Distributed feeding in photo-conducting antennas (PCAs) leads to simple optical designs, less prone to overheating, as well to terahertz (THz) antennas that can operate non-dispersively over wide bandwidths. However, the efficient analysis of pulsed PCAs was so far limited to architectures characterized by feeds small with respect to the THz wavelengths. In this thesis, an efficient and rigorous procedure for the time domain analysis of an infinitely long slot antenna printed on photo conductive material and excited by a distributed pulsed laser is presented. The procedure is electromagnetically rigorous, and relies on spectral representations of the fields in both the frequency and spatial domains. ... Read more

Increase in wind- and solar parks complicate grid stability due to their deterministic behaviour. ENTSO-E established requirements for generators for grid connection in Europe. A requirement is to have active- and reactive power control that implements a power setpoint given by the transmission system operator. This thesis describes the design and MATLAB implementation of these controllers in a combined wind- and solar power park module. Reactive power control is designed for two modes, namely reactive power control mode and voltage sub-mode 1. The active power control is designed as a rule based controller with a quadratic distribution of power over generator strings. The reactive power control mode is based on a variable structure PI with feedback and pro-rata distribution of reactive power. A design for voltage-submode 1 has been designed based on droop control, but is not corresponding the requirements of the considered case. The
controllers are implemented in model of a real-life case from the company [Blackened text]. ... Read more