Single Ended Primary Inductance Converter Research Articles

An intelligent converter and controller for electric vehicle drives utilizing grid and stand-alone solar photovoltaic power generation systems

In this study, a battery energy management system for electric vehicle (EV) applications is proposed with a standalone photovoltaic (PV) source and controlled based on the availability of grid, PV source, load consumption, and energy stored in the battery. This paper proposes a single-ended primary-inductance converter (SEPIC) DC-DC converter for charging the battery through the utility and PV source that provides good load regulation. The bidirectional nature of the proposed DC-DC converter provides the charging and discharging of the EV battery in the succeeding modes of operation, i) grid-tied charging, ii) PV-tied charging, iii) discharging to the load in the absence of utility and PV source, and iv) regenerative braking. An improved perturb and observe-based maximum power point tracking (MPPT) algorithm is proposed to track the maximum power from the PV source. In addition, to handle the four modes of operation, a dedicated controller is also proposed. Firstly, the proposed system is validated using MATLAB/Simulink software by considering different operating conditions, and the performance is compared with the traditional MPPT algorithms. Finally, the effectiveness of the suggested system is validated through an experimental prototype. The result proved the superiority of the converter and controller over the traditional systems.<div align="center"> </div>

Design of an integrated SEPIC and Buck Converter for High Step-down Applications

To overcome the issues related to special power supply called voltage regulator module (VRM) used for microprocessors, a special DC-DC converter will be designed in this work in which single-ended primary inductor (SEPIC) converter and the inverted form of buck converter are combine. As per available literature the problems associated with conventional VRM’s are slow transient response and narrow duty cycle. Other issue related to the voltage regulator module is the high voltage stress that occurs on switches of VRM. The solution to these problems is presented in the form of a new proposed dc-dc converter topology in which the single ended primary inductor is combined with the inverted form of buck converter. The proposed topology has the advantages of reducing the transient time at moderate duty cycle because of the parallel combination of the inductor. Similarly, the parallel combination of capacitor will step down the voltage from 12v to the appropriate voltage level required for the microprocessor. The steady state operation and transient state operation of the proposed VRM is discussed in this thesis. Various operating states of proposed converter are discussed and related equations for voltage gain, voltage stress and transient response have been derived. Output waveforms are plotted, and mathematical modeling is carried out. Simulation results for proposed and conventional VRM are obtained and from comparison of results, it is clear that proposed VRM is good in performances compared to conventional VRM’s.

A Three-Phase Phase-Modular Single-Ended Primary-Inductance Converter Rectifier Operating in Discontinuous Conduction Mode for Small-Scale Wind Turbine Applications

Small-scale wind turbines play an important role in distributed generation since customers can use their houses, farms, and business to produce electric energy. The development of the power electronics system that processes the electric energy from small-scale wind turbines is a concern due to cost, simplicity, efficiency, and performance trade-offs. This paper presents the results of applying a three-phase phase-modular single-ended primary-inductance converter rectifier to processing the energy of a small-scale wind turbine system. The rectifier was designed according to the specifications of a commercial small-scale wind turbine system and tested in an emulator workbench, providing experimental data on the operation of the rectifier in this application. The rectifier can process the energy of a non-sinusoidal three-phase system since the permanent magnet synchronous generator has trapezoidal waveforms. The results show that the rectifier has the advantages of (i) using the inductance of the generator as the input filter inductor of the rectifier, (ii) providing input currents with the same shape as the voltages and in phase without the use of a current control system, (iii) simplicity of control of the DC output voltage and PWM modulation, and (iv) phase-modular characteristics that allow operating with phase fault without any additional control techniques. Due to the operation in discontinuous conduction mode, low efficiency in high power and/or low input voltage specifications are disadvantages.

Efficiency Enhancement of a Hybrid Sustainable Energy Harvesting System Using HHHOPSO-MPPT for IoT Devices

The Internet of Things (IoT) is a network of interconnected physical devices, vehicles, and buildings that are embedded with sensors, software, and network connectivity, enabling them to collect and exchange data. This exchange of data between the physical and digital worlds allows for a wide range of applications, from smart homes and cities to industrial automation and healthcare. However, a key challenge faced by IoT nodes is the limited availability of energy to support their operations. Typically, these nodes can only function for a few days based on their duty cycle. This paper introduces a solution that aims to ensure the sustainability of IoT applications by addressing this energy challenge. Thus, we develop a design of a hybrid sustainable energy system designed specifically for IoT nodes, using solar photovoltaic (PV) and wind turbines (WT) chosen for their multiple benefits and complementarity. The system uses the single-ended primary-inductance converter (SEPIC) and is controlled using a hybrid approach, combining Harris Hawks Optimization and Particle Swarm Optimization (HHHOPSO). Each SEPIC converter boost the electrical energy generated to attain the required voltage level when charging the battery. The proposed methodology is implemented in MATLAB/Simulink and its performance is measured using appropriate metrics. In terms of efficiency and average power, the results show that the suggested method outperforms previous strategies. Our system powers also many sensor nodes, leading to a high level of sustainability and lowering the carbon footprint associated with traditional energy sources.

