| The coal mine is divided into low gas mines and high gas mines. In general, the down-hole motor vehicle powered stringing powered in low-gas mine, motor vehicle is powered batteries in high gas mine. Currently, lead-acid batteries used underground battery, however, because of lead-acid batteries have the larger pollution shortcomings, emerging lithium iron phosphate has the advantages of less polluting capacity, longer life expectancy and smaller, so, from the aspects of pollution, lead-acid battery will be gradually replaced by the new lithium iron phosphate batteries. Now, this title’s research is the circulation phenomena and current imbalances, lithium iron phosphate battery instead of lead-acid battery powered motor vehicle.Coal mine motor vehicle requires250volts or550volts and hundreds of amps, in view of the requirements of mine safety, the environment is a flammable and explosive in the following mine, therefore, the sealed single battery energy requirements can not be too large, this requires to produce the smaller capacity of monomer lithium iron phosphate battery, but, in order to reach the coal mine motor vehicle voltage and current requirements, lithium iron phosphate group must be used in parallel. Circulation phenomenon will occur when lithium iron phosphate group used in paralleled, this circulation can cause the battery energy’s waste, and will shorten the life of the battery. Since the terminal voltage of the battery pack, or the terminal voltage of the battery pack is the same but different internal resistance, current imbalances can also occur when the parallel use of the battery pack.In order to improve the utilization of the battery capacity and battery life, I have studied the circulation and imbalances in the parallel use of lithium iron phosphate battery pack, and design a control circuit to curb generated circulation and control the current balance.The article designed battery pack current control circuit, and we curb the circulation use this circuit. After experimental verification, balance control circuit of the battery pack is relatively stable, and can basically reach the battery pack current balancing purposes. |
