Static thyristor inverter system with battery energy store

A UPS of 2 MVA is not uncommon as a power source for modern large computer suites. Banks, building societies and credit card companies are all examples of large computer users whose profitability can be disproportionately affected by a short interruption in supply. Often the computers are linked by modem to other users, so multiplying the effect. The UPS also isolates the computer from the noise on the supply; noise which can cause data errors and unexplained hardware failures. With such a large power requirement, there are only a small number of switching devices that can be used economically. But one must look at other aspects of the UPS before making a choice.