Inductor Converter Research Articles

SiC switch‐based isolated DC‐DC converter for simultaneous charging of Li‐ion batteries of different voltage ratings for low‐ and medium‐power electric vehicle battery charging application

SummaryThe use of electric vehicles (EVs) has gained traction in recent years. With the widespread use of EVs in the future, the waiting time before charging will be high due to the use of slow chargers in developing countries. This work proposes a novel DC‐DC converter based on an isolated single‐ended primary inductor converter (SEPIC) and isolated Ćuk converter to enable simultaneous charging of batteries of low‐ and medium‐power EVs. The proposed converter operates without spikes in input and output currents, even during a sudden source disturbance. It can charge one battery at the output voltage level and simultaneously charge two batteries at half the output voltage. Simulation results for open‐loop and closed‐loop operations are provided to validate the converter operation and the simplicity of control. The proposed converter operation has been experimentally validated using a scaled‐down prototype by charging one 48 V lithium‐ion battery and then simultaneously charging two 24 V lithium‐ion batteries. The converter's response is provided to present the novelty and advantages of the proposed converter. The proposed converter uses fewer switches, diodes, inductors, and capacitors. The size of the system is reduced due to the high switching frequency operation of SiC devices. A low‐side gate driver is sufficient for driving the MOSFET, and the control is simple. The proposed converter offers a new and simple converter to charge multiple low‐ and medium‐power EV batteries of different ratings simultaneously with a low component count.

SEPIC-Based DC–DC Converter with Soft Switching Operation for Wide Conversion Operation of E-Automobiles

The article introduces a novel approach for designing a DC-to-DC converter utilizing the single-ended primary inductor converter topology for wide conversion operation in Electric Automobiles (E-Automobiles), with a focus on soft switching operation. A maximum power point tracking approach based on hierarchical multi-heuristic chicken swarm optimization is used to optimize the performance of the solar. The output of the converter is then fed into a three-phase inverter, where pulse width modulation is generated using a fuzzy logic controller (FLC). The inverted output is filtered using a low-pass filter before being supplied to the load, which is a brushless direct current motor in this case. The performance of the system is evaluated using traditional proportional-integral-derivative controllers and FLC controllers, considering parameters such as maximum amplitude (rise time), the time at which the system achieves its peak value (peak time), the time delay between input and output (delay time), the amplitude of the output voltage and current (output voltage and output current), and the discrepancy between the desired and actual values in a stable state (steady-state error). Comparative analysis indicates that the proposed design incorporating an FLC controller yields superior results compared to other approaches.

A novel step-up/step-down DC-DC converter based on flyback and SEPIC topologies with improved voltage gain

A novel step-up/step-down DC-DC converter with improved voltage gain characteristics is suggested in this paper. The proposed converter combines flyback and single-ended primary inductance converter (SEPIC) converters. The voltage control loop design is simplified due to the use of only a single controlled switch. It has been discussed how switch duty cycle affects voltage gain. This relationship demonstrates that the proposed converter voltage gain is improved compared with flyback and SEPIC converters. However, compared to flyback and SEPIC converters, it has a higher voltage gain at any given duty cycle. The proposed converter operation is thoroughly discussed, the associated equations are derived, and its parameters are expertly designed. Moreover, it is designed to supply a DC load of 2.5 kW, 500 V, and 5 A. The proposed converter efficiency exceeds 84% under rated load conditions. Additionally, it is also presented as an adapter for electric vehicles. The waveforms associated with the simulation of the converter across the universal line voltage of 110-260 Vrms are shown. At both line voltages, the total harmonics distortions (THDs) of the line current are 17.12% and 27.26%, respectively. MATLAB/Simulink is utilized for validation in order to validate the topology for different applications.

