Stationary battery energy storage systems are widely used for uninterruptible power supply systems. Furthermore, they are able to provide grid services. This yields in rising installed power and capacity. One possibility uses high voltage batteries. This results in an improvement of the overall system efficiency. High voltage batteries may be advantageous for future medium voltage DC-grids as well. In all cases, high availability and reliability is indispensable. Investigations on the operating behavior of such systems are needed. For this purpose, a test bench for high voltage storage systems was built to analyze these processes for different battery technologies. A special safety infrastructure for the test bench was developed due to the high voltage and the storable energy of approximately 120 kWh. This paper presents the layout of the test bench for analyzing high voltage batteries with about 4,300 volts including all components, the safety requirements with the resultant safety circuit and the aim of the investigations to be performed with the test bench.
Elastic syntactic foam is a special kind of composite material. It consists of a silicone gel matrix (called binder) and hollow spherical particles with a diameter in the range of 20 -200 μm (so called microspheres) which are mixed into the binder. This Material is very soft, elastic and features a high compressibility as well as a strong adhesion to other solids. In the field of insulation systems, it is already used to substitute mineral oil in cable terminations. For the dimensioning of insulation systems, it is necessary to have a precise knowledge about the phenomena occurring during a breakdown process. The breakdown mechanisms of syntactic foam under AC and DC stress was introduced in earlier papers. New applications in medium and high voltage systems also require knowledge about the behavior of elastic syntactic foams exposed to impulse voltage stress. In order to characterize the microspheres' influence on the electrical properties of the material, the lightning impulse voltage dielectric strength of elastic syntactic foams which are made of different polymeric microspheres (different diameters, different filling degrees) are determined and compared. Further tests deal with influence of temperature on the dielectric strength under impulse voltage. In combination with theoretical investigations and field simulations, the results of the experimental investigations are used to develop a model of the breakdown mechanism of elastic syntactic foam exposed to impulse voltage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.