配电网消弧与故障定位技术的研究

发布时间：2018-06-09 14:08

本文选题：配电网 + 消弧线圈　；参考：《福州大学》2014年硕士论文

【摘要】：6kV-35kV配电网是电力系统中电能的输送和分配的重要环节,配电网单相接地故障频发已是一个不争的事实。若配电网单相接地故障所产生的接地电弧短时内无法消除导致线路跳闸将直接影响到对用户供电的连续性,给人民生活和社会生产带来极大不便,所以配电网的安全稳定运行在整个电力系统中占有重要地位。而配电网的中性点接地方式直接关系着配电网消除接地电弧的能力和配电网的故障跳闸率。目前我国6kV-35kV的中压配电网大多采用中性点经消弧线圈的接地方式。但市面上的消弧线圈成套装置普遍无法满足响应快,补偿效果快,伏安特性的线性度好,并且可以连续地在大范围内调节等要求。而且若要极大降低配电网的故障跳闸率,还需要配备快速、准确、可靠的小电流接地选线装置及配套的保护跳闸装置与消弧线圈控制相配合。为了综合解决以上问题,作者在总结消弧线圈自动调谐成套装置数年运行经验的基础上,深入研究了新型的快速高短路阻抗型变压器式消弧线圈配套自动跟踪调谐消弧线圈(ATASC)装置。本文提出的新型成套装置其高压侧配置的消弧线圈是调匝式的,这主要是从系统的可靠性出发。当系统异常(电流互感器、电压互感器断线,或者装置失电)和发生单相故障接地时闭锁了消弧线圈有载调压开关,它所补偿感性电流并不需要二次设备来调节,保证了系统的可靠运行。此外,本套装置阻尼电阻的保护,是当单相接地故障发生时,凭借阻尼电阻自身电压触发大功率的可控硅,控制阻尼电阻在1毫秒快速短接。当接地故障消除后,控制可控硅自然关断。所以无需在阻尼电阻箱接入直流电源或交流电源,这种保护方式,可以使一、二次设备完全分开。新型成套装置可根据实际需要,还可完成两台及多台消弧线圈的并联运行。另外本文考虑了市面上的选线装置的优缺点,提出了并联中电阻选线法。并联中电阻选线法参照国外技术采用在消弧线圈两端并联电阻的方法,在接地时向故障点增加零序电流的有功分量,引起故障点的电流的相位和幅度均发生显著的波动,接地选线的准确性接近100%。最后,通过实际运行分析结果证明本文提出的配电网消弧线圈与故障选线成套装置的方案是可行的,具有一定的先进性。
[Abstract]:6kV-35kV distribution network is an important link in the transmission and distribution of electric energy in power system. It is an indisputable fact that single-phase grounding faults occur frequently in distribution network. If the grounding arc caused by single-phase grounding fault in distribution network can not be eliminated in a short time, the tripping will directly affect the continuity of power supply to users and bring great inconvenience to people's life and social production. Therefore, the safe and stable operation of distribution network plays an important role in the whole power system. The neutral grounding mode of the distribution network is directly related to the ability of the distribution network to eliminate the grounding arc and the fault tripping rate of the distribution network. At present, 6 kV V-35 kV medium-voltage distribution network mostly uses neutral point grounding through arc-suppression coil. However, the complete set of arc-suppression coil on the market can not meet the requirements of fast response, fast compensation effect, good linearity of volt-ampere characteristics, and can be continuously adjusted in a wide range. In order to greatly reduce the tripping rate of distribution network, it is also necessary to provide fast, accurate and reliable small current grounding line selection device and matching protection tripping device to cooperate with arc suppression coil control. In order to solve the above problems comprehensively, the author summarizes the operation experience of the automatic tuning complete set of arc-suppression coil for several years. A new type of fast and high short circuit impedance transformer type arc-suppression coil (ATASC) is studied in this paper. In this paper, a new type of equipment is presented, which is mainly based on the reliability of the system. When the system is abnormal (current transformer, voltage transformer disconnected, or the device is out of power) and when a single phase fault occurs, the arc suppression coil load regulator is blocked, and the inductive current compensated by it does not need to be adjusted by secondary equipment. It ensures the reliable operation of the system. In addition, the protection of the damping resistance of the device is to trigger the high power thyristor with the damping resistance voltage when the single-phase grounding fault occurs, and to control the damping resistance to be connected quickly in 1 millisecond. When the grounding fault is eliminated, the control SCR is turned off naturally. Therefore, there is no need to connect DC or AC power in the damped resistance box. This kind of protection can separate the primary and secondary equipments completely. According to the actual needs, two or more arc-suppression coils can be operated in parallel. In addition, considering the merits and demerits of the line selection devices in the market, a parallel middle resistance line selection method is proposed. With reference to the foreign technology, the method of parallel resistance selection in parallel middle resistance increases the active power component of zero sequence current to the fault point when grounding, which causes the phase and amplitude of the fault point current to fluctuate significantly, and the method of parallel resistance at the two ends of the arc-suppression coil is used to increase the active power component of the zero sequence current to the fault point when grounded. The accuracy of grounding line selection is close to 100. Finally, it is proved that the scheme of arc-suppression coil and fault line selection in this paper is feasible and advanced.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM727

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