Nonisolated High Step-Up DC–DC Converters: Comparative Review and Metrics Applicability

Abstract

Due to the extensive role of non-isolated high step-up DC-DC converters (NHSDC)s in industrial applications and academic research, many of these pulse width modulation converters have been presented in recent years. For each of these NHSDCs, some claims are introduced to verify its capabilities and features, which has been investigated in some review papers with different frameworks. Dissimilar to previous review papers, which have focused on the classification and derivation of voltage boosting techniques, this paper aims to evaluate the converters from various topological and operational points of view, and determine the superiority of each technique and converter according to applications. Some of these metrics are voltage gain, stresses, ripple, cost, power density, weight, size, control complexity and components count which lead to a comprehensive comparative study. Then, as the main purpose of this paper, effectiveness of these metrics is assessed to show how well they can lead us to the fair comparison results. Moreover, some new figures of merit are proposed in this paper to provide a helpful guideline in power electronic converters comparison studies. Finally, the feasibility discussion of single-and multi-objective figures of merit is followed by general practical conclusion and outlook about the NHSDC structures.

A new soft‐switching high gain DC/DC converter with bipolar outputs

“…In recent years, with the development of power electronics, the low-voltage DC distribution system based on renewable energy sources has become a proper alternative to replace the conventional ac distribution system [1]. For this purpose, DC-DC switched-mode converters have drawn particular attention to the use of renewable energy sources (RES) such as photovoltaic.…”

“…So far, many high step-up converters have been introduced to increase the low voltage level of renewable DC resources. To enhance the voltage gains, voltage boosting methods, including voltage lift, switched capacitors/inductors, voltage multipliers, and cascaded connections, are often used [1][2][3][4]. However, most of these structures suffer from hardswitching performance and large component count, which compromise the efficiency and power density of the converter.…”

“…However, most of these structures suffer from hardswitching performance and large component count, which compromise the efficiency and power density of the converter. For low-power applications, the non-isolated circuits give often better performance at a lower cost [1,4].…”

“…Today, magnetically coupled devices and other voltage boosting techniques are widely adopted to improve the performance of multi-output DC-DC converters. In these topologies, the turns ratio of the coupled-inductor, as an additional freedom degree, further enhances the voltage gains without needing an extreme duty cycle [1,18,19]. In such converters, to restrict the high voltage spike, the active/passive clamp circuits can be used [19].…”

A novel on high voltage conversion ratio DC‐DC converter for EV‐fed fuel cell application with hybrid MPPT controller

“…The converters reduce the currents transferring from the fuel stack to electric vehicles. In Tarzamni et al, 24 the authors compared different categories of power electronic circuits which are mainly differentiated as isolated and multiphase non‐isolated power electronics converter circuits. The isolated converter networks utilize another rectifier circuit and transformers for enhancing the voltage supply capability of the fuel stack.…”