Power converter

Patent metadata

Field	Value
Publication number	US-10103645-B2
Application number	US-201515126356-A
Country	US
Kind code	B2
Filing date	Mar 17, 2015
Priority date	Mar 19, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

This power converter is provided with: three clusters (CLu, CLv, CLw) in which unit cells are cascade-connected; and power supplies of the same kind which are respectively connected to one end of each of the three clusters. Terminals of the three clusters at the side not connected to the power supplies are respectively connected to other ends of the power supplies connected to the other clusters to form a delta-connection configuration. Three connections of the delta-connection configuration are respectively connected to each of the U, V, and W phases of a three-phase alternating current, and power conversion between the power supplies and the three-phase AC is enabled. If DC power supplies (Vdcu, Vdcv, Vdcw) are employed as the power supplies, power conversion between the DC power supplies and the three-phase AC power supplies can be performed. If in-phase single-phase AC power supplies are employed as the power supplies, power conversion between either the single-phase AC power supplies and the three-phase AC power supplies, or the three-phase AC power supplies can be performed.

First claim

The invention claimed is:

1. A power converter comprising:
three clusters in which unit cells are cascade-connected; and
power supplies of the same kind, a first end of each power supply connected to a first end of an associated cluster of the three clusters, wherein
a delta connection is formed by connecting a second end of each cluster to a second end of power supply associated with another cluster, and
three connection portions of the delta connection are configured to be connected to respective phases of a three-phase alternating current (AC) system for power conversion to be performed between the power supplies and the three-phase AC system.

2. The power converter according to claim 1 , wherein
the power supplies are direct current (DC) power supplies, and
the unit cells are chopper cells that include two semiconductor switches that are connected in series, a DC capacitor that is connected in parallel with the two semiconductor switches, and input and output terminals for a current that is discharged from the DC capacitor or charged in the DC capacitor according to a switching operation of the semiconductor switches.

3. The power converter according to claim 1 , wherein
the power supplies are direct current (DC) power supplies, and
the unit cells are bridge cells that include a set of parallelly connected two pairs of two semiconductor switches that are connected in series, a DC capacitor that is connected in parallel with the set of the two pairs of semiconductor switches, a series connection point for each pair of the two semiconductor switches, and input and output terminals for a current that is discharged from the DC capacitor or charged in the DC capacitor.

4. The power converter according to claim 1 , wherein
the power supplies are in-phase AC power supplies, and
the unit cells are bridge cells that include a set of parallelly connected two pairs of two semiconductor switches that are connected in series, a direct current (DC) capacitor that is connected in parallel with the set of the two pairs of semiconductor switches, a series connection point for each pair of the two semiconductor switches, and input and output terminals for a current that is discharged from the DC capacitor or charged in the DC capacitor.

5. The power converter according to claim 4 , wherein generation of a three-phase voltage and driving of a three-phase motor are enabled by using the three power converters in which the unit cells are bridge cells.

6. The power converter according to claim 4 , wherein the AC power supplies are formed by insulated AC power supplies using a single-phase transformer.

7. The power converter according to claim 1 , wherein
each of the semiconductor switches includes:
a semiconductor switching element that allows a current to flow in a single direction during ON; and
a feedback diode that is connected in reverse parallel with the semiconductor switching element.

8. A power converter comprising:
three clusters, each cluster including a plurality of unit cells that are cascade-connected; and
direct current (DC) power supplies, each power supply respectively inserted between arbitrary connection points of the plurality of unit cells of an associated cluster of the three clusters, wherein
a delta connection is formed by connecting an anode-side terminal of each cluster with an inserted DC power supply to a cathode-side terminal of another cluster with an inserted DC power supply, and
three connection portions of the delta connection are configured to be connected to respective phases of a three-phase alternating current (AC) system for power conversion to be performed between the DC power supplies and the three-phase AC system.

9. The power converter according to claim 8 , wherein the unit cells are chopper cells that include two semiconductor switches that are connected in series, a DC capacitor that is connected in parallel with the two semiconductor switches, and input and output terminals for a current that is discharged from the DC capacitor or charged in the DC capacitor according to a switching operation of the semiconductor switches.

10. The power converter according to claim 8 , wherein the unit cells are bridge cells that include a set of parallelly connected two pairs of two semiconductor switches that are connected in series, a DC capacitor that is connected in parallel with the set of the two pairs of semiconductor switches, a series connection point for each pair of the two semiconductor switches, and input and output terminals for a current that is discharged from the DC capacitor or charged in the DC capacitor.

11. A power converter comprising:
three clusters in which unit cells are cascade-connected; and
in-phase alternating (AC) power supplies, each power supply respectively inserted between arbitrary connection points of the plurality of unit cells of an associated cluster of the three clusters, wherein
a delta connection is formed by connecting a first end of each cluster with an inserted AC power supply to a second end of another cluster with an inserted AC power supply, and
three connection portions of the delta connection are configured to be connected to respective phases of a three-phase AC system for power conversion to be performed between the in-phase AC power supplies and the three-phase AC.

12. The power converter according to claim 11 , wherein the unit cells are bridge cells that include a set of parallelly connected two pairs of two semiconductor switches that are connected in series, a direct current (DC) capacitor that is connected in parallel with the set of the two pairs of semiconductor switches, a series connection point for each pair of the two semiconductor switches, and input and output terminals for a current that is discharged from the DC capacitor or charged in the DC capacitor.

13. The power converter according to claim 11 , wherein generation of a three-phase voltage and driving of a three-phase motor are enabled by using the three power converters in which the unit cells are bridge cells.

14. The power converter according to claim 11 , wherein the AC power supplies are formed by insulated AC power supplies using a single-phase transformer.

Assignees

• Tokyo Inst Tech

Inventors

• Akagi Hirofumi
• Hagiwara Makoto

Classifications

• H02M2007/4835

  Electricity · mapped topic

• H02M5/10

  using transformers · CPC title

• H02M7/537 Primary

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title

• H02M5/293

  using semiconductor devices only · CPC title

• H02M1/42

  Circuits or arrangements for compensating for or adjusting power factor in converters or inverters · CPC title