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.

Robust current-mode control of bridgeless single-switch SEPIC PFC converter

In this paper, the nonlinear model of the bridgeless single-switch ac-dc single-ended primary-inductor converter (SEPIC) in discontinuous conduction mode is derived. In addition, a robust control method is introduced to accommodate the variations in input voltage and load current. The current-mode controlled power converter is designed to operate in buck and boost modes. The proposed closed-loop SEPIC converter is simulated in MATLAB to validate the design approach. The current-mode control scheme is also compared with the conventional voltage-mode controller. It is confirmed that the proposed control scheme exhibits precise tracking performance and enhanced transient response under large disturbances.

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.

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.

High Gain Magnetically Coupled Single Switch Quadratic Modified SEPIC DC-DC Converter

This article proposes, analyzes, and tests an improved high voltage gain dc-dc converter based on a single-ended primary-inductor converter (SEPIC). The proposed magnetically coupled quadratic modified SEPIC converter (MCQ-MSC) employs a coupled transformer with an optimized design to obtain a high voltage boost factor by controlling the transformer's turn ratio along with the switching duty cycle. Thanks to the unique structure of the coupled transformer, high voltage gain is obtained at low turns ratio, which is highly desirable for high voltage applications and the compact size of the converter. In addition to the coupled transformer, a voltage-boosting module is utilized to achieve a very high output voltage for a low switching duty cycle. The proposed inverter has a single switch with a wide control range of duty cycle (0<D<1), causing low conducting losses and high efficiency. Furthermore, a clamping circuit is successfully designed to remove the leakage inductance effects of the coupled transformer on the power switch. The proposed MCQ-MSC drains a continuous current from the input dc source, which makes it a suitable choice for renewable energy sources (RES). The hardware prototype of the proposed converter is tested to verify the mathematical expressions and theoretical results.

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.

A Wide Conversion Ratio Bidirectional Modified SEPIC Converter with Non dissipative Current Snubber

This article presents a wide conversion ratio bidirectional dc-dc converter based on a bidirectional modified Single-ended primary-inductor converter (SEPIC converter). A key feature of this modified SEPIC converter is the non-dissipative current snubber circuit, which is used to achieve zero current switching and to suppress voltage spikes that occur during MOSFET switching. The snubber is made up of a capacitor, an inductor, and a diode that work together to form a resonant circuit that absorbs the voltage spike and returns it to the circuit without dissipating it. Even with conventional MOSFETs, high efficiency is achieved. The SEPIC converter differs from other bi-directional DC-DC converters in that it provides continuous output current, has fewer components, and can provide high conversion ratios of step-up and step-down voltage without exceedingly low or high duty-cycle. This paper presents a theoretical analysis with stages of operation in both step-up and step-down modes, theoretical waveforms, and the design procedure, as well as a comparison with other bidirectional dc-dc converter topologies. The experimental results are presented to validate the performance of the proposed converter using a 500-W prototype with Voltage Source V1 = 48 V and Voltage SourceV2 = 300 V.

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.

Voltage regulation of DC micro grid system using PV and battery coupled SEPIC converter

&lt;span lang="EN-US"&gt;This paper deals with the voltage regulation of DC micro grid system using photovoltaic and battery coupled single-ended primary-inductor converter (SEPIC) converter. SEPIC converter is a DC-to-DC boost converter, it can produce non pulsating DC current with less ripples when compared to buck and buck boost converters. Non pulsating DC current is the demanding condition required in maximum power point tracking (MPPT) applications and battery charging. This paper presents the simulation of the converters for both open and closed loop systems. Firstly, the proposed PV coupled SEPIC converter and the battery coupled buck boost converters are integrated to regulate the voltage in micro grid, and it is compared with the conventional methods in terms of output voltage, ripple voltage and power. The ripple voltage has been reduced to 0.1 V from 0.3 V in the proposed method. Secondly, PI and PID controllers are employed individually to SEPIC and buck boost converter for the voltage regulation of the DC micro grid system. The performance of the closed loop analysis is done in terms of time domain specifications, and it reveals that PID controller has the better response. The proposed system is simulated using MATLAB/Simulink and the prototype has been developed to verify the simulated results.&lt;/span&gt;