The paper deals with an approach to reduce the detent force of double-sided flat linear permanent magnet synchronous machines (PMSMs). The study is initiated by a finite element analysis (FEA)-based investigation of the detent and normal forces of a conventional concept with aligned PM rows mounted on both mover sides. It is found that while it exhibits a quasi-null normal force, the concept is penalized by a huge detent force. An attempt to reduce such a drawback consisting in shifting the PM rows is proposed. Its effectiveness in reducing the detent force is demonstrated by FEA. However, it leads to a remarkable increase of the normal force. In order to minimize this latter, a second design approach consisting in a unilateral extension of both sides of the stator magnetic circuit, is proposed. It is shown that selecting 50% for both PM shift-to-the pole pitch and stator extension length facing the air gap-to-the pole pitch ratios yields acceptable peak-to-peak values of the detent and normal forces. The force production of the resulting machine is then evaluated and compared to the conventional concept one. In spite of the minimization of the force ripple, its mean value is limited to 50%. An approach consisting in a reconfiguration based on the star of slots of the armature in both stator sides, is proposed and assessed by FEA. As a result, an increase of the mean force as well as a reduction of the force ripple are gained.
This paper presents a novel approach towards modelling energy usage of a high-performance, motorsport-purposed electric motorcycle (eBike) under racing use conditions. While the energy usage is assessed, the simulation robustness is also considered as it will confirm that the chosen modelling approach has a high degree of versatility. The presented research work showcases the presented modelling approach applied as a software model, indicates the chosen methodology for acquiring the required telemetry data and finally presents the results and related conclusions and interpretations and their meaning to the field of expertise and the related project.
A common approach to enhance the overall efficiency of an electric driven vehicle is to use a double motor concept. In the hereby presented research project TIOM (Two In One Motor) two different electric motors are used for traction, the compressor of the air conditioning (AC) system and the air compressor for the pneumatic systems in a public bus used in urban and suburban traffic. The main research questions in the following paper are first how the TIOM concept can be adapted to urban busses and second if the developed operation strategy leads to higher efficiencies. For this purpose a use case was defined and modelled with Dymola. A typical driving cycle was defined as use scenario. The model contains an operation strategy that can select between 16 different operation modes for the two motors based on the efficiencies of the motors, the torque requirements, the rotation speed of the wheel and the rotation speed range of the compressors. As a result, the energy consumption for the use case is evaluated and compared to a bus with a conventional motor concept with one large motor.
The permanent magnet linear machines with primary excitation (PE-PMLM) is a special type of linear machine derived from traditional permanent magnet linear machines, which has the advantages of high thrust force density, high efficiency, high precision and high reliability. In the field of long-stroke direct-drive linear motion, PE-PMLM exhibits its unique performance and cost advantages. This paper reviews and summarizes the research status and development trend of the PE-PMLM. First, the thrust force generation mechanism of the PE-PMLM is revealed based on the flux modulation theory. Second, the technical points and research progress of various kinds of PE-PMLM are reviewed. Third, comprehensive performances of all kinds of PE-PMLM are compared and analysed. Finally, the future development trend is discussed.
A Power Take-Off (PTO) is responsible to convert wave to electrical power and is one of the core sub-systems of any Wave Energy Converter (WEC). As result, assessing the PTO performance is one of the key aspects of the WEC design and, looking at the optimization of all WEC subsystems, it directly impacts the LCOE assessment and the commercialization of the technology. To address this need, it is crucial to approach WEC modeling with the awareness of the different techniques. The paper presents part of the results of the IMAGINE R&D program developed with the support of European Union's H2020 research and innovation programme. This project is aimed at the design and test of a novel PTO drive intended for a range of WEC configurations. In particular, the paper presents a complete simulation platform, which allows realistic simulations of the performance of a 250 kW modular electro-mechanical generator (EMG) when coupled to an oscillating wave surge converter (OWSC) device. This model is compared to a corresponding simplified model more suitable for real-time (RT) hardware-in-the-loop (HIL) testing. A comparison between the two is provided as fundamental check to guarantee that the simulated environment is as similar as possible to the real-space and hence to validate the product maturity even though with a certain level of simplification.
