Multilevel power conversion system and method

Patent metadata

Field	Value
Publication number	US-12119767-B2
Application number	US-202217660456-A
Country	US
Kind code	B2
Filing date	Apr 25, 2022
Priority date	Oct 25, 2019
Publication date	Oct 15, 2024
Grant date	Oct 15, 2024

Abstract

A system includes a first power conversion device connected to a first power source, a first isolated power conversion device connected to the first power source, and a second power conversion device connected to the first isolated power conversion device, wherein outputs of the first power conversion device and outputs of the second power conversion device are connected in series, and series-connected outputs of the first power conversion device and the second power conversion device are configured to drive a motor.

First claim

What is claimed is:

1. A system comprising:
a first power conversion device connected to a first power source;
a first isolated power conversion device connected to the first power source; and
a second power conversion device connected to the first isolated power conversion device, wherein outputs of the first power conversion device and outputs of the second power conversion device are connected in series and configured to drive a motor,
wherein the first power conversion device is a first inverter comprising a first inverting unit, a second inverting unit and a third inverting unit connected in parallel, and wherein each inverting unit of the first inverter includes two output terminals;
wherein the second power conversion device comprises a second inverter comprising a fourth inverting unit, a fifth inverting unit and a sixth inverting unit connected in parallel, and wherein each inverting unit of the second inverter includes two output terminals,
wherein two output terminals of the first inverting unit and two output terminals of the fourth inverting unit of the second inverter are connected in series and further connected to a first phase of the motor,
wherein two output terminals of the second inverting unit and two output terminals of the fifth inverting unit of the second inverter are connected in series and further connected to a second phase of the motor, and
wherein two output terminals of the third inverting unit and two output terminals of the sixth inverting unit of the second inverter are connected in series and further connected to a third phase of the motor;

wherein a common node of the first inverting unit and the fourth inverting unit is configured to be connected to a first phase of a three-phase power source;
wherein a common node of the second inverting unit and the fifth inverting unit is configured to be connected to a second phase of the three-phase power source; and
wherein a common node of the third inverting unit and the sixth inverting unit is configured to be connected to a third phase of the three-phase power source, and wherein the three-phase power source is configured to charge the first power source through a power factor correction device formed by windings of the motor and switches of the second inverter.

2. The system of claim 1 , wherein the first isolated power conversion device is a three-level inductor-inductor-capacitor (LLC) converter.

3. The system of claim 1 , wherein the first isolated power conversion device comprises a first primary switching network, a first resonant tank, a first transformer and a secondary rectifier connected in cascade.

4. The system of claim 1 , wherein the first isolated power conversion device comprises a first primary switching network, a first resonant tank, a first transformer, a second primary switching network, a second resonant tank, a second transformer and a secondary rectifier,
wherein the first primary switching network, the first resonant tank and a primary winding of the first transformer are connected in cascade,
wherein the second primary switching network, the second resonant tank and a primary winding of the second transformer are connected in cascade, and
wherein a secondary winding of the first transformer and a secondary winding of the second transformer are connected in series and further connected to the secondary rectifier.

5. The system of claim 1 , wherein the first isolated power conversion device comprises a first primary switching network, a first resonant tank, a first transformer, and a plurality of secondary rectifiers, and wherein the plurality of secondary rectifiers is configured to provide isolated power for a plurality of inverting units of the second power conversion device.

6. The system of claim 1 , wherein the first power conversion device is the first inverter having three legs and three output terminals;
wherein a first terminal of the first inverter is connected in series with outputs of the first inverting unit and further connected to the first phase of the motor;
wherein a second terminal of the first inverter is connected in series with outputs of the second inverting unit and further connected to the second phase of the motor; and
wherein a third terminal of the first inverter is connected in series with outputs of the third inverting unit and further connected to the third phase of the motor.

7. The system of claim 6 , wherein the first isolated power conversion device is an LLC converter comprising a primary winding, a first secondary winding, a second secondary winding and a third secondary winding,
wherein the primary winding is connected to the first power source through a primary switching network,
wherein the first secondary winding is connected to the first inverting unit through a first rectifier,
wherein the second secondary winding is connected to the second inverting unit through a second rectifier, and
wherein the third secondary winding is connected to the third inverting unit through a third rectifier.

8. The system of claim 1 , wherein the first power conversion device is the first inverter having three legs and three output terminals, and
wherein the second power conversion device comprises the fourth inverting unit having two legs and the fifth inverting unit having two legs, a first output terminal of the first inverter being both connected to the first phase of the motor and connected in series with outputs of the first inverting unit, a second output terminal of the first inverter being both connected to the second phase of the motor and connected in series with outputs of the second inverting unit, and a third output terminal of the first inverter being connected directly to the third phase of the motor.

9. The system of claim 1 , wherein the first power conversion device is the first inverter having three legs and three output terminals; and
wherein the second power conversion device comprises the fourth inverting unit having three legs and the fifth inverting unit having three legs,
wherein a first output terminal of the first inverter is connected in series with outputs of the first inverting unit and further connected to the first phase of the motor,
wherein a second output terminal of the first inverter is connected in series with outputs of the second inverting unit and further connected to the second phase of the motor, and
wherein a third output terminal of the first inverter is connected to the third phase of the motor directly.

10. The system of claim 1 ,
wherein the second power conversion device further comprises a third inverter, the third inverter comprising a seventh inverting unit, an eighth inverting unit, and a ninth inverting unit connected in parallel, each inverting unit of the third inverter including two output terminals,
wherein the two output terminals of the first inverting unit, the two output terminals of the fourth inverting unit, and two output terminals of the seventh inverting unit are connected in series and further connected to the first phase of the motor,
wherein the two output terminals of the second inverting unit, the two output terminals of the fifth inverting unit, and two output terminals of the eighth inverting unit are connected in series and further connected to the second phase of the motor, and
wherein two output terminals of the third inverting unit, two output terminals of the sixth inverting unit and two output terminals of the ninth inverting unit are connected in series and further connected to the third phase of the motor.

11. A system comprising:
a first inverter having inputs connected to a battery;
an isolated power converter having inputs connected to the battery

Assignees

• Huawei Digital Power Tech Co Ltd

Inventors

• Zhu Huibin
• Fu Dianbo
• Dai Heping
• Ye Liming

Classifications

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title

• H02M3/33584

  Bidirectional converters · CPC title

• B60L2220/00

  Electrical machine types; Structures or applications thereof · CPC title

• B60L2210/40

  DC to AC converters · CPC title

• B60L2210/30

  AC to DC converters · CPC title