A high performance boost converter with voltage multiplier

High voltage gain can be easily achieved by utilizing a coupled inductor, but high voltage stresses of switching devices can result from its leakage inductance. Hence, snubber circuits are required to alleviate voltage stresses but these can generally lead to power losses. In this paper, a single-switch high step-up DC-DC converter with a coupled inductor and low duty ratio is proposed. A resonant voltage doubler is integrated to obtain higher voltage gain. Zero-current-switching (ZCS) for the diodes in the voltage doubler is achieved by exploiting resonance of the leakage inductance. Additionally, there is no surge voltage in any of the switching device and this makes dissipative snubber circuits unnecessary. Furthermore, maximum voltage stresses of switching devices are much lower than the output voltage and high voltage gain with low duty ratio can be obtained due to the modified cascade boost structure. All this helps to improve overall power efficiency. The operational principle and characteristics of the proposed converter is provided in detail. Experimental investigation using an output 400V-140W prototype at an input 24V- 48V is conducted to verify its functionality.

Nowadays, with the high-power demand in industries, the need for high step-up converters has been a crucial part of interest. Power conservation is an essential aspect of innovation leading to improving the voltage gain of conventional converters such as boost, Cuk and SEPIC. Boosting techniques including voltage multiplier (VM) cells, voltage lift capacitors, coupled inductors, switched capacitor/inductor, etc., are used to enhance the conventional converters to meet high-voltage requirements of various applications. This paper proposes a new high voltage gain DC–DC converter using a coupled inductor and VM cell. The operation of the converter is based on charging the capacitor using a single MOSFET switch and adding it in series with the source to the load. Besides, a passive clamp circuit which is comprised of capacitor and diode has been selected over the active clamp to reduce the voltage stress on the MOSFET switch, which helps to improve the voltage gain of the converter. The turns ratio of the coupled inductor is chosen appropriately to get the required voltage gain. Reduction in voltage stress results in selecting MOSFET with small on-state resistance (Rds-on), which offers less conduction loss and high efficiency of the converter. The proposed converter is modeled, analyzed and simulated using PLECS simulation software. The results are experimentally verified by developing 150 W experimental prototype.

This paper proposes a new non-isolated single-switch DC/DC converter with an ultra-high voltage gain, low input current ripple, low voltage stress, soft-switching operation, and modular scalability for renewable sources applications. With the help of a Three-Winding Coupled-Inductor (TWCI) and Voltage Multipliers circuits, ultra-high voltage gains can be achieved without needing a large duty cycle. A regenerative clamp capacitor recycles the energy stored in the leakage inductor; thus, the maximum voltage across the single power switch is restricted. Moreover, at the turn-on instant of the power switch, a Zero Current Switching (ZCS) condition is achieved. By designing a resonant tank, the switched current value of the main switch at the turn-off instant is reduced significantly. Additionally, the leakage inductor of the TWCI helps all converter diodes to operate under the ZCS condition. Due to full soft-switching performance, the introduced topology can provide a wide output voltage range under a high conversion efficiency. The steady-state analysis and comprehensive comparisons are provided in this paper. A 160 W prototype with 24 V input and 250 V output voltage is developed to validate the theoretical analysis. Due to ZCS operation and low voltage stress (VDS ≈ 40 V), the power loss portion of the MOSFET is low. Moreover, the maximum voltage stresses of diodes are measured as 40 V, 60 V, 90 V, and 110 V, that are well below the output voltage. Furthermore, at the full-load condition, the input current ripple is about 20 % and the measured efficiency is about 96.3%.

Quadratic boost converter (QBC) is reported in literature by using two boost converter network to enhance the voltage gain over a conventional boost converter. However, the voltage stress on the switch and the output diode remains equivalent to the converter's output voltage. To enhance voltage gain and minimize voltage stress on the switch and output diode, a switched capacitor inductor network (SCLN) has been studied by adding a diode and a capacitor to the QBC. The voltage stress on the switch and output diode is reduced below the output voltage; however, it resembles QBC. To reduce the voltage stress on the switch of the SCLN converter, by substituting one of the diodes in the SCLN with a switch, a converter to reduced voltage stress of the switched capacitor inductor (RVSCL) converter is studied. However, the voltage gain remains the same as the SCLN converter. To obtain high voltage gain with reduce the voltage stress on the switch and continuous source current, two classical boost converter network is combined with a voltage multiplier stage and an intermediate capacitor-diode pair. This reduced voltage stress switched capacitor inductor configuration, referred to as the VM-RVSCL power circuit, is studied for performance assessment. The steady-state gain of the VM-RVSCL power circuit is discussed and comparison between the VM-RVSCL and traditional converters is given. The components of the VM-RVSCL power circuit have been designed to obtain an output voltage and power of 650 V and 500 W, respectively, and its performance is verified by simulation results.

