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sensitive small ground current. The paper introduces and analyzes the characteristic of all kind of grounding modes about l0kV network at first. With the comparison with technological and economy, the conclusion is drawn that the improved arc suppressing coil grounding mode shows a very big development potential.
Then, this paper researches and introduces some operation characteristics of the arc suppressing coil grounding mode of the l0kV distribution network. And then the paper put emphasis on how to extinguish the earth electric arc effectively by utilizing the resonance principle. This paper combines the development of domestic and international technology and innovative achievement, and introduces the computer earth protection and autotracking compensate device. It proves that the improved arc suppressing coil grounding mode have better operation characteristics in power supply reliability, personal security, security of equipment and interference of communication. The application of the arc suppressing coil grounding mode is also researched in this paper.
Finally, the paper summarizes this topic research. As a result of the domination of the arc suppressing coil grounding mode, it should be more popularized and applied in the distribution network in the future.The way of thinking, project and conclusions in this thesis have effect on the research to choose the neutral grounding mode not only in I0kV distribution network but also in other power system.
The basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, all costumers expect to pay the lowest price for the highest reliability, but don't consider that it's self-contradictory in the co-existence of economy and reliable. To improve the reliability of the power supply network, we must increase the investment cost of the network con- struction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic, between the investment and the loss by calculating the investment on power net and the loss brought from power-off. The thesis analyses on the economic and the reliable of the various line modes, according to the characteristics various
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line modes existed in the electric distribution net in foshan.
First, the thesis introduces as the different line modes in the l0kV electric distribution net and in some foreign countries. Making it clear tow to conduct analyzing on the line mode of the electric distribution net, and telling us how important and necessary that analyses are.
Second, it turns to the necessity of calculating the number of optimization subsection, elaborating how it influences on the economy and reliability. Then by building up the calculation mode of the number of optimization subsection it introduces different power supply projects on the different line modes in brief. Third, it carries on the calculation and analyses towards the reliability and economy of the different line modes of electric distribution net, describing drafts according by the calculation. Then it makes analysis and discussion on the number of optimization subsection.
