煤矿高压电网防越级跳闸系统研究

发布时间：2017-12-31 09:22

本文关键词：煤矿高压电网防越级跳闸系统研究　出处：《中国矿业大学》2016年硕士论文　论文类型：学位论文

【摘要】：煤矿供电系统的安全可靠不仅影响着煤矿生产的效益,还间接影响着煤矿员工的生命安全。受各种因素影响,我国煤矿高压供电系统在实际运行过程中经常会出现因下级变电所馈线故障导致上级变电所开关跳闸从而扩大了井下停电范围的现象,即所谓的“越级跳闸”。统计数据表明,大多数越级跳闸是由短路与漏电故障引起。研究越级跳闸发生的原因并采取相应的措施避免其发生,对提高生产效率与减少人员伤亡有着非常重要的意义。首先根据煤矿电网的特点分析了短路与漏电故障后电流分布特点,依据目前的保护配置理论研究了两种越级跳闸发生的真正原因并分析其差异。根据两种越级跳闸的相似性,提出了基于布尔代数逻辑算法的防越级跳闸主保护方案。为了尽可能快的切除故障,将高压开关分为三类,为每一类开关配置了相应的逻辑判断表达式,并以具体故障为例阐述了防越级跳闸主保护的原理。为了保证防越级跳闸系统的可靠性,同时为了解决在越级跳闸发生后因长时间找不出故障点导致系统迟迟无法恢复供电的问题,在防越级跳闸主保护的基础上,为短路与漏电分别配置了基于感知神经网络与BP神经网络的防越级跳闸后备保护方案。针对BP神经网络算法收敛速度慢、易陷入局部极小值、结构不确定的缺陷,进行了改进。选用故障后易于识别的故障特征值,通过理论分析、simulink模型搭建与仿真,验证了改进算法的优势。分别以STM32F417微处理器、和利时LM3108G型PLC、工控机为核心设计了煤矿高压智能综合保护装置、逻辑判断防越级主保护装置与集控防越级主机,在防越级跳闸方法的基础上设计了程序流程图,对防越级跳闸系统的关键技术进行了研究。
[Abstract]:The safety and reliability of coal mine power supply system not only affects the efficiency of coal mine production, but also indirectly affects the safety of coal mine employees. In the actual operation of high voltage power supply system of coal mine in our country, the phenomenon of switch tripping of higher substation caused by feeder line fault of subordinate substation often occurs, which expands the scope of underground power failure. The statistical data show that most of the tripping is caused by short circuit and leakage fault. The cause of overstep tripping is studied and the corresponding measures are taken to avoid it. It is very important to improve production efficiency and reduce casualties. Firstly, according to the characteristics of coal mine power network, the characteristics of current distribution after short-circuit and leakage fault are analyzed. According to the current protection configuration theory, this paper studies the real causes of the two kinds of leapfrog tripping and analyzes their differences, according to the similarity of the two kinds of leapfrogging tripping. In order to remove the fault as quickly as possible, the high voltage switch is divided into three categories, and the corresponding logic judgment expression is configured for each type of switch. In order to ensure the reliability of the system, the principle of the main protection against leapfrogging tripping is expounded with the example of specific faults. At the same time, in order to solve the problem that the system is unable to restore power supply due to long time failure point after the over-grade tripping occurs, it is based on the main protection against overstep tripping. The back-up protection scheme based on perceptual neural network and BP neural network is configured for short circuit and leakage respectively. The algorithm of BP neural network is easy to fall into local minimum because of its slow convergence speed. The defects of uncertain structure are improved. The fault eigenvalues which are easy to identify after failure are selected, and the Simulink model is built and simulated by theoretical analysis. The advantages of the improved algorithm are verified. The high voltage intelligent integrated protection device of coal mine is designed with the core of STM32F417 microprocessor, Hutchison LM3108G and industrial control computer. Based on the logic judgment of the main protection device and the centralized control anti-overstep host, the program flow chart is designed on the basis of the method of anti-leapfrog tripping, and the key technology of the anti-leapfrog tripping system is studied.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD608;TM727.3

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