Publications de Nicolai Hildebrandt

Robust and Cost Effective Synchronization Scheme for a Multicell Grid Emulator

Drazen Dujic, Min Luo, Nicolai Hildebrandt

Steadily increasing requirements for grid connected converters, their growing unit power and output voltage call for flexible high-power medium-voltage grid emulators. Four-quadrant cascaded H-bridge topology features high output voltage resolution and hig ...

2021

A Fast-Dynamic Unipolar Switching Control Scheme for Single-Phase Inverters in DC Microgrids

Nicolai Hildebrandt

This paper presents the digital implementation of a boundary controller with unipolar switching characteristic for single-phase voltage source full-bridge inverters. This paper expands the application of a second-order switching surface-based control metho ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2019

Supply Grid Synchronization and Operation of a Filterless Cascaded H-Bridge based Grid Emulator

Drazen Dujic, Nicolai Hildebrandt

Steadily increasing requirements for grid connected converters, their growing unit power and output voltage call for flexible high-power medium-voltage grid emulators. Four-quadrant Cascaded H-Bridge (CHB) topology features high output voltage resolution a ...

IEEE2019

Weak-lensing shear measurement with machine learning Teaching artificial neural networks about feature noise

Malte Tewes, Frédéric Courbin, Thibault Adrien Kuntzer, Nicolai Hildebrandt

Cosmic shear, that is weak gravitational lensing by the large-scale matter structure of the Universe, is a primary cosmological probe for several present and upcoming surveys investigating dark matter and dark energy, such as Euclid or WFIRST. The probe re ...

EDP SCIENCES S A2019

Cascaded H-Bridge Multilevel Converter for a High-Power Medium-Voltage Impedance-Admittance Measurement Unit

Marko Petkovic, Drazen Dujic, Francisco Daniel Freijedo Fernández, Nicolai Hildebrandt

Recent trends in power system design and inclusion of renewable energy sources and smart grids are creating different subsystem interactions that require proper investigation, understanding, describing and estimating global system stabilitythrough impedanc ...

2018

Medium Voltage Impedance-Admittance Measurement System Based on the Cascaded H-Bridge Multilevel Converter

Marko Petkovic, Drazen Dujic, Francisco Daniel Freijedo Fernández, Nicolai Hildebrandt

Recent trends in power system design such as an increasing share of renewable energy sources and smart grids are creating different subsystem interactions that require proper investigation, understanding, describing and estimating global system stability t ...

2018

Evaluation of 1.7 kV SiC MOSFETs for a Regenerative Cascaded H-Bridge Multilevel Converter Cell

Marko Petkovic, Drazen Dujic, Nicolai Hildebrandt

High fidelity AC grid emulators allow early testing and qualification of various equipment under conditions close to those expected in reality. Realizing this at medium voltage high power level is associated with certain challenges, some of which are discu ...

2018