814D
Publication Date: 2017-Apr-10
Document File: 6 page(s) / 153K

Publishing Venue

The IP.com Prior Art Database

Related People

Sjöroos Jukka-Pekka: AUTHOR [+2]

Abstract

This document proposes an AC & DC fed power supply with common coupled transformer. This configuration is used to minimize the amount of inductive components and to provide uninterruptable power during a power line dip without using UPS ("Uninterruptible power source"). The proposed power supply combines the AC-power primary stage and the DC-power primary stage with a common coupled transformer.

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This is the abbreviated version, containing approximately 40% of the total text.

Page 1 of 6  FI-1617601

© Copyright [2017] ABB. All rights reserved.

AC & DC FED POWER SUPPLY WITH COMMON COUPLED TRANSFORMER

Summary

This document proposes an AC & DC fed power supply with common coupled transformer. This

configuration is used to minimize the amount of inductive components and to provide

uninterruptable power during a power line dip without using UPS (“Uninterruptible power source”).

Background

A conventional power supply is supplied by either AC (“Alternating Current”) voltage or DC (“Direct

Current”) voltage which is converted to a regulated DC voltage. If galvanic isolation between the

primary and the secondary is needed, it is carried out by using a transformer. An UPS

(“Uninterruptible power source”) is used in front of the power supply to provide uninterrupted

power in case of a power line dip. However using an UPS increases the cost and dimensions of

the whole system.

Another conventional power supply that includes both AC input and DC input consists of two

different converter stages that each includes a transformer in a case where galvanic isolation is

needed between the inputs and the outputs. The use of two different converter stages requires

more space and the use of several inductive components increases the cost of power supply and

decreases reliability.

Invention

The proposed power supply solves all problems mentioned above by combining the AC-power

primary stage and the DC-power primary stage with a common coupled transformer. Also the use

of an UPS is avoided when the proposed configuration is used.

AC & DC Fed Power Supply with Common Coupled Transformer

The proposed system for AC & DC fed power supply with common coupled transformer is shown

in Fig. 1.

The proposed system includes an “AC-power primary circuit” and a “DC-power primary circuit”

both connected to a “common coupled transformer T1”. In this case the common coupled

transformer includes two secondaries. The invention also includes an “enable/disable circuit”

Page 2 of 6  FI-1617601

© Copyright [2017] ABB. All rights reserved.

which is used to enable only one primary (either the AC power primary or the DC power primary)

at a time and disable the other. Galvanic isolation between the two primaries is achieved by using

an isolator at “enable/disable circuit”.

The configuration in Fig. 1 is shown for a flyback converter with two outputs (uo1 & uo2) but can be

used with all typical converter topologies and any number of outputs.

Common Coupled

Transformer T1

AC-power primary circuit

Secondary circuit

Secondary circuit

AC- source

uin,dc

AC-enable

uin,ac

AC & DC fed Power Supply with Common Coupled Transformer

Isolation barrier enable/disable

circuit

DC-power primary circuit

DC- source

uin,dc +

-

Load

Load

uo1 +

-

uo2 +

-

DC-enable

Fig 1. Proposed system for AC & DC fed power supply with common coupled transformer.

The input of the AC-power primary circuit is connected to the power grid which provides voltage

uin,ac to the AC primary. The input of...