【正文】 ements of Buban, and the integrated automation and munications automation systems, such as weak secondary have been taken, such as shielding, grounding, isolation, filtering, and other measures, but it can not pletely avoid overvoltage powerful lightning And voltage of the system counter the disruption caused damage and, therefore, the second weak system substation and a minevoltage must also take the appropriate protective measures, in accordance with the IEC within the mine area EMP, the device39。s power cord, signal Lines, data lines, and the installation of lightning protection and internal overvoltage devices to prevent lightning sensors, channeling people along the lightning current, voltage counterattack, such as transient voltage surge too transient overvoltage caused by a fault and damaged electronic equipment. Overvoltage surge protection in accordance with its connection mode is divided into two series and parallel, the use of overvoltage surge protection tandem with, there may exist because of signal transmission does not match the causes of transmission of the signal interference, in particular data Communication Interface in the series were overvoltage surge protection in place, will have the normal data munications. Therefore, the data munications access I: I in the series were overvoltage surge protection in place, the transmission of data must be carried out conscientiously check if the data are not normal transmission, it may be due to the reasons do not match the transmission signal Interference, should be replaced to match the overvoltage surge protection for. If the use of overvoltage surge protection for use of parallel, the situation is basically nonexistent, but the connection mode of overvoltage surge protection for higher technical requirements. 3 secondary system overvoltage substation protection points overvoltage electricity system protection Substation installed in the munications dispatch automation systems are used AC power or a DC power supply equipment for the rectification of its links are generally larger capacity filter capacitance, the transient overvoltage shock absorption of a certain extent, the station Lowvoltage transformer side go to feed between the screen using a shielded cable and equipment have a good grounding, the use of modern technology to analyze mine, we must increase the circuit39。s segregation measures, because its grounding, protection and other electrical grounding all Grounding devices using the same equipment, and equipment are in a LPZOB, the relative strength of strong electromagic pulse, the station changed to prevent lowpressure side although there are lines intrusive wave arrester, but the residual pressure high, in the substation of lightning, through the line Coupling and the potential rise caused by overvoltage counterattack still exist, and highpressure side of the residual pressure as high as several thousand volts, it is necessary to these scheduling automation equipment for the power supply overvoltage circuit protection. Lightning Protection in accordance with the principle of regional division, substation equipment in the secondary power supply system overvoltage sensors lightning protection may be two (B, C level) for the protection of segregation. Bmine use is generally greater flow capacity of the mine installations, the Lightning could be more casual Liuxie people, to achieve the objective of current limit, overvoltage at the same time will reduce to a certain extent, cmine use With lower residual pressure of the mine installations, you can loop in the remaining scattered lightning Liuxie people, to limit the purpose of overvoltage, overvoltage equipment can be reduced to the level of tolerance. The main power supply system is inhibited lightning protection and operation of the power back to the road and overvoltage surge. According to the substation status of the substation of the second minesensing system and the operation and use of two overvoltage protection. As build more substations in the region more open, relatively strong electromagic streng