Conceptual adaptive protection design using a physical MV network demonstrator

摘要

The increasing share of distributed generation poses risks to the selectivity and reliability of power system protection. To begin with, this paper presents a selection of currently faced challenges, which lead to errors in locating of faults and secure functionality. As a result of the theoretical analyses, adaptive settings based on the current state of the protected electrical system are deducted as a feasible alternative to traditionally parametrised protection systems. Consequently, a concept of an adaptive protection system for a medium voltage distribution grid is proposed. As a first step, the current switching state of the protected electrical power system has to be estimated. Therefore, the results of previously conducted various load-flow simulations are compared to the real-time measurements taken from the physical network. The physical test facility is realised as a three-phase AC system with 80 V phase to phase, which represents a scaled version of a 20-kV-system. With the knowledge of the currently active topology and further required information about the equipment, corresponding short-circuit currents are calculated and suitable protection settings can be derived.