桂林城区配电网合环转负荷分析与对策研究

发布时间：2018-01-03 05:27

  本文关键词：桂林城区配电网合环转负荷分析与对策研究　出处：《广西大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 配电网 合环转负荷 潮流分析 对策

【摘要】：随着现代电网迅速发展,配电网的自动化、智能化进程也不断加快。智能配电要求配电高度自动化,配电网智能调度。为了提高供电可靠性,我国城市10kV配电网在进行设备停电检修、线路故障处理及负荷转移时,通常采用合环操作的模式。而在合环操作过程中,不同220kV变电站的10kV配网进行带电合环操作过程中,配网合环前两端母线的电压幅值差及其相位差通常很大,通常在合环操作后伴有较大的合环电流产生,致使10kV馈线保护装置动作,同时配网冲击电流过大对电力设备也可能造成极大的危害,大大降低电网供电的可靠性。为提高合环操作成功率及其供电的可靠性与安全性,将合环调控与配电网自动化相结合,以智能化代替人工操作,提供合环操作效率,降低劳动强度,因此对220kV变电站的10kV带电合环转电这一问题的探索有着重要的意义。本文重点对配网合环方式的类型及其合环操作运行条件进行介绍,分别针对合环的暂态与稳态过程进行理论分析。构建对合环稳态潮流进行求解的等值模型,为减少计算量将多节点支路等效为单节点支路。采用叠加法计算原理,推导了合环稳态电流的计算公式,分析了各个因素对合环稳态电流的影响。其次对合环冲击电流产生进行详细的分析,构建了求解冲击电流及其过电压的计算模型,运用PSCAD/EMTDC对合环的暂态过程进行量化。对桂林城区10kV配网不同运行方式下的合环点电压差、等值阻抗进行分析,运用BPA电力系统仿真计算软件分析了配网不同方式下合环前后的潮流大小各种参数的分布情况,通过仿真计算及其经验总结,分析了合环点电压差、合环等值阻抗及其配网负荷大小对桂林10kV配网合环成功率的影响。结合前述的理论研究以及城区合环操作经验总结,提出了设置合理的合环方式、调节变压器分接头,控制馈线载流量以及选择合适的合环操作时机等提高合环转负荷成功率的有效对策。通过对桂林城区10kV配网合环问题的深入研究,在城区配网今后的合环操作时有了可靠的理论指导,摆脱了以往仅仅依靠调度人员的经验完成合环操作的困境,提高了电网供电可靠性。
[Abstract]:With the rapid development of modern power grid, distribution network automation, intelligent process is also accelerating. Intelligent distribution requires distribution high automation, distribution network intelligent dispatch. In order to improve the reliability of power supply. In the urban 10kV distribution network of our country, when carrying on the equipment outage maintenance, the line fault treatment and the load transfer, usually adopts the closed loop operation mode, but in the closing ring operation process. The voltage amplitude difference and phase difference between the two ends of the bus in front of the distribution ring are usually very large during the operation of the 10 kV distribution network in different 220 kV substations. Usually, after the operation of the closed loop, a large current is generated, which results in the operation of the 10 kV feeder protection device, and the excessive impact current of the distribution network may also cause great harm to the power equipment. The reliability of power supply is greatly reduced. In order to improve the success rate of closed loop operation and the reliability and safety of power supply, the closed loop control is combined with distribution network automation to replace manual operation intelligently. Provide ring closing operation efficiency, reduce labor intensity. Therefore, it is of great significance to explore the conversion problem of 10 kV live closing ring in 220 kV substation. This paper mainly introduces the type of distribution network closing ring and its operating conditions. The theoretical analysis of transient and steady state processes of closed loop is carried out, and an equivalent model for solving involutive loop steady state power flow is constructed. In order to reduce the amount of calculation, the multi-node branch is equivalent to the single-node branch. The formula for calculating the steady current of closed loop is derived by using the superposition method. The influence of various factors on the steady current of involute ring is analyzed. Secondly, the generation of impulse current of involutive ring is analyzed in detail, and the calculation model for solving the impulse current and its overvoltage is constructed. The transient process of the PSCAD/EMTDC involute ring is quantified. The voltage difference and equivalent impedance of the closed ring point under different operation modes of 10kV distribution network in Guilin city are analyzed. The distribution of various parameters of power flow before and after closing loop in different modes of distribution network is analyzed by using BPA power system simulation software. Through simulation calculation and experience summarization, the voltage difference of combined ring point is analyzed. The influence of equivalent impedance and distribution load on the success rate of 10 kV distribution ring in Guilin. Based on the theoretical study and the summary of operation experience in urban area, a reasonable closing mode is put forward. The effective countermeasures such as adjusting transformer tap, controlling feeder carrier flow and selecting suitable operation time of closing ring to improve the success rate of closed loop transfer are discussed. Through the in-depth study of 10kV distribution network closing ring problem in Guilin urban area. In the future, there is a reliable theoretical guide for the closed loop operation of urban distribution network, which gets rid of the predicament of only relying on the experience of dispatcher to complete the closed loop operation, and improves the reliability of power supply in the power network.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM714
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本文编号：1372578