含DG的基于广域行波信息的配电网故障定位和布点优化研究

发布时间：2019-05-27 20:15

【摘要】：配电网作为与用户联系最紧密,同时也是电力输送的最后一环,配电网的供电可靠性将直接影响到用户的用电体验。配电网结构复杂,线路分支、设备较多,负荷变化大,所以发生故障概率较大,尤其是单相接地故障。由于中国配电网中性点广泛采用不接地或经消弧线圈接地方式,单相接地故障以后流过线路故障点电流很小,给故障信号采集和故障定位带来困难,因此目前很多故障选线和定位方法都不能有效的对小电流接地故障进行准确定位。行波定位法基本不受系统参数、过渡电阻的大小及系统运行方式等因素的影响,在输电网中得到了成功的应用,但是配电网线路分支众多,结构复杂,行波单端法需要对故障点的后续反射波头进行准确识别,这在配电网中会有一定困难。所以本文研究内容为基于双端法的广域故障电压初始行波信息的配电网故障定位以及配电网行波装置布点优化。对行波在配电网中的传输特性进行分析,对电磁式电压互感器和配电变压器的行波的传变特性进行分析,对分布式电源接入配电网的方式、接入点行波测量可行性进行分析,基于以上分析得出,可以在配电变压器二次侧以及分布式电源接入点处安装行波故障测距装置,基于各测点的广域电压初始行波信息进行配电网故障定位;但是分布式电源接入点以及配电变压器二次侧如果都安装行波测距装置会导致成本过高,所以需要研究配电网中行波故障定位装置布点优化,以配电网拓扑约束为基础,分析行波的传播规律,在保证本网络中所有线路故障可观的前提下,基于配电网分层分解以及行波双端定位思路建立约束条件,基于模拟退火粒子群算法对装置布点位置进行优化;最后以布点结果为基础,基于各测点获取的故障电压首波头信息,在本文中称为广域行波信息,综合各测点波头达到时刻对故障位置进行定位,设置基于零序电压变化对故障和扰动进行判别的装置启动方案,基于各测点之间信息匹配对错误波头进行识别和剔除,提高故障定位准确率。本文的理论研究和基于PSCAD的仿真结果表明:本文中采用的装置优化布点方案可以有效的减少布点位置,保证本馈线中所有分支故障都可观。同时基于布点方案提出的利用广域多组首波头数据故障定位方法可以对故障位置进行定位,以上研究可以促进相关行波故障定位方法在配电网中的应用。
[Abstract]:Distribution network is not only the most closely related to users, but also the last link of power transmission. The reliability of distribution network power supply will directly affect the user's power consumption experience. The distribution network structure is complex, the line branch, the equipment is many, the load changes greatly, so the failure probability is large, especially the single-phase grounding fault. Because the neutral point of distribution network in China is widely connected by ungrounding or arc suppression coil, the current of fault point flowing through the line after single-phase grounding fault is very small, which brings difficulties to fault signal acquisition and fault location. Therefore, many fault line selection and location methods can not effectively locate the small current grounding fault. The traveling wave location method is not affected by the system parameters, the size of the transition resistance and the operation mode of the system, and has been successfully applied in the transmission network, but there are many branches of the distribution network and the structure of the distribution network is complex. The traveling wave single-terminal method needs to accurately identify the subsequent reflected wave head of the fault point, which will be difficult in the distribution network. Therefore, the research content of this paper is the fault location of distribution network based on the initial traveling wave information of wide area fault voltage based on two-terminal method and the optimization of distribution network traveling wave device. The transmission characteristics of traveling wave in distribution network are analyzed, the traveling wave transmission characteristics of electromagnetic voltage transformer and distribution transformer are analyzed, and the mode of distributed power supply access to distribution network and the feasibility of traveling wave measurement of access point are analyzed. Based on the above analysis, it is concluded that the traveling wave fault location device can be installed on the secondary side of distribution transformer and the access point of distributed power supply, and the fault location of distribution network can be carried out based on the wide area voltage initial traveling wave information of each measuring point. However, if both the distributed power access point and the secondary side of the distribution transformer are installed, the cost will be too high, so it is necessary to study the optimization of the location of the traveling wave fault location device in the distribution network, which is based on the topology constraints of the distribution network. The propagation law of traveling wave is analyzed. On the premise of ensuring that all the line faults in the network are considerable, the constraint conditions are established based on the hierarchical decomposition of distribution network and the idea of traveling wave dual-terminal location. Based on the simulated annealing particle swarm optimization algorithm, the location of the device is optimized. Finally, based on the results of the distribution point, based on the fault voltage head information obtained by each measuring point, it is called wide area traveling wave information in this paper, and the fault position is located at the time of each measuring point. The device start-up scheme based on zero sequence voltage change to distinguish fault and disturbance is set up, and the error wavefront is identified and eliminated based on the information matching between the measuring points, so as to improve the accuracy of fault location. The theoretical research in this paper and the simulation results based on PSCAD show that the optimal location of the device used in this paper can effectively reduce the location of the distribution point and ensure that all branch faults in the feeder are considerable. At the same time, the fault location method based on the location scheme can be used to locate the fault location by using the wide area multi-group first wave head data. The above research can promote the application of the related traveling wave fault location method in the distribution network.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM755

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