Single Ended Primary Inductance Converter Research Articles

A Modified SEPIC-Based High Step-Up DC–DC Converter With Quasi-Resonant Operation for Renewable Energy Applications

In this paper, a new modified single-switch single-ended primary inductor converter (MS2-SEPIC)-based high step-up dc–dc converter is presented. The proposed topology uses the coupled-inductor (CL) technique and a voltage tripler rectifier, which results in a high voltage gain for the converter. Here, the switching loss has been reduced significantly owing to the quasi-resonance operation of the circuit created by the leakage inductance of the CL along with circuit capacitors. The operational principles and steady-state analysis are discussed. Experimental results based on a 100 W laboratory prototype verify the validity of theoretical analysis.

Bilgisayar Sistemlerinde SEPIC Dönüştürücü Uygulaması ve Benzetim Çalışması

In this study, the analysis and simulation studies on Single Ended Primary Inductor Converter (SEPIC) technology used as a energy source in computer systems are proposed. In computer systems, these converters are inevitable and used widely. To step up or step down voltage, different type circuit topologies are available (Buck, Boost, Cuk etc.). While buck converter can only decrease the voltage, boost converter steps up the voltage. Cuk and SEPIC can be used both process. Some issues like large amounts of electrical stress on the buck, boost and Cuk converter components, the main board power supplies can be overheating. Also negative regulated output voltage is obtained in these converters. These problems are not seen in SEPIC converters. Also they provide to wide operation with high efficiency. By controlling of the gate signal of switching devices, desired output voltage is obtained as positive regulated in SEPIC converter. This study proposed a development of PI control method that provides the proper dynamic and static performance compared to other methods. The simulation and implementation of SEPIC converter is simulated in Matlab/Simulink software.

Modular Self-Balancing Battery Charger Concept for Cost-Effective Power-Assist Wheelchairs

The paper deals with a power charger capable of quick simultaneous charging of several unevenly discharged batteries. The charger is designed for use in conjunction with a recently developed power-assist wheelchair composed of two armrest modules associated with wheels—each with its own motor, driver and battery. Uneven discharge of the batteries is very possible in this application. Taking into account the charging power and energy comparable with the most powerful household electrical devices, the refreshing of these batteries and integration of the entire power supply chain into the household grid become a topical and challenging task. Solving of this task requires a special charger that has several channels and can unevenly apply charging power to these channels. At the same time, the charger must not generate current harmonics or reactive power, must operate with good efficiency and satisfy size constraints. In the given research, a configuration of several interleaved isolated single-ended primary-inductor converters is studied. The synthesized mathematical model of the proposed charger provides data about its static and dynamic characteristics while its experimental investigation focuses on operation details (power losses, control features etc.). The obtained results prove that the proposed concept complies with the above-mentioned requirements and can be applied in the discussed application.

Benefits of the CI‐CCS converter

An enhanced DC–DC converter is proposed in this paper, based on the combination of the Cuk converter and single-ended primary-inductor converter (SEPIC). This converter uses a single switching node which is common to both Cuk and SEPIC energy transfer stages. The converter uses only one switch, yet provides dual outputs in the form of a bipolar DC bus with a common ground. Since the switch is grounded, a simple, non-isolated gate driver may be used. The proposed converter uses integrated magnetic cores to couple the input and output inductors, which significantly reduces the input current ripple. The new converter is referred to as the Coupled-Inductors Combined Cuk-SEPIC (CI-CCS) converter.

Performance evaluation of SEPIC, Luo and ZETA converter

<p><span>DC-DC converters are devices which convert direct current (DC) from one voltage level to another by changing the duty cycle of the main switches in the circuits. These converters are widely used in switched mode power supplies and it is important to supply a constant output voltage, regardless of disturbances on the input voltage. In this work, the performance of three different converters such as Single-Ended Primary-Inductance Converter (SEPIC), Luo converter and ZETA converter have been analyzed. Further, the parameters values such as ripple voltage, switching losses and efficiency of the proposed three different converters were compared with each other. Also, the simulation work has been carried out using MATLAB/SIMULINK software. From the comparison of obtained results, it is observed that the ZETA converter has high significance than the SEPIC and Luo converter.</span></p>

Internet of things (IoT) based I-V curve tracer for photovoltaic monitoring systems

<span>This paper presents a low-cost PV current-voltage or <em>I-V</em> curve tracer that has the Internet of Things (IoT) capability. Single ended primary inductance converter (SEPIC) is used to develop the <em>I-V</em> tracer, which is able to cope with rapidly changing irradiation conditions. The <em>I-V</em> tracer control software also has the ability to automatically adapt to the varying irradiation conditions. The performance of the <em>I-V</em> curve tracer is evaluated and verified using simulation and experimental tests.</span>