At last, the article make conclusion on the economy and reliability of different line modes, as well as, its application situation. Accordion to the actual circumstance, the thesis puts forward the beneficial suggestion on the programming and construction of the l0kV electric distribution net in all areas in foshan. Providing the basic theories and beneficial guideline for the programming design of the 10kVelectric distribution net and building up a solid net, reasonable layout, qualified safe and efficiently-worked electric distribution net.
References
[1] Wencheng Su. Factories power supply [M]. Machinery Industry Publishing House. 1999.9 [2] Jiecai Liu. Factories power supply design guidance [M]. Machinery Industry Publishing House.1999.12
[3] Power supply and distribution system design specifications[S].China plans Press. 1996 [4] Low-voltage distribution design specifications [S].China plans Press. 1996.6
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供配电系统
摘要：
电力系统的基本功能是向用户输送电能。lOkV配电网是连接供电电源与工业、商业及生活用电的枢纽，其网络庞大及复杂。对于所有用户都期望以最低的价格买到具有高度可靠性的电能。然而，经济性与可靠性这两个因素是互相矛盾的。要提高供电网络的可靠性就必须增加网络建设投资成本。但是，如果提高可靠性使用户停电损失的降低小于用于提高可靠性所增加的投资，那么这种建设投资就没有价值了。通过计算电网的投资和用户停电的损失，最终可找到一个平衡点，使投资和损失的综合经济性最优。
关键词：供配电，供电可靠性，无功补偿，负荷分配
电力体制的改革引发了新一轮大规模的电力建设热潮，从而极大地推动了电力技术革命，新技术新设备的开发与应用日新月异特别是信息技术与电力技术的结合在很大程度上提高了电能质量和电力供应的可靠性。由于技术的发展又降低了电力建设的成本，进而推动了电网设备的更新换代。本文就是以此为契机，以国内外配电自动化中一些前沿问题为内容，以配电自动化建设为背景，对当前电力系统的热点技术进行一些较深入的探讨和研究。主要完成了如下工作：
(1)提出了配电自动化建设的两个典型模式，即―体化模式和分立化模式。侧重分析了分立模式下的配电自动化系统体系结构，给出了软硬件配置主站选择管理模式、最佳通讯方式等是本文研究的前提和实现平台。
(2)针对配电自动化中故障测量、定位与隔离以及供电恢复这一关键问题，分析了线路故障中电压电流等电量的变化，导出了相间短路工况下故障定位的数学描述方程，并给出了方程的解以及故障情况下几个重要参数s 、U&s 、I& e 、I& 。选择表通过对故障的自动诊断与分析得出了优化的隔离和恢复供电方案。自动实现故障快速隔离与网络重构，减少了用户停电范围和时间，有效提高配网供电可靠性。文中还给出了故障分段判断以及网络快速重构的软件流程和使用方法。
(3)状态估计是实现配电自动化中关键技术之一。本文在阐述状态估计方法基础上给出了不良测量数据的识别和结构性错误的识别方法，针对状态估计中数据对基于残差的坏数据检测和异常以及状态量中坏数据对状态估计的影响及存在的问题，提出了状态估计中拓扑错误的一种实用化检测和辩识方法。针对窃电漏计电费问题，独创性提出一种通过电量突变和异常分析防止窃电的新方法，并在潍坊城区配电得到验证。
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(4)针对配电网负荷预测建模困难，参数离散度大以及相关因素多等问题。本文在分析常规负荷预测模型及方法基础上，引入了气象因素日期类型、社会环境影响等参数，给出了基于神经网络的电力负荷预测方法，实例验证了方法的正确性。
(5)针对无源滤波在抑制谐波和无功补偿方面的不足，以及补偿度的不连续性，本文提出了一种PWM 主电路拓朴结构和基于无功功率理论的有源滤波方案，建立了基于Saber Designer 仿真平台仿真分析，证明了方案的可行性。同时结合配电自动化技术，对配电网动态无功优化补偿和降低线损的方法进行了设计、分析。通过实例计算验证了其客观的经济效益。
(6)针对中国电力市场未来的发展趋势以及政府监管下的电力市场公平交易，设计了一种适合我国电力市场现状。按照电价分组、电量协调分组、竞价的短期电力交易模式，给出了基于边际电价的机组组合算法，制订交易计划的数学模型以及安全经济约束等，在竞争比例逐步提高的情况下，能够较好地解决原有中长期合同电价和短期竞争电价的矛盾，减少电厂不公平的收益差异，同时也可在电力市场全网的负荷曲线上对所有电厂进行限量优化，减少总的系统购电费用。
配电网是电力系统中的一个重要环节，配电网接地方式和安全运行直接关系到电力系统的安全和稳定。而接地方式的选择，是与本国国情、自然环境、设备制造和运行水平等有关的，例如，雷电的活动情况、绝缘结构的设计、对周边的干扰等因素，都会影响中性点接地方式的选择；反过来，中性点接地方式对电力系统的设计、运行、调试以及发展都有很大影响。一般在电压等级较高的系统中，绝缘费用在设备总价格中占相当大的比重，降低绝缘水平带来的经济效益很显著，通常就采用中性点直接接地的方式，而采用自动重合闸来保证供电可靠性；相反，在电压等级较低的系统中，通常都采用中性点不接地的方式来提高供电可靠性。因此，在综合考虑供电可靠性、安全因素、过电压因素、继电保护的选择、投资费用等各方面因素的情况下，来论证正确选择配电网接地方式的重要性，以及如何不断开发，利用新型接地装置来应用在配电网接地系统中是当今配电网接地方式的一个重要课题。
本文主要工作是对lOkV配电网接地方式进行研究和比较选择。分别论述各类接地方式的优缺点，主要有国内外比较常用的中性点不接地方式、中性点经消弧线圈接地方式(也称谐振接地方式)、中性点电阻接地方式、中性点直接接地方式。通过技术比较确定最优接地方式，还利用一种近几年研究开发的，应用在谐振接地方式中的自动跟踪补偿装置，再配以灵敏的小电流接地选线保护，能够有效限制电网的故障接地电弧，更有利
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