Markus Bienholz

Dr.-Ing. Markus Bienholz

Research Topic


Interaction of power electronics through the power grid


Due to the increase in renewable energies and the efforts to increase efficiency the amount of power electronic converters connected to the power grid are increasing. All power electronic circuits emit noise at and around the frequency multiples of their switching frequency. This research topic deals with the influence these emissions have on other power electronic devices. Two different approaches are taken as explained below.

Frequency domain simulation

Frequency domain model of two converters using K-Matrices
Frequency domain model of two converters using K-Matrices


The goal of this investigation is to model the transmission of emitted frequencies through the power grid in order to explain resonant phenomena in filters or combinations of other power electronic building blocks. Therefore a frequency domain simulation is developed using network theory (see figure 1). All components must be measured over a wide spectrum to be modeled in frequency domain. The simulations made are verified at a lab setup.


Time domain controller evaluation


Due to nonlinear consumers connected to the power grid the voltage waveform is anything but sinusoidal. For optimal utilization of power electronic converters the controller has to know the grid waveform as precisely as possible. Therefore the grid interfaces and measurements of the power electronic controller are studied in time domain. Special interest is put on Phase-Locked-Loops (PLL) and possibilities to determine the harmonics present in the power grid.

Supervised Bachelor and Master Theses

  • Bachelorthesis: Vermessung von Leistungsdrosseln und Konzipierung eines Modells in MATLAB Simulink unter Berücksichtigung von Sättigung sowie des Frequenzverhaltens
  • Bachelorthesis: Design and evaluation of a three phase current and voltage measurement device
  • Masterthesis: Untersuchungen zur Überlastfähigkeit eines „Active Infeed Converters“ unter Einsatz von On-Line Temperaturüberwachung
  • Masterthesis:Active Infeed Regelung basierend auf einem Repetitive Control Algorithmus unter Verwendung des H-unendlich Prinzips (Diese Arbeit wir zusammen mit dem Fachgebiet Regelungstechnik und Mechatronik betreut.)
  • Masterthesis: Automation of an active infeed test rig with Matlab Simulink and implementation of multiple control algorithms
  • Masterthesis (Wi.-Ing.): Entwurf und Verifikation einer Schaltung zur Impedanzmessung induktiver Bauteile mit überlagertem Gleichanteil
  • Masterthesis: Development of a test platform fort he comparison oft he static and dynamic behaviour of PLLs
  • Masterthesis: Entwicklung einer Regelung für einen galvanisch getrennten DC/DC-Wandler für hohe Spannungsübersetzung (Ext. Partner: Fraunhofer ISE)
  • Masterthesis: Auslegung eines aktiven Filters zur Kompensation von Oberschwingungen
  • Masterthesis: Comparison of Adaline and FFT Techniques for the Estimation of Power Line Harmonics
  • Masterthesis: Paralleling of two 3-level T-type Modules with Reverse Blocking IGBTs (Ext. Partner: Fuji Electric)
  • Masterthesis: Design & Development of a DC-DC Converter with Two Inputs & One Output for PV Power Plants (Ext. Partner: Fraunhofer ISE)
  • Masterthesis: Modeling of Electrical Double Layer Capacitor Energy Storage System with active balancing unit in MATLAB/SIMULINK (Ext. Partner: SIEMENS AG)

Publications

  • „Prediction of harmonic current frequencies and amplitudes generated in Power Inductors due to Saturation in Ferrite and Iron Powder Cores“, Markus Bienholz, Gerd Griepentrog, SPEC 2016

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