分布式串联电抗器原理及其应用分析

Theory and Application of Distributed Series Reactance

柔性交流输电技术利用基于大功率电子技术的控制器改善交流输电系统可控性,并能增加输送功率的容量,是未来输电系统的三项支撑技术之一。首先分析分布式串联电抗器的工作原理,然后梳理某省级电网的220 k V输电环网,研究分布式串联电抗器的适用场合及其对系统的影响,包括对潮流分布、静态安全、暂态稳定、短路电流、电压无功分布、输电能力、网损以及继电保护的影响。研究表明,针对特定的有瓶颈限制的输电断面,选择适当的方案,能够增强断面的输电能力,同时对相关线路的潮流分布、暂态稳定、短路电流、继电保护、母线的电压和线路输送无功以及变压器下注无功的影响均很小,网损增加量很小。综合而言,分布式串联电抗器的应用对局部电网有明显改善,同时对主电网的影响较小,具有明显的经济效益。最后总结查找分布式串联电抗器适用场合的规律。

FACTS technology is one of the three supporting technologies of power transmission system in the future, and it utilizes controllers based on large power electronic technology to improve the controllability of AC transmission systems and it can increase the capacity of transmission power. The operational principle of distributed series reactance (DSR) is analyzed firstly, and then all of the 220 kV ring networks of a provincial power grid are summarized. The application situation of DSR and its effect on power grid are studied, including the effect upon power flow, static security, transient stability, fault current, voltage and reactive power distribution, transmission capacity, loss in the network, and protection relay. The result shows that it’s helpful to enhance transmission capacity of some certain transmission cross section by selecting an appropriate application scheme of DSR, and the effect on power flow, transient stability, fault current, protection relay, bus voltage, and reactive power transmitted through lines is rather small. The increase of power loss is also rather small. In general, application of DSR is of obvious economic benefit, which can obviously improve partial electric network and has small effect upon the main grid. At last, the laws of looking for application situation of DSR are summarized.