Analysis of short circuit consequences and causes of batteries used in UPS uninterruptible power supply

Analysis of short circuit consequences and causes of batteries used in UPS uninterruptible power supply. At present, UPS power supply in computer room is basically "maintenance-free lead-acid batteries". In the use of UPS batteries in computer room, output short circuit is very dangerous. Short circuit will cause fire, severe and even explosion. The short circuit of positive and negative electrodes in lead-acid batteries can cause the pole to become hot because of the excessive instantaneous current, and even cause fire or explosion because of the excessive internal reaction.
Short Circuit Achievement of UPS Battery in Computer Room
Short circuit of UPS battery in computer room will release excessive power instantaneously, which will lead to the melting of internal confluence drain and the expansion of battery. Basically, the battery after the short circuit of the positive and negative poles is discarded. Lead-acid batteries are one of the most widely used high-efficiency batteries in high-power power supply. In the process of operation, short circuit will be formed for different reasons, and then affect the use of the whole battery.
(1) Open-circuit voltage is low, and closed-circuit voltage (discharge) quickly reaches the stop voltage.
(2) When high current discharge occurs, the terminal voltage decreases rapidly to zero.
(3) When open circuit, the density of electrolyte is very low, and the electrolyte will freeze in low temperature environment.
(4) When charging, the voltage rises very slowly and keeps a low value (sometimes drops to zero).
(5) When charging, the temperature of electrolyte rises very quickly.
(6) When charging, the density of electrolyte increases very slowly or almost unchanged.
Reasons for Electrical Short Circuit of UPS Battery
1. The UPS battery itself has some quality problems, and there are hidden dangers in the connection between the pile head and the plate.
2. When UPS batteries are transported or equipped, cracks appear in the shell and are not found in time. After equipments, the acid in the batteries separates and passes through the electric short circuit of the battery rack.
3. The connection between battery and cable is not strong, which makes the contact resistance too large. After the temperature rises, the contact surface oxidizes severely, and then the contact resistance continues to increase, which leads to electric ignition and arc-drawing, and finally ignites the adjacent combustibles to form a fire.
4. The voltage withstanding value of the connecting cable of UPS battery group is not good, which constitutes the insulation breakdown between the cables and the short-circuit ignition of the cables.
5. The battery configuration is unreasonable and exceeds the discharge limit of the battery.
6. The battery connection cable is short-circuited when it is cut by the iron sheet of the battery rack when it enters the UPS battery rack.
Handling Method of Short Circuit of UPS Battery in Computer Room
Reduce charging current, decrease charging voltage and check whether the safety valve body is blocked. Charge and discharge regularly.
In UPS power supply system, the floating charge voltage and discharge voltage of lead-acid batteries have been debugged to the rated value when they are out of the factory, and the discharge current increases with the increase of the load, so the load should be adjusted reasonably, such as controlling the number of electronic devices such as computers. Normally, the load should not exceed 60% of the UPS rated load. Within this range, there will be no excessive discharge of the battery.
The storage capacity of UPS batteries will be lost due to self-discharge. Therefore, before UPS batteries are put into operation after equipments, the remaining capacity of batteries should be judged according to the open-circuit voltage of batteries, and then different methods should be selected to compensate the charging of batteries.
Compensation charging should be carried out every 3 months for the backup UPS batteries. The battery can be judged by measuring the open-circuit voltage of the battery.
Reasons for Bulging Deformation of UPS Battery
1. In the charging operation of ups batteries, especially in series batteries, if the batteries are overcharged, if the batteries are of poor quality, bad gas recombination and other phenomena will often occur, and then the phenomenon of bulging will occur.
2. Safety valve opening pressure is too high, perhaps the safety valve is blocked. When the internal pressure increases to a certain extent, the valve can not open normally, in this case, it will inevitably constitute a bulge deformation.
3. Because the UPS batteries in the sealed machine room belong to the lean liquid type planning, there are reserved avenues for gas combination. If there is "rich liquid" phenomenon, it will obstruct the onset of oxygen ripple to the negative pole, reduce the rate of oxygen composition, and increase the internal pressure.
4. The high floating charging voltage and high charging current lead to the acceleration of the oxygen separation on the positive plate, which is less than the composite of the negative plate. The temperature in the battery body rises rapidly. When the exhaust gas is less than enough and the pressure reaches the required time, the VRLA battery appears bulging deformation.
Above is the result and reason analysis of UPS battery short-circuit in computer room. Short-circuit of storage battery is a major manifestation of internal damage of UPS battery. It will make a great impact on the use of storage battery, but different batteries have different effects.