In this study, a new non-isolated high voltage gains dc/dc converter using coupled inductor and voltage multiplier techniques (diode/capacitor) is presented The voltage gain will be increased by increasing the turns ratio (N) and the number of stages of the VM units The proposed converter capable to more increase the output voltage gains with transfer energy which is stored in coupled inductance Also, the voltage multiplier unit causes to further increase in the output voltage level of the proposed converter Besides, the nominal value of the semiconductors is low due to these are clamped to the capacitors available on the voltage multiplier units The normalized voltage stress across the semiconductors is low which this case is compared in the comparison section Therefore, the power loss of switch can be reduced by using a switch with a lower rating (lower RDS(on)) and power diodes with the low nominal rating As a result, the overall efficiency of the proposed converter will be high To confirm the benefits of working in this paper, comparison results for different items with other works are provided in section 4 The principle of operation, the theoretical analysis and the experimental results of a laboratory prototype for N(N2/N1) = 2 and n = 2 stage in about 260W with operating at 40kHz are provided

/pdf/high-voltage-gain-dc-dc-converter-using-coupled-inductor-and-50qxfblnrh.pdf

High Voltage Gain DC/DC Converter Using Coupled Inductor and VM Techniques

A bi-directional DC-DC converter,which can boost DC voltage from 24 V to 240 V and also can buck DC voltage from 240 V to 24 V,used in low or medium power application is presented in the paper.An isolation transformer is used in the converter and two full-bridges are on the both sides of transformer.Achieving bi-directional flow of power using the same power components,the converter essentially operates in the buck mode,the main DC power,which usually converted from ac or fuel cell,provides power to the load and charges battery to 24 V,only on failure of the main source,it uses battery to replace the main power.A new control strategy is applied in the converter to realize zero voltage switching without additional devices in the circuit.The operating principle and theoretical analysis are also provided in the paper,and simulation and experimental results verifying the system of high efficiency,reliable and simplicity.

A ZVS Bi-directional DC-DC Converter

The solar PV based power generation systems are growing faster due to the depletion of fossil fuels and environmental concerns Combining PV panels and energy buffers such as battery through multi-port converter is one of the viable solutions to deal with the intermittency of PV power The goal of this paper is to design and analyze the proposed triple port DC-DC buck-boost converter for high step-up/step-down applications It has two unidirectional ports (port-1 and port-3) and one bi-directional port (port-2) for harnessing photovoltaic energy and charging the battery At port-1, the combined structure of buck and buck-boost converter is used with a particular arrangement of switches and inductors The step-up/step-down voltage conversion ratio is higher than the conventional buck-boost converter, and the polarity of the output voltage is maintained positive The battery is added at the bi-directional port, for the storage of energy through the bi-directional boost converter The switches operate synchronously for most of the modes making the control strategy simple The characteristics and modes of operation along with a switching strategy, are elaborated Experimental results are presented which validate the agreement with the developed theoretical expectation

/pdf/non-isolated-high-gain-triple-port-dc-dc-buck-boost-518e15sph5.pdf

Non-Isolated High-Gain Triple Port DC–DC Buck-Boost Converter With Positive Output Voltage for Photovoltaic Applications

In this study, a new non-isolated high step-up DC-DC converter is presented with high-voltage gain which is suitable for renewable applications. The proposed converter uses coupled inductor and voltage multiplier cell (diode capacitor) for increasing the voltage level. The voltage gain of the proposed converter can be increased by selecting the appropriate turns ratio of coupled inductor. Voltage multiplier cell consists of two diodes and two capacitors which are used to obtain high-voltage gain. The diode-capacitor cell is used as a clamp circuit, which leads to reducing the voltage stress across the semiconductors. The proposed converter has a single power switch which causes the control of the proposed converter is simple. Also, the power switch is used with lower ON-state resistant (
 R
 DS-ON
). The zero-current switching of the diode is obtained in OFF state. Therefore, the conduction losses are decreased with lower normalised voltage stress across semiconductors. To prove the performance of the proposed converter, theoretical analysis and comparison with other converters are provided. To confirm the benefits of the proposed converter, a laboratory prototype with 20 V input voltage, 200 V output voltage and about 200 W power level at operating 25 kHz is built and tested.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-pel.2018.5414

