Multi-level medium-voltage inverter

Patent metadata

Field	Value
Publication number	US-9270222-B2
Application number	US-201414314888-A
Country	US
Kind code	B2
Filing date	Jun 25, 2014
Priority date	Jul 2, 2013
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A multi-level medium-voltage inverter that receives three-phase power and outputs a three-phase voltage to a three-phase motor, includes: a plurality of unit power cells connected in series to output a single phase voltage, individual unit power cells each having a phase voltage forming a single level to configure multiple levels; and a module-type phase shift transformer configured to convert the three-phase power and applying the converted power to three unit power cells constituting one level, wherein the module-type phase shift transformer includes a plurality of modules.

First claim

What is claimed is:

1. A multi-level medium-voltage inverter that receives three-phase power and outputs a three-phase voltage to a three-phase motor, the multi-level medium-voltage inverter comprising:
a plurality of unit power cells connected in series to output a single phase voltage, wherein each of the plurality of unit power cells outputs multi-level voltage outputs forming the single phase voltage; and
a module-type phase shift transformer configured to convert the three-phase power and apply the converted power to three unit power cells constituting one level;
wherein the module-type phase shift transformer includes a plurality of modules, and each of the plurality of unit power cells comprises:
a rectifying unit configured to rectify an output received from the module-type phase shift transformer;
a smoothing unit configured to smooth a DC voltage rectified by the rectifying unit; and
an inverter unit comprising a plurality of switch units, each switch unit including a diode and a power semiconductor connected in parallel, wherein the plurality of switch units are configured in a cascaded T-type neutral point clamped (NPC) manner; and

wherein, in the module-type phase shift transformer, a phase shift angle of a primary winding is determined using the number of the module-type phase shift transformers, the number of outputs of a secondary side of the module-type phase shift transformer, and the number of pulses of a rectifying unit of the unit power cell.

2. The multi-level medium-voltage inverter of claim 1 , wherein the number of modules of the phase shift transformer corresponds to the number of multi-level voltage outputs or the number of unit power cells.

Assignees

• Lsis Co Ltd

Inventors

• Yoo Anno

Classifications

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02M7/49

  Combination of the output voltage waveforms of a plurality of converters · CPC title

• H02M7/487 Primary

  Neutral point clamped inverters · CPC title

• H02M7/483 Primary

  Converters with outputs that each can have more than two voltages levels · CPC title

• H02M7/4835 Primary

  comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage · CPC title