Markus Henke

Mechatronic design of a modular railway carriage

The mechatronic design methodology allows to efficiently design highly complex technical systems. The modular railway system presented here is driven by a linear drive, with an active suspension/tilt system being employed to enhance ride comfort. The two modules, along with their mechanics, sensors, actuators and digital signal processing, make up intelligent mechatronic function modules. They are part of an autonomous mechatronic system, the railway vehicle.

Pitch analysis and control design for the linear motor of a railway carriage

At the University of Paderborn a mechatronic railway system (NBP-Neue Bahntechnik Paderborn) is designed and developed, which is guided by ordinary wheels and rails and is driven via a doubly fed linear motor. The concept is based on the operation of small shuttle units. The drive modules are designed as single axle units. As a result of thrust and normal forces the secondaries can pitch up and down because of the rising torque around the axle. So the pitching angle of the secondary remains in an unstable state. Each of them includes two independently fed secondaries, one axle and the respective primary element. This motion should be controlled to ensure a constant airgap between primaries and secondaries. In this paper the modelling of the system and a method for pitch control with state feedback and output integration for flexible mounted linear drives is described. A Kalman filter is used for estimation of the state variables. Finally the simulation and experimental results of pitch control for two secondaries are presented.

Modelling and Control of a Longstator-Linearmotor for a Mechatronic Railway Carriage

Abstract This contribution presents a linear drive module as mechatronic actuator for a new railway carriage. Here, according to the mechatronic methods, a double-fed longstator- linearmotor will be chosen and the control structure will be designed by means of modelling. The next steps in mechatronic design procedures are simulation and experimental validation. The presented motor propells a mechatronic railway carriage, which is also fitted with active suspension/tilting and steering modules.

A free-piston PM linear generator in vernier topology using quasi-Halbach-excitation

This paper deals with the investigation of a linear generator used in an internal combustion engine. The introduction reviews the state of the art of free-piston linear generators. Then, the mechanical structure of this generator is presented. The main part treats a finite-element-analysis (FEA) of the generator comparing different armature magnetizations with the numeric simulation program FLUX. A cylindrical design with radial, axial and a quasi-Halbach magnetization in Vernier topology is examined. The number of pole-pairs in a Vernier machine differs by one from stator teeth in principle. This paper is focusing on a Vernier machine with five armature pole-pairs coinciding within six stator teeth (Vernier 5/6). Several geometric parameters, like height of the magnets, slot pitch ratio or length of the magnets are varied in order to find the optimal design with regard to a high thrust force and low force ripple. The paper concludes with the determination of losses and electrical efficiency.

Design of a Railway Carriage, Driven by a Linear Motor with Active Suspension/Tilt Module

Abstract This paper presents the design of a railway carriage whose drive is realized by a linear motor. An integrated suspension/tilt module makes possible increased ride comfort and cornering speed in comparison to existing systems.

A new analytical approach to determine slotting based eddy current losses in permanent magnets of PMSM taking into account axial and circumferential segmentation

Purpose – The purpose of this paper is to calculate slotting-based eddy currents in permanent magnet excited synchronous machine (PMSM) taking into account axial and circumferential segmentation of magnets. Design/methodology/approach – An analytical approach to calculate eddy current losses in PM caused by slotting harmonics of PMSM is presented. The eddy current reaction field is taken into account as well as axial and circumferential segmentation of the magnets. Findings – The analytical model provides results comparable to 3D-FEM calculations even at high frequencies at reduced computation costs. To generalize the results the magnetic Reynold’s number is introduced. Originality/value – Taking into account the axial and circumferential segmentation in the PDE; the approach is much more accurate compared to known approaches; accuracy is comparable to 3D-FEA.

Design process and topology comparison for a high performance PM-machine for sustainable traction drive technology

In this paper a design process for an electric machine is presented. With the focus on PM-machines with tooth-coil windings a new design methology is explained to identify the most interesting windings for a certain application. By adapting a special methodology multiple winding configurations are found. This process is applied to the design of a main drive for an electric vehicle. Different winding topologies are identified and compared. Especially a six-phase topology is introduced and analysed. The strengths and weaknesses of the investigated designs are explained and discussed.

Control of the NBP linear drive system

Abstract The control of the linear motor of the NBP railway carriage is presented in this paper. The doubly fed long-stator linear motor is designed by means of modelling, according to mechatronic methods. Next steps in mechatronic design procedures are simulation, analysis and experimental validation. The presented motor propels a mechatronic railway carriage, which is also fitted with active suspension/tilt and support/guidance modules.

Topology comparison of ferrite magnet synchronous machines with consideration of low inertia

In order to replace rare-earth magnets five different machine topologies are considered, designed and studied in detail. With a synchronous reluctance machine (SRM) a machine without magnets is included in this comparison. The improvement by the insertion of cheap ferrite magnets in a SRM is studied by designing two different types of a permanent magnet assisted synchronous reluctance machine (PMASRM). With this approach torque density and power factor can be significantly increased. As an alternative a spoke-type PMSM with ferrite magnets and a Vernier machine containing a Halbach ferrite cylinder are designed and studied. Despite all optimizations and improvements in design, electrical machines without rare earth magnets lead to greater weight and ultimately to a greater moment of inertia. Therefore the reduction of the moment of inertia is also considered in this comparison.

Novel highly integrated current measurement method for drive inverters

Measuring the load current of drive inverters is still inevitable for a precise current control. In common industrial and automotive inverters hall effect based current sensors are widely used. [1] The presented novel current measurement method is based on an inductive current sensor like a Rogowski coil. This can be fabricated much smaller and cheaper than hall based current sensors and can be integrated into drive inverter systems easily. Unlike using the standard evaluation electronic for Rogowski coils, AC and DC components of the load current can be measured using a special evaluation scheme. The arrangement of the sensors also allows them to be used for fast short-circuit detection and di/dt measurement, so that some synergies with the gate drive circuitry can be used to create a more compact and reliable system.