A fully soft switched high step‐up SEPIC‐boost DC‐DC converter with one auxiliary switch

SummaryThis paper proposed a new single‐ended primary inductor converter (SEPIC)‐boost DC‐DC converter that uses only one auxiliary switch to create soft switching condition for all semiconductor devices. The auxiliary circuit comprises one power switch (Sa), one resonant inductor (Lr), one resonant capacitor (Cr), and one diode (Do2). The auxiliary switch (Sa) controls the resonance during switching instants. The converter has simple structure and its control circuit remains pulse width modulation (PWM). Besides, the proposed converter has high voltage gain without using any transformer or coupled inductors. In addition, the auxiliary switch is not located in the main power path. Moreover, using soft switching techniques is the best way for reducing the size, weight, and volume of the converter. Furthermore, reduction of input inrush current and voltage stress for the main switch is obtained by using SEPIC‐boost structure. A laboratory prototype converter is designed and implemented. The experimental results presented confirm the theoretical and features of the proposed converter.

Design and Analysis of the Performance of a Solar Driven Micro-Inverter Using Single Ended Primary Inductance Converter Topology

In typical solar power installations, multiple modules are connected to the grid through a single high-power inverter. However, an alternative approach is to connect each solar module directly to the grid through a micro-inverter. This approach makes the system robust to single module failures and results in better power tracking. PV based cower conditioning system need a high-efficiency dc–dc converter capable of regulation over a wide input voltage range for Maximum Power Point Tracking (MPPT) and a high-efficiency micro-inverter. To diminish the ground leakage currents, also to use a high-efficiency system, the proposed concept is required for this micro-inverter to provide galvanic isolation between the PV module and the inverter. This concept involves the design of a micro-inverter topology which includes design of Single Ended Primary Inductance Converter (SEPIC) dc/dc converter, isolated resonant inverter and a cyclo-converter. The SEPIC converter topology yields high efficiency through constant voltage MPPT algorithm. The Resonant inverter topology produces efficient output through low circulating currents, Zero Voltage Switching (ZVS), low-current switching of the primary side devices, and Zero Current Switching (ZCS) of the output diodes. This Resonant inverter topology is also able to provide voltage regulation through basic fixed-frequency Pulse Width Modulated (PWM) control. The features of proposed system can able to achieve w the simple addition of a secondary-side bidirectional ac switch to the isolated series resonant converter.

An Approximate Short Circuit Strategy for Transient MPPT Performance of Uniformly Irradiated Photovoltaic Modules

This paper presents an improved strategy to provide better maximum power point tracking (MPPT) performance and increase energy yield during transient state of MPPT process. This strategy is based on the estimation of short circuit current (SCC) of the photovoltaic (PV) system without short circuit. Besides that, this strategy aims to decrease convergence time to maximum power point (MPP) by preventing real short circuit of PV source and eliminating the additional switch requirement. To determine performance of the proposed strategy, simulation studies have been performed in MATLAB/Simulink and this strategy has been compared with fractional SCC (FSCC) technique and perturb and observe (P&O) algorithm. In addition, to make validation experimentally, a low powered single ended primary inductance converter (SEPIC) is realized. Both simulation and experimental results show that proposed strategy performs better transient MPPT performance than FSCC technique and P&O algorithm.

Analysis and design of genetic algorithm-based cascade control strategy for improving the dynamic performance of interleaved DC–DC SEPIC PFC converter

Switched-mode power supplies used for powering new generation devices like microprocessors, utility grids and electric vehicles need to operate with faster dynamic response. This paper proposes cascade control technique using genetic algorithm to obtain the optimal proportional integral outer voltage and inner current controller parameters of interleaved DC–DC single-ended primary inductance converter for power factor correction in SMPS with fast dynamic response. The state space model of the interleaved DC–DC SEPIC converter is derived using state space averaging technique. The system is of higher order, and hence, the reduced-order model of the interleaved DC–DC SEPIC converter is realized using Hankel matrix approach to reduce the computational complexity in controller design. The optimal controller parameters are then obtained for the reduced-order system using genetic algorithm for improving the dynamic performance of the system. The performance of the closed-loop system is analyzed in terms of input power factor, % total harmonic distortion of source current, % efficiency and % load voltage regulation for variations in the line, load and reference voltage using Matlab/Simulink software tool. A prototype of the converter controlled by TMS320C2000™ microcontroller for an output power of 200 W is tested and validated with the simulation results.

