An alternate topology for multi-input DC-DC converter with performance analysis

Fuel cells are renowned for their direct energy conversion, quiet operation, fuel flexibility and zero CO2 emissions. However, each fuel cell (FC) produces a very low output voltage of around 0.5-0.7 V. Therefore, it is necessary to design high gain DC-DC converters for boosting such low voltages either from a single FC or FC stack besides minimising the current ripples. Moreover, DC-AC converters are required to produce an AC voltage either for the single or three phase utility loads. This paper presents a review on various prominent DC-DC and DC-AC converter topologies. The performance of various DC-DC converter topologies is analysed in terms of number of components, converter switching frequency, galvanic isolation, power rating and efficiency. The salient features of potential DC-AC converters with low total harmonic distortion and high efficiency are presented. This paper is very useful for the design engineers in choosing the right topology.

Fuel cells are renowned for their direct energy conversion, quiet operation, fuel flexibility and zero CO2 emissions. However, each fuel cell (FC) produces a very low output voltage of around 0.5-0.7 V. Therefore, it is necessary to design high gain DC-DC converters for boosting such low voltages either from a single FC or FC stack besides minimising the current ripples. Moreover, DC-AC converters are required to produce an AC voltage either for the single or three phase utility loads. This paper presents a review on various prominent DC-DC and DC-AC converter topologies. The performance of various DC-DC converter topologies is analysed in terms of number of components, converter switching frequency, galvanic isolation, power rating and efficiency. The salient features of potential DC-AC converters with low total harmonic distortion and high efficiency are presented. This paper is very useful for the design engineers in choosing the right topology.

A new topology of multi-input bidirectional DC-DC converters is proposed in this paper. The converter has a boost behavior, i.e., the output voltage is higher than the sum of the input voltages. This family of converters is particularly suited for hybrid energy storage systems, where different DC sources are connected together and where the output voltage is significantly higher than the voltage of a single storage. The proposed converter reduces the number of required switches, leading to higher efficiency and reduced complexity compared to traditional n-input converters. The new topology demonstrates superior performance by enabling higher efficiency with fewer components. A dedicated control, based on PI controllers, is provided to ensure stable operation under dynamic conditions. The effectiveness of the proposed solution is tested using experimental results on a four-input 20 A/100 V converter prototype.

Review on non-isolated multi-input step-up converters for grid-independent hybrid electric vehicles

In current epoch of increased RES applications in power engineering, there is a wide-spread research on DC-DC converter topologies to strap renewable energy source (RES) to load. In the context of boosting the voltage output of RES using DC-DC converter, many DC-DC converter topologies are discussed in the literature. This paper intends to present a comprehensive review of three coupled inductor based non-isolated type DC-DC converter topologies operated with single power switch for voltage lift in RES applications. Voltage gain formulations are presented for reviewed topologies of non-isolated DC-DC converters operating with single power switch for voltage lift in RES applications. Simulation results are presented showing voltage across switch, current through inductor, voltage across diode. DC-DC converter topologies are developed and the results are obtained using MATLAB/SIMULINK software.

With the expansion of E-mobility technology, the demand for Medium-Voltage (MV) Electric Buses (E-buses) charging infrastructure has significantly increased. In this regard, the effective connection of E-bus chargers to a medium voltage power grid is essential to provide fast charging and carry out multiple charging processes simultaneously. One of the main building blocks for E-bus charging is the DC-DC converter stage responsible for regulating the power flow and matching the different voltage and power levels. Accordingly, this paper presents a comprehensive review of DC-DC converter topologies applicable to MV E-bus fast charging. This review discusses and compares the basic isolated DC-DC converter topologies. In addition, the DC-DC converters are classified based on their conversion stages. Moreover, isolated DC-DC converter topologies applicable for MV E-bus fast charging applications, including Dual Active Bridge (DAB) modular-based structure converter and Modular Multilevel Converter (MMC)-based DAB, are discussed where the merits and demerits of each topology are highlighted. Moreover, this review illustrates how DAB converters are employed in different power level applications through the multimodule converter or the MMC-based DAB structure. Furthermore, the challenges and required features for MV DC-DC converter topologies are discussed.

Half-Bridge (HF), Full-Bridge (FB), Push-Pull (PP) types of DC-DC converter were designed and simulated in MATLab-2009a with input voltage of 12V. The Zero Current Switching technique (ZCS) at primary side, Zero Voltage Switching technique (ZVS) at secondary side of the High frequency (HF) transformer based converter were used in these topologies. The performance analysis and comparison between HF, FB and PP topologies were carried out. The performance of Push-Pull DC-DC converter topology was comparatively better than other topologies for electrical vehicle applications.

Energy sources and multi-input DC-DC converters used in hybrid electric vehicle applications – A review

In this paper, couple of non-isolated high gain multi-input DC-DC converter (MIC) topologies are presented and their salient features are compared. Each of the high gain MICs are synthesized from two identical high gain (HG) DC-DC converter structures. The input power supply to each of the MIC topologies comprising of two parallel connected HG converters is obtained from two separate sources. The individual outputs of the two HG converters are connected in parallel with each other through ORing diodes and deliver the required load power. The individual HG converter is developed from an interleaved boost converter (IBC) configuration. Its voltage gain is enhanced by judiciously adopting hybrid combination of various gain extension techniques like (i) coupled inductors, (ii) voltage-lift technique and (iii) voltage multiplier cells. The presented MIC topologies yield a voltage gain of about 10.33 and 21.11 at 200 W power level. Moreover, experimental results demonstrate the power sharing concept of both the MICs when both the input sources are available. In addition, the ruggedness of the proposed MIC structure is clearly validated through the experimental results obtained when only one source supplies the load.

