Dr.-Ing. Ralf Wegener
Contact:
Rainer-Gruenter-Str. 21
42119 Wuppertal
Room: FH.01.01
ralf.wegener[at]uni-wuppertal.de
+49 202 439 1462
Personal career
High school diploma 1996
Studies of electrical engineering at the University of Dortmund from 1997 to 2002
Scientific employee at the University of Dortmund from August 2002 to July 2008
From August 2008 scientific employee at the University of Wuppertal
Since 2012 academic councilor at the University of Wuppertal
Since 2015 Akademischer Oberrat at the University of Wuppertal
Lectures
Publications
- 18.C. Junge, T. Ruhland, S. Gruber, R. Wegener and S. Soter, "Controlled input-output-shaft synchronisation by a linear drive actuated hydraulic clutch-brake-combination" in 2011 IEEE AFRICON, 2011, pp. 1--5.
Abstract:
The focus of this paper is the control to accelerate and decelerate a drive shaft exactly with a hydraulic clutch-brake-combination (CBC). The CBC is actuated by a permanent magnet linear synchronous machine (PMLSM) with an integrated hydraulic cylinder. The servo-converter-controlled-PMLSM is able to generate the pressure for the CBC. A superposed control cascade with a pressure control and a special synchronization control is implemented to vary the transmitted torque and therefore the accurate acceleration and deceleration of the drive shaft within a preset angle. This development ensures a controlled synchronization of the input-output shaft by a CBC in a specific point of time within a preset mechanical angle. - 17.S. Gruber, C. Junge, R. Wegener and S. Soter, "Overview of a special Developed Linear Drive Concept with integrated Hydraulic Cylinder für Clutch-Brake-Combinations in Eccentric Presses" in Proceedings / LDIA 2011, the Eighth Symposium on Linear Drives for Industry Applications, July 3 - 6, 2011, Eindhoven, The Netherlands, Eindhoven: {TU Eindhoven}, 2011.
ISBN: 978-90-386-2524-9
- 16.K. Nötzold, A. Uphues, R. Wegener and S. Soter, "Highly integrated inverter with multiturn encoder and software-based PFC for low cost applications" in 2010 IEEE International Conference on Industrial Technology, 2010, pp. 764--768.
Abstract:
Motor control gets more and more common in fields where it was not applicable a few years ago. The prizes for computing power due to higher integration of the power electronics are going down. Because of this, brush-less DC and permanent magnet synchronous machines capture new markets and replace simple grid connected induction machines. The rising standards for electromagnetic interference (EMI) emissions make a power factor correction (PFC) in a lot of applications necessary. In addition a PFC offers some advantages because of the DC bus regulation. In this paper an inverter with a particularly low prize and a high performance is presented. A software based PFC is integrated into the motor control circuit and a low cost absolute position encoder has been developed. In addition some synergetic effect between motor control and PFC will be shown. The experimental results show the feasibility of the integration of a field orientated control with an integrated PFC in one low cost microcontroller. - 15.S. Gruber, C. Junge, R. Wegener and S. Soter, "Reduction of detent force caused by the end effect of a high thrust tubular PMLSM using a genetic algorithm and FEM" in IECON 2010 - 36th Annual Conference of the IEEE Industrial Electronics Society, 2010, pp. 968--973.
ISBN: 1553-572X
Abstract:
In order to meet industrial safety standards in eccentric presses, the detent force of the acting high force tubular permanent magnet linear synchronous machines (PMLSM) should be reduced. The detent force is caused by two components: the slot effect and the end effect. Both effects are based on the reluctance change between permanent magnet (PM) and stator teeth. The slot effect is already optimized by the closing slot technique which is proven by measurements presented in this paper. The main topic is the reduction of detent force by using auxiliary poles at the end of the machine. Therefore a special genetic algorithm (GA) is developed which rates the simulation results of the FEM and produces new auxiliary poles. The combined simulation tries to find an optimal size and position for auxiliary poles to reduce the whole detent force. The numerical calculations propose a minimized detent force caused by the located poles, which is independent from the length of the machines (2, 3 or 5 modules). - 14.C. Junge, J. Gallep, R. Wegener and S. Soter, "Simulation and verification of an eccentric press system actuated by hyraulic-clutch-brake-combination controlled by a linear drive" in 2010 IEEE Region 8 International Conference on Computational Technologies in Electrical and Electronics Engineering (SIBIRCON), 2010, pp. 800--805.
