Fault analysis on DC transmission system of PV generation

作者：Dai, Zhihui^*; Su, Huaibo; Huang, Min; Zhu, Huijun; Ma, Mingzhu

来源：International Transactions on Electrical Energy Systems, 2019, 29(2): e2721.

DOI：10.1002/etep.2721

• clamp double submodule
• DC transmission system of PV generation
• fault analysis
• fault stage
• modular multilevel converter

Compared with conventional AC transmission systems of PV generation, its DC counterpart is more resilient for improving the PV utilization. However, in the clamped double submodule-modular multilevel converter (CDSM-MMC) and DC/DC converter-based PV grid-connection system, pole-to-ground and pole-to-pole fault characteristics still need investigation. The equivalent model of PV stations and current circuits of the CDSM-MMC, before and after the fault, are studied first. Secondly, the influence of different connection groups of the converter transformer on the DC fault characteristic and that of DC faults on AC-side electrical quantities are discussed. Subsequently, development stages of DC faults are divided according to the charging and discharging processes of the CDSM-MMC and the DC/DC converter, and corresponding equivalent models are established and solved. Finally, the DC transmission system of the PV generation is modeled in Power Systems Computer Aided Design/Electromagnetic Transients including DC to verify the theoretical analysis. The DC fault analysis can provide reference for the subsequent protection system design.

• 出版日期2019-2
• 单位华北电力大学