With the development of distributed energy resources (DER) and semiconductor devices, DC electric networks have become a competitive alternative to conventional AC-based systems, with key moti- vations among which the higher power generation and conversion efficiency, and ease of renewable integration. Compared to AC grids, the increased amount of converter devices in DC networks leads to higher a network capacitance owed to their filter components. Unlike AC systems, fault clearing in DC networks generally considers current flow interruption by a DC solid-state circuit breaker (SSCB) rather than by its mechanical counterpart. After such protective operation, the DC network is reconnected by the breaker device and large inrush current is provoked by the increased network capacitance, because it imitates a short circuit when being charged rapidly. Inrush current potentially causes undesired be- haviour or damage in network components or the SSCB itself, and must be avoided. This research proposes to use the solid-state power device of a SSCB in current saturation region in order to limit the inrush current, but without the use of additional current limiting elements. The proposal is addressed by development of a variable voltage gate driver to excite a silicon-carbide metal-oxide-semiconductor field-effect transistor (SiC MOSFET) power device in current limiting mode, without exceeding its safe operation limits by conducting low continuous current or higher pulsed current, and while controlling its behavioural dependence on thermal and electrical conditions. Inrush current limiting performance of ten different power devices is compared to identify important characteristics of the power device itself, the proposed inrush current limiting method, and the power device control method. By assessment, the considered low voltage DC industrial network is estimated to contain 2.8mF network capacitance combined with negligibly low resistance and inductance. Network reconnection while limiting inrush current according to the developed soft-start procedure is experimentally achieved in 6.2s, satisfying the project objective to reconnect within 10s. This work showcases the availability of cost-effective methods for using SSCBs as apposite protection devices in low voltage DC networks.

Over the years, care givers in nursing homes have seen their workload gradually increase. With no end of this trend in sight, the need for smart support systems increases. Especially systems which decrease the time spent on menial tasks are valued highly, because this frees more time for high quality and personal care.
To achieve this, Momo Medical is expanding on its nurse support system. This is a network of integrated smart solutions aiming at supporting care givers in nursing homes to provide better, faster and more personal care. The backbone of this nurse support system consists of the BedSenses, sensors which are placed under mattresses of each resident and can measure a variety of things.
This thesis describes the process of designing and creating a localization algorithm for this nurse support system. This algorithm can find residents by tracking the panic buttons they wear, so that in case of an emer- gency or whenever a care giver wants to know where a resident is located, they do not need to undertake a time consuming search in order to find them. These panic buttons send out an alive signal once every minute as well as a signal whenever the button is pressed. These signals are received by any nearby BedSenses. The algorithm looks at the signal strength with which each BedSense receives these signals and uses this to per- form localization.