Robust Development of Active Learning-based Surrogates for Induction Motor

A robust open-source cloud-based workflow is developed for finite element (FE) data generation for active learning (AL)-based surrogate modeling. Special attention is paid to making the FE solution procedure as robust and fast as possible without human intervention by, e.g., implementing special convergence criteria, reliable parallel computation, and variable timestep length. In AL, a surrogate model automatically improves itself by iteratively querying more FE data. Using AL and large datasets generated with parallelized cloud FE simulations, we develop a surrogate model to rapidly predict induction machine steady-state torque, torque ripple, total losses, and current harmonic distortion, as a function of motor frequency, voltage, and slip. Results show that AL performs better than grid sampling and on average works as well as random sampling, but with some outputs, the results vary less with AL. In addition, accurate ripple estimation requires a much larger training dataset than the other variables.</p

Comparative study of inner and outer rotor bearingless synchronous reluctance motors

In this study, the authors presented a systematic design procedure of outer rotor bearingless synchronous reluctance motor (SynRM). The proposed motor is compared with an already prototyped inner rotor bearingless SynRM at different operation points. It has been shown that a properly designed outer rotor SynRM can produce higher levitation forces than the inner rotor counterpart. The inner rotor motor produces higher torque and eccentric forces than the outer rotor motor.Peer reviewe

The emission reduction potential of electric transport modes in Finland

The transportation sector has become the fastest growing source of greenhouse gas (GHG) emissions. One solution to mitigate the impacts is a shift towards electric modes. Where previous studies have only focused on the replacement of individual modes, our study presents a more holistic approach by comparing land-based, water-based and airborne transportation modes. We study the GHG emission reduction potentials of electric cars, buses, trains, ferries and aircraft in comparison to existing modes on 34 routes within Finland and across the Baltic Sea to Sweden and Estonia. By comparing the GHG emissions in carbon dioxide equivalents (CO2-eq) per passenger kilometer for each mode, we also consider the emissions generated from battery production as well as the differences in the energy mix from electricity production of the three studied countries. In addition to CO2-eq emissions per passenger kilometer, we also take real door-to-door travel times into account. Our study found that electric transportation modes possess great potential for emissions reduction. Nevertheless, depending on the energy mix used for electricity production, the emissions of electric transportation modes can exceed those of existing modes significantly. In addition, the emissions generated by battery production can have a significant share of the total emissions and should therefore always be considered. Finally, while also taking into account the door-to-door travel times, our study the great potential of electric aircraft to provide a less carbon intensive transportation option paired with short travel times starting on routes beyond 300 km where no high-speed rail exists as well as on routes across the water.peerReviewe

Future trends of hybrid and electric powertrains in nonroad mobile machinery

This paper examines the future trends of hybrid and electric powertrains in non-road mobile machinery (NRMM) with the focus on the challenges and opportunities related to the electrification of NRMM. The underlying trends and drivers, such as regulations, policies and market development, are analysed in order to draw conclusions about possible future scenarios. Required technology enablers and foreseen challenges are identified based on a state-of-the-art review of electrical components and systems. Future scenarios are developed based on the technological development of key components, scientific literature and the status of the non-road mobile machinery industry. These scenarios are divided into two time horizons: short to medium term and long-term periods. The key results are summarised in the form of actions required for the successful electrification of non-road mobile machinery. Some recommendations are also given in relation to the development of the technology and NRMM markets.Peer reviewe

Overview of Powertrain Electrification and Future Scenarios for Non-Road Mobile Machinery

Powertrain electrification continues to be a growing trend in vehicular applications. Electric powertrains have numerous advantages over traditional mechanical and hydraulic powertrains but there are still important challenges to overcome for long-term commercial success. This research presents a technological assessment of present and future developments of powertrain electrification in non-road mobile machinery (NRMM). The challenges and opportunities of NRMM electrification are described in detail. The trends and drivers related to technological development such as regulations, policies and market development are analyzed, and technology enablers are highlighted. Future scenarios are formulated based on the prevailing trends and drivers, development of key components, scientific literature and status of the non-road mobile machinery industry. Some recommendations are also given in relation to the development of hybrid and electric powertrains for NRMM. The key findings of this research indicate that the electrification of NRMM is slowly started and the progress is demonstrated by hybridization of some specific, successful mobile machines. In short-term, high component and technology development costs remain the main barrier for higher adoption of electric and hybrid powertrains. In the long-term scenario, many NRMM can operate autonomously and powertrain electrification has become mainstream technology.Peer reviewe