Pseudo zero vectors for space vector modulation and enhanced space vector modulation

Patent metadata

Field	Value
Publication number	US-9479084-B2
Application number	US-201314011867-A
Country	US
Kind code	B2
Filing date	Aug 28, 2013
Priority date	Feb 20, 2013
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A method of performing space vector modulation for PWM control for creating AC waveforms includes generating and sampling a reference signal to generate reference samples and performing a reference vector approximation to synthesize a reference vector associated with at least one of the reference samples. The reference vector approximation employs active vectors, one or more zero vectors, and one or more pseudo zero vectors in the formation thereof. Another method of performing space vector modulation (SVM) includes generating a reference signal and sampling the reference signal at a sampling frequency to generate a plurality of reference samples. The method also includes performing a reference vector approximation to synthesize a reference vector associated with at least one of the reference samples, wherein the reference vector approximation has a first portion that employs two adjacent active vectors and a remaining portion that employs two non-adjacent active vectors in the formation thereof.

First claim

What is claimed is:

1. A method of performing space vector modulation (SVM) for pulse width modulation (PWM) control for creating alternating current (AC) waveforms, comprising:
generating a reference signal and sampling the reference signal at a sampling frequency to generate a plurality of reference samples; and
performing a reference vector approximation to synthesize a reference vector associated with at least one of the reference samples,
wherein the reference vector approximation employs active vectors, one or more zero vectors, and one or more pseudo zero vectors in the formation thereof, and
wherein each of the one or more pseudo zero vectors comprises either a combination of two active vectors that have an angle difference therebetween of 180° or a combination of two active vectors that have an angle difference therebetween of 120°.

2. The method of claim 1 , wherein at least one of the one or more pseudo zero vectors comprises a combination of two active vectors that have an angle difference therebetween of 180°.

3. The method of claim 2 , wherein the two active vectors that in combination form the at least one of the one or more pseudo zero vectors have a scalar amplitude that is the same.

4. The method of claim 1 , wherein at least one of the one or more pseudo zero vectors comprises a combination of three active vectors that have an angle difference therebetween of 120°.

5. The method of claim 4 , wherein the three active vectors that in combination form the at least one of the one or more pseudo zero vectors have a scalar amplitude that is the same.

6. The method of claim 1 , wherein the active vectors in the reference vector approximation comprise adjacent active vectors.

7. The method of claim 6 , wherein a portion of the reference vector is approximated by two adjacent active vectors, and a remaining portion of the reference vector is approximated by two non-adjacent active vectors.

8. The method of claim 7 , wherein the portion of the reference vector is represented by a variable m, wherein 0≦m≦1, and wherein the remaining portion of the reference vector is represented by 1−m, wherein when m=1, the entire reference vector is approximated by two adjacent active vectors, and wherein when m=0 the entire reference vector is approximated by two non-adjacent active vectors.

9. The method of claim 7 , wherein the non-adjacent vectors are separated from one another by 120°.

10. A control system, comprising:
a space vector modulator configured to receive a plurality of reference signal samples and perform a reference vector approximation to synthesize a reference vector associated with at least one of the reference signal samples, wherein the reference vector approximation employs active vectors, one or more zero vectors, and one or more pseudo zero vectors in the formation thereof, and wherein the space vector modulator outputs timing signals based on the reference vector approximation;
a pulse width modulation unit configured to receive the timing signals from the space vector modulator, and output pulse width modulation control signals based thereon; and
a three phase inverter configured to receive the pulse width modulation control signals and generate alternating current waveforms based thereon,
wherein each of the one or more pseudo zero vectors comprises either a combination of two active vectors that have an angle difference therebetween of 180° or a combination of two active vectors that have an angle difference therebetween of 120°.

11. The control system of claim 10 , wherein at least one of the one or more pseudo zero vectors comprises a combination of two active vectors that have an angle difference therebetween of 180°.

12. The control system of claim 11 , wherein the two active vectors that in combination form the at least one of the one or more pseudo zero vectors have a scalar amplitude that is the same.

13. The control system of claim 10 , wherein at least one of the one or more pseudo zero vectors comprises a combination of three active vectors that have an angle difference therebetween of 120°.

14. The control system of claim 13 , wherein the three active vectors that in combination form the at least one of the one or more pseudo zero vectors have a scalar amplitude that is the same.

15. The control system of claim 10 , wherein the active vectors in the reference vector approximation comprise adjacent active vectors.

16. The control system of claim 10 , wherein a portion of the reference vector is approximated by two adjacent active vectors, and a remaining portion of the reference vector is approximated by two non-adjacent active vectors.

17. The control system of claim 16 , wherein the portion of the reference vector is represented by a variable m, wherein 0≦m≦1, and wherein the remaining portion of the reference vector is represented by 1−m, wherein when m=1, the entire reference vector is approximated by two adjacent active vectors, and wherein when m=0 the entire reference vector is approximated by two non-adjacent active vectors.

18. The control system of claim 16 , wherein the non-adjacent vectors are separated from one another by 120°.

19. The control system of claim 10 , wherein the three phase inverter comprises:
a first series-connected switch pair connected together at a node that forms a first phase output;
a second series-connected switch pair connected together at a node that forms a second phase output;
a third series-connected switch pair connected together at a node that forms a third phase output;
a shunt resistor connected with a first terminal to a bottom node of each of the first, second and third series-connected switch pairs, and a second terminal coupled to a reference potential; and
an amplifier having first and second inputs coupled to the first and second terminals of the shunt resistor, respectively, wherein an output of the amplifier reflects a current level conducting through the shunt resistor.

Assignees

• Infineon Technologies Ag

Inventors

• Zhao Tao
• Rabenstein Arno
• Gan Theng Kiong
• Kok Choon Keat
• Wong Sze Main

Classifications

• H02M7/53875

  with analogue control of three-phase output · CPC title

• H02M2007/53876

  Electricity · mapped topic

• H02M7/5395 Primary

  by pulse-width modulation · CPC title

• H02M7/53876

  based on synthesising a desired voltage vector via the selection of appropriate fundamental voltage vectors, and corresponding dwelling times · CPC title