Enhanced auto-scaling incremental conductance MPPT method, implemented on low-cost microcontroller and SEPIC converter

This paper proposes a new maximum power point tracking (MPPT) algorithm for photovoltaic (PV) systems, which is tested in simulations and practical implementations. In the proposed PV-MPPT system, a new control strategy is applied to create two operating areas. In each area, the step-size is different in the function of the closeness to the MPP. Because of this strategy, some drawbacks of the conventional incremental conductance (IncCond) methods are eliminated. A single-ended primary-inductor converter (SEPIC) DC–DC converter is controlled with the proposed MPPT technique. The modified IncCond method is validated under simulation with test data, real data and real scenarios of solar irradiation. The results of the proposed approach show higher MPPT efficiencies and shorter convergence times than the conventional IncCond method even in rapidly changing conditions of solar radiation.

Design and Analysis of Non-Isolated Three-Port SEPIC Converter for Integrating Renewable Energy Sources

An efficient way of synthesizing a three port non-isolated converter from a single-ended primary inductor converter (SEPIC) is proposed in this paper. The primary SEPIC converter is split into a source cell and a load cell. Two such source cells are integrated through direct current (DC) link capacitors with a common load cell to generate a three-port SEPIC converter. The derived converter features single-stage power conversion with reduced structural complexity and bidirectional power flow capability. For bidirectional power flow, it incorporates a battery along with an auxiliary photovoltaic source. Mathematical analyses were carried out to describe the operating principles and design considerations. Experiments were performed on an in-house-built prototype three-port unidirectional converter, and the results are presented to validate the feasibility of the designed converter.

Switched-Boost Action Based Multiport Converter

Multioutput converters with single input source are currently studied as an alternative to conventional dc–dc topologies in order to improve power density in low-power multiload applications. This paper reviews three different ways in which a boost topology can be customized to supply multiple outputs. The first way uses a charge-sharing approach using individual switches to distribute inductor energy to different capacitors. The second method of creating a multiport converter (MPC) combines two converters with similar front end to generate two outputs using only one controlled switch. Using this method, a boost converter can be combined with single–ended primary–inductor converter (SEPIC), Cuk, and current source converter topologies. The third method uses time multiplexing of switches to produce two regulated ports and is referred to as switched-boost action. This method uses relatively less number of switches and allows regulation and control of all the outputs. Practical utility of switched-boost action based MPC is reported in this paper. This switched-boost MPC is applied to a renewable power converter system to interface a solar panel, a battery, and home loads to produce a 12-V and a 48-V bus. The 12-V bus is interfaced to battery and capable of optimally charging the battery in constant current–constant voltage (CC-CV) mode. The converter is demonstrated to operate with solar panel as it supplies a 12-V battery and a 48-V load bus. When the solar power is not available, the converter automatically goes into a mode in which the 12-V battery supplies the loads on the 48-V bus.

Design and Analysis of a Repetitive Current Controller for a Single-Phase Bridgeless SEPIC PFC Converter

This paper studies a repetitive controller design scheme for a bridgeless single-ended primary inductor converter (SEPIC) power factor correction (PFC) converter to mitigate input current distortions. A small signal modeling of the converter is performed by a fifth-order model. Since the fifth-order model is complex to be applied in designing a current controller, the model is approximated to a third-order model. Using the third-order model, the repetitive controller is designed to reduce the input current distortion. Then, the stability of the repetitive controller is verified with an error transfer function. The proposed controller performance is validated by simulation, and the experiment results show that the input current total harmonic distortion (THD) is improved by applying the proposed controller for an 800 W bridgeless SEPIC PFC converter prototype.

Fractional order controller design for SEPIC converter using metaheuristic algorithm

Fractional order proportional, Integral and a derivative controller is a special kind of controller which is used to regulate the output voltage of a class of sepic converter to the desired level. Tuning of fractional Proportional, Integral and Derivative controller (FOPID) is achieved by different metaheuristic algorithm and the optimization performance target is chosen as minimizing the integral square error (ISE). This paper presents a performance analysis of Single Ended Primary Inductance Converter (SEPIC) by time response specifications such as rise time, settling time and steady-state error and further, the results are compared with the controllers designed by Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Queen Bee based Genetic Algorithm (QBGA). The design and implementation of fractional order controller for a closed loop control of converter is done by utilizing a MATLAB/SIMULINK environment. Results show that QBGA algorithm exhibit better performance as compared to other optimization technique for voltage mode controller in terms of disturbance rejection.

