Lehrstuhl für Elektrische Maschinen und Antriebe

Prof. Dr.-Ing. Prof. Stefan Soter

Contact us:

Rainer-Gruenter-Str. 21

42119 Wuppertal

Room: FH.01.07

Stefan.Soter[at]uni-wuppertal.de

+49 202 439 1950

For requests please contact my Secretary

Personal career

  • 10/1984 to 11/1989 University of Bochum; Degree: Dipl.-Ing. Electrical Engineering

  • 01/1990 to 04/1996 Distance University Hagen Institute Solatec (Prof. Dr.-Ing. D. Hackstein)

  • 01/1994 Doctorate (Dr.-Ing.) in Electrical Engineering

  • Topic of the dissertation: "System technology for photovoltaically fed asynchronous machines for driving water pumps".

  • 05/1996 to 03/2007 Technical University of Dortmund (Prof. Dr.-Ing. Dr.-Ing. S. Kulig) Chair of Electrical Drives and Mechatronics, formerly Chair of Electrical Machines, Drives and Power Electronics

  • scientific assistant, senior engineer (from 07/1997), academic councilor (from 03/2001), academic senior councilor (from 03/2004)

  • since 04/2007 freelance manager of industrial projects in cooperation with the University of Wuppertal, Chair of Electrical Machines and Drives, Prof. Dr.-Ing. Ralph Kennel

  • 04/2005 Offer of the W3 deputy professorship "Power Electronics" of the Helmut-Schmidt-University Hamburg

  • from 10/2008 Lectureship at the Rheinisch-Westfälische Technische Hochschule Aachen (RWTH) (Prof. Dr.-Ing. Dr. h.c. dr hab. Kay Hameyer) Institute for Electrical Machines. Lecture title: Design and grid operation of wind turbines

  • 10/2008 to 02/2010 W3-professorship for "Electrical Machines and Drives" at the University of Wuppertal, Germany

  • from 03/2010 W3-Professorship for "Electrical Machines and Drives" of the University of Wuppertal

Lectures

Publications



67.
A. Uphues, K. Nötzold, R. Wegener and S. Soter, "Crowbar-less ride through of asymmetrical gric faults with DFIG based WECS" in 2017 IEEE AFRICON, 2017, pp. 1026--1031.

Abstract:
Due to the increased renewable power penetration level renewable power plants have to provide low-voltage ride-through (LVRT) capability with simultaneous dynamic voltage support, to ensure the grid stability during grid faults. Concerning doubly fed induction generator (DFIG) based wind energy conversion systems (WECS) large electromotive forces and rotor currents, which may damage the rotor-side converter, or adversely affect the DFIG's controllability are induced into the rotor circuit in case of voltage dips. To handle and limit the rotor currents in case of asymmetrical voltage dips without crowbar triggering, a virtual resistance control approach based on the standard dq-control in the synchronous reference frame is discussed. The theoretical results are compared with those of more demanding virtual inductance control. The LVRT capability is verified with measurement results, recorded during a certification campaign at a 2.1 MW WECS concerning the Indian grid code.
66.
A. Uphues, K. Nötzold, R. Wegener and S. Soter, "Comparison of parameter identification approaches with linearised process models based on RLS for induction machines with P {\textgreater} 100 kW" in 2016 IEEE International Conference on Industrial Technology (ICIT), 2016, pp. 134--140.

Abstract:
This paper presents a comparison between a continuous time domain approach (CTD) and a discrete time domain approach (DTD) for parameter identification of induction machines P{\textgreater}100 kW fed with a voltage source inverter (VSI). The machine parameters are identified off-line, based on the reference voltage and the measured current at standstill and single-axis excitation by the VSI. The quality of the identified parameters is verified with the comparison of measured and estimated torque for the whole operating range, exclusively the field weakening region.
65.
S. Gruber, R. Wegener and S. Soter, "Design Process for High Force Tubular Linear Drive with DiscreteWound Coils" in The 10th International Symposium on Linear Drives for Industry Applications, 2015.
64.
A. Uphues, K. Nötzold, R. Griessel, R. Wegener and S. Soter, "Overview of LVRT-capability pre-evaluation with an inverter based test bench" in 2015 IEEE 24th International Symposium on Industrial Electronics (ISIE), 2015, pp. 748--753.

