Research On Leakage Protection Technology For Coal Mine

Leakage is the common fault form in power supply system for coal mine, and it accounts for about 70% in the total. Leakage of power supply wills not only cause personal electrocuted, but also may lead to the gas, coal-dust explosion even detonate premature. So, it is quite necessary to research and develop a set of leakage protection system with performance of trustworthy, easy to use and cost-effective.The paper firstly introduces the development of leakage protection internal and external. For the existing problem of various selective leakage-protection theories, the article developed a set of leakage protection device which combined additional DC sources leakage detection and selective leakage detection of zero sequence power direction type by analyzing and contrasting the electrical parameters under normal and leakage state for coal mine.This system selected C8051F040 as control core. The leakage protection principle of total switch is based on additional dc sources leakage detection, while the sub-branch based on selective leakage detection of zero sequence power direction type. Leakage resistance can be field calibration in real-time which makes the commissioning simple. Experiments show that the device is simple in operation; reliable on switch action. And this device has achieved desired effect in the 2KV pulse disturbance group of experiment.