SummaryThis paper proposes a single‐ended primary‐inductor converter (SEPIC)‐based DC‐DC converter with higher voltage gain, continuous input current, and lower voltage stress. Suggested converter uses three‐winding coupled inductors and voltage multiplier for boosting function. The proposed structure stores lower amount of energy due to lower current magnitudes of used inductors. Moreover, using voltage multiplier reduces the voltage stress of the elements connected to the output terminals of the proposed converter. By reducing the voltage stress, in addition to reducing the rating of output elements and costs, the overall efficiency will also be increased. Also, a clamping circuit is used to diminish the voltage stresses on power switch. In order to represent the advantages of the proposed converter over some other converters in the viewpoints of the number of the used elements, continuity of input current, voltage gain, the voltage stress on power switch, and output diode, a comparison study is provided. To validate the practicability of the proposed converter, a 200‐W prototype is implemented and the experimental results are provided.

In this paper a novel SEPIC converter is designed for continuous input current operation. The SEPIC converter's voltage gain is greater than that of traditional converters. This converter works via a single switch and there is less voltage stress around the switch. The input side filter circuit is not needed because the proposed converter's input current is continuous. It is also suitable for applications involving renewable energy and fuel cells. The non-inverting output voltage is obtained in this converter. So, only by altering the duty cycle of the power switch pulse can it work at a wide output voltage range. This voltage regulation of the converter is regulated by the PI controller. Controller parameters are managed and varied by the PSO algorithm. This converter, due to the use of a single power switch, can easily control continuous conduction mode operation. Finally, the validity of the suggested dc-dc converter is checked by the simulation results and the output voltage control of the proposed converter is explained.

A non-isolated high step-up DC-DC converter with a coupled inductor is proposed in this paper. The proposed converter provides high voltage gain and soft-switching operation of all semiconductor devices. A voltage doubler and a coupled inductor increase the voltage gain. Zero-voltage-switching (ZVS) of all switches and zero-current-switching (ZCS) of all diodes are achieved. Also, the voltages across the semiconductor devices are effectively clamped. Due to the soft-switching operation of all switching devices, the switching loss is significantly reduced and the high efficiency is obtained. The feasibility and performance of the proposed converter were verified on an experimental prototype

The design of high voltage gain DC-DC boost converter is carried out with the addition of the Voltage Multiplier (VM) method. Here the coupled inductor and VM methodologies are proposed to reduce the switching and conduction losses of the Metal Oxide Semiconductor Field Effect Transistor (MOSFET). The Zero Current Switching (ZCS) technique with coupled inductor leakage inductance is used to operate the MOSFET. The leakage inductance is used to decrease the reverse recovery current across the diode. The design procedure of the boost converter and corresponding output waveforms are presented in this paper. Photovoltaic (PV) source converter with coupling inductors soft switching technique has been analyzed and tested in this paper.

This paper proposes an interleaved high step-up DC-DC converter with the coupled inductor (CI) and built-in transformer (BIT) for renewable energy applications. Two double-winding (2W) CIs and one triple-winding (3W) BIT are integrated with the switched-capacitor (SC) voltage multiplier cells (VMCs) to achieve high-voltage gains without extreme duty cycles. The CIs and BIT turns-ratios provide two other degrees of freedom—in addition to the duty cycle—to adjust the voltage gain that leads to increased design flexibility. The diodes turn off naturally under the zero-current switching (ZCS) conditions because their current falling rates are controlled by the leakage inductances of the CIs and BIT; therefore, the diodes’ reverse-recovery problems are alleviated. Moreover, employing passive diode-capacitor clamp circuits, the voltage stresses of the switches are limited to a low value far less than the output voltage. Additionally, the leakage inductances energies are recycled and transferred to the output to further extend the voltage gain. Furthermore, due to the interleaved structure, the input current ripple and current stresses of the components are reduced. The proposed converter is analyzed in detail and then compared with similar converters that employed CIs and/or BIT along with passive/active clamp circuits for the MOSFETs. Finally, to verify the feasibility of the proposed converter, the experimental results of a 200 W prototype with output voltage of 400 V and voltage gain of 25 are presented.

In this article, a novel high step-up interleaved dc-dc converter is presented, which is composed of an interleaved structure, an asymmetric voltage multiplier cell (AVMC), and a passive lossless clamped circuit. Compared to the classical interleaved boost converter, the proposed converter has a higher voltage gain owing to the employment of the AVMC and the coupled inductor. In addition, the input current ripple is limited to low values with the help of the interleaved structure, which gives more lifetime to the input power source. The voltage stresses of main switches are substantially low so that the MOSFETs with low voltage rate and ON-resistance (RDS(ON)) can be used. In addition, the voltage stresses and the reverse recovery problems of diodes are improved dramatically. Moreover, the zero current switching (ZCS) turn-on of switches and the ZCS turn-off of the clamp diodes are realized to reduce the switching losses. The leakage inductor energy is recycled and the voltage spikes are improved greatly by the passive lossless clamped circuit so that the efficiency can be upgraded further. Finally, a 400-W, 40-V-input, 400-V-output prototype is established to demonstrate the performance of this converter. The highest efficiency is about 97.3% and the full-load efficiency is approximately 97%.

