Comparison of UPS battery uninterrupted power supply and EPS emergency power supply system
Compared with the UPS uninterruptible power supply and EPS emergency power supply system, the standby UPS is directly supplied by the municipal power supply during normal power supply. When the power supply exceeds the working range or the power is cut off, it is converted into a battery inverter power supply through a switch. The utility model has the advantages of simple structure, small size, low cost, etc., but the input voltage range is narrow, the output voltage is stable and the precision is poor, the switching time is long, and the output waveform is generally a square wave.
2. When the power supply is normal, the online interactive UPS is directly provided to the load by the power supply. When the power supply is on the low or high side, the output is stabilized through the internal voltage regulator line of the UPS; When the power supply is abnormal or out of power, it is converted into a battery inverter power supply through a transfer switch, which has the characteristics of wide input voltage range, low noise, and small size, but also has the characteristics of switching time.
3. When the city power supply is normal, the online UPS will provide DC voltage to the inverter and AC power to the inverter load. When the power supply is abnormal, the inverter is powered by a battery, and the inverter is always in working condition to ensure uninterrupted output. It is characterized by a wide input voltage range, basically no switching time, and stable output voltage with high precision, which is especially suitable for high power sources. Requirement, but the cost is higher. At present, almost all UPSs with power greater than 3KVA are online UPS.
UPS also has functions such as voltage stabilization and filtering. In the event of a failure or overload, some UPSs can be switched to power supply through the mains bypass.
The backup voltage output fluctuates greatly. Between 170V and 260V, high-speed relay is used to realize the conversion between municipal power supply and battery, the conversion time is less than 10 milliseconds, and the online inverter circuit is adopted, and the voltage stability is high, basically within the range of 220V±5%, and the battery basically has no conversion. Time, the use of mains bypass conversion static switch, the conversion time can reach the microsecond level.
UPS has high output accuracy, fast conversion time, high cost (about twice that of EPS), high energy consumption (online), and short host life (8-10 years) ).
EPS emergency power supply is actually similar to a backup UPS power supply. Usually the inverter is not working. When the city's power supply is cut off, it will switch to battery operation. 'Under normal circumstances, the power supply is not affected by constant current and constant voltage. Usually use contactor conversion, the switching time is 0.1≤0.25s. The utility model has the advantages of simple structure, low cost, low energy consumption, no noise, and long service life (15-20 years) of the main machine, can adapt to inductance, capacitance and comprehensive load, and can realize frequency conversion soft start when needed. Contact: 18038382979
