Converter For Renewable Energy Applications Research Articles

Implementation and reliability analysis of a new transformerless high‐gain DC‐DC converter for renewable energy applications

AbstractIn this paper, a new high‐gain quadratic boost DC‐DC converter is proposed for a DC microgrid. The converter has a voltage multiplier cell made up of switched inductors to obtain a high voltage at the output. It has a common ground and continuous input current, which makes the converter feasible for renewable energy and DC microgrid applications. The proposed topology consists of a single switch which makes the control simple. The converter achieves a gain of four times the traditional quadratic boost converter and can also operate in continuous and discontinuous conduction modes. The voltage stress across the switch and all the other passive components is less than the output voltage. The variation of voltage gain in the case of parasitic resistances is also shown. The reliability analysis of the proposed converter using Markov modeling is also presented by considering both open‐circuit and short‐circuit faults across the semiconductor devices. A 200 W prototype of the converter is also prepared and the hardware results of the converter are also presented in the paper. The converter operates at high efficiency of 96% at 100 W output power operation. The variation of reliability with different converter parameters like the duty cycle and the input voltage is also discussed in the paper. The experimental results in fault conditions are also shown.

Design and Performance Evaluation of DC - DC Step up Sepic Converter for Photovoltaic Based off Grid Application

Solar energy resourses is abundantly available but its exploitation through PV system is not economically feasible. In order to optimize the power output, an electronics device should be integrated with solar PV system. A high classical classical single ended primary inductor converter SEPIC converter for renewable energy applications was designed, constructed and experimentally tested. The voltage multiplier cell (consists of two diodes and two capacitors) was incorporated with SEPIC to design a DC – DC boost converter for PV application. The new converter can improve the capacity of 10 V DC input to output 60 V DC, the design circuit will boost input voltage and maintain a constant voltage output. The performance of the proposed topology was authenticated and the result achieved from the implemented prototype are in good agreement with the design strategies. The effects of input parameters such as sun radiation and useful power input on PV system and DC-DC converter outputs were investigated. Results comfirmed that the DC-DC converter was perfectly designed using Multisim software and accurately constructed, when integrated with solar PV system under no load and on load conditions.

Switched Inductor Based Transformer less Buck-Boost Converter For Renewable Energy Application

Switched Inductor Based Transformer less Buck-Boost Converter For Renewable Energy Application

Revealing the effect of various organic ligands on the OER activity of MOF-derived 3D hierarchical cobalt oxide @ carbon nanostructures

Intensive research work on the robust and highly active non-precious electrocatalysts for oxygen evolution reactions (OERs) under lenient conditions has been attracted much attention to industrialize water-splitting processes. In this work, we design and develop the cost-effective and highly active Co3O4@C nanostructures derived from two different metal-organic framework (MOF) ligands, including terephthalic acid (PA) and trimesic acid (TMA), through a wet chemical strategy. The unique morphologies (donuts and nanorods over a carbon layer) and excellent surface area of the as-prepared catalysts including Co3O4@C-PA and Co3O4@C-TMA are resulted the increased active centers for OER activity. Among the prepared electrocatalysts, Co3O4@C-TMA exhibits favorable Tafel kinetics (85.18 mV dec−1) and small overpotential (320 mV@10 mA cm−2) for oxygen evolution. In addition to design the effective Co3O4@C electrodes for OER activity, this study also proposes the various multi-functional catalysts for renewable energy conversion applications.

New Structure of Single-Switch Ultra-High-Gain DC/DC Converter for Renewable Energy Applications

This study introduces a new modified high-gain single-switch single-ended primary-inductor converter-based dc/dc converter. The low input ripple of the proposed converter makes it very suitable for renewable energy applications. In the proposed topology, a three-winding coupled-inductor and a voltage doubler rectifier are used to achieve high voltage gain without needing an extreme duty cycle. This circuit can provide an ultra-high voltage conversion ratio without requiring a large number of the turns ratio of the three-winding coupled-inductor (TWCI). Due to a regenerative clamped circuit, the leakage energy of the coupled-inductor is recycled; thus, the maximum voltage spike across the single-power switch is restricted. Therefore, <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> with a low maximum voltage rating can be utilized, which can alleviate the conduction power dissipations of the converter. Here, the switching power losses have been reduced significantly due to the circuit's soft-switching operation for the switch and all diodes. The steady-state analysis of the proposed converter is discussed thoroughly. Finally, the theoretical analysis is verified through the experimental results from a sample prototype (400-W, 25-400 V).