High gain modified SEPIC converter with asymmetrical switched inductor super lift cell for renewable energy applications

ABSTRACT This paper provides a modified single-ended primary inductor converter (SEPIC) with an asymmetrical switched inductor super lift cell (ASISLC) for renewable energy applications. Solar, fuel cells, and so on, provide low output voltage, which is not sufficient for high voltage dc grid or dc loads. Therefore, the existence of a high gain DC-DC converter is mandatory. The proposed converter provides high gain, high efficiency, and less voltage stress at a low duty cycle. The proposed converter incorporates switched inductor together with a super lift cell. The super lift cell has a charge pump capacitor is connected in an asymmetrical fashion. The proposed converter offers continuous current at the input together with the above-mentioned advantages. This paper explains the operation of the ASISLC SEPIC converter in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The operating principle, theoretical analysis, design process, and comparison of the suggested converters with converters from the literature that use similar operating principles are all discussed in this paper. A MATLAB simulation is done and their results are provided. Finally, a hardware prototype for 200W, 50 kHz switching frequency is built and their results are validated to authenticate the effectiveness of the proposed converter.

Comparison of efficiency of various DC-DC converters connected to solar photovoltaic module.

In this paper, an attempt is made to build an effective solar photovoltaic (PV) system considering geographical aspects such as irradiance and temperature using the single-diode equation model. Furthermore, a comparative analysis of various DC-DC converters (buck, boost, inverting buck-boost, non-inverting buck-boost (NIBB), Cuk, and single-ended primary inductance converter (SEPIC)) connected to a solar photovoltaic (PV) module was conducted in order to determine the optimal combination of DC-DC converter and solar PV. Moreover, the R, L, and C parameters for the converters have also been proposed to gain optimum efficiency from the solar PV system, and it has been shown that increasing the resistance decreases the ripple value. Furthermore, it has been shown that Ns and Np values of 36 and 1, respectively, result in 199 W of output power from a solar PV module at the maximum power point (48V). The obtained results show that NIBB and SEPIC simulations gave the best results, with efficiencies of 93.27% and 92.35%, respectively.

Switched inductor‐capacitor‐based quasi‐Z source converter for renewable energy source integration

SummaryIn applications involving renewable energy sources such as solar PV and fuel cells, the high‐gain DC–DC converter must have the following desirable characteristics: high voltage gain, continuous input current with low ripple content, common ground structure, reduced voltage stress on the components, and high efficiency. In addition, the requirement of a lower duty ratio to produce a higher voltage gain aids in reducing the converter's inductor core saturation issue. In this research, a converter employing switched capacitor–inductor cells and a quasi‐Z source network with the aforementioned features is proposed. The steady‐state analysis in both CCM and DCM is presented. The performance of the converter including the parasitic effect of converter components is analyzed. This paper also includes a comprehensive comparative analysis highlighting the benefits of the proposed converter. A small signal model and the output‐to‐control transfer function are derived. The analytical performance of the proposed converter is validated using a hardware prototype of 500 W, 50 kHz. A compensator is designed to improve the dynamic closed‐loop performance and validated experimentally. The experimental findings for boosting 48 V input to 650 V output are provided. The results prove that the proposed converter has the advantages of high gain with a lower duty ratio, low voltage stress on components, continuous input current with low ripple content, and a common ground structure.

Design and Development of SECU Converter Cascaded Control for EV Applications

A power factor correction-based hybrid converter operating in continuous conduction mode with high efficiency and voltage conversion ratio is presented in this publication. The proposed converter is obtained by integrating the single-ended primary inductance converter (SEPIC) and the Cuk converter to produce a DC symmetrical balanced dual output voltage across the load without a common ground between source and load. The modeling of the converter by state space model is derived using the state space averaging technique. The cascaded control strategy using a multiplier approach with a cascaded controller and PI-Hysteresis-based controller is employed for shaping the source current and load voltage. The performance analysis of the suggested converter under steady state and transient conditions is carried out in MATLAB/Simulink software tool. The observed result displays that cascaded control yields excellent performance compared to PI-Hysteresis control in satisfying the IEC 61000-3-2 standard by maintaining a power factor close to unity, and reduced total harmonic distortion.

Analysis and Design of Two-Switch Enhanced Gain SEPIC Converter

A two-switch, enhanced gain single-ended primary inductor converter (SEPIC) is proposed with key benefits of enhanced voltage gain, reduced voltage stress and better efficiency, as it is suitable for low voltage green energy applications. Further, reduced voltage stress between the intermediate capacitors is a notable attribute of this converter. The converter components are designed with proper design procedure and a steady-state analysis is performed to study its operation. A small-signal analysis of the proposed converter is also presented to examine the pole-zero positions. Also, this paper includes the performance comparison with other similar converters. Simulation and experimental results of the proposed converter with a rating of 100 W/50 kHz and input and output voltages of 20 V and 200 V, respectively are provided. Efficiency as well as power loss distribution are also investigated in this study.

