Möbius, Patrick

New concepts for the future grid and the energy supply also demand changes in future emergency power supply solutions. It is often not possible to simply replace conventional diesel generators with renewable energy sources. In order to make alternative emergency power supplies viable in the real world, new procedures and structures are needed. A basic distinction is made between stationary and mobile emergency power supplies. Stationary emergency power systems may be found in hospitals, large server farms and other critical infrastructure. The mobile emergency power systems, such as those used by the Technical Relief Agency (THW) or the fire brigade, can be used much more flexibly. One conceptual idea is to use existing electric bus fleet infrastructures as a mobile emergency power supply. This green alternative could replace the conventional diesel generators used today. This paper investigates the use of electric bus fleets as mobile energy storages for emergency power supply usecases. The goal is to examine the general need for buses to be used in a case of emergency power supply, the possible area of coverage depending on the distributed bus depots in Hamburg and the effects on the power requirements of the depots.

The time- and frequency-variant impedance is gaining importance as a necessary parameter to describe and determine systems and devices. There is a multitude of use-cases ranging from structural health monitoring to PLC applications. Many measuring concepts have been developed and were implemented in prototypes and first commercial solutions. In regard to the power-flow, all active concepts may be divided into either source-based systems, which actively feed a current into a measuring setup, or load-based approaches, which switch passive loads and therefore draw a current from the setup. The main objective of this paper is to compare and distinguish the two basic concepts within a controlled laboratory environment by switching between a constant and a sub-periodically influenced load scenario.