The difference between the three backup power supplies of UPS power supply, diesel generator and EPS power supply

May 06, 2023

With the continuous improvement of the economy and the increasing popularity of computer applications, equipment requires higher and higher reliability for power grid power supply.


In order to ensure the uninterrupted power supply of important emergency lighting, monitoring system, computer, fire protection, especially important equipment in metallurgy and chemical industry, special UPS power supply, diesel generator and EPS power supply are generally equipped. The following briefly introduces the three major backup power sources. Hope that after reading this article, you can have a further understanding of the differences between the three major backup power sources: UPS power, diesel generators and EPS power.


●Basic concepts


EPS is an emergency power supply. When the mains fails, it can continue to supply power to the load to ensure non-stop power supply to protect the safety of people's lives and property. EPS power supplies can be divided into three categories: emergency lighting, power and power frequency conversion.


UPS is an uninterruptible power supply. When the mains power is abnormal or suddenly interrupted, it can continue to supply power to the equipment for a certain period of time, giving users plenty of time to deal with work.


Diesel generator sets are divided into prime diesel generator sets and standby diesel generator sets. Relevant electrical regulations and national standards stipulate that Class I high-rise buildings should be powered by Class I load, and standby diesel generator sets must be used.


●Application fields


EPS is mainly used for fire-fighting loads and some electrical equipment that does not require high power supply quality but needs to ensure continuous power supply. It only emphasizes the function of continuous power supply.


UPS power supply is generally used in occasions such as computers and digital information systems. For loads that require high power supply quality, the main emphasis is on inverter switching time, output voltage, frequency stability, purity of output waveform, and no interference.


Diesel generators are used where there is no connection to the grid, or as emergency power in the event of a grid failure, and for more complex applications such as peak tripping, grid support and grid export. Important communication facilities, nuclear power plants, hospitals, industrial manufacturing plants, hotels and office buildings are also equipped with backup emergency diesel generator sets.

●Power supply method


When the mains power is normal, all kinds of EPS power supplies directly supply the mains power to the load through the bypass. The backup UPS and online interactive UPS in the UPS power supply provide the load with regulated and purified mains power through the bypass. The online UPS in the UPS power supply always provides the load with pure inverter alternating current with the same frequency and phase as the mains, and with a small error.


When the utility power is interrupted, both the EPS power supply and the UPS power supply provide the load with inverter alternating current. In order to better protect information and equipment, when the mains power is abnormal: including power surges, high-voltage spikes, transient overvoltages, voltage sags, wire noise, frequency deviation, continuous low voltage, etc., the UPS power supply will automatically turn to Inverter power supply.


Diesel generators belong to a type of AC power supply equipment for self-contained power stations. Diesel generators are devices that convert the mechanical energy of diesel engines into electrical energy. They are powered by diesel engines and drive generators. They are small independent power generators. The equipment, powered by an internal combustion engine, drives a synchronous alternator to generate electricity.