含分布式发电的配电网故障定位与供电恢复策略研究

发布时间：2019-01-26 17:33

【摘要】：含分布式发电的配电网故障定位与供电恢复策略研究是保证配电系统安全稳定运行的重要环节,确保快速准确地判定并找到故障,对于充分保障电网安全,防止大规模停电事故具有重要意义。完善的供电恢复策略,对于提高供电可靠性具有重要意义。因此,本文围绕含分布式发电的配电网故障定位算法和供电恢复策略展开研究。首先,针对目前分布式发电大规模接入配电网使得原有故障定位算法精度降低甚至失效等不足,结合π型线路模型和过渡电阻消耗无功功率为零的特性,提出了通用于各种故障类型的改进阻抗型故障测距算法。为量化各分布式电源提供的短路电流,建立了有源配电网的故障点电流和逐条线路区段电压、电流的计算方法。并在此基础上利用各电源接入点FTU装置的监测数据,建立了考虑线路损耗的负荷功率迭代计算方法,降低负荷波动对故障测距算法精度造成的严重影响。仿真分析验证了不同故障情况下所提方法的有效性。其次,通过确定分布式电源升压并网变压器绕组接线方式,研究了分布式电源升压并网变压器在四种接线方式下,中性点经消弧线圈接地的含分布式发电的配电网单相接地故障的电流特性,建立了基于零序电流突变量的故障选线与定位算法。该故障处理时序流程中,先利用分布式电源接入后单相接地故障时各电气量谐波含量增加,提出了基于零模电压暂态突变能量的接地故障启动判据算法。通过电力电子开关调节消弧线圈参数,利用消弧线圈调节前后的录波数据计算零序电流突变量,提出了根据零序电流幅值变化量特性进行故障定位的小电流接地含分布式发电的配电网在线故障定位算法。最后,针对供电恢复,提出了基于广度优先搜索算法、综合考虑分布式电源类型与运行特性、联络开关可操作性以及负荷优先级等因素的孤岛划分策略,并建立了孤岛稳定裕度指标衡量孤岛区域可持续稳定运行能力。对于供电恢复中分布式电源的再并网问题,扩展了FTU同期并网功能模块,制定了基于改进V/f控制策略的快速调节并网措施。通过在PSCAD仿真软件搭建了含分布式发电的配电网模型对分布式电源再并网进行仿真,验证了FTU同期并网功能模块和基于改进V/f控制策略的并网调节措施之间协调配合的可行性。
[Abstract]:The study of distribution network fault location and power supply recovery strategy with distributed generation is an important link to ensure the safe and stable operation of distribution system. It is of great significance to prevent large-scale power outages. Perfect power supply recovery strategy is of great significance to improve the reliability of power supply. Therefore, this paper focuses on the distributed generation distribution network fault location algorithm and power supply recovery strategy. First of all, in view of the shortcomings of the current distributed power generation large-scale access to the distribution network, the original fault location algorithm accuracy is reduced or even invalidated, combined with the 蟺 type line model and the characteristics of zero reactive power consumption of the transition resistance. An improved impedance fault location algorithm for various fault types is proposed. In order to quantify the short-circuit current provided by each distributed power supply, the calculation method of fault point current and voltage and current of each line in active distribution network is established. Based on the monitoring data of each power access point FTU device, an iterative calculation method of load power considering line loss is established to reduce the serious influence of load fluctuation on the accuracy of fault location algorithm. Simulation results show the effectiveness of the proposed method in different fault cases. Secondly, through the determination of the winding connection mode of the transformer connected to the grid by the distributed power source, the paper studies the four connection modes of the transformer connected to the grid by the boost voltage transformer of the distributed power source. Based on the current characteristics of single-phase grounding fault in distribution network with distributed generation, a fault line selection and location algorithm based on zero sequence current mutation is established. In the sequence flow of fault processing, the harmonic content of each electrical quantity increases when the single-phase grounding fault is connected with distributed power supply, and a starting criterion algorithm of grounding fault based on the transient abrupt energy of zero-mode voltage is proposed. The parameters of the arc-suppression coil are adjusted by power electronic switch, and the zero sequence current abrupt quantity is calculated by using the recording data before and after the arc-suppression coil adjustment. An on-line fault location algorithm for distribution network with small current grounding and distributed generation is proposed, which is based on the characteristics of zero sequence current amplitude variation. Finally, aiming at power recovery, an islanding strategy based on breadth-first search algorithm is proposed, which considers the type and operation characteristics of distributed power supply, the maneuverability of contact switch and load priority, and so on. The index of island stability margin is established to measure the sustainable and stable operation ability of isolated island region. In order to solve the problem of reconnection of distributed power supply in power supply recovery, this paper extends the function module of FTU synchronization, and formulates the fast adjustment and connection measures based on the improved V / F control strategy. The distribution network model with distributed generation is built in the PSCAD simulation software to simulate the reconnection of distributed generation. The feasibility of coordination and coordination between the FTU simultaneous grid-connected function module and the grid-connected regulation measures based on the improved V / F control strategy is verified.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM732

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