design and simulation of new zcs dc–dc closed loop full-bridge boost converter

DESIGN AND SIMULATION OF NEW ZCS DC–DC CLOSED LOOP FULL-BRIDGE BOOST CONVERTER WASEEM AHMED HALWEGAR & MOINUDDIN M SHIRBADGI Assistant Professor, Department of E & E, AITM, Bhatkal, Karnataka, India ABSTRACT There are a number of applications where an output dc voltage that is considerably larger than the input dc voltage is needed. Such applications include fuel cell and photovoltaic (pv) applications, where the voltage obtained from the fuel or pv cell is low, and hybrid vehicles where the voltage required to run the motor is much higher than that provided by the battery. Pulse width modulation (PWM) full bridge dc–dc boost converters are typically used in applications where the output voltage is considerably higher than the input voltage, these converters can be implemented with either zero-voltage switching (ZVS) or zero-current switching (ZCS) depending on the application. ZCS converters are rarely used in applications where the input voltage is very low (i.e, 12 V–48 V) such as in fuel cell converters, because the converters in these applications are implemented with MOSFETs and not IGBTs. If a review of the power electronics literature is made, it can be seen that ZCS techniques are associated with IGBT and ZVS techniques are associated with MOSFETs, and that it has, thus been assumed that ZCS techniques are, therefore, unsuitable for converters with very low input voltages. This paper begins with a review of the operation of ZCS converters in general; the disadvantages of previous ZCS converters are stated. A new ZCS-PWM dc–dc boost full-bridge converter is then introduced. The operation of the new converter is explained and analyzed, and a procedure for the design of its key components is given. Simulation results obtained from simulation are compared with analytical results. Finally, two types of disturbances at the input side are created and closed loop control is provided to maintain constant output voltage with variation in the input voltage. KEYWORDS: Active Clamp, Dc–Dc Power Conversion, LC Resonance, Low-Power Converters INTRODUCTION There are a number of applications where an output dc voltage that is considerably larger than the input dc voltage is needed. Such applications include fuel cell and photovoltaic (pv) applications, where the voltage obtained from the fuel or pv cell is low, and hybrid vehicles where the voltage required to run the motor is much higher than that provided by the battery. Because they have two mechanisms by which the input voltage can be stepped up the main power transformer, which is a step-up transformer and A PWM full-bridge boost converter can be implemented with either zero-voltage switching (ZVS) [1],[2] or zero-current switching (ZCS) [3]depending on the application. In general, the use of ZVS converters is preferred for applications where MOSFETs are used where the input voltage is high and the input current is low or medium, and where turn-on switching losses dominate. The use of ZCS converters is preferred in applications where insulated gate bipolar transistors (IGBTs) are used [4], [5] where the input current is high, and where conduction losses dominate. The low dc voltages that the converter switches are exposed to do not allow for the use of IGBTs as very low voltage IGBTs (<400 V) are unavailable. If a review of the power electronics literature is made, it can be seen that ZCS techniques are associated with IGBT and ZVS techniques are associated with MOSFETs, and that it has, thus, been assumed that ZCS techniques are, therefore, unsuitable for converters with very low input voltages. The objective of this International Journal of Electrical and Electronics Engineering Research (IJEEER) ISSN(P): 2250-155X; ISSN(E): 2278-943X Vol. 4, Issue 6, Dec 2014, 107-120 © TJPRC Pvt. Ltd.

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