_applied sciences_  
_Article_  
**Improved Operation of the Step-Up Converter with Large Voltage Gain and Low Voltage Gain and Low Voltage on Capacitors**  
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required to feed the domestic appliances or push the power into the utility grid. Those renewable energy sources are important, but their output voltage (usually in the range of tens of volts) may be excessively low for feed inverters (dc-ac converters) to feed electric appliances. For example, a dc-dc converter may be used to step up the voltage from PV panes and FC stacks to feed the traditional H-bridge inverter, producing an ac voltage that can feed electric appliances. This article focuses on the dc-dc power conversion, which means changing the amplitude of a dc voltage in an interchange of the current. There are well-known traditional converters, such as the standard boost converter depicted in Figure 1[4]. It is made of one inductor, one capacitor, and two switches; one of the switches must be a transistor, and the other may be a transistor or a diode (depending on the power flow or synchronous rectification requirements). The boost converter can increase the voltage level from the input to output. The ratio of the voltage at the output port divided by the voltage at the input port is called voltage gain. Evidently, in the boost converter, the voltage gain is larger than the unity. However, as the voltage gain becomes larger or the duty cycle (or duty ratio) approaches one, the efficiency of the converter decreases [4; 5]. As a result, practical converters using the boost topology usually increase the input voltage up to four to five times (or a duty ratio of 0.8) [5]. The power electronics industry is seeking to create high-gain converters for scenarios where the voltage gain is excessively high for a standard boost converter, such as generating electricity from renewable energy sources. There are various ways to attain a high voltage gain, including using magnetic coupling in either transformer-based converters or coupled-inductor-based converters [6; 7; 8; 9]. These are plausible solutions, but in applications where electrical isolation is not required, it may be preferable to avoid magnetic coupling elements since transformers and coupled inductors may be expensive, and it may not be easy to find the appropriate element (with the desired parameters) off-the-shelves. Furthermore, transformer-based topologies are relatively complex compared with transformer-less topologies. On the other hand, transformer-less converters are usually manufactured with what we call \"components off-the-shelves\". This means that they are commercially available (most of the time, transformers must be designed and manufactured for a particular application). Other methods for achieving high voltage gain in the literature include charge pump topologies, which are converters made by semiconductors and capacitors (without inductors) which can attain a large voltage gain with a lightweight [10; 11]. There are also hybrid topologies of multiplier converters. In other words, dc-dc converters made by the combination of a traditional converter and charge pumps, also called voltage multiplier converters [12; 13; 14; 15], are a kind of circuit that might use a traditional converter with a diode capacitor voltage multiplier to increase their voltage gain. Another solution is the use of quadratic converters [14; 15; 16; 17], converters whose voltage gain is a quadratic function of their duty cycle (the terms duty ratio or duty cycle and voltage gain will be further explained). These are the reason why the development of non-isolated large voltage-gain dc-dc converters is a very active research field. One of the recent contributions in the field of high-voltage gain converters was the proposition of the low-voltage in capacitors (LVC) converter.