Super UPS Fault Protection Design

Super uninterruptible power system (UPS) suitable for communication systems, data centers, precision manufacturing, nuclear power plants etc that require higher power supply reliability. Super UPS use DC bus structure, each energy independent infrastructure, energy storage elements and inverter is connected to the DC bus through a modular bidirectional AC/DC or DC/DC converter. Therefore, the DC bus side short-circuit failure has serious implications for the reliable power supply. In this paper, the super-UPS DC bus side short circuit fault protection model and technology were studied.The first chapter introduces the background of DC energy storage systems research, followed by an overview of protection schemes, which contain the characteristic of protection devices and design of protection system, and finally the significance and main work of this article is introduced.The second chapter introduces the fault model of super UPS system. Analysis of the fault and non-fault module parameters impact fault current are studied. Finally, typical fault condition of Super UPS is verified by preliminary simulation and experimental.Directional current protection scheme which use SSCB as protection device and can realize rapid fault detection and fault isolation is discussed in the third chapter based on the Super UPS fault current direction characteristics. Then the basic principles of directional current protection are introduced, and the directional current protection based on the IGBT CE terminal voltage detection is designed and analyzed in details. Finally, simulation and experimental of Super UPS system directional current protection are carried out.