This paper proposes a new topology for multi-input multi-output Buck-Boost DC-DC converter based on the concept of matrix and Buck-Boost Converters to interface efficiently between DC loads and various DC power sources in a microgrid. A power sharing process can be applied among the input sources and output loads to control the contribution of each input sources in supplying the output loads. The input sources can be used in various power and voltage ranges and the output voltages can change from values greater than the maximum to lower than the minimum input voltages. Theoretical analysis and simulation results are presented.

In this paper, a comparative performance analysis was proposed for PV fed EV charging system for ZETA and SEPIC DC-DC converter topologies. The utilization of Electric vehicles has gained significance in recent years due to societal awareness and increasing concern for environmental sustainability. EV charging time plays a vital role in modern-day vehicle commuting with energy-efficient performance. The selection of an appropriate DC-DC converter topology plays a significant role for fast charging with improved efficiency. The paper presents an optimized parameter selection, design, simulation methodology & relative performance analysis between the ZETA and SEPIC converter topologies with and without MPPT algorithm for EV charging applications. The MPPT algorithm based on P&O and IC techniques investigates for switching time of the ZETA and SEPIC converters under standard test conditions of solar PV panel i.e., at irradiance of 1000 W/m2 and temperature of 25oC. In this article MATLAB/Simulink was developed to explore the performance of both topologies with and without MPPT approaches for battery SoC, battery voltage and charging current. The study shows that the battery charged from an SoC of 50% to 50.035% for SEPIC converter while the ZETA converter charges from 50% to 50.025% with a similar simulation time of ten seconds with Solar power input. The results demonstrate the DC-DC SEPIC converter is the best choice for EV charging applications through the PV system.

Fuel cells are being increasingly used in wide range of applications for stand-alone and grid connected systems due to their high efficiency and low emissions. A power conditioning unit, consisting of DC-DC converter and an inverter, is invariably used as an interface between the fuel cell and the load in a typical fuel cell system for ac applications because of unregulated nature of fuel cell voltage. In this research, a comparative analysis of different input ripple reduction methods, input current ripples, the output voltage ripples, and the size of passive components with high efficiency compared with the other topologies is done. The different dc/dc converter topologies is compared such as conventional Boost Converter (BC), Multi Device Boost Converter (MDBC), and Two-Phase Interleaved Boost Converter (IBC), Multi Device Interleaved Boost Converter(MDIBC) to verify its dynamic performance. The DC-DC converter topologies are designed and investigated by using MATLAB/Simulink. The simulation and experimental results have signified that interleaved converter topology is more efficient than other dc-dc converter topologies in achieving high performance and reliability for high-power dc-dc converters.

This paper introduces a Two-input Switched Inductor Capacitor Hybrid Buck-SEPIC DC-DC converter (TISICHBSC) topology useful for various DC power applications. The converter falls into a category of electrically coupled Multi-input DC-DC Converters (MICs) which can provide adequate bucking of voltage even at higher duty ratios. As it offers excessive bucking the converter uses additional energy storage elements, so it is of sixth order family MIC. It is a modified converter topology of earlier proposed Two-input Hybrid Buck SEPIC (TIHBSC) converter. A 36/12 V to 24 V, with power capacity of, 100W prototype is considered to validate the proposed concept. The controllers are designed in discrete domain based on Quantitative feedback theory (QFT) to obtain the robust performance. The theoretical analysis is validated through simulations.

Dual input dc-dc converters have two input voltage sources or one input source and an energy storage system like ultra capacitor, PV, battery, super capacitors and a single output load. In order to process the power in hybrid energy systems using reduced part count, researchers have proposed several multi-input dc-dc power converter topologies to transfer power from different input voltage sources to the output. This paper compares non-isolated dual-input converter topologies topologically ,based on the components count, various fields of application and different modes of operation for hybrid systems mainly used in electric vehicles and renewable energy systems composed of energy storage systems (ESSs) with different voltage-current characteristics. Dual input dc-dc converter topologies considered in this paper are investigated using MATLAB and PSIM software and output voltage and inductor current waveforms are shown.

The high power dc-dc converters emerged as the key circuit element for the future multi-terminal dc grid due to rapid increase in the number of HVDC transmission lines. Beside power conversion, it can provide many functionalities such as bidirectional power flow, power flow control and dc fault isolation. Recently, many high power dc-dc converter topologies have been proposed in the literature for applications in the dc grid. The problem with these, however, is that they are not classified in to various categories based on different parameters such as internal isolation, power density or conversion ratio. This review proposes a taxonomy of most efficient state-of-the-art dc-dc converter topologies based on the structural affinities. Most prominent converters are classified in to two major groups based on the internal isolation. Then, the basic structure, operating principle and performance capabilities accompanied by key advantages and major limitations of each converter is discussed. Furthermore, this study highlights the most suitable converter topologies for the application of HVDC grid interconnection.