http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Aditya Shekhar,Thiago Batista Soeiro,Laura Ramirez-Elizondo,Pavol Bauer 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
During the operation of a three line ac link in parallel with a ac-dc-ac link system that employs Back-to-Back (B2B) Medium Voltage Modular Multilevel Converters (MMC), a path for the low frequency zero sequence currents is shown to exist. Apart from causing additional losses, these currents can result in limitations on power capacity. A detailed analysis on the influence of cell capacitance, arm inductance and link conductor length on the circulating zero sequence currents and the means to mitigate them through a simulated control strategy is investigated. The simulations show that the dc link employing B2B-MMC can successfully operate in parallel with ac link without transformer isolation by controlling the zero sequence currents.
Aditya Shekhar,Lucia Beloqui Larumbe,Thiago Batista Soeiro,Yang Wu,Pavol Bauer 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
There is an increasing focus on integrating flexible dc links for bulk power routing in medium voltage distribu-tion grids. In such applications, the ac-dc Modular Multilevel Converter (MMC) devised for medium voltage and high-power ratings can be an interesting choice. This paper highlights some less explored design trade-offs arising due to the limitation on N in relation to modulation frequency and arm inductance. Specifically, the study intends to describe the interdependent influence of each degree of freedom on several aspects such as capacitor voltage balancing, circulating currents and harmonic performance. Finally, the importance of considering interhar-monics in the performance assessment of the MMC instead of the conventional interpretation of distortion calculation is highlighted.