Johannes Gehring

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

This work introduces a short-circuit current device (SCCD) for low voltage DC grids. This device aims to provide a fault current for protection devices which require an overcurrent for a rather long period in order to trip, e.g. melting fuses, in grid installations where such currents are usually not available because of converter current limits and smaller grid-side capacitors.

This paper introduces an innovative non-destructive device designed to detect and limit short-circuit currents in LVDC grids. The proposed solution utilizes a transformer fully saturated by a permanent magnet during normal operation. When a short-circuit condition occurs, the transformer desaturates, reducing the rise in current and triggering the detection and protection mechanism. The structure and functionality of the device, along with the design criteria, are discussed. Additionally, optimization measures are presented, examined, and validated. Experimental results from the advanced device prototype demonstrate its effectiveness in detecting and limiting overcurrents. The device features a stable tripping threshold and can safely and reliably interrupt even low time constant capacitive short-circuits. This hardware-based detection solution is ideally suited for installation in a semiconductor circuit breaker.

In extensive DC grids and during DC charging of electric vehicles, line and filter inductances play a crucial role in the design of switching elements. The inductively stored energy significantly influences the energy dissipated in the switching elements during the switching process. Therefore, a measurement system for the energy-equivalent inductance is required. This paper presents a novel measurement principle and a measurement system based on it. Laboratory measurements demonstrate that the proposed measurement system provides accurate and reliable results, enabling precise estimation of the energy dissipation in switching elements and facilitating the selection of appropriate switching components.