Abstract
The appropriate control strategy, which takes the unbalanced grid connected voltage and unbalanced compensation current into account, is needed to keep the DC side voltage of each phase H bridge constant in star connection cascaded H-bridge multilevel static var generator (SVG). The common method is to add the zero sequence voltage to the SVG. Considering the unbalanced grid voltage or unbalanced compensation current, the requirements for the normal operation of the SVG were analyzed based on the zero sequence voltage component superposition method. The relationship of the grid voltage unbalance degree, compensating current unbalance degree and the rated voltage was analyzed. The compensation characteristic of the negative sequence current was deduced with the certain grid voltage. The influence of grid voltage variation on the output voltage was also considered with the certain compensating current. Finally, the correctness of the relevant theoretical analysis was verified by simulation and experiment. These quantitative analyses have directive significance for the application and selection of the star connection cascaded H-bridge multilevel SVG.
| Original language | English |
|---|---|
| Pages (from-to) | 861-869 |
| Number of pages | 9 |
| Journal | Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering |
| Volume | 38 |
| Issue number | 3 |
| DOIs | |
| State | Published - 5 Feb 2018 |
Keywords
- Cascaded H-bridge SVG
- Star connection
- Unbalance degree
- Zero sequence voltage