Frank Rinderknecht

Design of future concepts and variants of The Free Piston Linear Generator

The Free Piston Linear Generator (FPLG) is capable of transforming chemical stored energy into electric energy by means of an internal combustion process. As explained in [6], it achieves high degrees of efficiency at full and particularly at part load. Besides a wide area of applications, the FPLG especially meets the requirements of vehicles with range extenders or serial hybrid drives. Hence, this publication deals with the explanation of different package concepts of the FPLG for the use in electric vehicles with a generating unit. For this purpose, two different FPLG modules for future production cars are designed and the package for different combinations are illustrated in a vehicle model. This comparison presents an outlook for possible vehicle concepts of the future.

Comparison of range extender technologies for battery electric vehicles

The aim of this publication is a comparison of a wide selection of range extender technologies. Thereby a large amount of criteria are looked into. This assures that the comparison is feasible for a diversity of performance specifications. Hence an information level is achieved, that allows for a justified choice of technology according to the desired range extended electric vehicle concept.

Calculation of a linear generator for a hybrid vehicle concept

This publication deals with the design calculation of a linear generator intended for use in a hybrid power train design for a vehicle. The system surrounding the linear generator and some parameters have an influence on the linear generator. They will be explained to achieve a fundamental understanding of the requirements and the resulting topology selection. Then, the analytical and numerical calculations are presented. Furthermore, the question if the forces from a linear generator can be calculated either analytically or numerically will be discussed. From this, there results a presentation and analysis of the differences in the forces calculated. The calculated values are compared with the values measured on a prototype to permit an assessment of the quality of the calculations.

Preliminary investigations of an inductive power transfer system for the rotor power supply of an electric traction drive

The paper is devoted to the substitution of slip rings through an inductive power transfer system (IPT) for field winding supply in wound rotor traction drives. By an inductively coupled rotational transformer, the rotor-side energizing of the excitation windings can be provided isolated and free of wear. For preliminary investigations, an analytical model of the inductive link and the compensation network has been set up. Based on this, possible types of compensation networks regarding an optimal integration into an electric traction drive were carried out and compared among themselves by parameter studies. Using an experimental prototype system and on the basis of accompanying FEM calculations, the analytical model has been validated and the system tested both stationary and transient.

Integrating Phase-Change Materials into Automotive Thermoelectric Generators

Because the heat emitted by conventional combustion-engine vehicles during operation has highly transient properties, automotive thermoelectric generators (TEG) are intended for a particular operating state (design point). This, however, leads to two problems. First, whenever the combustion engine runs at low load, the maximum operating temperature cannot be properly utilised; second, a combustion engine at high load requires partial diversion of exhaust gas away from the TEG to protect the thermoelectric modules. An attractive means of stabilising dynamic exhaust behaviour (thereby keeping the TEG operating status at the design point for as long as possible) is use of latent heat storage, also known as phase-change materials (PCM). By positioning PCM between module and exhaust heat conduit, and choosing a material with a phase-change temperature matching the module’s optimum operating temperature, it can be used as heat storage. This paper presents results obtained during examination of the effect of integration of latent heat storage on the potential of automotive TEG to convert exhaust heat. The research resulted in the development of a concept based on the initial integration idea, followed by proof of concept by use of a specially created prototype. In addition, the potential amount of energy obtained by use of a PCM-equipped TEG was calculated. The simulations indicated a significant increase in electrical energy was obtained in the selected test cycle.

Innovation examples for ecological vehicles based on aerospace research

In this paper innovative technologies from the aerospace research are presented, which are usable for a successful electric mobility of the future. They represent a selection of the German aerospace center research projects, where synergies between space and aviation applications as well as between rail and road traffic applications are used. The work relates to the fields of vehicle-energy concepts, alternative energy converters and lightweight design. Within the individual development projects hardware demonstrators were created and are shown here.

Highly integrated electric drives for automotive application

Aerospace development needs an optimum in weight and volume reduction. In addition there is a high research potential on vehicle energy concepts and alternative energy converters by using synergies from aerospace research [1]. The understanding of the system behavior leads to the development of several concepts of electric drives which combine more than one function in a single technical component. The paper describes three examples of highly integrated electric drive concepts which can be used in next generation cars. The concepts are partly based on international cooperation and also on individual investigation work.

Free-piston linear generator and the development of a solid lubrication system

The free piston linear generator is a new electromechanical generator. It converts chemical energy into electrical energy by means of a combustion process, a linear generator and a gas spring. Thereby the technology aims to have better properties than other electromechanical generators. Therefore this publication deals with the explanation of the concept, the characteristics of a free piston linear generator and one of the challenges in the development. In order to use a port scavenging the emission issue is the challenge and has to be solved. One possible solution is the use of solid lubricants to substitute motor oil. The development methodology and one aspect of the development will be explained.

Free-Piston Linear Generator and the Development of a Solid Lubrication System

The free piston linear generator is a new electromechanical generator. It converts chemical energy into electrical energy by means of a combustion process, a linear generator and a gas spring. Thereby the technology aims to have better properties than other electromechanical generators. Therefore this publication deals with the explanation of the concept, the characteristics of a free piston linear generator and one of the challenges in the development. In order to use a port scavenging the emission issue is the challenge and has to be solved. One possible solution is the use of solid lubricants to substitute motor oil. The development methodology and one aspect of the development will be explained.

Simplified model of eddy current brakes and its use for optimization

The electrification of vehicles makes it possible to think about new concepts to substitute conventional technologies. For example in an electrical drive train, with a traction motor for each wheel mechanical friction brakes can be replaced by eddy current brakes. In this work a method for optimizing the torque density of eddy current brakes is presented. For a fast optimization process the model of the eddy current brake is split up in two levels of detail. In the first level a global model including a simplified eddy current model and a lumped parameter magnetic circuit to calculate the primary magnetic flux will be described. The second level includes a detailed eddy current model and will be described in further works. The simplified eddy current model include fitting parameters which allow to fit the torque curves to the ones of the detailed eddy current model. As a result, the method allows to optimize the entire system represented by the global model in a very fast way. The development of the global model, its verification and the method for optimizing the entire system represented by the global model is shown.