Analysis and Implementation of a New SEPIC-Based Single-Switch Buck–Boost DC–DC Converter With Continuous Input Current

In this paper, a novel buck–boost dc–dc converter with continuous input current is proposed. The voltage gain of the presented converter is higher than conventional converters, such as buck–boost, single-ended primary-inductance converter, Cuk, and Zeta converters. This converter works only by one switch and voltage stress across the switch is low. Input current of the proposed converter is continuous so a large filter at the input is not needed. Furthermore, continuous input current has made this converter suitable for renewable energy and fuel cell applications. In this converter, noninverting output voltage is obtained and high gain of voltage is achieved as well. So it can operate at wide output voltage range only by changing the duty cycle of the power switch pulse. The presented converter can easily controlled in continuous conduction mode operation, because of using only one power switch. In the following, the principle of operation and the mathematical analyses of the proposed converter are explained, finally, validity of the proposed dc–dc converter is verified by the experimental results.

A Universal Input, Single-Stage AC–DC LED Driver for an Auditorium Light

Analysis, design and simulation of 126[Formula: see text]W power supply with better power quality are presented in the proposed work to run an auditorium light emitting diode (LED) light operating at universal AC input mains (90–270[Formula: see text]V). A single-ended primary inductance converter (SEPIC) topology is designed and driven in continuous conduction mode (CCM) with advance feedback system to maintain constant voltage at output. A proportional integral (PI) controller is also proposed to make the system stable, and stability analysis is discussed in detail with the help of transfer function derived from the state space model. Bode, Nyquist and Polar plots are clearly drawn using the MATLAB tool to claim the system stability. For justification of mathematical analysis, a simulation of the proposed LED driver is also performed in MATLAB–Simulink using sim-power toolbox. The simulation results show the improved value of power quality indices like power factor (PF), total harmonic distortion (THD) and crest factor (CF) with constant rating of 84[Formula: see text]V, 1.5[Formula: see text]A at output. Improved PF and reduced THD are under the limit of international standards like IEC-61000-3-2 Class C requirement.

Control Strategies of a Smart Topology of EVs Charging Station Based Grid Tied RES-Battery

In this paper, control strategies of a smart topology of EV charging station based on grid tied renewable energy sources and battery are designed and analyzed. The renewable energy sources (RES) that power EV charging station are composed by photovoltaic system and wind energy conversion system (WECS). Thus, a dc/dc boost converter based on a maximum power tracking controller is connected to the photovoltaic array, the WECS is tied to the DC link through a single ended primary inductor converter (SEPIC), and four charging points are associated to four dc/dc converters in order to secure a large scale of power to charge electric vehicles battery. However, the PV/WECS is tied both to the grid and to the battery storage buffer (BSB) of the charging station via a three-phase bidirectional inverter and a bidirectional dc/dc converter respectively. The aim of this work is to achieve an improved power management approach, that consists of an optimization algorithm set to mind the gap of energy deficiencies of a multi sources system, for instance an unfavorable weather conditions for RES, an overloading phenomena of the grid and a limited capacity of the BSB. Simulation results in Matlab/Simulink have shown the effectiveness of the proposed power management strategy via seven operating modes.

An integrated grid-connected system for multi-port energy processing by microcontroller

The requirement for converters to process different kinds of energy has been urgent. Developing new type of power converter to deal with multi-port energy therefore becomes much more important than before. In this paper a multi-port single-stage converter (MPSSC) is proposed, which is an integrated system (IS) and can handle power direction among battery bank, AC mains and LED load. Even though the MPSSC processes three ports, its main power stage is a single-stage configuration instead of the combination of multiple converters. That is, it can process power effectively and more easily comply with industry standards. The MPSSC is mainly derived from a single-ended primary-inductance converter (SEPIC) incorporating interleaved structure. While the MPSSC draws energy from utility to charge battery bank and/or powers DC load, it is able to perform power factor correction (PFC) over universal line input. In the case of power failure, the MPSSC can instantaneously change energy direction and then discharges the battery so as to power load consecutively. The integrated system of MPSSC is analyzed theoretically. In addition, a 200-W microcontroller-based prototype is built to validate the converter with practical measurements.

An Improved Bridgeless SEPIC Converter Without Circulating Losses and Input-Voltage Sensing

In order to overcome the drawbacks of conventional bridgeless single-ended primary inductance converter (SEPIC) power factor correction (PFC) circuits, an improved bridgeless SEPIC PFC circuit is introduced by adding an additional output diode and an inductor. The undesired capacitive coupling loop and the circulating loss are removed. Thus, the high efficiency can be achieved. The operation principle and design consideration of the proposed converter are introduced in detail. Furthermore, a novel control method is employed to control the current continuous mode bridgeless SEPIC PFC circuit without input-voltage sensing. Meanwhile, the UCC28019-based modified hardware implementation circuit is designed and described. A 100-W prototype with 90–135 Vrms input line voltage and 60-V output voltage is built and tested. The corresponding experiment shows the validity of the proposed circuit topology and control strategy. A peak efficiency of 94% and power factor above 0.99 are achieved under 65-kHz switching frequency operation condition.