This paper presents a novel single-switch converter with high voltage gain and low voltage stress for photovoltaic applications. The proposed converter is composed of coupled-inductor and switched-capacitor techniques to achieve high step-up conversion ratio without adopting extremely high duty ratio or high turns ratio. The capacitors are charged in parallel and discharged in series by the coupled inductor to achieve high step-up voltage gain with an appropriate duty ratio. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit, and the conduction losses are reduced. In addition, the reverse-recovery problem of the diode is alleviated by a coupled inductor. Thus, the efficiency can be further improved. The operating principle, steady state analysis and design of the proposed single switch converter with high step-up gain is carried out. A 24 V input voltage, 400 V output, and 300W maximum output power integrated converter is designed and analysed using MATLAB simulink. Simulation result proves the performance and functionality of the proposed single switch DC-DC converter for validation.

In this writeup a new converter having multiple step-gain voltage output for solar PV applications is introduced. The proposed converter is an improved buck-boost converter and its voltage gain is expandable. The gain is higher when compared to conventional converters such as ordinary boost,ZETA, SEPIC and Cuk converters, for a specific duty ratio. This converter makes use of only one power switch. Also the voltage stress across it is low. As the converter has only single switch, it is easy to control, and implement MPPT(maximum power point tracking) to it, thereby providing maximum output of the most available renewable energy resource. Incremental Conductance MPPT control is used along with this converter for MPP tracking, desirable for solar PV applications. N level voltage output can be obtained from this same converter by repeatedly following the same topology. The converter is also capable of supplying power to the connected loads at all its port at various voltage levels. Ordinary switches are used to separate different volage levels. The operating principle and the mathematical analysis for voltage gain and output current of the proposed converter are discussed. Simulation results with InCond MPPT and converter hardware are presented to validate the designed converter and its working.

Two new soft-switching converters for switched reluctance motor drives are proposed and analyzed. The proposed zero-voltage-transition (ZVT) converter possesses the definite advantages that both main transistors and diodes can operate with zero-voltage switching (ZVS), as well as unity device voltage and current stresses. On the other hand, the proposed zero-current-transition (ZCT) converter offers the advantages that both the main and auxiliary switches operate with zero-current switching (ZCS), as well as minimum current and voltage stresses. Both converters have the merits of simple circuit topology, minimum component count and low cost.

In this article, a new high step-up interleaved DC–DC converter is presented for renewable energy systems. The converter circuit is based on the interleaved two-phase boost converter and integrates a voltage-lift capacitor and a voltage multiplier cell. A high voltage gain of the converter can be achieved with a reasonable duty ratio and the voltage stresses of semiconductor devices are reduced. Because of low voltage stress, the switches with low on-resistance and the diodes with low forward voltage drops can be adopted to minimize the conduction losses. Additionally, the switching losses are reduced because the switches are turned on under zero-current switching (ZCS) conditions. Due to the existence of leakage inductances of the coupled inductors, the diode reverse-recovery problem is alleviated. Moreover, the leakage energy is recycled and the voltage spikes during switch turn-off are avoided. The parallel input architecture and interleaved operation reduce the input current ripple. The operating principles, steady-state characteristics, and design considerations of the presented converter are proposed in detail. Furthermore, a closed-loop control is designed to maintain a well-regulated output voltage despite variations in input voltage and output load. A prototype converter with a rated 1000 W output power is realized for demonstration. Finally, experimental results show the converter effectiveness and verify the theoretical analysis.

In recent days there is a vast development in the field of power electronic converters. Necessity of multiple level of voltage demand is raised for single supply system. To meet different level of load demand single input and multiple output topologies (SIMO) are created. There are many such converters fall under SIMO converters. The Integrated Dual Output Converter (IDOC) is one among them. The IDOC is a DC-DC converter that performs boost and buck operations simultaneously with a single input. It is basically evolved from boost converter, replacing a single switch by couple of switches. Both the switches are connected in series not only to perform both buck and boost operation but also to provide continuous input current. Main advantage of IDOC over conventional boost and buck converter is the reduced number of switches. Comparisons among another six buck-boost converters and the proposed IDOC converter are presented. It is found that the proposed converter’s voltage gain is smaller than the other converters’ in step-down mode. Also, based upon the comparisons among the same kind and same number of components, the voltage and current stresses on the power switch of the proposed IDOC converter are less than or equal to those of the comparative converters, and the voltage stress on the charge pump capacitor and the switching device power rating of the proposed IDOC converter are always lower than those of other comparative converters. These advantages make component selection for the proposed converter much easier, and it can be used for industrial application. In order to check the behavior of the converter simulation is carried out in a MATLAB/SIMULINK. The simulation results validated the operation of the converter.