The principle of the power supply system is that when the utility power is normal, the machine will convert the alternating current of the utility power to direct current, and then charge the battery for use when the power is interrupted; it is emphasized here that the power supply system will not only act when the power is out, such as when the voltage is too low or high, or when there are instantaneous surges, etc., which are enough to affect the normal operation of the equipment and the quality of the power, the power supply system will be acted to provide stable and clean power for the equipment. When the utility power supply is normal, the utility power system will operate to provide equipment with stable and clean power. When the utility power is normally supplied, the utility power is filtered and divided into two circuits, one of which is charging the battery pack through the charging circuit, and the other is rectified as the input of the inverter, which is then converted to provide power for the loads to use; from this, it can be seen that the output of the on-line uninterruptible power supply system is supplied by the inverter, so that regardless of the quality of utility power, the output is stable and not affected in any way. Therefore, regardless of the quality of utility power, the output is stable and not affected in any way.

2、Battery operation mode
Once the utility power abnormalities occur, the DC power stored in the battery will be
converted to AC power, at this time the input of the inverter to be supplied by the battery pack, the inverter continues to provide power to supply the load to continue to use, to achieve the function of the uninterruptible power supply UPS uninterruptible power supply system source of power is the battery, and the capacity of the battery is limited, so the uninterruptible power supply system will not be like the utility power supply unlimited supply, so no matter how large the capacity of the uninterruptible power supply system under its full load state must be limited to the time of power supply. Therefore, no matter how large the capacity of the uninterruptible power supply system, in its fully loaded state, the power supply time must be limited, if you want to extend the discharge time, you must purchase a long time type of uninterruptible power supply system.

3、Bypass operation mode
When the on-line UPS is overloaded, bypass command (manual or automatic), overheating of the inverter or machine failure, the UPS generally turns the inverter output to bypass output, i.e., it is directly powered by the utility. Due to bypass, the UPS output frequency phase needs to be the same as the utility frequency phase, and therefore the use of phase-locked synchronization technology to ensure that the UPS output is synchronized with the utility. Bypass switch bi-directional thyristor parallel mode of operation, to solve the problem of bypass switching time, truly uninterrupted switching, control circuit is complex, generally used in medium and high power UPS. If the load must be artificially reduced in case of overload, otherwise the bypass circuit breaker will automatically cut off the output.


4, bypass maintenance mode when the UPS for maintenance, through the manual bypass to ensure the normal power supply of the load equipment, when the maintenance operation is completed, restart the UPS, UPS to normal operation. Extremely low maintenance rate, greatly improving the availability of UPS uninterruptible power supply.