High step-up DC–DC converter with coupled inductor suitable for renewable applications

In this study, a new high step-up high step-down bidirectional dc–dc converter is proposed. In the proposed converter, the voltage conversion ratio is increased by using two coupled inductors and switched capacitor circuit in both boost and buck operations. The proposed bidirectional converter in comparison with other presented high-voltage gain boost converters with two coupled inductors in the literature has the highest voltage conversion ratio. In this study, the proposed topology is analysed in all operating modes and the current and voltage stresses of all switches, voltage gain and maximum and minimum current through the inductors are calculated for both boost and buck operations. Finally, the accuracy of the obtained analytical results and correct operation of the proposed converter are verified through PSCAD/EMTDC simulation and experimental results.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-pel.2016.0977

High step-up high step-down bidirectional DC/DC converter

In this study, two new high voltage gain dc-dc converters are proposed. In the proposed converters, two coupled inductors are used to increase and decrease the output voltage more than the traditional dc-dc converters in boost and buck operations, respectively. In these converters, by increasing the turns ratio of the coupled inductors, the voltage conversion ratio is increased for the whole range of duty cycles. The proposed topologies are analysed in all operating modes and the values of current stresses of all switches, voltage stresses on all switches, input current ripples and voltage gains are calculated for boost and buck operations. Finally, the accurate performance of the proposed converters is verified through experimental and Power System Computer Aided Design (PSCAD)/Electro Magnetic Transient Design and Control (EMTDC) simulation results.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-pel.2017.0051

High voltage gain dc–dc converters based on coupled inductors

In this article, a nonisolated three-port dc–dc converter with high voltage conversion ratio is proposed. In the proposed converter, by changing the place of input voltage source between each of the three ports, three different single-input two-output operation modes are achieved. The input current ripple of the proposed converter is eliminated at the low voltage side for the whole range of duty cycles. The voltage conversion ratios of the proposed converter can be increased by increasing the turns ratio of second winding of coupled inductors. Moreover, the proposed converter has achieved proper output voltage regulations for all output ports, simultaneously. The proposed converter can be utilized in the renewable energy conversion systems such as in photovoltaic and fuel cells. In this article, the voltage conversion ratios of the output ports, the voltage stress on switches, the average currents of switches and inductors, and the required condition for cancelling input current ripple at low voltage side are calculated theoretically. The theoretical results are verified and experimental results for 24 V input voltage and 304 V, 240 V output voltages with 400 W power are extracted for two different operation modes.

Three-Port High Step-Up and High Step-Down DC-DC Converter With Zero Input Current Ripple

A new non-isolated free ripple input current bidirectional DC-DC converter with capability of zero voltage switching

In this paper, a new non-isolated two-input single-output dc–dc converter with high voltage gain is proposed. In the proposed converter, there are two three-winding coupled inductors used to achieve a high voltage gain and ripple-free input currents. The proposed converter has two switches, and their control pulses are the same as the control pulses of the two-phase interleaved converters with a phase shift equal to $\text{180}^{\circ} $ . The voltage stresses of switches and diodes are reduced and are always lower than the high output voltage. The proposed converter is extendable to a four-input single-output converter in which the switches have the control pulses the same as those in four-phase converters with phase shifts equal to $\text{90}^{\circ} $ . In this paper, the proposed topology is analyzed in all operating modes, and the values of current and voltage stresses of all switches and diodes, voltage gain, and required conditions for input current ripple cancelation are calculated during a switching period. Finally, the accuracy performance of the proposed converter is reconfirmed through experimental results for 225- and 298-W prototypes.

Zahra Saadatizadeh

Papers

High step-up high step-down bidirectional DC/DC converter

High voltage gain dc–dc converters based on coupled inductors

Three-Port High Step-Up and High Step-Down DC-DC Converter With Zero Input Current Ripple

A new non-isolated free ripple input current bidirectional DC-DC converter with capability of zero voltage switching

A New Two Input-Single Output High Voltage Gain Converter With Ripple-Free Input Currents and Reduced Voltage on Semiconductors