【正文】 user electricity. Coal mine reliable, safe, economical and rational power, to enhance economic efficiency and to ensure the safe production of coal mine has a very important significance. Coal mining enterprises of the power supply system has the following requirements: 1. Reliability of supplyReliability of supply which requires an uninterruptible power supply. In the event of disruption of supply mine, all mine shutdown will not only cause, but also lead to some important equipment to ensure the production of mine (also known as security load), such as fans, pumps and other main drain is stopped, endanger the safety of mines and underground staff severe cases can cause destruction of the mine. Therefore, in order to ensure the supply of coal mine absolutely reliable, Coal Mine Safety Regulations provides that: Each mine should be a twoloop power supply line, when any one circuit to stop power supply fails, the other circuit should be able to bear the load of the whole mine. Under normal circumstances, the use of a loop run, and the other circuit must be charged spare coal mine to ensure continuity of supply in the production process.2. The security of supplySince the coal mine environment is plex, harsh natural conditions, particularly the presence of gas and coal dust explosion hazards, power lines and electrical equipment vulnerable to damage in the underground, in the use of electrical energy in the process, the slightest negligence will cause leakage and personal electric shock and it will lead to serious consequences of gas and coal dust explosion. Therefore, the coal mine explosion must be taken, electric shock, moisture and overcurrent protection and a series of safety technical measures, strict pliance with the relevant provisions of the Coal Mine Safety Regulations in order to ensure security of electricity supply coal mines.3. guarantee a good quality of supplyPower quality refers to the supply voltage, frequency amplitude excursions not exceed the specified allowable range。 otherwise, the normal operation of electrical equipment will significantly deteriorate, or even damage the electrical equipment. The socalled voltage, frequency deviation is due to various reasons, to the terminal voltage and rated frequency difference on electrical equipment and that it is an important indicator of quality. The quality of the power supply requirements are: supply voltage deviation increases do not exceed the rating of 177。 5%。 frequency offset margin requirements than 3000kW system does not exceed the rating of 177。 , 3000kW following systems do not exceed the rating of 177。 .4. guarantee adequate supply capacityThis requires not only the power system or power plant capable of supplying sufficient power coal mines, mine facilities and requires the power supply system, but also has enough power supply capacity.5. The power supply of the economyMine supply system on the basis of the above meet the basic requirements to minimize capital investment at all levels of the mine substation and power grid。 to minimize the consumption of equipment and materials and nonferrous metals。 try to make the power supply system is simple, easy to operate, infrastructure investment and operation and maintenance costs low. With the power is widely used in mine production, mine security of supply must also pay attention to, due to the characteristics of electricity, you need the emphasis on safety.Common problems are the following aspects: load calculations, safety lines, protection, production safety, lightning issues.Electric load is the sum of all the electrical equipment of the power system power consumption. Here talked about coal power load refers to the electrical equipment or power user Mine. Coal power load based on the importance of electrical equipment and uninterrupted power supply for personal safety, as well as other aspects of economic applicability to electric load is the sum of all the electrical equipment in the power system power consumption. Here talked about coal power load refers to the electrical equipment or power user Mine. Coal power load based on the importance of electrical equipment and uninterrupted power supply different to personal safety, and economic applicability and other requirements, the power load is divided into three managed to obtain reasonable supply in different situations. Seek different, the power load is divided into three managed to obtain reasonable supply in different situations. Where suddenly interrupt the power supply may result in personal injury or death, damage to vital equipment and difficult to repair, resulting in longterm can not resume production, and other aspects of the economy are causing heavy losses, were a power load level, there are main mine fan, mining main drainage pump, central variable downhole each level (with) the electricity, Shaft lifting personnel lifting equipment, gas drainage equipment, etc., are all level of users. Such electricity customers are concerned with the protection of mine safety, it is also called the security burden. For a user must set up two independent power supply, absolutely reliable power supply requirements, all the way to the power supply fails, the other way to ensure the power supply immediately put into operation. Where suddenly interrupted power supply and other aspects of the economy would cause greater damage or affect the important equipment is working properly, and both primary and secondary load. There are two major coal mine inclined shaft power load lifting personnel lifting equipment, lifting shaft coal and material lifting equipment, ground centralized pressor stations, lamp charging equipment, wellbore insulation equipment, electric motor car as the main mode of transport and rectification charging equipment, mining area substation and mechanized mining face of electrical equipment, as well as up and down the main mine