At present, many manufacturers in the market are promoting parallel UPS systems and adopting a configuration scheme of shared UPS power battery packs. The so-called shared UPS battery pack scheme refers to a solution where two or more UPS hosts use one or more sets of UPS batteries simultaneously.
In fact, very few customers use public battery pack solutions. No matter how UPS manufacturers prove the reliability, maturity, and stability of this technology, there are always many hidden dangers in the application of public battery pack solutions:
- When a short circuit occurs in a group of parallel batteries, it is equivalent to a short circuit in the rectifier circuit of two UPS systems, which will cause the failure of both UPS systems;
- If a UPS inverter short circuits and the rectifiers of two UPS are connected in parallel, due to the shared use of batteries, both UPS systems will malfunction simultaneously.
- When the rectifiers of two UPS are connected in parallel, there will be a voltage difference in the DC voltage output by the two UPS. Although the control system of the UPS can monitor and automatically adjust the voltage to ensure that the DC voltage output by the two UPS is the same, if the control fails, there will be a circulating current between the rectifiers of the two UPS. When it reaches a certain value, the rectifier of the UPS will automatically shut down, causing a fault.
- If a shared battery solution is adopted, two independent UPS systems with redundant parallel power supply will be invisibly connected into one system through batteries, which is also the purpose of losing redundant parallel connection.
Overview: Large and medium-sized UPS power supplies are equipped with a large number of batteries, which are connected through circuits to form a battery pack to meet the needs of UPS DC power supply. Configuring appropriate batteries on the UPS host can maximize the effectiveness of the UPS system.