Bridgeless isolated sepic PFC for EV battery charging using ANN controller

The power quality of an Electric Vehicle (EV) battery charger is improved in this work using a bridgeless isolated single ended primary inductance converter (SEPIC). Owing to the excessive amount of conduction losses associated with the conventional Diode Bridge Rectifier (DBR) based Power Factor Correction (PFC) circuit; a Bridgeless circuit model is preferred in this work. The safe functioning of the PFC circuit is further ensured by selecting an isolated topology over a non-isolated converter topology. With the use of an artificial neural network (ANN) controller, the converter's operation is improved in terms of rising time, overshoot, steady state error and settling time. Distortions in the input current are curtailed with the aid of Hysteresis Current Controller (HCC). The entire work of the proposed converter in terms of design equations and several operating modes is detailed elaborately. The input current displays functioning with a unity power factor for the full charging period. The proposed Bridgeless Isolated SEPIC PFC's efficacy in improving the power quality of the EV charger system is determined using simulation results from MATLAB and hardware implementation utilising a DSP30F411 controller.

A new single ended primary inductor converter with high voltage gain, low voltage stress and continuous input current

SummaryThis paper proposes a single‐ended primary‐inductor converter (SEPIC)‐based DC‐DC converter with higher voltage gain, continuous input current, and lower voltage stress. Suggested converter uses three‐winding coupled inductors and voltage multiplier for boosting function. The proposed structure stores lower amount of energy due to lower current magnitudes of used inductors. Moreover, using voltage multiplier reduces the voltage stress of the elements connected to the output terminals of the proposed converter. By reducing the voltage stress, in addition to reducing the rating of output elements and costs, the overall efficiency will also be increased. Also, a clamping circuit is used to diminish the voltage stresses on power switch. In order to represent the advantages of the proposed converter over some other converters in the viewpoints of the number of the used elements, continuity of input current, voltage gain, the voltage stress on power switch, and output diode, a comparison study is provided. To validate the practicability of the proposed converter, a 200‐W prototype is implemented and the experimental results are provided.

A Novel Variable On-Time Control Scheme for Boundary Conduction Mode SEPIC PFC Converter

Power factor correction (PFC) can be achieved by a single-ended primary inductor converter (SEPIC) operating in boundary conduction mode (BCM) with conventional constant on-time (COT) control, but it is challenging to achieve low total harmonic distortion (THD) and high-power factor (PF), particularly at high input voltage. A variable on-time (VOT) control strategy for BCM SEPIC PFC converter without input voltage feedforward and multiplier circuits is proposed to realize unity PF in this paper. By using a variable slope sawtooth generator whose slope is controlled by the duty cycle of the main switch to adjust the conduction time of the main power switch of the converter, the proposed VOT control scheme can use a simple and easy-to-implement circuit to enhance the PF and decrease the THD significantly, especially at high input voltage. The simulation model and 100W experimental prototype are built to verify the feasibility of the suggested control method. Simulation and experiment results demonstrated that the novel VOT control scheme remarkably enhances PF and decreases THD without affecting the efficiency by contrast with the conventional COT control.

Optimizing PI Controller for SEPIC Converter with Optimization Algorithm

This paper refers to work evaluating the performance of PI controllers integrated with optimization techniques designed for Single Ended Primary Inductance Converters (SEPIC). With the SEPIC converter, a constant voltage output can be retained while switching a range of dc voltages. Performance of PI controller has been combined with Artificial Bee Colony (ABC) Algorithm, Particle swarm optimization (PSO) Algorithm, Whale optimization algorithm (WOA). In this research, a performance analysis of the SEPIC dc-dc converter controller constructed with the aforementioned optimization strategies is carried out. Statistics proves WOA provides best stability exhibited with fast response when compared to other optimization techniques.

