System and method for neutral point balancing for back-to-back voltage source converters
US11258387B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2020 |
| Grant date | Feb 22, 2022 |
| Priority date | — |
| Expiry date | Oct 30, 2040 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/76
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method for controlling a three-level back-to-back voltage source power conversion assembly includes receiving an indication of a DC or AC unbalance occurring in voltage of a DC link. The power conversion assembly has a first power converter coupled to a second power converter via the DC link. In response to receiving the indication, the method includes activating a balancing algorithm that includes determining a deviation of a midpoint voltage of the DC link as a function of a total voltage of the DC link, calculating a voltage compensation needed for pulse-width modulation signals of the power conversion assembly based on the deviation, and coordinating common mode voltage injection from each of the power converters independently at a neutral point of the power conversion assembly based on the voltage compensation, thereby minimizing the at least one of the DC unbalance or the AC unbalance at any given operating condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.