Uninterrupted power bank capable of supplying high DC voltage during interruption of main supply and providing AC voltage as normal supply of the main supply

An uninterrupted power bank, being electrically connected between a power supply device and a main supply, and comprising:

• a first switch unit, being coupled to the main supply;
• a rectifier unit, being electrically connected to the first switch unit for converting an AC power provided by the main supply to a first DC power;
• a first power conversion unit, being electrically connected to the rectifier unit for converting the first DC power to a second DC power;
• a second switch unit, being electrically connected to the first power conversion unit;
• a battery unit, being electrically connected to the first power conversion unit via the second switch unit, and used for storing the second DC power as a backup power;
• a second power conversion unit, being electrically connected to the first power conversion unit for converting the second DC power to a plurality of third DC powers;
• a third power conversion unit, being electrically connected to the battery unit and the second switch unit;
• a third switch unit, being electrically connected between the third power conversion unit and the power supply device;
• and
• a plurality of output ports, being electrically connected to the second power conversion unit;
• wherein the battery unit releases the backup power by a form of the second DC power to the second power conversion unit and to the third power conversion unit in the case of an interruption of the main supply;
• and wherein the third power conversion unit converting the second DC power to a fourth DC power, and subsequently outputting the fourth DC power to the power supply device through the third switch unit.