Direct Electrical Heating Arrangement with a Power Electronic Converter

Patent metadata

Field	Value
Publication number	US-2020252000-A1
Application number	US-202016855358-A
Country	US
Kind code	A1
Filing date	Apr 22, 2020
Priority date	Aug 8, 2011
Publication date	Aug 6, 2020
Grant date	—

Abstract

An arrangement provides an AC current to a load for direct electrical heating. The arrangement includes a AC-DC-AC converter cell. The converter cell has at least two converter input terminals connected to at least two transformer output terminals. The converter cell has a first converter output terminal and a second converter output terminal, wherein the first converter cell output terminal is adapted to be connected to the load.

First claim

I claim:

1 . A direct electrical heating power supply comprising:
a converter comprising at least one AC-DC-AC converter cell, the converter cell having an AC-DC section, a DC link and a DC-AC section, a first, a second and a third AC converter input, wherein the first converter input is connectable to a first secondary winding of a three phase transformer, the second converter input is connectable to a second secondary winding of the three phase transformer, and the third converter input is connectable to a third secondary winding of the three phase transformer, an AC converter output connectable to an electrically conductive pipeline section forming a single phase load for direct electrical heating of the pipeline section, wherein the converter is configured supply AC electric power to the single phase load and to distribute the load equally between the first, the second and the third AC converter inputs.

2 . The direct electrical heating power supply according to claim 1 , wherein the converter comprises at least three power cells, one power cell providing the first AC converter input, one power cell providing the second AC converter input and one power cell providing the third AC converter input, wherein the output of the at least three power cells is connected in series to provide the AC converter output, the converter being configured to synchronize the generation of an AC voltage by the DC-AC sections of the at least three power cells to provide a single phase AC output at the AC converter output.

3 . The direct electrical heating power supply according to claim 1 , wherein the power cell comprises three AC inputs providing the first, the second and the third AC converter inputs, wherein the AC-DC section of the converter cell is configured to convert a three phase AC voltage received on the first, the second and the third AC converter inputs into a common DC voltage on the DC link, thereby symmetrising the load on the first, the second and the third AC converter inputs.

4 . The direct electric heating power supply according to claim 1 , wherein AC-DC-AC converter cell comprises a first converter output terminal and a second converter output terminal, wherein the first converter output terminal is connectable with the load, wherein at all three inputs of the transformer, a symmetrical load is achievable by controlling the AC-DC-AC converter cell.

Assignees

• Siemens Ag

Inventors

• Haugan Espen

Classifications

• H02M5/4505 Primary

  having a rectifier with controlled elements · CPC title

• H02M1/0085

  Partially controlled bridges · CPC title

• F16L53/35

  Ohmic-resistance heating · CPC title

• F16L53/37

  the heating current flowing directly through the pipe to be heated · CPC title

• H02M5/4585

  having a rectifier with controlled elements · CPC title