Refine
Document Type
Language
- English (13)
Has Fulltext
- no (13)
Reviewed
- Begutachtet/Reviewed (11)
Keywords
- Air conditioning;Electric potential;Biological system modeling;Production;Automobiles;Next generation networking;Engines (1)
- DC power supply ; Design ; Converter circuit ; Measurement ; Power Supply (1)
- DC/DC converter ; efficiency ; tapped transformer ; wide input voltage range (1)
- IPM (1)
- Model predictive control, FCS-MPC, VSP2CC, VV-MPC, multi-phase, PMS (1)
- Multi-phase machines (1)
- PLCopen (1)
- PMSM (1)
- V-PMSM (1)
- asymmetric rotor geometry (1)
Institute
- Fakultät für Elektrotechnik Feinwerktechnik Informationstechnik (10)
- Institut für leistungselektronische Systeme ELSYS (8)
- Fakultät Maschinenbau und Versorgungstechnik (2)
- Fakultät Angewandte Mathematik, Physik und Allgemeinwissenschaften (1)
- Lehr- und Kompetenzentwicklung (1)
- Nuremberg Campus of Technology (1)
Development of a Two In One Motor System as a new Vehicle Energy Concept for Next Generation Car
(2020)
Design of a Wide Input Voltage Range Current-Fed DC/DC Converter Within a Reduced Duty-Cycle Range
(2020)
A design of a current-fed push-pull converter for wide input voltage ranges within a reduced duty-cycle range is presented. Based on the converter conversion ratios of three different clamping configurations, the potential of the input clamping is shown analytical, simulative and by measurements. A differentiation is made between the four possible operating modes, which can be distinguished in the control of the semiconductors and the magnetomotive force in the reactor. By optimizing the turn ratios of both transformers, the wide input voltage range capability of the input clamped current-fed push-pull converter was improved, which has been proved by measurements on a real prototype.
Control of multi-phase machines is a challenging topic due to the high number of controlled variables. Conventional control methods, such as field-oriented control (FOC), address this issue by introducing more control loops. This, however, increases the controller design complexity, while the tuning process can become cumbersome. To tackle the above, this paper proposes a deep deterministic policy gradient algorithm based controller that fulfills all the control objectives in one computational stage. More specifically, the proposed approach aims to learn a suitable current control policy for six-phase permanent magnet synchronous machines to simplify the commissioning of the drive system. In doing so, physical limitations of the drive system can be accounted for, while the compensation of imbalances between the two three-phase subsystems is rendered possible. After validating the training results in a controller-in-the-loop environment, test bench measurements are provided to demonstrate the effectiveness of the proposed controller. As shown, favorable steady-state and dynamic performance is achieved that is comparable to that of FOC. Therefore, as indicated by the presented results, reinforcement learning-based control approaches for multi-phase machines is a promising research area.
In laboratory practicals (labs), students actively investigate technical and scientific phenomena and thus experience autonomy, competence, and social embedding, factors that promote motivation. However, labs mostly rely on highly structured and instructive concepts and often require costly equipment. Therefore, the research question in this paper is: How can learner-centered teaching methods and learning formats be improved by rethinking the digitization of lab practicals?
Depending on the application range, there are various recommendations in the literature which converter topology should be used. These are mostly based on experience or more or less deeper considerations. For DC/DC converters, which are operated over a wide input voltage range, such recommendations rarely exist. Therefore, this contribution shows the evolution of two input voltage dependent selection matrices, which should facilitate the selection of future topologies based on known publications and basic considerations. The focus here lies on converters for λ = V i_max /V i_min ≥ 3 with galvanic isolation. First, the data set is introduced, where a distinction is made between flyback converters, forward converters and other 1stage or 2stage converters before the evolution of the novel input voltage dependent matrices is carried out. These two matrices support the selection of a suitable topology and whether the energy transfer should be done by one or two stages.
The concept of the digital twin (DT), which accompanies a plant or machine throughout its entire life cycle, has further reinforced the role of Virtual Commissioning (VC). Of decisive importance for the economically and technically sensible use of the DT is its creation as early as possible in the life cycle. In the field of mechanical engineering, therefore, the first digital artifacts of the DT should ideally already be created in parallel with the mechanical design phase. The first step is the kinematization of the CAD model. This paper presents a new method for the semi-automated kinematization of 3D CAD models. The method uses a verbal description of the motion sequence desired by the designer, based on DIN EN 60848 (GRAFCET) [2] and using elements from VDI Guideline 2860 (handling functions) [8]. The presented method is easy to use and self-describing to a large extent. It enables designers to define in their own domain, in parallel to their mechanical designs, the desired motion sequence of the machine they have designed in machine-readable form. The actual kinematization of the CAD model is performed automatically. At the end, the kinematized design is available in COLLADA format and can be imported via the import interfaces of common simulation tools and can therefore be used for the DT.
Because of the absence of rare earth magnets, the reluctance synchronous machine has a more favourable sustainability balance compared to the permanent magnet synchronous machine with NdFeB magnets. Additional advantages include the absence of copper in the rotor and the ease of manufacture of the non modified rotor. A clear disadvantage of the reluctance synchronous machine is the relatively high torque ripple if no measures such as skewing are taken. Therefore, the machine is mainly used in applications such as fans where the torque ripple is not critical for the operation. The paper makes a contribution to addressing the problem of torque pulsation. For the reduction of torque harmonics, the usage of various rotor designs as well as asymmetric rotor geometry are presented. In addition, the aspect of torque harmonics, which is predicted by the finite element analysis is discussed and possibilities of torque ripple reduction for further investigations are shown. The description of a reluctance network of the machine is addressed with a semi-analytical approach for this purpose. Finally, the results of the preliminary calculation are validated by finite element analysis (FEA) and the quantities are verified with measurements on a device under test. The deviations between the methods are shown and discussed.
A transformer with variable primary windings for wide input voltage range DC/DC converters is presented. This transformer structure allows three states of the primary winding to be converted by only two individual windings. Based on the evaluations of a two-switch flyback converter, the potential of DC/DC converters with variable structures, the implementation of such a transformer and the advantages and disadvantages are shown and discussed. Real measurement results demonstrate the noticeable increase in efficiency and the reduction in component stress, having a positive influence on the operation of the converter and the component selection during the design process.
Finite control set model predictive control (FCS-MPC) is a promising method for the control of multi-phase machines, due to its capability to directly account for nonlinearities and multiple controlled variables. To overcome the drawback of high current ripples and excitation of harmonic currents in the so-called xy-subsystem, several methods have been proposed in the literature so far. This paper proposes an MPC-based method that achieves high granularity of switching by not only switching at the discrete time steps, but also within the sampling interval. In doing so, the discussed algorithm, referred to as variable switching point current control (VSP 2 CC), produces low current distortions, while still keeping the advantages of conventional FCS-MPC, such as fast dynamic behavior during transients. To highlight the above, VSP 2 CC is applied to a six-phase permanent magnet synchronous machine (PMSM) and compared with conventional FCS-MPC and MPC that employs virtual voltage vectors (VV-MPC).