A NOVEL TOPOLOGY FOR A HIGH EFFICIENCY DC/DC RESONANT POWER CONVERTER FOR SOFT SWITCHING WITH RCN NETWORK #1 SREELATHA - M.TCH(PE Student), #2 N.GANESH- Associate Professor, SIDDHARTHA INSTITUTE OF TECHNOLOGY AND SCIENCES, HYDERABAD, T.S., INDIA. Abstract: This paper introduces another topology for a high productivity dc/dc thunderous force converter that uses a resistance pressure system (RCN) to give concurrent zero-voltage exchanging and almost zero-present exchanging over an extensive variety of information voltage, yield voltage, and force levels. The RCN keeps up sought current waveforms more than an extensive variety of voltage working conditions. The utilization of ON/OFF control in conjunction with narrowband recurrence control empowers high productivity to be kept up over an extensive variety of force levels. The converter usage gives galvanic disconnection and empowers vast (more prominent than 1:10) voltage transformation proportions, making the framework suitable for substantial stride up change in applications, for example, dispersed photovoltaic converters. Exploratory results from a 200-W model working at 500 khz demonstrate that more than 95% proficiency is kept up over an info voltage scope of 25 40 V with a yield voltage of 400 V. It is likewise demonstrated that the converter works proficiently more than a wide yield voltage scope of 250 400 V, and a wide yield force scope of 20 200 W. These test results show the viability of the proposed output. Key words: Dc to Dc converters, ZVS, full bridge, rcn network, soft switching converters. 1. INTRODUCTION HIGH-voltage-pick up dc/dc converters are found in a mixture of utilizations [1] [4]. For instance, to join photovoltaic boards to the matrix, interface hardware is required. A few architectures for this reason consolidate dc/dc converters to support voltage of individual photovoltaic boards to a high dc-join voltage, with take after on hardware for changing over dc to air conditioning (e.g., see, [5] and [6]). The progression up dc/dc converter is a basic piece of this framework, and must work effectively for an extensive voltage venture up and for a wide voltage range (e.g., at the converter data and/or yield contingent on the framework). Moreover, to be conservative, it must work at high exchanging frequencies. In routine hard-exchanged force converters, the cover of current and voltage is huge amid exchanging, bringing about critical force misfortune, particularly at high frequencies. Delicate exchanged resounding converter topologies giving zero-voltage exchanging (ZVS) or zero-present exchanging (ZCS) can significantly decrease misfortune at the exchanging moves, empowering high proficiency at high frequencies (e.g., see, [7] and [8]). Shockingly, while some delicate exchanged thunderous outlines accomplish incredible execution for ostensible working conditions, execution can corrupt rapidly with variety in info and yield voltages and force levels [9], [10]. Impediments on the productive working scope of thunderous converters are fixed to both converter structure and control. Various control strategies are workable for repaying varieties in info voltage, yield voltage, and force level. These incorporate recurrence control [7], [8], stage shift PWM control [11], unbalanced obligation cycle PWM control [12], and ON OFF or burst mode control [13]. Each of these control systems in conjunction with routine resounding tank structures forces noteworthy configuration limits. Case in point, the traditional half extension arrangement resounding converter (SRC) [8] obliges wide-band recurrence variety to control the force when yield load or information voltage changes such that the magnetics can't be ideally planned. Moreover, to look after ZVS, the recurrence must increment to diminish force, harming the productivity at light load. For a full-connect form of the SRC, stage movement control can be utilized to control the force and reject transformation proportion varieties (e.g., see, [11]). Notwithstanding, this outcomes in deviated current levels in the switches at the exchanging moments, with the switches in the main leg killing at high streams. The powerful impedance of the rectifier in a resounding converter additionally frequently causes challenges, as it changes with working conditions. This paper presents another high effectiveness thunderous dc/dc converter topology, the resistance pressure system (RCN) converter, which tries to conquer the previously stated difficulties. This converter works with synchronous ZVS and close ZCS over an extensive variety of information voltage, yield voltage, and force levels, bringing about low exchanging misfortunes. This study speaks to a development on a prior meeting paper [14], and Paper Available @ ijgis.com JUNE/2014 Page 38
