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In this study, a new non-isolated six-phase interleaved boost dc-dc converter is presented for photovoltaic (PV) applications. The suggested structure consists of two symmetric three-phase interleaved boost dc-dc converters along with two switched-capacitor cells, in order to obtain high conversion ratio. For different values of duty-cycles, the voltage conversion ratio of the proposed topology is high. Also, the voltage stress of switches for various duty cycles is low and the efficiency of proposed topology is high. Moreover, the value of input current ripple is low with the utilisation of interleaving techniques. These advantages cause the proposed topology to be a good candidate for PV systems. The operation modes and mathematical analysis of the presented converter is introduced. In order to show the merits of presented converter, comparison results with other boost dc/dc converters are provided. Both experimental and simulation works based 453 W are presented to verify the operation of recommended converter. PSCAD/EMTDC software is used for simulation work.

In this study, a non-isolated high step-up direct current (dc)/dc converter with a diode-capacitor is presented. To obtain high-voltage gain, the voltage multiplier units (diode-capacitor) can be extended to n stages which are used between the phases in up section and down section of the proposed converter. By increasing the number of voltage multiplier units, the nominal value of the components decreases. Therefore, the maximum voltage value of diodes and power switches compared with the output voltage is decreased and finally, the normalised voltage of these devices will decrease, significantly. In addition, the power level of the proposed converter can be increased for different values of duty cycles and voltage multiplier units and also leads to high efficiency. To illustrate the advantages of the proposed converter, comparison results with other topologies are provided. The principle of operation at n = 1, 2 stages, both theoretical analysis and experimental results of two prototypes in 100 and 250 W with operating at 40 kHz are provided. 2 Proposed converter and principle of operation The power circuit of the proposed structure is shown in Fig. 1. The proposed converter is a non-isolated four-phase high step-up dc/dc converter which consists of the input dc voltage source, four power IET Power Electron.

This study suggests a novel ultra-step-up dc-dc converter with low normalised voltage stress across the power devices. The proposed converter incorporates the conventional boost converter with a self-lift circuit and charge pump concept and utilises a voltage multiplier cell at the output side. In the input side, two inductors are magnetised during the switch on-time. During the switch off-time, the stored energy in these inductors, charge pump capacitor and input source, is delivered to the load. Accordingly, the proposed converter is capable of providing high voltage gains with a small duty cycle. Besides, the voltage stress across the power devices is low. Therefore, the MOSFET switch with low R DS-on and devices with reduced nominal voltage can be used which in turn reduces the conduction and turn-on losses. The analysis of the voltage and current stresses is accomplished. The circuit performance is compared with other solutions in the literature in terms of voltage gain and normalised voltage stress of the semiconductors. Eventually, to validate the theoretical analysis, the experimental results are given.