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In order to obtain a high step-up voltage gain, high-efficiency converter, this paper proposed a dual switches dc/dc converter with three-winding-coupled inductor and charge pump. The proposed converter composed of dual switches structure, three-winding-coupled inductor, and charge pump. This combination facilitates realization of high step-up voltage gain with a low voltage/current stress on the power switches. Meanwhile, the voltage across the diodes is low and the diode reverse-recovery problem is alleviated by the leakage inductance of the three-winding-coupled inductor. Taking all these into consideration, the efficiency can be high. This paper illustrated the operation principle of the proposed converter; discussed the effect of leakage inductance on voltage gain; the conditions of zero current shutting off of the diodes are illustrated; the voltage and current stress of the power devices are shown; a comparison between the performance of the proposed converter and previous high step-up converters was conducted. Finally, a prototype rated at 500 W has been established, and the experimental results verify the correctness of the analysis. [ABSTRACT FROM AUTHOR]

This paper introduces a SEPIC-derived bidirectional dc–dc converter. The proposed converter utilizes tapped inductor and charge pump techniques to achieve steep voltage conversion ratio and an active lossless regenerative snubber to attain lossless switching and high efficiency. The paper presents the principle of operation, steady-state analyses, and experimental results obtained from a 400-W, 48-V/380-V prototype. The efficiency of the proposed topology is demonstrated to peak at 96.4% for boost mode and 95.0% for buck mode. [ABSTRACT FROM AUTHOR]

A novel high-conversion-ratio bidirectional dc–dc converter with coupled inductor is proposed in this paper. Compared with the bidirectional converters based on coupled inductor, this new topology can realize a higher step-up voltage gain and lower step-down voltage gain with a lower turn ratio in an appropriate duty cycle. In proposed converter, the windings of the coupled inductor are reversely connected to transfer energy from high voltage source or low voltage source. Then, a clamp capacitor is applied to reduce voltage stress on main switch; therefore, the conduction loss of the main switches can be reduced by using a low resistance switch, and the clamp capacitor can also recycle the energy of the leakage inductor in coupled inductor. Besides, the soft-switching technique is used to achieve zero voltage switching, so the efficiency can be further improved. The main circuit and its steady-state operating principle are analyzed in detail. Finally, a 25–200 V 200 W bidirectional dc–dc converter is implemented to verify its performance. [ABSTRACT FROM AUTHOR]

This paper presents a dc–dc boost converter topology for low input and high output voltage applications, such as photovoltaic systems, fuel cell systems, high-intensity discharge lamp, and electric vehicles. The suggested configuration consists of a three-winding coupled-inductor, a single switch and two hybrid voltage multiplier cells. Furthermore, two independent hybrid voltage multiplier cells are in parallel when the single switch S is turned on, and they are in series when the switch S is turned off. So, the advantages of the proposed converter structure are summarized as follows: 1) A coupled inductor with three windings is introduced in the presented converter structure. The two secondary windings of the coupled inductor are, respectively, used to form a hybrid multiplier cell on the one hand, on the other hand, it increases the control freedom of the voltage gain, enhances the utility rate of magnetic core and power density, and reduces the stress of power components to provide a stable constant dc output voltage. 2) The two hybrid multiplier cells can absorb synchronously the energy of stray inductance, which not only reduces the current stress of corresponding diodes, but also greatly alleviates the spike voltage of the main switch, which improves the efficiency. 3) The two hybrid multiplier cells are connected in series to supply power energy for the load, so the voltage gain is extended greatly due to this particular structure. Thus, low-voltage low-conduction-loss devices can be selected and the reverse-recovery currents within the diodes are inhibited. The operating principles and the steady state analyses of the proposed converter are discussed in detail. Finally, a test prototype has been implemented in the laboratory, and the simulated and experimental results show satisfactory agreement with the theoretical analysis. [ABSTRACT FROM AUTHOR]

A new high step-up interleaved converter is proposed in this paper. This new high step-up converter utilizes the interleaved boost converter to be in series connection with the voltage-double module. The secondary sides of the coupled inductors are in interleaved series connection and shared by two voltage-double modules to accomplish the interleaved energy storage. Then, the input voltage, coupled-inductors, and multiplier capacitors are in series connection with the output to achieve the purpose of high voltage gain. The proposed circuit can be operated at a lower duty cycle to achieve high voltage gain by adjusting the turn ratio of the coupled inductors. The proposed circuit has less elements and the voltage stress of the switches and diodes can be decreased to reduce the cost. The conduction loss can be reduced and the efficiency can be increased when the switch with lower conduction resistance is applied. Finally, a prototype circuit of a 400 W high step-up converter with input voltage of 24 V and output voltage of 400 V is realized. Through simulation and experiments, the validity and property of the proposed converter can be verified. [ABSTRACT FROM PUBLISHER]