incorporates extra exploratory results and appraisals of misfortune breakdown. The rest of this paper is composed as takes after: depicts the topology and control of the proposed RCN dc/dc converter. Fig. 1. Architecture of the proposed dc/dc converter. ON-OFF CONTROL Fig.2. Topology of the proposed RCN dc/dc converter. 2. SYSTEM DESCRIPTION AND CONTROL STRATEGY A simple control system in which the device being controlled is either full on or full off, with no intermediate operating positi ons. Also known as on-off control system. A very common example of on-off control theory is fan controlling scheme of transformer cooling system. When transformer runs with such a load, the temperature of the electrical power transformer rises beyond the preset value at which the cooling fans start rotating with their full capacity. As the cooling fans run, the forced air (output of the cooling system) decreases the temperature of the transformer. When the temperature (process variable) comes down below a preset value, the control switch of fans trip and fans stop supplying forced air to the transformer. After that, as there is no cooling effect of fans, the temperature of the transformer again starts rising due to load. Again when during rising, the temperature crosses the preset value, the fans again start rotating to cool down the transformer. Theoretically, we assume that there is no lag in the control equipment. That means, there is no time day for on and off operation of control equipment. With this assumption if we draw series of operations of an ideal on off control system, we will get the graph given below. Paper Available @ ijgis.com JUNE/2014 Page 39
But in practical on off control, there is always a non zero time delay for closing and opening action of controller elements. This time delay is known as dead time. Because of this time delay the actual response curve differs from the above shown ideal response curve. Let us try to draw actual response curve of an on off control system. Fig: Implementation of the proposed RCN dc/dc converter. At time T O the temperature of the transformer starts rising. The measuring instrument of the temperature does not response instantly, as it requires some time delay for heating up and expansion of mercury in temperature sensor bulb say from instant T 1 the pointer of the temperature indicator starts rising. This rising is exponential in nature. Let us at point A, the controller system starts actuating for switching on cooling fans and finally after period of T 2 the fans starts delivering force air with its full capacity. Then the temperature of the transformer starts decreasing in exponential manner. 2. MATHEMATCAL MODELING Paper Available @ ijgis.com JUNE/2014 Page 40
3.2 Results Fig: main circuit Paper Available @ ijgis.com JUNE/2014 Page 41
For 24V International Journal Of Global Innovations -Vol.2, Issue.I Fig: S1,S3, Il,Vds3 Paper Available @ ijgis.com JUNE/2014 Page 42
For 40V: International Journal Of Global Innovations -Vol.2, Issue.I 4. CONCLUSION This paper exhibits another thunderous dc/dc converter topology that uses a RCN and a mix of ON/OFF control and narrowband recurrence control. The converter usage gives galvanic disengagement and empowers extensive (more noteworthy than 1:10) voltage transformation proportions. The proposed converter accomplishes high proficiency by keeping up ZVS and close ZCS more than a wide data voltage, yield voltage, and force range. The exploratory results from a 200-W model demonstrate that the converter keeps up a productivity of more than 95% over its whole 25 40 V info voltage range at the outlined yield voltage of 400 V; a proficiency of more than 93.7% as yield voltage is decreased down to 250 V; and an effectiveness of more than 93.4% even as yield force is diminished to 20 W. This exhibits the viability of the methodology REFERENCES : [1] S. M. Chen, T. J. Liang, L. S. Yang, and J. F. Chen, A cascaded high step-up dc/dc converter with single switch for microsource applications, IEEE Trans. Power Electron., vol. 26, no. 4, pp. 1146 1153, Apr. 2011. [2] S. V. Araujo, R. P. Torrico-Bascope, and G. V. Torrico-Bascope, Highly efficient high step-up converter for fuel-cell power processing based on hree-state commutation cell, IEEE Trans. Ind. Electron., vol. 57, no. 6, pp. 1987 1997, Jun. 2010. [3] Q. Zhao and F. C. Lee, High-efficiency, high step-up dcdc converters, IEEE Trans. Power Electron., vol. 18, no. 1, pp. 65 73, Jan. 2003. [4] B. York,W. Yu, and J. S. Lai, An integrated boost resonant converter for photovoltaic applications, IEEE Trans. Power Electron., vol. 28, no. 3, pp. 1199 1207, Mar. 2013. [5] J. S. Lai, Power conditioning circuit topologies, IEEE Ind. Electron. Mag., vol. 3, no. 4, pp. 24 34, Jun. 2009. [6] Q. Li and P.Wolfs, A review of the single-phase photovoltaic module integrated converter topologies with three different DC link configurations, IEEE Trans. Power Electron., vol. 23, no. 3, pp. 1320 1333, May 2008. [7] R. L. Steigerwald, High-frequency resonant transistor DC-DC converters, IEEE Trans. Ind. Electron., vol. IE-31, no. 2, pp. 181 191, May 1984. [8] R. L. Steigerwald, A comparison of half-bridge resonant converter topologies, IEEE Trans. Power Electron., vol. 3, no. 2, pp. 174 182, Apr. 1988. Paper Available @ ijgis.com JUNE/2014 Page 43