The difference between UPS and EPS is as follows:
One, UPS:
1, UPS is an uninterruptible power supply, which is mainly used to provide power protection to important loads, including eliminating all kinds of power nuisances in the grid, such as blackouts, voltage fluctuations, frequency fluctuations, harmonics, voltage distortion, electrical noise, spiking and so on. It is an internationally and domestically recognized product for protecting important loads with strict international and national standards.
2, UPS output high precision, fast conversion time, while the higher cost (about twice as much as EPS), usually large energy consumption (online), the host life is shorter (8-10 years).
Two, EPS:
1, EPS for emergency power, mainly in the utility power outage to the load to provide a certain amount of power supply time, therefore, it is from the utility power outage to the output is intermittent. When the utility power is normal, there is utility power to the load power supply, but not on the utility power in the existence of a variety of nuisances to deal with, a little like a backup UPS.
But this product in China only in the fire law in each place a definition, no clear explanation, there is no similar products in the international community, so there is no corresponding international standards and national standards.
2. Generally, the power supply is not constant current, constant voltage processing. Usually use the contactor conversion, switching time are 0.1 ~ 0.25 S. Its advantages are simpler structure, lower cost, usually small energy consumption without noise, long life host (15-20 years), can be adapted to the inductive, capacitive and integrated loads, need to realize the frequency conversion soft start.
Expanded Information:
The UPS power system consists of five parts: the main, bypass, and battery power input circuits, the rectifier (REC) for AC/DC conversion, the inverter (INV) for DC/AC conversion, the inverter and bypass output switching circuits, and energy storage batteries.
The voltage stabilization function of the system is usually completed by the rectifier, the rectifier device adopts silicon controlled or high-frequency switching rectifier, which has the function of controlling the output amplitude according to the change of the external power, so that when the external power changes (the change should meet the system requirements), the output amplitude is basically unchanged by the rectified voltage.
The purification function is accomplished by the energy storage battery. Because the rectifier cannot eliminate transient pulse interference, the rectified voltage still has interference pulses. Energy storage battery in addition to the function of DC direct energy can be stored, for the rectifier is like connecting a large container capacitor, the size of its equivalent electric capacity, and the size of the storage battery capacity is proportional to the size.
Because the voltage at the ends of the capacitor can not be changed abruptly, that is, the use of the capacitor on the pulse of the smoothing characteristics of the elimination of the pulse interference, play a purification function, also known as the shielding of interference.
Frequency stabilization is completed by the converter, frequency stability depends on the degree of stability of the converter's oscillation frequency. In order to facilitate the daily operation and maintenance of the UPS power supply system, the design of the system work switch, the host self-test fault after the automatic bypass switch, maintenance bypass switch and other switch control.
When the grid voltage is working normally, it supplies power to the load and, at the same time, charges the storage battery; when there is a sudden blackout, the UPS power supply starts to work, supplying the required power to the load from the storage battery to maintain normal production (as shown in the bold black →); when, due to the production needs, the load is seriously overloaded, it supplies power to the load directly from the grid voltage through rectification.
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