【作者】 张慧颖；

【导师】 王继东；

【作者基本信息】 天津大学 ， 电气工程， 2014， 硕士

【摘要】 低频低压减载是保证电力系统安全稳定运行的最后一道防线,是维系电力系统功率平衡、防止电力系统频率和电压崩溃的有效控制方法。广域量测体系的建设、需求侧响应技术的发展和智能电网背景下智能家电的推广应用为传统的减载方法提供了新的发展方向。本文主要研究了基于智能家电的低频低压减载模型及其敏感性分析。首先分析低频低压减载的基本原理及其传统整定方法,对电力系统频率特性与电压失稳机理进行了深入的研究。然后研究智能电网背景下智能家电性能特征,以电冰箱和热水器为例,分析其运行方式和动作特性,建立适用于大电网分析的智能家电的实用模型,并在需求侧响应技术的基础上提出适用于智能减载的控制方法。接下来提出一种基于智能家电的智能化低频低压减载策略并在测试系统中进行仿真验证,仿真结果表明此减载策略能在电力系统受到扰动后快速有效的抑制频率和电压的跌落甚至崩溃,减少切负荷量,减少经济损失并提高电力系统的灵活可靠性。最后,对切负荷点和切负荷量两个变量进行敏感性分析,研究切负荷点和切负荷量对系统频率和节点电压的影响,为优化智能化低频低压减载方案提出指导性建议。更多还原

【Abstract】 Under frequency load shedding(UFLS) and under voltage load shedding(UVLS) are the last line of defense to ensure safe and stable operation of the power system. Meanwhile, they also can maintain the power balance of power system and prevent frequency and voltage collapse of power system as an effective control method. The construction of wide area measurement system, the development of demand response technologies and the application of smart appliances under the background of smart grid provide a new direction for the development of traditional load shedding methods.This paper addresses on the UFLS/UVLS model based on smart appliances and its sensitivity analysis. Firstly, this paper analyzes the basic principles of UFLS/UVLS and their traditional tuning method. Frequency characteristics of the power system and voltage instability mechanism are carried out in-depth research. Then the performance characteristics of smart appliances are studied. This paper takes refrigerators and water heaters as research subjects, analyzes their operation mode and operating characteristics, establishes their practical model and proposes their control method on the basis of the demand side response technology. Next an intelligent under frequency and under voltage load shedding strategy is proposed and simulated in a test system. Simulation results show that this strategy can well work to suppress the frequency and voltage fall or even collapse, reduce the amount of load shedding, reduce economic losses and improve the reliability and flexibility of the power system. Finally, this paper carries the sensitivity analysis on the load shedding point and amount of load shedding, studies their impact on the frequency and voltage of power system and provides recommendations for optimizing intelligent under frequency and under voltage load shedding method.更多还原