含分布式电源配电网自适应保护研究

发布时间：2018-04-10 06:09

本文选题：分布式电源　切入点：配电网　出处：《中国石油大学(华东)》2014年硕士论文

【摘要】：电力系统的安全稳定运行是国民经济和社会民生的重要基础。电力系统的保护配置作为电力系统稳定运行的重要环节之一,决定整个系统的可靠性、可控性和稳定性。而随着分布式发电的发展,越来越多的分布式能源渗透到配电系统中,改变了传统配电网的单一辐射式结构,这意味着传统保护之间配合机制可能失效。因此,研究自适应保护在含分布式电源配电网中的应用具有重要的意义。本文首先介绍了分布式电源的概念、背景、分类、并网方式及并网要求。其次详细分析了分布式电源的类型、容量和接入位置对现有配电网继电保护影响。分布式电源会对流过保护的故障电流产生分流、助增和逆流作用,并利用Matlab/Simulink软件进行了仿真验证。自适应继电保护能够根据电力系统运行方式和故障状态的变化而实时改变保护性能、特性或定值的保护,能使保护尽可能地适应电力系统的各种变化,改善保护的性能,因而能够很好的解决分布式电源带来的保护误动和拒动问题。为实现自适应保护,本文提出应用强跟踪滤波的方法,实现保护背侧系统等效阻抗的在线实时计算。该方法摒弃了传统的故障分量的方法,通过系统参数在线辨识,精确跟踪系统参数变化,实现系统等效阻抗的在线实时估计。通过仿真,与基于FFT的故障分量方法结果对比研究,证明该方法不受故障电流衰减直流分量、电源初始相角以及风机故障电流的影响,并且能够满足自适应电流速断保护中参数计算的实时性与精确性要求。最后,针对含DG配电网特点,提出自适应保护的方案,并通过仿真验证了含分布式电源配电网自适应保护的可行性。
[Abstract]:The safe and stable operation of power system is the important foundation of national economy and people's livelihood.As one of the important links in the stable operation of power system, the protection configuration of power system determines the reliability, controllability and stability of the whole system.With the development of distributed generation, more and more distributed energy is permeated into the distribution system, which changes the single radiation structure of the traditional distribution network, which means that the coordination mechanism between the traditional protection may fail.Therefore, it is of great significance to study the application of adaptive protection in distribution network with distributed generation.This paper first introduces the concept, background, classification, grid-connected mode and grid-connected requirements of DG.Secondly, the influence of the type, capacity and access location of the distributed generation on the relay protection of the existing distribution network is analyzed in detail.Distributed power supply can generate shunt, increase and countercurrent to the fault current of current protection, and the simulation results are verified by Matlab/Simulink software.Adaptive relay protection can change the protection performance in real time according to the change of operation mode and fault state of power system. It can make the protection adapt to all kinds of changes of power system as much as possible and improve the performance of protection.Therefore, it can solve the problem of protection malfunction and rejection caused by distributed power generation.In order to realize adaptive protection, a strong tracking filtering method is proposed to realize the on-line real-time calculation of the equivalent impedance of the protection backside system.In this method, the traditional fault component method is abandoned, and the on-line real-time estimation of the equivalent impedance of the system is realized by the on-line identification of the system parameters and the accurate tracking of the variation of the system parameters.The simulation results are compared with the results of the fault component method based on FFT. It is proved that the method is not affected by the DC component attenuation of the fault current, the initial phase angle of the power supply and the fault current of the fan.And it can meet the requirement of real time and accuracy of parameter calculation in adaptive current fast break protection.Finally, according to the characteristics of distribution network with DG, an adaptive protection scheme is proposed, and the feasibility of adaptive protection with distributed power supply is verified by simulation.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM77

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