【正文】 nsitive to outside interference, especially the lightning and electromagic pulse, such as overvoltage tolerance is low. When thunder and lightning, such as overvoltage and acpanied by the electromagic fields reach a certain threshold, ranging from system failure caused, resulted in heavy equipment or permanent damage to its ponents. Despite the thunder and lightning viewpoint of electronic systems (equipment) is unlikely, but lightning strike near the land, buildings, munication and air supply line directly Leiyun discharge form, or because of electrostatic induction and the impact of electromagic induction formation of overvoltage, There might be connected to the power lines, signal lines or grounding system, through various interfaces to transfer, coupling, radiation and other forms of invasive electronic system (equipment) and lead to serious disturbances or incidents. Therefore, strengthening and improving the electronic system (equipment) protection, to minimize the impact of interference by lightning and other damage caused direct losses and indirect losses, has bee the urgent need to solve the problem. 2 overvoltage protection design IEC (International Electrotechnical Commission) TC/81 mine technical mittee will be divided into internal and external mine mine in two parts, the external mine is lightning rod (or with lightning, lightning work), Yin Xiaxian and grounding system, Objects to be protected from direct lightning strikes, mine is to prevent internal lightning and other internal overvoltage damage caused by invasive equipment. A prehensive mine and overvoltage protection systems must be integrated use of discharge (segregation), both pressure (and other potential), shielding (isolation), grounded, limit pressure (clamp) protection, and other technology, in accordance with the external mine And the principle of internal mine, in accordance with the targets of protective features, flexible application to take concrete measures, constitute a plete protection system. Overvoltage substation in the form are: Lightning overvoltage, the resonant frequency overvoltage and overvoltage, overvoltage operation, these overvoltage transmission or electromagic induction to the way the lines and equipment on a dangerous overvoltage, in particular, Lightning overvoltage, lightning substation, in the lowvoltage power supply system and weak system to produce a strong overvoltage sensor, while the substation to potential rise (for example: the substation grounding resistance to 1 Q, lightning current 10 kA, while the potential for 10 kV), due to the increased potential of the counter lines and equipment damaged lines and equipment and the events have occurred, therefore, despite the substation outside the mine system (lightning rod. Yin Xiaxian And grounding devices) in line with national standards and the requirements 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 ability to bear a very low voltage, several hundred volts of overvoltage is enough to damage the equipment, so must the high side arrester the residual pressure (thousands of volts) to further curb to meet equipment Insulation level of need, and because of the potential rise to power and the induction loop is also overvoltage line up on KV, to be used in the exchange of integrated automation system to the exchange on the clevel singlephase installation of a surge Voltage protection. Location should choose to install automatedping in the Composite Air switch the AC power. did not ask off power supplies (UPS) overvoltage protection Protection here: because of the internal puter systems, hubs, monitoring equipment, electric energy bi