In today's digital age that is highly dependent on electricity, UPS (uninterruptible power supply) systems play a vital role in ensuring the stable operation of equipment. As two common types of UPS, online UPS and line-interactive UPS each have unique characteristics and applicable scenarios. Understanding the differences between them will help you make the right choice based on your actual needs.

Working principles of online and line interactive ups

Online UPS: Always in working state. When the mains power is normal, the AC mains power is converted into DC power by the rectifier, charging the battery, and then converted into pure AC power by the inverter to supply the load. When the mains power is interrupted, the DC power stored in the battery is converted into AC power by the inverter to continue to power the load, realizing complete isolation of the mains power. Regardless of whether the mains power is normal or not, the power used by the load comes from the inverter.

Online interactive UPS: When the mains power is normal, the load is directly powered by the mains power, while charging the battery, and the output voltage is adjusted by adjusting the transformer tap through the intelligent switch. When the mains power is interrupted, the load is powered entirely by the battery after being converted by the inverter. The inverter is in reverse working state to charge the battery pack, acting as a charger.

online and line interactive ups power quality

Online UPS: It can provide high-quality, stable sine wave power with high voltage stabilization accuracy. The general voltage stabilization accuracy is ±2%-3%. It can effectively eliminate interference such as harmonics, spikes, and surges in the mains power, and provide a pure power environment for load equipment. It is suitable for precision instruments, medical equipment, data centers and other places with extremely high power quality requirements.

Online interactive UPS: It has a certain improvement effect on the mains power. The voltage stabilization accuracy is relatively lower than that of the online type. The output is usually adjusted within the range of ±8%-15% of the nominal voltage. It is basically sufficient for general office equipment, computers and other equipment that do not have particularly strict requirements on power quality, but for equipment with extremely strict voltage requirements, it may not meet its stable power supply needs.

online and line interactive ups switching time

Online UPS: There is no switching time problem, because the inverter is always in working state. When the mains power is cut off, its automatic switching time is zero, which can ensure that the load equipment is not affected at the moment of mains power outage, realize true seamless switching, and maximize the continuous operation of key equipment.

Online interactive UPS: The switching time is about 2-4 milliseconds. Although this time is short enough and will not cause obvious interruption to most equipment, it may cause certain risks for some special equipment that has extremely high requirements for power supply continuity and cannot withstand any minor interruptions.

Efficiency and energy consumption of online and online interactive UPS

Online UPS: Since it is always in working state, it needs to charge the battery and maintain the operation of the inverter at the same time, so the energy consumption is relatively high, and the heat generation is also more. A good cooling system is required to ensure the normal operation of the equipment, which also increases the operating cost to a certain extent.

Online interactive UPS: When the mains power is normal, it is mainly powered directly by the mains power. The inverter only starts working when the mains power is abnormal. Therefore, the energy consumption is relatively low, the efficiency is higher, and the operating cost is relatively low.

Applicable scenarios of online and online interactive UPS

Online UPS: It is mainly used in key places with extremely high requirements for power quality and no risk of power outages, such as large data centers, intensive care units in hospitals, trading systems of financial institutions, broadcasting systems of TV stations, etc. The equipment in these places has a high dependence on the stability and reliability of the power supply, and any power problems may lead to serious consequences.

Online interactive UPS: It is suitable for occasions that have certain requirements for power supply quality but are more sensitive to costs, such as ordinary corporate office environments, schools, small server rooms, etc. It can guarantee the normal operation of equipment to a certain extent, while having a high cost-effectiveness.