Abstract
Submodule (SM) fault is a common potential problem in the modular multilevel converter (MMC), which may lead to current distortion and even the collapse of the control system. This article proposes a novel operation scheme for SM fault in medium-voltage MMC applications. First, when the fault number is low, the capacitor voltages increase to a lower value according to the operation status. Second, when the fault number is higher, the capacitor voltages increase to the rated value and the zero-sequence voltage (ZSV) is injected to maintain the normal operation of MMC. In addition, a virtual voltage idea is applied to simplify the modulation under SM faults, where the reconfigurations of carriers are not necessary. Compared with the conventional fault-tolerant method, the proposed method can enhance the ride-through capability of MMC and simplify the modulation process under SM faults. Simulation and experimental results verify the effectiveness of the proposed operation scheme under severe SM faults.
| Original language | English |
|---|---|
| Article number | 8962196 |
| Journal | IEEE Journal of Emerging and Selected Topics in Power Electronics |
| Volume | 9 |
| Issue number | 2 |
| Pages (from-to) | 1258-1268 |
| Number of pages | 11 |
| ISSN | 2168-6777 |
| DOIs | |
| Publication status | Published - Apr 2021 |
Bibliographical note
Funding Information:This work was supported by the National Key Research and Development Program of China under Grant 2017YFB0903300, in part by the Project of National Natural Science Foundation of China under Grant 51625702 and Grant 51807135, and in part by the Joint Fund Project of National Natural Science Foundation-State Grid Corporation under Grant U1766210.
Publisher Copyright:
© 2013 IEEE.
Keywords
- Fault-tolerant control
- modular multilevel converter (MMC)
- submodule (SM) fault
- virtual voltage
- zero-sequence voltage (ZSV)