This paper presents a novel design of step-up DC-DC converters whose merits are: (i) The continuity of the input current has been kept; (ii) The polarity of the output voltage has been kept positive which provides the same ground of the input source and load; (iii) The low voltage gain of the quadratic converters has been solved that it can increase the input voltage to 10 times more by the low value of the duty cycle; (iv) Apart from the high value of the voltage gain, the semiconductors' voltage and current stresses were lower than the output voltage and input current of the converter which are the highest value of the voltage and current respectively and semiconductor based components do not suffer from high value of the current/voltage stresses; (v) Additionally, the voltage/current stresses are low, and the efficiency is good according to its 90 percent value. The analysis of the non-ideal voltage gain has been done and its better function has been deduced by comparing it with the recently proposed non-isolated topologies. Additionally, the non-isolated voltage gain has been studied for different output power levels. The efficiency has been extracted and discussed for varying duty cycles and output power based on ignoring some losses. Experimental results and simulation outcomes from the PLECS software have been compared along with theoretical relationships. The prototype of the topology has been tested at 100 W output power, 100 V output voltage, and 10 V input voltage.INDEX TERMS DC-DC converters, high step-up converters, high voltage gain, voltage doubler structure.

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We designed and implemented a single-switch step-up DC-DC converter based on cascaded boost and Luo converters. The proposed converter demonstrated a quadratic voltage gain and a high efficiency, which makes it suitable for renewable energy applications, where a high voltage gain ratio is desired without imposing a high number of bulky items or employing a high duty cycle of the active switches. This converter benefits from the continuity of the input current waveform, which equips the maximum utilisation of renewable energy sources. While a transformer-less high voltage-gain was achieved, the voltage and current stresses of the power switch and diodes were kept low in comparison with the existing quadratic DC-DC converters. We analysed the converter in both continuous and discontinuous conduction modes. A non-ideal model of components was considered for power loss and efficiency calculations and comparisons. Finally, the simulation results were extracted with PLECS and validated with experiments on a 120 W prototype.

In this article, an ultra‐high step‐up DC‐DC converter has been proposed. The topology of the converter is a combination of a cascaded boost converter, positive output super lift Luo converter (POS LLC), and a voltage multiplier cell (VMC). The lower values of the duty cycle provide a more than 10 times voltage gain. Consequently, the high voltage gain has been provided beside the lower value of the voltage/current stress of the semiconductor and an acceptable value of the efficiency. With a detailed look, it can be understood the voltage gain and efficiency of the converter have become 12 times and 90.5% based on the experimental results while the percentage of the duty cycle has become 50%. Moreover, by the mentioned percentage of the duty cycle, the normalized value of the voltage/current stress of the semiconductors has become lower than 50% by exception of only 3 semiconductor‐based components which have voltage/current stresses more than 50% and lower than the unity. In addition to all the mentioned advantages, the input current has remained continuous which solves the challenges of the input filter's capacitor. Moreover, the voltage/current stresses have been kept low‐valued. The ideal mode of the topology has been discussed for both continuous/discontinuous current modes. The non‐ideal mode of the topology and its related comparisons have been done. A comparison of the voltage/current stresses of the semiconductor‐based components has been done. Moreover, the comparison of the losses and efficiency have been done for the proposed converter and recently suggested topologies. In addition, the efficiency has been discussed for the different values of its effective factors and the resulted behavior has been expressed. Finally, the simulation and experimental outcomes have been extracted for a 120 W output power and compared with the theoretical relations' results.

This paper has designed an upgraded form of the boost topology. The voltage ratio of the traditional step-up topology has been increased in quadratic form. Moreover, a low value of the duty cycle, number of components, and voltage/current stresses besides a high efficiency are bold features. The different parameters have been extracted for the ideal/non-ideal modes of the components and continuous/discontinuous current modes. In addition, the different features, such as the current/voltage stresses, have been compared. The efficiency of the designed topology has been extracted, and its various kind of power losses have been compared. The small-signal analysis has been done, and the bode diagram of the system has been extracted. Besides the increased voltage ratio of the designed topology compared to the traditional step-up converter, the continuity of the input current has remained a brilliant feature. Moreover, the semiconductors' stresses have been low-value compared to the recently proposed topologies. Moreover, higher efficiency besides higher voltage gain has been achieved. Finally, the experimental results have been compatible with the simulation and theoretical outcomes. The higher voltage gain of the proposed converter has been caused by the lower value of the duty cycle in comparison with the conventional boost converter, besides an acceptable efficiency and semiconductor stresses.