Abstract:
With increased renewable power penetration level the system operators of power grids require low-voltage ride-through (LVRT) capability of renewable power plants. The LVRT-capability has to be verified during the process of certification with precisely defined short circuit tests on a reactance based test bench. For the development of the fault ride through (FRT) capability the cost intensive reactance based test configuration is replaced by an inverter based voltage sag generator (VSG). This paper deals with an overview of the whole inverter based test configuration including the control structure of the grid emulator and the adjustment of the grid side converter's control structure to reach LVRT-capability as well as measurement results for the pre-evaluation.
63.
A. Uphues, K. Nötzold, R. Wegener and S. Soter, "Frequency adaptive PR-controller for compensation of current harmonics" in IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society, 2014, pp. 2103--2108.

Abstract:
The use of proportional resonant (PR) current controller in grid side wind power converters instead of the traditional proportional integral (PI) controller has gained a large popularity. Particularly its capability for compensating harmonics in the current waveforms is an essential feature. Due to the replacing of the generator side converter by a simple diode rectifier, harmonics with variable frequencies into dependence of the generator frequency appear in the current waveforms. To reach the IEEE standard for the total harmonic distortion (THD) a frequency adaptive PR-controller for compensating these harmonics is required.
62.
F. Senicar, M. Döpker, A. Bartsch, B. Krüger and S. Soter, "Inverter based method for measurement of PMSM machine parameters based on the elimination of power stage characteristics" in IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society, 2014, pp. 702--708.

Abstract:
This paper presents the precise measurement of the stator inductance as well as the stator resistance, using an inverter. Precise measurement results are created, although the actual output voltage of the inverter is not known exactly. This paper analyzes the different effects of an output power stage, and how they degrade the quality of the output voltage. This knowledge is used to cancel out this output voltage error in enabling a precise measurement of the machine parameters. This allows an easy auto commissioning of the current controller and furthermore an auto commissioning of an optimal torque control. The presented methods are verified with extensive measurement results.
61.
A. Bartsch, K. Klitzke, F. Senicar and S. Soter, "Optimized design of a scalable FPGA based inverter by implementing an application-specific instruction-set processor" in IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society, 2014, pp. 1672--1678.

Abstract:
This paper presents an improvement of a field programmable gate array (FPGA) based scalable inverter drive to control electrical machines. In order to enhance the average utilization of the resources (logic cells and dedicated hardware) of the FPGA, an application-specific instruction-set processor (ASIP) is designed and implemented on the FPGA. To promote better organization of the source code, it is possible to write instructions in a MATLAB based syntax, which are translated into the instruction set for the ASIP.
60.
A. Uphues, K. Nötzold, R. Wegener, K. Fink, M. Bragard, R. Griessel and S. Soter, "Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter" in 2013 15th European Conference on Power Electronics and Applications (EPE), 2013, pp. 1--5.

Abstract:
With increased wind power penetration, grid codes of system operators require low voltage ride through (LVRT) capability for wind turbines (WT). This paper describes a full power test bench, designed to evaluate the functionality of grid connected converter in nominal operating mode and in case of LVRT. To verify the LVRT capability an inverter based voltage sag generator (VSG) is developed which emulates grid failures.
59.
A. Uphues, K. Nötzold, R. Wegener, S. Soter and R. Griessel, "Support of grid voltages with asymmetrical reactive currents in case of grid errors" in 2013 IEEE International Conference on Industrial Technology (ICIT), 2013, pp. 1781--1786.

Abstract:
Due to the increasing wind power penetration, grid codes of system operators require low voltage ride through (LVRT) capability for wind turbines (WT). Additionally the WT has to support the power system stability in LVRT cases by supporting the grid with reactive power. By feeding symmetrical reactive currents in case of asymmetrical grid errors, as required in many actual grid codes, the phase voltage of the undistorted phase will increase above the upper voltage limit. This paper shows a strategy to feed asymmetrical reactive currents into the distorted grid without increasing the phase voltage in the undistorted phase.
58.
A. Uphues, K. Nötzold, R. Wegener and S. Soter, "SOGI based grid fault detection for feeding asymmetrical reactive currents to fulfill LVRT requirements" in 2013 IEEE AFRICON, 2013, pp. 1--5.

Abstract:
Due to the increasing wind power penetration, grid codes of system operators require low voltage ride through (LVRT) capability for wind turbines (WT). Additionally the WT has to support the power system stability in LVRT cases by supporting the grid with reactive power. The amount of reactive power feed-in depends on the type of grid fault and the depth of the voltage dip. Therefore this paper shows a reliable grid voltage monitoring consisting on a second order generalized integrator (SOGI) structure. The resulting phase locked loop (PLL) is tolerant against grid faults and the amplitudes and phase angles of the individual phase voltages are detected.

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