Drive and control for six-phase electrical machines with negligible common-mode voltage

Patent metadata

Field	Value
Publication number	US-10773922-B2
Application number	US-201615549076-A
Country	US
Kind code	B2
Filing date	Feb 3, 2016
Priority date	Feb 5, 2015
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A drive and motor system and method for a six phase machine with negligible common-mode voltage is provided. The six-phase machine includes six phase windings divided into at least two windings groups configured to generate a zero common-mode pulse width modulation. The drive and motor system and method can also include at least one direct current source and a six phase inverter switching between positive and negative power of the at least one direct current source.

First claim

The invention claimed is:

1. A motor and drive system, comprising:
at least one direct current source;
a six phase inverter switching between positive and negative power of the at least one direct current source;
a six phase machine including six phase windings divided into at least two windings groups configured to result in a zero common-mode pulse width modulation across the at least two windings groups;
wherein the six-phase inverter includes phase-legs of two switches, each phase leg connected to one phase of the six phase windings;
wherein the phase-legs are arranged into at least two phase groups corresponding to the at least two windings groups;
wherein, to maintain a common-mode voltage at zero, a switching pattern for the switches of a first phase group of the at least two phase groups is complementary to a switching pattern for the switches of a second phase group of the at least two phase groups.

2. The motor and drive system of claim 1 , wherein common-mode noises are conducted through the six phase windings of the six-phase machine through at least one parasitic capacitor to a ground during the zero common-mode pulse width modulation.

3. The motor and drive system of claim 1 , wherein the six phase windings are distributed at a 60 degrees difference in space.

4. The motor and drive system of claim 1 , wherein the each windings group forms a three-phase, 120° phase-shift machine.

5. The motor and drive system of claim 1 , wherein the six phase windings include at least two separate neutral connections, where a maximum modulation index is approximate to 1.15.

6. The motor and drive system of claim 1 , wherein a parasitic capacitance between windings and ground is modeled as one common-mode capacitor for a common-neutral connection or two substantially equal common-mode capacitors for two separate neutral connections.

7. The motor and drive system of claim 1 , wherein the six phase windings include a common neutral connection, where a maximum modulation index is 1.

8. The motor and drive system of claim 2 , wherein the at least one parasitic capacitor is a single parasitic common-mode capacitors that concentrates a common-mode capacitance from a common neutral connection.

9. The motor and drive system of claim 1 , wherein the six-phase inverter includes twelve switches.

10. The motor and drive system of claim 1 , wherein the switching pattern is generated by reversing duty cycles and carriers for the first phase group when generating switching actions for a the second phase group.

11. The motor and drive system of claim 1 is included in a ropeless elevator system.

Assignees

• Otis Elevator Co

Inventors

• Jiang Dong
• Krishnamurthy Shashank
• Marvin Daryl J

Classifications

• H02P25/22

  Multiple windings; Windings for more than three phases · CPC title

• H02P27/08 Primary

  with pulse width modulation · CPC title

• H02P21/00 Primary

  Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation · CPC title

• B66B1/306 Primary

  with DC powered elevator drive · CPC title