DC–DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which fundamental energy storing elements (inductors and capacitors) and/or transformers in conjunction with switch(es) and diode(s) are utilized in the circuit. These techniques include switched capacitor (charge pump), voltage multiplier, switched inductor/voltage lift, magnetic coupling, and multistage/-level, and each has its own merits and demerits depending on application, in terms of cost, complexity, power density, reliability, and efficiency. To meet the growing demand for such applications, new power converter topologies that use the above voltage-boosting techniques, as well as some active and passive components, are continuously being proposed. The permutations and combinations of the various voltage-boosting techniques with additional components in a circuit allow for numerous new topologies and configurations, which are often confusing and difficult to follow. Therefore, to present a clear picture on the general law and framework of the development of next-generation step-up dc–dc converters, this paper aims to comprehensively review and classify various step-up dc–dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc–dc converters are presented and summarized with comparative study of different voltage-boosting techniques. [ABSTRACT FROM AUTHOR]

A three-port dc–dc converter integrating photovoltaic (PV) and battery power for high step-up applications is proposed in this paper. The topology includes five power switches, two coupled inductors, and two active-clamp circuits. The coupled inductors are used to achieve high step-up voltage gain and to reduce the voltage stress of input side switches. Two sets of active-clamp circuits are used to recycle the energy stored in the leakage inductors and to improve the system efficiency. The operation mode does not need to be changed when a transition between charging and discharging occurs. Moreover, tracking maximum power point of the PV source and regulating the output voltage can be operated simultaneously during charging/discharging transitions. As long as the sun irradiation level is not too low, the maximum power point tracking (MPPT) algorithm will be disabled only when the battery charging voltage is too high. Therefore, the control scheme of the proposed converter provides maximum utilization of PV power most of the time. As a result, the proposed converter has merits of high boosting level, reduced number of devices, and simple control strategy. Experimental results of a 200-W laboratory prototype are presented to verify the performance of the proposed three-port converter. [ABSTRACT FROM AUTHOR]

This paper presents a soft-switching pulsewidth modulation (PWM) nonisolated boost dc–dc converter embedding an edge-resonant switched capacitor (ER-SWC) cell and its interleaved circuit topology. The conceptual boost dc–dc converter treated herein can achieve high-frequency zero-current soft-switching turn-on and zero-voltage soft-switching turn-off operations in the active switches and minimization of a reverse recovering current in the freewheeling diode under discontinuous conduction mode partially including critical conduction mode in the input current. Those advantageous properties enable a wide range of soft-switching operations together with a high-voltage step-up conversion ratio with a reduced current stress. Circuit design guideline based on the soft-switching range is introduced; then, a theoretical analysis is carried out for investigating the step-up voltage conversion ratio. For demonstrating the effectiveness of the ER-SWC soft-switching PWM boost dc–dc converter and its newly developed interleaved topology, laboratory prototypes are evaluated in experiments; then, their performances are discussed from a practical point of view. [ABSTRACT FROM PUBLISHER]

This paper presents simplified nonlinear averaged large-signal and linear small-signal models of the three basic dc–dc converter topologies, boost, buck, and noninverting buck–boost, respectively, operating in peak current-mode control. Models have been derived for the continuous and discontinuous conduction mode. The modeling methodology used is the equivalent current injected method. The derived models have been compared to the existing full-order large-signal nonlinear models and have been found to exhibit simulation time reduction by a few magnitudes in complex distributed power systems, such as today’s popular microgrids. The models developed have been experimentally verified on a custom-built 120-W boost converter prototype, showing great accuracy in steady state and in dynamical behavior in all operating points, as determined by the output resistance. [ABSTRACT FROM PUBLISHER]

In this paper, a soft-switching bidirectional dc/dc converter with a LC series resonant circuit is proposed. The proposed converter has been obtained by adding LC series resonant tank in the conventional bidirectional dc/dc converter. The proposed topology performs soft switching at both buck and boost operations. Through the theoretical boost and buck mode analysis, zero voltage switching operation is explained. Moreover, characteristics of the proposed topology are verified with simulation and experimental results. [ABSTRACT FROM AUTHOR]

To achieve the best optimized performance in terms of stability and dynamic behavior of power electronic converters, it is necessary to use a more advanced control technique and accurate mathematical model. This paper proposes a fixed-frequency hysteretic current (FFHC) controller that uses both sliding-mode control (SMC) technique and fixed-frequency current controller with a hysteresis band to achieve all properties of the variable structure controller. However, realizing such fixed-frequency sliding-mode controller using small-signal-averaged (SSA) model of the power converters and Utkin’s equivalent control technique may not be valid for all conditions. We show that it can be applicable only when the fast-scale dynamics of the converter system is stable, which can be achieved successfully by analyzing the stability of the FFHC-controlled buck converter using Filippov method and Floquet theory. The regions of stability are then presented to show the domains of existence of nominal period-1 and higher periodic orbits in 2-D parameter space. We also demonstrate how to derive the equivalent control law from the modified tristate converter topology to design the controller. Finally, the experimental results are presented to validate the effectiveness of this hybrid FFHC controller. [ABSTRACT FROM PUBLISHER]