Analysis and Treatment of Common Faults of UPS Power Supply
UPS is UninterruptiblePowerSupply short, that is, we often say UPS uninterruptible power supply. It is a kind of energy storage device, the inverter as the main component of the constant voltage constant frequency power supply equipment, communication equipment, computer systems, etc. can not power off the system indispensable one of the peripheral equipment, its role is In the case of external power supply, in a timely manner to the computer and other equipment power supply, so as not to affect the communication interrupt, the loss of important data and hardware damage. However, when we use the UPS power supply as a protection of other objects at the same time, the UPS power supply itself is often a number of failures, if the UPS power supply failure, we can not provide protection to load. So we UPS power failure common analysis of the phenomenon described: Question 1: When the power supply UPS power output is normal, and no electricity when the buzzer long, no output. Failure analysis: from the phenomenon to determine the battery and inverter part of the fault, the following procedures can be checked: 1, check the battery voltage, see if the battery is insufficient, if the battery charge is insufficient, you have to check whether the battery itself is faulty or charging circuit failure. 2, if the battery voltage is normal, check the inverter drive circuit is working properly, if the drive circuit output is normal, indicating that the inverter is damaged. 3, if the inverter drive circuit is not working properly, then check the waveform generator circuit with or without PWM control signal output, if the control signal output, indicating the fault in the inverter drive circuit. 4, if the waveform generator circuit without PWM control signal output, then check whether the output of the protection circuit is blocked, if there is to identify the reasons for protection; 5, if the protection circuit is not working and the working voltage is normal, and the waveform generator circuit without PWM waveform output is that the waveform generator circuit is damaged The above sequence can also be reversed, and sometimes faster to find the fault. Question 2: inverter power level of a pair of amplifier transistor damage, replace the same type of transistor, run for some time and burn the reason is the current is too large, and cause the current is too large reasons: 1, overcurrent protection failure. When the inverter output overcurrent, the overcurrent protection circuit does not work; 2, pulse width modulation (PWM) component failure, the output of the two complementary waveform asymmetry, a long conduction time, while the other conduction time is short, so that the arms work unbalanced, and even arms at the same time conduction, resulting in two Tube damage; 3, the power tube parameters vary greatly, this time even if the input symmetrical waveform, the output will be asymmetric, the output transformer by the output, resulting in bias, that is, magnetic flux imbalance, accumulated to lead to saturation of the transformer and current surge Power tube, and one burned, the other also will burn out. Question three: battery voltage is low, but the boot charge more than 10 hours, the battery voltage is still not up. Failure analysis: from the phenomenon to determine the battery or charging circuit failure, the following steps can be checked: 1, check the charging circuit input and output voltage is normal; 2, if the charging circuit input is normal, the output is not normal, disconnect the battery and then test, if not normal for the charging circuit failure; 3, if the battery after charging the battery input and output are normal, then the battery has been due to long-term non-charging, over discharge or has been to life and other reasons and damage. Question four: UPS power supply, the panel without any display, UPS power does not work. Failure analysis: from the fault to determine the fault in the mains input, battery and electricity detection part and the battery voltage detection circuit: 1, check the mains input fuse is burned; 2, if the mains input fuse is intact, check the battery insurance is burned, because some UPS when the self-check the battery voltage, the UPS will be all the output and display off; 3, if the battery insurance is intact, check the mains detection circuit is working properly, if the electricity detection circuit is not working properly and UPS does not have no electricity start function, UPS will also turn off all the output and display. 4, if the city test circuit is working properly, and then check the battery voltage detection circuit is normal. Problem 5: When the mains power is turned on, the UPS power is turned on, the inverter work indicator flashes, the buzzer is intermittent, and the UPS power supply can only work in the inverter state and can not switch to the mains working state. Failure analysis: can not carry out the inverter power supply to the mains power conversion, indicating the inverter power supply to the mains power supply conversion part of the fault, to focus on detection: 1, the mains input fuse is damaged; 2, if the mains input fuse intact, check the mains rectifier filter circuit output is normal; 3, if the mains rectifier filter circuit output is normal, check the mains detection circuit is normal; 4, if the mains detection circuit is normal, and then check the inverter power supply to the mains power supply control output is normal. Question 6: a backup UPS when the electricity is working properly, no electricity when the inverter has output, but the output voltage is low, while the transformer issued a larger noise. Fault analysis: the inverter has an output that the final drive circuit is basically normal, the transformer has a noise that push-pull circuit arm asymmetry, the detection steps are as follows: 1, check the power is normal; 2, if the power is normal, and then check the pulse width output circuit output signal is normal; 3, if the pulse width output circuit output is normal, and then check the drive circuit output is normal. Question 7: In the case of access to electricity, each time you turn on the UPS uninterruptible power supply, you hear the repeated action of the relay sound, UPS power panel battery voltage is too low indicator light and the buzzer long. According to the above phenomenon can be judged: the fault is caused by the battery voltage is too low, resulting in UPS failure caused by the start. Remove the battery, the first balanced charge (all batteries in parallel to charge), if still unsuccessful, then only replace the battery. Question 8: UPS power supply can only be powered by electricity and can not be converted to power supply. Failure analysis: can not carry out electricity to the inverter power conversion, indicating that the electricity to the inverter power supply conversion part of the fault, to focus on detection: 1, the battery voltage is too low, the battery fuse is intact; 2, if the battery part of the normal, check the battery voltage detection circuit is normal; If the battery voltage detection circuit is normal, and then check the mains to the inverter power supply control output is normal. Question 9: backup UPS power supply When the load is close to full load, the mains power supply is normal, and battery-powered battery fuse blown. Failure analysis: battery fuse blown, indicating that the battery power supply is too large, the detection steps are as follows: 1, whether the inverter breakdown; 2, the battery voltage is too low; 3, if the battery voltage is too low, and then check the battery charging circuit is normal; 4, if the battery charging circuit is normal, and then check the battery voltage detection circuit is working properly.