EPS emergency power system is the abbreviation of Emergency Power Supply, which is the emergency power supply to meet the special requirements of the fire service industry. UPS is the abbreviation of uninterrupted power supply, which is the UPS uninterruptible power supply we often said. The common UPS power supply on the market is available for OnLine and OffLine two kinds.a
Standby UPS and Online interactive UPS
Online interactive UPS directly supply power by mains when the mains are normal; when the mains are lower or higher, it will output by the UPS internal regulated voltage regulator circuits; when the mains is abnormal or power outage, it will transform to a battery inverter power through the switch. Its characteristics are: wide input voltage range, low noise, small size and other characteristics, but there are also switching time. Online UPS supply power to the load by the mains when the mains are normal. When the mains are abnormal, the inverter is powered by the battery and the inverter is always in working condition, to ensure uninterrupted output. The ups backup power directly supply power to the load by the mains when mains are normal, when mains beyond the scope of their work or blackout, it will transform to a battery inverter power through the switch. Its characteristics are: simple structure, small size, low cost, but the narrow range of input voltage, poor output voltage stabilization accuracy, switching time, and the output waveform is generally square wave.
Advantages of Online UPS
UPS has voltage regulation, filtering and other functions at the same time. Some UPS can be powered by municipal electric at the fault or overload. The reserve-voltage output has greater fluctuation between 170V-260V, which uses high-speed relay to realize conversion between the mains and the battery, the conversion time is less than 10 milliseconds. The online ups systems always use the inverter circuit, which has high voltage stability, basically in the range of 220V ± 5% and basically has no conversion time for the battery; using static switch for mains bypass conversion, the conversion time can achieve microsecond level.
Difference between EPS and UPS
UPS has high output precision, fast conversion time, while the cost is higher (approximately twice of EPS), the energy consumption is large (online) and host life is short (8-10 years). EPS is somewhat similar to the reserve UPS. The inverter usually does not work, which only put into the battery when there is a mains failure. It generally does not carry out power constant current and constant voltage processing. It usually use the contactor for conversion, the average switching time is 0.1 ~ 0.25S. The advantage is that the structure is relatively simple, low cost, usually no noise and low energy consumption, the host life is long (15-20 years), which can be adapted to the inductive and capacitive load. In addition, frequency conversion soft start can be realized when needed.
The article is come from:http://www.everexceedcorp.com/blog/index.php/main-difference-between-ups-power-and-eps-power.htm