Robust sliding mode controller for buck DC converter in off-grid applications

This paper presents a robust sliding mode controller of DC-DC buck converter for renewable energy applications, such as photovoltaic systems in off-grid configurations. Photovoltaic systems in off-grid configuration are exposed to significant variations in input voltage and power loads. The proposed sliding mode controller presents a simple and efficient method of continuously updating the duty cycle of a pulse width modulation unit (PWM) of a buck converter. The PWM unit is operated at constant switching frequency of 10 kHz carrier signal and varying duty cycle. The differences in input voltage and power load are treated as two bounded uncertainties, thus eliminating the need for input voltage sensor and output current sensors leaving the system with a single sensor required to measure the converter output voltage. That is, measured output voltage is compared with the reference voltage to continuously update the average duty cycle value of PWM unit. Adjustment of PWM duty cycle is performed while maintaining the sliding condition always fulfilled. The simulation results of the proposed controller showed robustness and accuracy against power load fluctuation, changes in desired output voltage, and variations in the input supply voltage that may result from the varying level of irradiance and temperature.

A variable wind harvesting based induction generator using variable voltage and variable frequency converter for renewable energy applications

ABSTRACT This paper proposes the design and development of a power electronic converter intended for induction generator (IG) to harvest the power generated from variable wind in a wind energy conversion system (WECS). The squirrel cage induction generator (SCIG) is anticipated for fairly fixed speed operation, while its speed should be super-synchronous with respect to the synchronous speeds corresponding to the frequency of the receiving alternating current bus bar. In the existing WECS, SCIG requires a minimum wind velocity below which generation is not possible. The novelty of the proposed method is that the range of wind velocities can be selected over which generation is possible. To achieve this, the proposed system makes use of a variable voltage and variable frequency converter (VVVFC). Depending upon the wind velocity, the frequency of the VVVFC is adjusted such that the speed of the turbine and hence the IG are virtually maintained at super synchronous speeds with respect to the frequency of the AC side of the VVVFC. In addition, the perturb and observe-based maximum power point tracking (MPPT) scheme is also implemented. The proposed methodology also includes a series compensated buck–boost converter (SCBBC) inserted between the battery and the direct current link of the final inverter that feeds an RL load. Simulation in the MATLAB Simulink environment is carried out, and an experimental prototype has also been developed to validate the proposed method. Based on the results, it is found that the proposed variable speed system with the integration of VVVFC, SCBBC, and MPPT harvests is 78% greater than the conventional fixed speed system.

Design and Analysis of a New Coupled Inductor-Based Interleaved High Step-Up DC-DC Converter for Renewable Energy Applications

In this paper, a novel nonisolated interleaved high step-up DC-DC converter is proposed based on the coupled inductor and voltage multiplier cell (VMC) methods. Due to the interleaved structure, its input current ripple is low. The low input current ripple and also high power efficiency make the proposed converter suitable for renewable energy applications like photovoltaic (PV) and fuel cell (FC) power generation systems. The windings of the coupled inductors are combined with VMCs to further increase the output voltage with a low power switch’s duty cycle. This combination also leads to obtaining a flexible voltage gain that can be adjusted by coupled inductors’ turns ratio and power switches’ duty cycle. The voltage peaks over semiconductors are much lower than the output voltage. Therefore, low-rated semiconductors can be used for the implementation of the proposed converter, which can reduce the cost and volume. Generally, high voltage gain, low voltage, current stress of power switches, low input current ripple, high efficiency, common ground between the input and output ports, and a low number of elements are the main benefits of the suggested structure. The operation principle, steady-state analysis, and comparison with other converters are presented to show the advantages of the suggested converter. Also, a prototype is built, and the experimental results are presented to prove the theoretical analysis. This prototype is implemented with 200 W rated power, 25 V∼400 V voltage conversion, and 50 kHz switching frequency. Additionally, the efficiency is measured at 95.3% at the rated power.

Investigation of a Novel Interleaved Buck Converter for Renewable Energy Applications: Design and Analysis

In this paper, a new interleaved buck converter with soft-switching is investigated. The soft-switching condition, zero voltage zero current switching (ZVZCS) of IGBTs during turn-on is obtained with the help of a soft-switching cell that includes active and passive devices that is incorporated in the interleaved buck converter (IBC). The presence of the soft-switching cell reduces the switching losses and improves the overall efficiency. The IGBTs in the converter achieved ZVZCS turn on operations, while converter is operated under both light and heavy loads. The principles of operation and theoretical aspects of the proposed converter system 400 V / 110 V / 2.5 kW are verified with simulation analysis.

