Novel

A Novel HVDC Architecture for Offshore Wind Farm Applications

Otavio Dezem Bertozzi Junior, MS Student, Physical Science and Engineering

Nov 10, 15:00 - 16:00

KAUST

Novel HVDC architecture Offshore wind

Advances in power electronics have enabled many renewable energy applications. Wind energy harnessing is very promising and offshore farm installations have grown considerably in the past years. In this thesis, we introduce a novel power converter solution for the parallel connection of high-power oﬀshore wind turbines, suitable for HVDC collection and transmission. For the parallel operation of energy sources in an HVDC grid, DC link voltage control is required. The proposed system is based on a full-power rated uncontrolled diode bridge rectiﬁer in series with a partially-rated fully-controlled thyristor bridge rectiﬁer. The thyristor bridge acts as a voltage regulator to ensure the ﬂow of the desired current through each branch, where a reactor is placed in series for ﬁltering of the DC current. AC ﬁlters are installed on the machine side to mitigate harmonic content. The mathematical modeling of the system is derived and the control design procedure is discussed. Guidelines for equipment and device speciﬁcations are presented. The concept is validated through simulation, and an experimental framework for testing of the system is suggested.

A novel structure preserving scheme for Schrondiger-Poisson systems.

Dr. Th. Katsaounis

Feb 28, 16:00 - 17:00

B2 L5 R5220

Novel structure preserving Schrondiger Poisson Systems

In this talk I will present a new structure preserving, second order in time relaxation-type scheme for approximating solutions of the Schrodinger-Poisson system. We use the Crank-Nicolson scheme as a time-stepping mechanism, whilst the nonlinearity is handled by means of a relaxation approach. For the spatial discretisation we use the standard conforming finite element scheme. The resulting scheme is explicit with respect to the nonlinearity, i.e. it requires the solution of a linear system for each time-step, and satisfies discrete versions of the system’s mass conservation and energy balance laws for constant discretization parameters.