1. Normal operation mode
The power supply principle of UPS power supply system is that when the mains power is normal, the machine will convert the AC of the mains power into DC, and then charge the battery in case of power interruption; It should be emphasized that the UPS system does not work only when there is a power failure. In case of low or high voltage, transient surge, etc., which is enough to affect the power quality of the normal operation of the equipment, the UPS system is in the working state to provide stable and clean power for the load equipment.
2. Bypass operation mode
When the On-line UPS encounters power overload, bypass command (manual or automatic), inverter overheating or machine failure, the UPS power supply generally converts the inverter output to bypass output, that is, it is directly powered by the mains power. When bypassing, the phase of UPS output frequency needs to be the same as that of mains frequency, so phase-locked synchronization technology is adopted to ensure that UPS output is synchronized with mains frequency. The two-way thyristor parallel working mode of bypass switch solves the problem of bypass switching time, truly achieves zero time switching, and the control circuit is complex. It is generally used in medium and high-power UPS power supply. If the UPS is overloaded, the load must be reduced artificially, otherwise the bypass circuit breaker will automatically cut off the output.
3. Battery operation mode
Once the mains power is abnormal, the DC stored in the battery will be converted into AC. at this time, the input of the inverter will be supplied by the battery pack. The inverter will continue to provide power, and the supply load will continue to use, so as to achieve the function of continuous power supply. The power source of the UPS power supply system is the battery, and the capacity of the battery is limited, so the UPS system will not continuously supply power like the municipal power. Therefore, no matter how large the capacity of the UPS system, under its full load state, its power supply time must be limited. If you want to extend the discharge time, you must buy a long-time delayed UPS power supply.
4. Bypass maintenance mode
When the UPS power supply is overhauled, manually set the bypass to ensure the normal power supply of the load equipment. When the maintenance operation is completed, restart the UPS power supply, and the UPS power supply turns to normal operation at this time.
