In future , several hvdc systems will set in shanghai , which is expected to create a multi - inked hvdc system 摘要未来多个直流输电系统落点于上海地区，将构成多馈入直流输电系统。
Hvdc ( high voltage direct current ) has many merits , and it will take an important role in national grid 直流输电有很多优点，在全国联网工程中，直流联网将发挥不可替代的作用。
Power is therefore transmitted along high - tension ac lines and then “ stepped down ” to usable voltages in local sub - stations 不过，开发风电使得直流输电技术现在又重新被人们重视起来。
A notable advantage of dc transmission systems is that it is highly controllable . this is very helpful for improving the stability of systems 直流输电的一个显著特点是其高度可控性，这对改善整个系统的稳定性是有益的。
The general situation of converter transformer and smoothing reactor is presented . the development of light dc transmission technilogy is prospected 摘要介绍了换流变压器和平波电抗器的概况，展望了轻型直流输电技术的发展。
The stability problems of hvdc systems will become important . this thesis aims at controlling hvdc systems to improve the stability of power systems 本论文主要是提出了一种有效的控制方法来改善高压直流输电系统的动态性能。
Research on the fundamental theories and key technologies on the performance , control and protection , simulation and test , project design and system test 直流输电基本性能、控制保护、仿真试验、工程设计及系统调试等基础理论和关键技术研究。
Uhvdc is particularly suitable for vast countries like china , where the centers that need power are often located far from power sources 超高压直流输电技术特别适合类似中国这样领土广阔的国家，这些国家需要电力的中心区域一般离发电站都较远。
The main works are as follows : a new hybrid simulation model of hvdc system is established based on netomac ' s hybrid simulation function in this paper 主要内容包括： 1基于netomac软件的混合仿真功能，建立了直流输电系统的混合仿真计算模型。
This paper designed a nonlinear controller for hvdc system by the relation extent method . then validate it by digital simulation 本文在系统数学模型的基础上采用关系度和零动态结合的方法设计了高压直流输电系统非线性控制器，并进行了仿真验证。
