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EPE Journal Volume 18-1 - Papers
- IGCT Electro-Thermo-Fluidic Modelling
- Task Preservation of Multi-Degree-of-Freedom Motion Using Interaction Mode Control
- Design Method of Low Loss and Fast Response LC Filters Based on Locomotive Battery Testing System
- Computational Modeling and Polarization Characteristics of Proton Exchange Membrane Fuel Cell with Evaluation of its Interface Systems
EPE Journal Volume 18-1 - Editorial
By Krzysztof Zawirski
On behalf of the Power Electronics and Motion Control Council, the EPE Association and the National Organising Committee it is Prof. Zawirski's pleasure to invite the whole power electronics community to the 13th Power Electronics and Motion Control Conference, EPE-PEMC 2008, held in Poznan´ , Poland, from September 1 to September 3, 2008.
EPE Journal Volume 18-1 - Papers
By H. Feral; Ph. Ladoux
In high power applications, thermal considerations are fundamental. The voltage and current capabilities of today’s semiconductors increase steadily and so, too, do their power dissipations, reaching several kW per package. Generally, thermal modelling is used to design the cooling system of a power converter and to obtain an accurate prediction of the cooling system’s performance. In so doing, it is important to consider the coupling between cooling water, junction temperature and dissipated power. This paper presents a comprehensive modelling method, based on a 3D thermal model, which takes into account the electric and fluidic interactions with the temperature field in a press-pack device. The modelling method is applied to an IGCT (Integrated Gate-Commutated Thyristor) working in a high power chopper. Internal temperature measurements in switching, transient and steady-state modes are performed. Measurement results are used to fit the 3D model by adjusting the value of the thermal contact resistances between the different parts of the IGCT device. Thus, the differences between measurement and modelling result are less than 10% both in transient and steadystate modes. Finally, the model is used to determine the influence of water-flow direction on the IGCT junction temperature. Furthermore, the model is used to estimate IGCT losses and junction temperature fluctuations in the case of a DC arc furnace power supply.
By S. Katsura; K. Ohishi
Recently, skill preservation of an expert and skill training have been a serious problem of the medical or production fields. This paper proposes a task preservation and reproduction of multi-degree-of-freedom motion using interaction mode control based on bilateral motion control. The proposed task preservation system is composed of two modes; acquisition mode and reproduction mode. In the acquisition mode, the control system is based on bilateral control. Since a touching motion is subject to the “law of action and reaction”, it is possible to decompose force information into action force and reaction force by using the bilateral control. Furthermore, human motion is acquired in decoupled modal space by using the quarry matrix. The decoupled modes correspond to “moving”, “yawing”, “grasping” motions. Thus the multi-degree-of-freedom motion by a human is easily obtained and analyzed in the modal space. In the reproduction mode, the acquired human motion is reproduced in the modal space by using the interaction mode control. The proposed task preservation system is applied for grasping motion by three fingers. The experimental results show viability of the proposed method.
By Li Heming; Zhang Lixia, Yan Xiangwu, Kang Wei
The locomotive battery is sensitive to the fluctuation of its charge/discharge current, so the battery test system is proposed to offer high quality current, such as low ripples (# 0.5 %), fast response and wide adjustable extent. Because the battery test system is a non-matched network to the filter, there is a flat decay for the DC current which can’t be avoided. Besides, the locomotive battery has a very tiny inner resistance which is capacitive and with opposing voltage, it makes the filter design more difficult. This paper introduces a method for bidirectional DC/DC filter design. The synthesis method for single-end system is introduced to minimize the flat decay to the DC current. The influence to the characteristic of the filter caused by component dissipation is demonstrated. The dissipation factor of the lossy filter made a left shift to the normalized pole and zero of its transfer-function, this feature is imposed to enhance the response speed of the filter. Simulations and tests proved that the filter possesses low transient peak value, fast converse ability and good filtering result.
By Nabil A. Ahmed
This paper presents a computational model of proton exchange membrane (PEM) fuel cell stack. The proposed model is simple and at the same time includes all the important phenomena present in the fuel cell. The fuel cell electrical output voltage and current (V-I) characteristic is described for the first time by a simplified closed form suitable for modeling and computation. The characteristics obtained through simulation are compared with the experimental results obtained on a commercial Ballard Nexa 310-0027 power module as well as to the manufacturer available data. Close agreement between the simulation, manufacturer and experimental results confirms the validity and usefulness of the proposed model. In addition, the paper explores several power interface options for fuel cell power generation systems and proposes a power conditioning unit composed of boost DC-DC converter cascaded sinusoidal PWM inverter.