Design and Simulation of Multi-element Resonant LCTLC Converter with HF Transformer J. Koscelnik, M. Prazenica, M. Frivaldsky, S. Ondirko Department of Mechatronics and Electronics, Faculty of Electrical Engineering, University of Zilina,Zilina, Slovakia, juraj.koscelnik@fel.uniza.sk Abstract-The paper deals with design, simulation analysis and experimental verifcation of electrical properties of resonant converter with LCTLC resonant network. The LCTLC topology belongs to multi-element resonant topologies. The converter consists of the two resonant tanks and HF transformer. The paper shows the design of the resonant elements and shortly the design of HF transformer. First the topology of proposed converter is being described, whereby main focus is given for application feld and on possibility of its variable use. Presented analysis and simulation experiments of proposed converter have been performed by OrCAD sofware. Finally for verifcation of expected operation, the experimental results of resonant converter with LCTLC elements have been created. Keywords-Multi-elements resonan convereter, design LCTLC, HF transformer, simulation of resonant convereter. I. INTRODUCTION The progress in the development of semiconductor devices has resulted in formation of new feld of science generally called power electronics. The newer and higher quality parts affect the design of resonant converter and therefore it is necessary to use sophisticated control algorithms. In some involvement inverters with high fequency transformers the number of the semiconductor devices in converter may be reduced and this results in the price of the product [1], [3]. Concept of the resonant converters had greatly expanded into various industrial and consumer applications, such as power supplies for distributed systems, laptops, LCD televisions and for aerospace and automotive sector as well. As we focus on the development of power electronic semiconductors, the involvement of resonant converters into various applications is a must due to continual improvements in technology of manufacture of power semiconductors. It is therefore natural for switched mode power supplies to target the highest switching fequency together with the highest efciency that is possible. A high effciency high step-up dc-dc converter can be proposed for renewable energy harvesting where are used the sustainable power sources [1], [4]. One of the alteratives, by which it is able to reach parameters as a high power density, high efciency and with low EMIIEMC infuence, is the resonant converter topology. 978-1-4799-3721-9/14/$31. 00 mOl41EEE 307 The paper shows the possibilities to use special resonant flter with HF transformer. The flter removes higher haonic components fom the DC supply voltage to reach the harmonic distortion up to 5 %. This paper shows analysis of resonant converter with LCTLCnetwork tuned for fequency of fndamental harmonic component. II. RESONANT CONVERTERS The group of resonant and quasi-resonant converters consists of serial, parallel and serial-parallel resonant circuit. By combining the basic resonant circuits arise modifed multi elements resonant circuits. Resonant converters use two kinds of the switching technique: Zero voltage switching (ZVS) and Zero current switching (ZCS) [1]. Those techniques are now as sof switching. The converter can operate in ZVS and/or ZCS. The basic scheme of the resonant converter is given in the fg. l. SITCHING NETWORK RESONANT FILTER Fig. l. Block scheme of the resonat converter MULTIFUNCTION OUTPUT LOAD The scheme describes basic connection of the resonant converter composed by the DC source; switching network; resonant flter and multifnction outut connected to load. The converters are used for the high power devices in half bridge or bridge confguration. Mainly used swathing technique when do the device is switching at the zero of the voltage. ZVS can be achieve when the current through the transistor (through ant-parallel connected zero diode) have inverted polarity against voltage [3]. The reversing of curent is achieved by LC circuits. Compare to the parallel resonant circuit is circulating curent is signifcantly lower and compare to the serial resonant circuit is just is slightly higher [9], [12]. A. Switching tequinchs in resonant converters Briefy descried in previous paragraph, the resonant converters can operate in two operation regions. The best case is the converter operates on the border in both, ZCS and ZVS regions [ll].In fact, this case cannot occur.However, it is not possible. So, depend on the type of used switching component can be chose one of the operation area, which is preferred by