【作者】 周宏宇；

【导师】 罗隆福；

【作者基本信息】 湖南大学 ， 电气工程， 2010， 硕士

【摘要】 随着国民经济的迅速发展和城市人口的不断增加,地铁作为一种无污染、快速便捷的新型城市交通方式越来越受到很多大中型城市的欢迎。现有的地铁供电系统中采用的直流断路器在极端短路故障时容易烧损,对地铁的维护和运营造成了不利影响。本文针对这一问题,从电弧的角度,通过对传统直流断路器进行仿真研究,认为烧损直流断路器触头的主要原因是直流断路器无法熄灭极大故障电流产生的直流电弧。从而本文中提出了一种新型地铁用直流断路器设计方案,并对新型直流断路器开展了仿真研究,仿真结果证明新型直流断路器在抑制电弧产生、快速开断直流电路方面效果显著。直流断路器仿真模型的构造是建立在实地调研所得到的数据基础上的。该电路将实际地铁供电系统简化后,引入麦也尔(Mayr)电弧模型作为直流断路器主触头,在Matlab平台上对传统直流断路器和新型直流断路器进行仿真研究。文中给出了麦也尔模型具体参数的选择、电路参数的选取以及新型直流断路器的工作原理。通过对传统直流断路器的仿真证明了烧损断路器触头的直接原因是电弧无法熄灭；通过对新型断路器的仿真证明了新型断路器能有效抑制电弧并产生人工过零点,将直流电弧的熄灭转化为交流电弧的熄灭,降低了熄灭大电流电弧的难度。新型地铁用直流断路器的设计包括断路器主电路的设计和控制装置的设计。主电路设计部分主要给出了各个原件在断路器中的作用和选择方法；控制装置的设计包括硬件设计和软件设计两个部分。控制装置以DSP2812作为控制核心,设计了数据采集板、数据处理板等元器件,电流电压值的计算采用DSP自带FFT函数库进行,保证能快速地计算出电流电压的数值,提供给控制装置进行分析。更多还原

【Abstract】 With the rapid development of national economy and a huge population migration to the country’s cities, the subway, as a pollution-free, faster and convenient urban traffic mode, is popular in many large or middle cities. The DC breaker used in the existing power supply system for subway is easily burned when there is extreme short circuit,which causes adverse impact to the maintain and operation of the subway. To solve the problem, based on the arc and simulation study on traditional DC breaker, this paper points out that it is the DC breaker’s failure to burn out the DC arc with extreme short circuit caused the contact burning. The paper puts forward a new design concept of subway DC breaker and simulation is also carried out.The result indicates that the new DC breaker has meaningful results on preventing the arcing and fast-speed switching of DC breaker circuit.The whole simulation circuit is designed on the data from survey and study. After simplifying subway power supply system, the circuit introduce Mayr arc as the Main contact of the DC breaker, do research both on the traditional DC breaker and the new DC breaker based on the matlab platform. The paper gives out the selection of detail parameters of the Mayr model and circuit parameter. It also gives the principle of new DC breaker. The simulation of the traditional DC breaker shows that it is the failure to burn out the arc caused the contact burning, the simulation of the new DC breaker shows that it can reduce the arc and produce artificial zero value,change the DC arc extinguish to the AC extinguish. This makes it is more easy to put out the arc.The design of the new subway DC breaker includes the design of the breaker main circuit and design of the control device. Design Process of the main circuit gives the action and the Selection method of each part, the design of the control device includes two parts, they are hardware design and software design. Based on DSP2812, the control device has designed the parts of data acquisition board and data processing board and so on. The calculation of current and voltage value adopt FFT Function Library with the DSP. Make sure that it can calculate the data quickly and supply to the Control Segment to analyze.更多还原