Fuzzy Logic Control-Based Charge/Discharge Equalization Method for Lithium-Ion Batteries

Abstract In this article, a grouping equalization circuit based on the single-ended primary inductor converter (SEPIC) circuit is proposed, which can transfer energy between any single cell or grouped cells. Compared with the traditional equalization circuits that transfer energy between adjacent cells, the SEPIC circuit can directly connect any two batteries that need to be equalized; the number of circuit equalization paths is calculated based on a directed graph and then used as a basis for grouping the batteries to improve the equalization efficiency. In the charging or discharging condition, the amount of charge remaining in the battery to be charged or discharged is used as the control variable for equalization, and intragroup equalization is completed before intergroup equalization starts. To ensure the equalization efficiency of the battery, the equalization current is controlled by fuzzy logic control (FLC). Taking ten single cells as an example based on the calculation of the number of equalization paths, two 5-cell groups can be confirmed as the optimal solution. Experiments were performed on matlab/simulink simulation platform, and the results show that compared with the traditional adjacent inductance equalization circuit, the equalization circuit proposed earlier reduces the time needed for equalization by 35.8%; compared with the traditional average difference method, in charging and discharging conditions, the FLC algorithm saves times by 20.5% and 31.3%, respectively, and energy loss is reduced by 9.1% and 5.5%, respectively, which verifies the feasibility of the proposed equalization scheme.

New PWM Soft Single Switched Step-Up Coupled Inductor Converter with Improved Efficiency

This article presents a new high-step-up converter based on the combination of the diode-coupled inductor technique and a Zeta-Flyback converter. This technique helps to achieve high-step-up gain, also provides soft-switching condition. The switch turns on at zero-current switching (ZCS) and extremely near zero-voltage switching (ZVS) and turns off at ZVS. The diodes are turned off at ZCS, so the reverse recovery problem is alleviated. Experimental results were obtained as a 100 W to validate the converter’s performance, and the concepts are presented in the article. At the end of article, a family of nonisolated and isolated converters based on the studied converter is proposed. The proposed converters, which are based on the CUK family converters, benefiting from the intrinsic magnetizing isolation property.

A Double-Switch Single-Transformer Integrated Equalizer for the Recycled Power Battery String of Automatic Guided Vehicles

Applying the recycled power battery to automatic guided vehicles can greatly reduce system cost and prolong the life cycle of the battery. However, the consistency of recycled power batteries is poor, and the imbalance of battery voltage will occur during the charging or discharging process. Therefore, a double-switch single-transformer integrated equalizer is proposed to balance automatic guided vehicles in both charging and discharging operations. The equalizer's multiwinding transformer shares the dc–dc converter's inductor, and the secondary side generates current by utilizing the current ripple on the primary windings. The battery string is balanced by the multiwinding transformer, without extra switches, when the circuit works in charging and discharging mode. A prototype for four battery cells is built to verify the proposed equalizer and its dynamic balance conditions, and a comparison with existing equalizers is presented. The results show that the system in both modes can realize the automatic balance without affecting the function of the dc–dc converter. The proposed circuit requires fewer components than the existing bidirectional integrated equalizer.

A Single-Stage Bridgeless Isolated AC–DC Conversion System for Light Electric Vehicles Charging Application

A 1- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\phi $ </tex-math></inline-formula> single-stage ac–dc power conversion unit employing bridgeless isolated modified single-ended primary inductor converter (BLIMSEPIC) is presented in this work for the light electric vehicles (LEVs) charger applications. Unlike the existing SEPIC and Cuk high-power factor (HPF) ac–dc converters, the presented BLIMSEPIC HPF ac–dc converter incorporates continuous input and output current features while operating under discontinuous current mode (DCM) condition. Therefore, it demonstrates excellent applicability in charging applications. The DCM operation considerably simplifies overall control architecture, as the presented BLIMSPEIC ac–dc converter exhibits inherent power factor correction capability under DCM operation, and therefore, significantly reduces the cost of control implementation. Besides, the continuous input and output currents attribute lessen the filter’s size and associated losses. Furthermore, the reduced voltage stress and zero current switching of semiconductor devices, together with the front-end bridgeless structure, considerably improve the conduction and switching losses of the charger. The operation, design, control, and performance of the BLIMSEPIC HPF ac–dc converter are experimentally verified, and corresponding results are presented to justify its efficacy for LEVs charging applications.

