Voltage source converter

• US 7,239,535 B2
• Filed: 08/31/2004
• Issued: 07/03/2007
• Est. Priority Date: 08/31/2004
• Status: Expired due to Fees

• Current Assignee: ABB Power Grids Switzerland AG (ABB Limited)
• Original Assignee: ABB Technology Limited (ABB Ltd.)
• Inventors: Dofnas, Lars, Siljestrom, Roland, Jiang-Hafner, Ying
• Primary Examiner(s): HAN, YOUNGHUIE JESSICA
• Application Number:
  US10/929,409
• Publication Number:
  US 20060044849A1
• Time in Patent Office: 1,036 Days
• Field of Search: 363/17, 363/40, 363/41, 363/98, 363/131, 363/132
• US Class Current: 363/41
• CPC Class Codes: H02M 1/12 Arrangements for reducing harmonics from ac input or output
• CPC Class Codes: H02M 7/5395 by pulse-width modulation

Abstract

An apparatus for controlling a voltage source converter with at least two bridges of semiconducting self commutating elements connected in anti-parallel with a diode, including circuitry for producing a switching control pulse train to form a fundamental frequency, circuitry for effecting a switching order and circuitry for detecting a switching event.

Claims

1. An apparatus for controlling a voltage source converter with at least two bridges of semiconducting self commutating elements connected in anti-parallel with a diode, the apparatus comprising:

means for producing a switching control pulse train to form a fundamental frequency,

means for effecting a switching order and means for detecting a switching event,

computer means for calculating a reaction time between a switching order and a switching event for a selected pulse of the pulse train, and

means for adaptively adjusting the switch order of an equivalent pulse in a subsequent period of a harmonic period of the fundamental frequency utilizing the calculated reaction time.

2. The apparatus according to claim 1, wherein the means for adaptively compensating the switch order comprises a memory means for storing the calculated reaction times of each pulse of the harmonic period of the fundamental frequency.

3. The apparatus according to claim 1, wherein the means for detecting a switching event comprises means for measuring a voltage across electrodes of at least one semiconductor device in a valve.

4. The apparatus according to claim 1, wherein the means for producing a switching control pulse train comprises an optimum pulse width modulator.

5. The apparatus according to claim 1, wherein the computer means for calculating a reaction time comprises means for calculating a mean value for the reaction time of each pulse in the harmonic period of the fundamental frequency.

6. The apparatus according to claim 5, wherein the mean value comprises an exponential mean value.

7. A method for controlling a voltage source converter comprising at least two bridges including semiconducting self commutating elements, each connected in anti-parallel with a diode, and a control equipment, the method comprising:

arranging a pulse train for forming a fundamental frequency, defining an instant to send a switching order of a pulse of the pulse train of the fundamental frequency,

sending the switching order,

determining the actual switching event,

comparing the actual switching event with a desired switching event, and

adjusting the instant to send the switching order of an equivalent pulse in a next harmonic period of the fundamental frequency based upon the comparing of the actual switching event and the ideal switching event.

8. The method according to claim 7, wherein the determination of the actual switching event comprises measurement of a voltage across electrodes of at least one of the semiconducting elements.

9. The method according to claim 7, wherein adjusting the instant to send the switching order of the equivalent pulse in the next harmonic period comprises a blanking time adjustment.

10. A method for controlling a voltage source converter by a pulse width modulation pulse signal comprising an ideal switching instant for each switching pulse, the method comprising:

detecting an actual switching event for a selected switching pulse in a first period of a fundamental frequency,

adjusting an action time for the selected switching pulse by comparison of the ideal switching instant and the actual switching event, and

correcting a switching order of a corresponding pulse in a following period of the fundamental frequency utilizing the adjusted action time.

11. A computer program product, comprising:

a computer readable medium; and

computer program instructions recorded on the computer readable medium and executable by a processor for performing a method comprising arranging a pulse train for forming a fundamental frequency, defining an instant to send a switching order of a pulse of the pulse train of the fundamental frequency, sending the switching order, determining the actual switching event, comparing the actual switching event with a desired switching event, and adjusting the instant to send the switching order of an equivalent pulse in a next harmonic period of the fundamental frequency based upon the comparing of the actual switching event and the ideal switching event.

12. The computer program product according to claim 11, wherein the method further comprises providing the computer program instructions at least in part over a network.

13. The computer program product according to claim 11, wherein the method further comprises providing the computer program instructions at least in part over the Internet.