Analysis of the UPS fault in Qinshan nuclear power plant

To make sure the safety of nuclear power plants and the stabilization of generators, UPS are widely used in all kinds of nuclear power plants, whose status is directly connected with the whole plants. Through some analysis and testing, this paper introduces the root cause of the fault which caused the power supply broke down because of an unexpected shutdown of the UPS in Qinshan Nuclear Plant and relevant solutions to the problem. At the same time, the cases could be useful for other plants suffering from the same problems. (authors)