Postprints (KEV)
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Item Rack mounted low-profile indirect frequency converter(University of West Bohemia, 2019) Glasberger, Tomáš; Košan, Tomáš; Molnár, JanA new indirect frequency converter is introduced in this paper. The main goal of the new proposal is to simplify installation and running as supply unit for industrial applications. It fulfills minimum dimensions requirement and also enables parallel connection and full energy recuperation mode. The proper function of the designed converter has been performed on a prototype of linear actuator for a 6DOF motion platform.
Item Converter power losses computation by FPGA-based HIL simulator(University of West Bohemia, 2019) Dragoun, Jaroslav; Talla, Jakub; Košan, TomášConverter losses play a crucial role in the process of power converter design. Especially semiconductor components and heat sink selection are strongly dependent on the total power converter losses and thus affect the power converter size and its price. The most popular techniques for determination of the losses are based on the computer simulation of the power converter. These kinds of simulations could be very time consuming, because on one side, the simulation needs very short steptime for differential equations calculation to model power converter switching. On the other side, the temperature dynamics of heat sink are commonly slow and depend on power cycles of converter. With the help of FPGAbased hardware in the loop (HIL), the simulation could run real-time and it is possible to test different scenarios, different modulation techniques and see their influences on converter losses. This approach can lead to reduction of losses to the state, when it is possible to reduce the size of converter. Furthermore, the HIL simulation could be used for testing and developing control algorithm in real time conditions. It also offers flexibility in the easy change of model parameters and monitoring values which are not or hardly obtainable in real machine. This paper presents the FPGA-based HIL simulator of induction motor drive with three phase voltage source inverter based on Semikron IGBT modules.Item A novel ZCS/ZVS bidirectional DC-DC converter for energy storage applications(University of West Bohemia, 2019) Bhajana, V.V.Subrahman. Kumar; Drábek, PavelIn this paper, a new soft-switched non-isolated bidirectional converter is proposed. This proposed converter is operated with soft-switching (zero current switching / zero voltage switching). It is implemented during the turn-on of main switching devices, with the addition of auxiliary resonant circuit that consists of an auxiliary switch, diode, capacitor and an inductor. The switching losses are significantly reduced due to soft-switching operation of the main switches. Therefore, the efficiency of this topology is improved. The additional benefit of this topology is that the auxiliary switches are also operated with soft-switching. The proposed topology observes ZCS turn-on for boost mode and ZVS turn-on for buck mode operations. The principles of operation, design analysis and simulation verifications are discussed in detail. The soft-switching capabilities are obtained from design simulations on the 150V/250V/500W converter system.