Adaptive Maximum Power Point Tracking Control Algorithm for Wind Energy Conversion Systems

For small-scale wind energy conversion systems (WECSs), an adaptive maximum power point tracking (MPPT) algorithm is presented in this paper to increase wind energy harvesting. For its adaptability across a wide range of WECSs and quick tracking of maximum power point, the proposed algorithm combines the computational behavior of hill climb search, tip speed ratio, and power signal feedback control algorithms. Using buck–boost-featured single-ended primary inductor converters, the proposed MPPT algorithm is implemented in this paper to extract maximum power from the entire wind velocity profile. A laboratory-scaled dc motor drive-based WECS emulator is used to test the proposed algorithm. The in-lab experimental setup's control schemes are carried out with the help of a 32-bit floating point digital signal controller called TMS320F28335. The experimental results demonstrate that the proposed algorithm's tracking capability is effective and efficient in both sudden and gradual wind conditions.

SWITCHING TECHNIQUE BASED ON HYBRID ALGORITHM OF MAXIMUM POWER POINT TRACKING APPLIED IN THE SINGLE-ENDED PRIMARY INDUCTOR CONVERTER INTEGRATED WITH GRID-TIED INVERTER PHOTOVOLTAIC GENERATION

This article aims to present a hybrid algorithm to control the performance of the maximum power point tracking of photovoltaic systems. The hybrid algorithm embedded in the controller generates a pulse width modulation with a predetermined frequency to set the converter with the single-ended primary inductor converter (SEPIC) topology via the metal-oxide-semiconductor field-effect transistor (MOSFET) drive. Furthermore, the output of SEPIC is integrated into the grid-tied inverter. This research can improve the performance of photovoltaic systems with SEPIC topologies integrated into grid-tied inverters. The results show that by using a hybrid algorithm-based switching technique, it is possible to save electricity consumption by 33.4 Watts. The novelty of this research is using a hybrid algorithm embedded in a low-priced controller and implemented in a converter based on SEPIC. To verify the results obtained, experimental and comparative results are also provided. Thus, the proposed technique can perform well and effectively. Keywords: Photovoltaic Technology, Hybrid Algorithm, Grid-Tied Inverter, Single-Ended Primary Inductor Converter DOI： https://doi.org/10.35741/issn.0258-2724.58.1.35

DC–DC Converter with Pi Controller for BLDC Motor Fuzzy Drive System

The Brushless DC Motor drive systems are used widely with renewable energy resources. The power converter controlling technique increases the performance by novel techniques and algorithms. Conventional approaches are mostly focused on buck converter, Fuzzy logic control with various switching activity. In this proposed research work, the QPSO (Quantum Particle Swarm Optimization algorithm) is used on the switching state of converter from the generation unit of solar module. Through the duty cycle pulse from optimization function, the MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) of the Boost converter gets switched when BLDC (Brushless Direct Current Motor) motor drive system requires power. Voltage Source three phase inverter and Boost converter is controlled by proportional-integral (PI) controller. Based on the BLDC drive, the load utilized from the solar generating module. Experimental results analyzed every module of the proposed grid system, which are solar generation utilizes the irradiance and temperature depends on this the Photovoltaics (PV) power is generated and the QPSO with Duty cycle switching state is determined. The Boost converter module is boost stage based on generation and load is obtained. Single Ended Primary Inductor Converter (SEPIC) and Zeta converter model is compared with the proposed logic; the proposed boost converter achieves the results. Three phase inverter control, PI, and BLDC motor drive results. Thus the proposed grid model is constructed to obtain the better performance results than most recent literatures. Overall design model is done by using MATLAB/Simulink 2020a.

High Gain Converter Design and Implementation for Electric Vehicles

In this paper, a new Single Ended Primary Inductance Converter based dc- dc converter operate in boost converter mode is proposed. The converter is designed by incorporating the quasi-Z source structure and switched capacitor cell. The salient features of the proposed converter are high range of voltage gain, less voltage stress across the semiconductor devices and high efficiency. This characteristic creates the high gain converter an exceptional interface among the dc source and the load inside the electric vehicle. The steady state analysis of this topology in continual operating mode and the transient behavior are analyzed. Finally, a prototype of the converter 100W/200V is fabricated to confirm the practicability with conceptual analysis of the high gain converter.