【作者】 李培蓉；

【导师】 牟道槐；

【作者基本信息】 重庆大学 ， 电气工程， 2003， 硕士

【摘要】 随着国民经济的发展，我国配电网正在发生深刻的变化。尤其在城市，一方面，电网正逐渐由架空线换为电缆，使其减少电磁污染和避免杆树矛盾，增加城市绿地，美化环境。但是，电缆的电容效应将导致配电网产生稳态过电压。另一方面，现代配电网上用于冶炼的电弧炉和铁路牵引机车等波动性负荷，会使电网电压频繁波动，造成电压闪变。 上述变化和特征将使现代配电网的运行状态产生变化。本文从影响配电网的三个因素：工频过电压、谐振过电压以及电压闪变入手，分析了现代配电网的运行状态。并提出用静止无功补偿器(SVC)抑制电压闪变的控制策略。 本文用集中参数等值电路和分布参数等值电路分析了现代配电网的工频过电压。并对典型的现代配电网进行了谐振过电压分析计算，明确了现代配电网的谐振过电压与电缆长度和负荷的大小相关。 文中分析了电容器补偿对抑制电压闪变的不利影响，固定的电容补偿将增大电压闪变。 本文提出用静止无功功率补偿器(SVC)对配电网的电压闪变进行抑制的控制策略。静止补偿器是基于电力电子技术发展起来的新型无功发生器，它能实现动态的无功补偿，响应速度快。通过数值仿真曲线分析，对比了电容补偿和静止无功补偿器(SVC)补偿的效果，得到的结论是电容补偿有扩大闪变的影响，而静止无功补偿器(SVC)是抑制闪变的最佳装置，并且调差系数Ks和时间常数T_f越小，SVC补偿效果越好。更多还原

【Abstract】 With the development of the country economy, a great change of power distribution network is occurring, especially in the city. On the one hand, distribution circuit is changing from overhead power line to cable line, it lead to reduce electromagnetism pollution, avoid the contravention between pole and tree, add the greenbelt of the city, and beautify the environment. However, capacitance effect resulted from the cable will make the steady-state over-voltage on the power distribution network. On the other hand, because of the fluctuating load, such as arc furnace and railway traction locomotive, the voltage of the network will frequently fluctuate and lead to voltage flash.The change and characteristics above will change the running state of the network. So this paper analyzed the running state by taking account of power over-voltage, resonance over-voltage and voltage flash, and propounded the strategy that voltage flash were controlled by using Static var compensator (SVC).The paper discussed the power over-voltage of the network through central parameter equivalence circuit and distribution parameter equivalence circuit. And analyzed the resonance over-voltage with a typical power-distribution-net model, the result showed that cable length and load value could avoid the resonance over-voltage.The adverse effects of capacitor about voltage flash was discussed in this paper, and attested that fixed capacitor compensation add the voltage flash.The paper propounded that used the SVC to control voltage flash of the network. SVC is a new var generator based on the electric power and electronic technology, which can realize the dynamic var compensation and speed is quick. By simulating, this paper compared the effect of capacitor compensation to that of SVC compensation, the results showed that capacitor compensation add the voltage flash, and SVC was the optimal equipment to restrain the flash. Furthermore, the smaller value of Ks and Tf, the better effect of SVC.更多还原