- April 23, 2019
- ATO Automation Inc
UPS power supply is a common emergency power supply system. It works in different ways under normal and abnormal conditions. The following are four working modes of UPS power supply introduced by ATO: normal operation, battery operation, bypass operation and bypass maintenance.
1. Normal operation mode
The power supply principle of UPS power supply system is that when the local power is normal, the machine will convert the AC power of the local power into DC power, and then charge the battery for use in case of power interruption. It should be emphasized that uninterruptible power supply system does not work only when power failure occurs. For example, when the voltage is too low or too high, instantaneous sudden waves and so on, UPS system is in working state, providing stable and clean power for load equipment.
2. Bypass operation mode
When on-line UPS encounters power overload, bypass commands (manual or automatic), overheating of inverters or machine failure, UPS power supply generally converts the inverters output to bypass output, that is, direct power supply from municipal power. Because the output frequency and phase of UPS need to be the same as the city power frequency in bypass, phase-locked synchronization technology is adopted to ensure the synchronization of UPS power supply output with the city power. Bidirectional thyristor parallel operation mode of bypass switch solves the problem of bypass switching time. It really achieves zero time switching, and the control circuit is complex. It is generally used in medium and high power UPS power supply. If UPS is overloaded, the load must be artificially reduced, otherwise the bypass short circuit will automatically cut off the output.
3. Battery working mode
Once the city electricity is abnormal, the direct current stored in the storage battery is converted to alternating current. At this time, the input of the inverters is supplied by the battery pack. The inverters continue to provide power and supply the load to continue to use, so as to achieve the function of continuous power supply. The power source of UPS power supply system is battery, and the capacity of battery is limited, so UPS system will not continue to supply electricity like city power. Therefore, no matter how large the capacity of UPS system is, its power supply time must be limited under its full load condition. To prolong the discharge time, long-delay UPS power supply must be purchased.
4. Bypass Maintenance
When the UPS power supply is repaired, the normal power supply of the load equipment is guaranteed by manual bypass. When the maintenance operation is completed, the UPS power supply is restarted, and then the UPS power supply turns to normal operation.