高压直流输电是未来电网的发展方向,研究一种能够在直流系统故障时限制直流电流的装置,已经成为国内外研究的热点。该文提出一种固态直流限流器拓扑结构,它具有结构简单,采用的半导体器件少,成本低,效率高,工作可靠等优点。介绍了该结构的工作原理和控制模式,推导了其数学模型,最后通过仿真验证以及和其他方案的对比研究,证明了该固态直流限流器拓扑结构的性能。分析表明该拓扑结构不但限流效果较好,电抗器也没有直流偏磁饱和问题,并且电流小,频率高,工程实现起来比较容易,可广泛应用于直流输配电领域。
The high voltage direct current(HVDC) is the future of power transmission. Developing equipment which can limit the DC current to protect from faults is a key area of research. This paper proposes a solid DC current limiter(SDCCL) topology which, when compared to other DC current limiters, features a simple structure, fewer components, lower cost, and higher efficiency. The operation principle and control scheme is demonstrated in detail and a mathematical model is developed. Ideal performance of the SDCCL topology is verified through simulation and compared with other DC current limiter solutions. The SDCCL not only shows better performance with no DC reactor core saturation, but also lower current values, higher frequency tolerance, and easy engineering and implementation. It can be adopted as a solution throughout the growing DC grid.