A Nonisolated Transformerless High-Gain DC–DC Converter for Renewable Energy Applications

Dc–dc converters with a high gain, continuous input current, and common ground are usually employed in renewable energy applications to boost the generated output voltage of renewable energy sources. In this paper, a high-gain dc–dc converter comprising a voltage multiplier cell (VMC) and a common ground with continuous input current and low-voltage stress across semiconductor devices is proposed. The converter produces a voltage gain of about ten times compared to the conventional boost converter at a duty ratio of 50% by utilizing switched capacitors and switched inductors. The simultaneous operation of both the switches with the same gate pulse offers easy and simple control of the proposed converter with a wide range of operations. The boundary operation of the converter is analyzed and presented in both modes, i.e., continuous conduction mode (CCM) and discontinuous conduction mode (DCM). Ideal and nonideal analysis of the converter is carried out by integrating real models of passive elements and semiconductor devices by using PLECS software. The simulation is also used to calculate the losses and hence the working efficiency of the converter. The performance of the converter analyzed in the steady state is compared with various similar converters based on the voltage boosting capability and switching stresses. A hardware prototype is also developed to confirm and validate the theoretical analysis and simulation of the proposed converter.

Design and modelling of a new three winding coupled inductor based high step‐up DC–DC converter for renewable energy applications

This paper proposes a new three winding coupled inductor (TWCI) based DC–DC converter with high voltage gain capability. Continuous input current with low ripple, low number of components, simple structure, high efficiency, and common ground between input and output ports make it suitable for renewable energy applications such as photovoltaic (PV) systems. Voltage multiplier cells (VMCs) are utilized to enhance the output voltage and reduce the voltage stress across the power switch. The voltage gain can be adjusted by the duty cycle of the power switch and turns ratio of the TWCI. Thus, a flexible voltage gain is obtained, and there is no need for a higher duty cycle. On the other hand, the proposed converter has only one power switch with reduced voltage stress and low ON-state resistance. Therefore, a low-rated power switch can be used, which decreases the cost and volume of the presented converter. Operation principles, steady-state analysis, and comparison with other similar structures are provided. To frequency behaviour investigation, modelling and dynamic analysis are presented. Additionally, the effect of the proposed converter's parameters on the frequency response is evaluated. Finally, experimental results are presented to prove the effectiveness of the suggested converter.

A non‐isolated high step‐up MIMO DC–DC converter for renewable energy applications

This article offers a non-isolated DC–DC converter with dual-ports for input and dual-ports for output with high step-up ability. The converter has different levels of output voltage. The benefits of the proposed topology consist of the capability of giving high voltage gains with low duty cycle amount, the simple control of each duty cycle, and low per-unit peak voltage stress (PPVS) over the semiconductors. The presented structure is suitable for clean energy applications. The operation principles, steady-state analysis, voltage, and current equations extraction in continuous conduction mode (CCM) are carried out. To confirm the superiority of the proposed topology, the efficiency of the converter is compared to other multi-input (MI) and multi-output (MO) converters which were recently published in the literature. Eventually, an implemented prototype in the laboratory is used to verify the performance of the proposed structure.

Resonant Power Converters for Renewable Energy Applications: A Comprehensive Review

Studies on resonant power converters (RPCs) have received much attention due to the rapid growth of their potential in modern power and renewable energy applications such as photovoltaic, electric vehicles, wind, and fuel cells. Consequently, a significant number of studies focusing on RPC topologies for renewable energy applications is available. Generally, these studies have addressed several aspects, such as the development of their soft switching feature, smooth waveforms, high power density, and high efficiency. With this in mind, the present paper aims to review the development of the RPCs, challenges in their development, and comparison between common topologies as highlighted in literature. In addition, the use of RPCs in various applications of renewable energy is highlighted, focusing on some of the recently utilized topologies based on their constructions and achievements. There are still several issues and challenges in research that need to be considered for future improvement of the RPC performance in renewable energy applications. The improvement may require modifications on the circuit design or control strategies.

Presenting of the Magnetic Coupling-Based Transformer-Less High Step-Up DC-DC Converter for Renewable Energy Applications

This study presents a new high step-up converter based on the voltage multiplier cell and coupled inductor for renewable energy applications such as fuel cell and photovoltaic power systems. This converter achieves a high voltage conversion ratio using a coupled inductor and voltage multiplier cell (VMC). The voltage multiplier cell acts as a passive clamp circuit and reduces the maximum voltage across the power switch. The suggested topology has only one power switch in its structure, which leads to low cost and volume. The other benefits of the proposed structure are low components count, low input current ripple, low voltage stress throughout the semiconductors, high efficiency, zero-current switching (ZCS), and zero-voltage switching (ZVS) of diodes. Besides, due to the soft-switching condition of the diodes, the reverse recovery problem can be decreased. To show the effectiveness of the suggested topology, operation survey, steady-state analysis, and efficiency calculation are provided. Additionally, the comparison study with other similar converters illustrates the superiority of the proposed structure. Finally, an experimental prototype with 150 W rated power, 50 kHz switching frequency, and 24 V input voltage is implemented to prove the mathematical analysis and effectiveness of the proposed DC-DC converter.

