UPS is short for Uninterruptible Power Supply, which is an emergency replacement for utility power when there is a power outage, supplying power to equipment, just like emergency lighting. But the design of the system is more precise, can make the utility power and battery or converter conversion time is shorter, to make up for the generator or other emergency power interruption time is too long shortcomings of the uninterruptible power supply system is not a blackout will act, such as encountering voltage sag, sharp waves, voltage surge, noise interference, high (low) voltage transient, enough to affect the normal operation of equipment power quality problems, uninterruptible power supply system will be automatic voltage stabilizer Filtering noise, to provide equipment with a stable and clean power environment. Because UPS function and price is higher than other emergency power supply equipment, it is generally used to protect important equipment, such as computer equipment, monitoring equipment, fire equipment, medical equipment.... etc., in order to meet the strict requirements of computers and various precision instruments on the quality of electricity. At present, UPS has been recognized by the high-tech industry, the computer industry as a true and complete solution to the power problem of the necessary equipment.
The power distribution unit is able to control, accept and distribute the electrical energy of the electrical device. Because it is functionally complete, so the power distribution unit must have a variety of functional electrical equipment. Such as converging bus, circuit breakers, disconnect switches, reactors, surge arresters, voltage transformers, capacitors, cables and measuring instruments and other secondary equipment.