# US 2008/0175028 A1 · Multilevel converter arrangement and use thereof

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- Number: US 2008/0175028 A1
- Document ID: US20080175028A1
- Status: Published application
- Kind: A1
- Application number: 12/025,393
- Filed: 2008-02-04
- Published: 2008-07-24
- Earliest claimed: 2005-08-03
- Assignees: ABB Research Ltd.
- Inventors: Philippe STEFANUTTI; Nicolas Hugo; Luc Meysenc; Philippe Noisette; Alice Piazzesi
- Web page: https://patentgrep.com/patent/US20080175028A1

## CPC

- H02M 7/483: Converters with outputs that each can have more than two voltages levels
- H02M 7/003: {Constructional details, e.g. physical layout, assembly, wiring or busbar connections}
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## Abstract

The present disclosure is concerned with the provision of the necessary power to the gate-drives controlling the semiconductor devices of a multilevel converter used in railway traction applications. A power loop with a power-loop emitter and a power-loop receptor located in different housings and connected via a power-loop conductor that is at least partially exterior to both housings is proposed. By means of a current transformer inductively coupling the conductor to the emitter or receptor, the power-loop also provides for electrical insulation between the emitter and the receptor. The fact that emitter and receptor are distant from each other offers greater flexibility in the positioning and design of the galvanic separation between the emitter and the receptor or the supplied gate-drive, respectively. In particular, the local voltages of converter levels ranging up to the supply voltage of e.g. 21 kV RMS of the multilevel converter can thus be insulated from the global earth potential of the power-loop emitter. Several power-loop receptors can be coupled to the same power-loop conductor and thus fed by the same power-loop emitter.

## Claims

### Claim 1

A multilevel converter arrangement with N≧2 converter levels, each level comprising a primary converter connected to a primary winding of a transformer unit of a transformer arrangement, and a secondary converter connected to a secondary winding of the transformer unit, wherein the arrangement comprises a gate-drive for controlling a controllable power semiconductor device in a primary converter with electrical power supplied to the gate-drive by a rectifier unit,
wherein a power-loop with a power-loop emitter and a power-loop receptor comprising the rectifier unit, wherein the emitter is inductively coupled to the receptor via a current transformer and a power-loop conductor that is at least partially exterior to housings of both the emitter and the receptor.

### Claim 2 (depends on 1)

The arrangement according to claim 1, wherein the power-loop emitter feeds several power-loop receptors.

### Claim 3 (depends on 1)

The arrangement according to claim 1, wherein the power-loop conductor is a cable with a high or medium voltage insulation.

### Claim 4 (depends on 3)

The arrangement according to claim 3, wherein the current transformer comprises a toroidal transformer core and a conductive screen arranged between the core and the power-loop conductor.

### Claim 5 (depends on 1)

The arrangement according to claim 1, wherein a capacitor is provided between the rectifier unit and the gate drive as a short-term backup power supply to the gate-drive.

### Claim 6 (depends on 1)

A use of a multilevel converter arrangement according to claim 1 for converting a single-phase high voltage of a supply line to a lower voltage of a DC link in railway traction applications, wherein the transformer units operate at a medium frequency above the frequency of the supply line.

### Claim 7 (depends on 5)

A use of a multilevel converter arrangement according to claim 5 for converting a single-phase high voltage of a supply line to a lower voltage of a DC link in railway traction applications, wherein the transformer units operate at a medium frequency above the frequency of the supply line.