Abstract:
This paper deals with a Matlab/Simulink-Simulation of an eccentric press with an hydraulic Clutch-Brake-Combination (CBC) and the verification on a standard moulding press. The outstanding characteristic of this system is the special control of the CBC. A servo converter controlled linear drive with an integrated hydraulic cylinder generates the pressure for the CBC. A developed pressure control is able to control the torque of the CBC and therefore the acceleration and deceleration of the powertrain. The simulation has been made to predict the behavior of the controlled CBC in an eccentric press. The simulation results are finally compared with the measurements at the real system. - 13.A. Bartsch, S. Gruber, R. Wegener and S. Soter, "Testbench for electrical drive systems in hybrid applications" in 2010 IEEE International Conference on Industrial Technology, 2010, pp. 1136--1140.
Abstract:
This paper deals with the development of a test bench for mild hybrid drives used in construction machines. Due to the special conditions under which construction machines are operating this test bench needs to be adapted. Hence the bearing of the electrical drive, which is mounted directly to the internal combustion engine, the temperature control by a cooling circuit and the integration of an appropriate inverter as well as an electrical drive to complete the system are defining the specific requirements of the test bench. These circumstances also affect the measurements and have to be considered during the evaluation of the results. - 12.R. Wegener, S. Gruber and S. Soter, "Development of a low cost embedded diagnosis system for servo controlled drives including data mining technologies" in 2009 IEEE 18th International Symposium on Industrial Electronics (ISIE), 2009, pp. 373--377.
Abstract:
This paper deals with an embedded diagnosis device which improves the reliability of a machine including servo controlled drives by monitoring the system parameters and detecting abnormalities and creeping changes. The detection algorithm is based on data mining technologies, well known in business administration. The presented system consists of a low cost processor board with an SD-card slot for data storage and a field bus connection and is completely independent of the main machine control. The additional benefits are online monitoring possibilities and the storage of the process variables in a high efficient way during the complete lifetime of the machine. - 11.C. Junge, F. Senicar, R. Wegener and S. Soter, "Pressure control of a nonlinear system with a linear-PMSM and a standard inverter" in 2009 IEEE International Electric Machines and Drives Conference, 2009, pp. 83--88.
Abstract:
This paper deals with a high dynamic hydraulic pressure control. The pressure is generated by an inverter driven linear drive which applies a force on a hydraulic cylinder. The linear drive has to generate a pressure profile into the hydraulic system and has to keep it at a constant value after reaching the demanded pressure. The controlled system, containing hydraulic oil, dissolved air and overall three spring packs, is showing a highly non-linear characteristic. The control cascade of the inverter is based on a standard position control loop, which is enhanced by a PI based pressure controller, a dynamically adapted position feed-forward and an active anti-windup of the controller in order to provide optimal control behavior of the nonlinear system. - 10.R. Wegener, S. Gruber, K. Nötzold and S. Soter, "Optimization of a Low-Cost Position Sensor for a Permanent Magnet Linear Drive" in PCIM Asia 2008, 2008.
- 9.R. Wegener, S. Gruber, K. Nötzold, F. Senicar, C. Junge and S. Soter, "Development and Test of a High Force Tubular Linear Drive Concept with Discrete Wound Coils for Industrial Applications" in 2008 IEEE Industry Applications Society Annual Meeting, 2008, pp. 1--5.
ISBN: 0197-2618
Abstract:
This paper deals with the development of a tubular permanent magnet linear drive with radial magnetized armature and discrete wound coils mounted on a star-shaped stator part. The rated force of the developed machine is 500 N per segment. This presented particular design results in a very economic product because all primary parts, except of the permanent magnets and coils, are made of standard non-laminated steel and are optimized for easy production and assembly. The control of this machine with a specially built low cost linear sensor based on the Hall-effect is also presented. The suitability of the design is proven by the demonstration of a prototype with measurements of thrust and cogging force.