A non‐isolated high voltage gain DC–DC converter based hybrid switched LC network for renewable energy applications

AbstractThis paper presents a new high voltage gain DC–DC converter for renewable energy applications without the need for a galvanic isolation. The converter combines the active switched‐inductor network and the switched‐capacitor network to boost the voltage gain ratio without a high duty ratio. The presented converter uses clamping capacitors to minimize the maximum voltage stress of the power‐switching devices; hence, low power rating devices can be employed. Furthermore, the converter operates at a high switching frequency. Therefore, the use of small inductors and capacitors is the main advantage. The paper describes in detail the operating mode and design procedures of the converter. Additionally, the associated power losses and the efficiency are calculated. A 200‐W laboratory prototype was fabricated, and experimental results verified the theoretical analysis.

Evaluation and Improvement of a Transformerless High-Efficiency DC–DC Converter for Renewable Energy Applications Employing a Fuzzy Logic Controller

Evaluation and Improvement of a Transformerless High-Efficiency DC–DC Converter for Renewable Energy Applications Employing a Fuzzy Logic Controller

Non-Isolated Interleaved Hybrid Boost Converter for Renewable Energy Applications

DC-DC boost converters are necessary to extract power from solar panels. The output voltage from these panels is far lower than the utility voltage levels. One of the main functions of the boost converter is to provide a considerable step-up gain to interface the panel to the utility lines. There are several techniques used to boost the low panel voltage. Some of the issues faced by these topologies are a high duty ratio operation, complex design with multiple active switches and discontinuous input current that affects the power drawn from the panel. This paper presents a boost converter topology that combines the advantages of an interleaved structure, a voltage lift capacitor and a passive voltage multiplier network. A mathematical analysis of the proposed converter during its various modes of operation is presented. A 100 W prototype of the proposed converter is designed and tested. The prototype is controlled by a PIC16F18455 microcontroller. The converter is capable of achieving a gain of 10 without operating at extremely high duty ratios. The voltage stress of the switch is far lower than the maximum output voltage.

An Improved double input dc converter for renewable energy application

A hybrid renewable energy system with more than one source like solar photovoltaic, wind energy, battery, and fuel cell increase the system’s reliability and flexibility. A suitable power electronic converter is required to integrate these sources and interface with the load simultaneously. Therefore, the paper’s main objective is to recommend a novel double input dc converter for a hybrid renewable energy system. This power electronic converter efficiently integrates the sources and supplies the load demand. The critical waveforms for various modes of operation of the proposed converter are discussed in detail and the output voltage equation is derived. The proposed double input converter has a simple structure and reduced components. The performance comparison with the currently reported converters in the literature is presented, and the double input converter is simulated and analysed using MATLAB/Simulink software. The theoretical analysis is validated through the simulation results of the designed double input dc converter for renewable energy application.

A Novel Hybrid High Gain DC-DC converter for Renewable Energy Applications

A Novel Hybrid High Gain DC-DC converter for Renewable Energy Applications

An interleaved DC charging solar system for electric vehicle

&lt;span lang="EN-US"&gt;This paper investigates the performance of conventional boost converter, &lt;br /&gt; 2-phase interleaved boost converter and 3-phase interleaved boost converter for renewable energy applications especially for solar-powered energy. The advantages of using coupled inductors in interleaved boost converters include increased system efficiency, reduced core size, and also reduced overall current and voltage ripples which increases the lifetime of renewable energy resources. In this paper, the uses of boost converters have been focused explicitly on the interleaved DC-DC charging from a solar-powered battery into electric vehicle (EV) battery storage. Hence, this paper aims to investigate a suitable charging process mechanism from a photovoltaic (PV) battery storage system into EV powered battery system. Using the application of a boost converter with reduced ripple current and ripple voltage decreases switching losses and increases conversion efficiency. The simulation is carried out by using Simulink/MATLAB to evaluate the performance of each boost converter. The results successfully demonstrate the ability of the proposed charging system with an energy efficiency of 90%.&lt;/span&gt;