Joachim Böcker

Learn More
A test track of 530 m length for linear motor driven railway vehicles in scale of 1:2.5 was built at the University of Paderborn in 2002. A doubly-fed long stator linear motor does not only drive the vehicles, but offers the opportunity of a contactless energy transmission into the vehicle's on-board supply system, too. In this pape, the motion control(More)
—A problem encountered with electrically driven vehicles are resonances in the drive train caused by elasticity and gear play. Disadvantageous effects caused by this are noticeable vibrations and high mechanical stresses due to torque oscillations. The oscillations can be damped using a control structure consisting of a nonlinear observer to estimate the(More)
—The switching frequency of an inverter under direct torque control is mainly decided by the flux-and torque-controller output switching counts. It is known that, with fixed hysteresis bands, the switching frequency varies as the operating point changes. It is possible, however, to keep the switching frequency constant by the adaptation of hysteresis bands.(More)
We present a new concept for online multiobjective optimization which has been applied to a real–world application, that is the optimization of the assignment of an operating point to a doubly fed linear motor. This problem leads to a time–dependent multiobjective optimization problem. In contrast to classical optimization where the aim is to find the(More)
— This paper presents a 1MW, 12-pulse thyristor rectifier with passive filter and DSTATCOM for low voltage, high current industrial dc loads. The considered process act (electrically) as a current controlled, variable voltage load. Moreover the load characteristic varies extensively with number of hours of operation. Variable compensation capabilities are(More)
An energy supply system based on a hybrid energy storage unit combined of batteries and ultracapacitors for a railway vehicle is studied. In order to optimize the energy supply system architecture and to manage the energy distribution the power electronic converters connecting ultracapacitors, batteries and the DC-link are investigated together with control(More)
— 1 A linear switched reluctance drive with large airgap was developed and manufactured for a test track of autonomous railway vehicles (RailCab). Control structure and current shaping algorithms are presented providing smooth transitions between the motoring and dynamic braking operation modes at low switching losses. In both modes low force and torque(More)
— Field-oriented control has become state-of-the-art in AC drives. Nevertheless it is undisputed that other control approaches like the direct torque control can outperform the field-oriented control in some operating conditions, e.g. in terms of torque dynamics or voltage utilization in the flux weakening region. Therefore, this paper's purpose is to(More)
Subject of this contribution is a novel PWM controlled inverter of the kW power range, feeding a multi- mass ultrasonic motor (MM-USM) via a LLCC-type filter. The system is designed in a way to reduce the total harmonic distortion of the motor voltage and to locally compensate for the reactive power of the motor. Operating a three- level inverter with PWM(More)