Design of Off-Grid Photovoltaic Power Generation System

Both EPS and UPS are backup power sources that provide power to the load when the AC power fails and is interrupted.

EPS is a fire emergency power supply. It is mainly used in emergency lighting, sign lights, fire elevators, fire pumps, fire gates, alarm systems, smoke exhaust fans, etc. It only provides power during power outages.

The purpose of UPS uninterruptible power supply is important equipment such as computer room, computer system, instrumentation, and so on.

The application of UPS requires a relatively high inverter switching time. The backup switching time is less than 0.02s, and the online switching is 0. The inverter switching time standard of EPS is less than 5s, and the design of special requirements is less than 0.25s, which is generally larger than that of UPS. Therefore, the general EPS cannot be used in the use of UPS. If the EPS special design improves the inverter switching time to less than 0.02s, and the quality of the load power supply is not high, it can be used instead of the UPS, and the purpose of energy saving can also be achieved.

EPS is generally equipped with strong inductive loads. UPS with a strong inductive load will inevitably cause economic waste in the power matching ratio, and when the online UPS is in normal mains, the rectifier and inverter have been working uninterruptedly, resulting in about 10% to 20% of the power failure. Power consumption is wasted. The other biggest problem is that the UPS can be simply installed and used in place of EPS at that time. However, when it comes to fire inspection, it is generally not passed or accepted. In the event of a fire, no one can escape the responsibility for fatal accidents caused by EPS. Therefore, UPS can never be used in fire-fighting places instead of EPS.