Single Ended Primary Inductance Converter Research Articles

Soft Switching Technique in a Modified SEPIC Converter with MPPT using Cuckoo Search Algorithm

: MPPT refers to the process of continuously tracking and adjusting the operating point of a photovoltaic (PV) system to maximize the power output from the solar panels. The operating point at which a PV system produces the most power under a specific set of environmental circumstances is known as the maximum power point (MPP). The Maximum power point tracking (MPPT) technique is used to overcome the challenges of PV arrays with variable irradiance levels, which collects the greatest power from the PV array. Standalone PV systems, as well as gridconnected systems, can benefit from a DC-DC converter with MPPT. This study compares the standard perturbation and observation (P&O) technique with the soft-switching method used in the SEPIC converter utilizing the cuckoo search (CS) algorithm using MATLAB/Simulink. Reviewing the simulation results and assessing the SEPIC converter's performance. Background: SEPIC soft-switching converter, the soft-switching technique is applied to the SEPIC converter topology. It typically uses additional components, such as inductor and capacitors, to enable soft-switching operation. These additional components help to control the voltage and current waveforms across the main switching devices, reducing switching losses. Methods: The proposed method uses a soft switching technique to reduce switching losses and to improve efficiency. Soft switching is used in SEPIC (Single Ended Primary Inductor Converter) converters, a type of DC-DC converter, to enhance their performance. The projected solution further addresses the maximum power point tracking (MPPT) issue in PV systems using the Cuckoo Search (CS) method. Results: Soft switching technique is implemented in SEPIC converters to reduce these switching losses. In this system, Zero Voltage Switching (ZVS) involves turning on the switch when the voltage across it is zero. This allows the current to flow through the switch without creating any significant switching losses. CS algorithm can track the MPP quickly and accurately, it exhibits less prone to oscillations, easily monitor the MPP under a variety of weather circumstances. However, it exhibits negligible oscillation in a steady state, which results in significant power savings. Conclusion: The modified SEPIC converter with a soft-switching MPPT cuckoo algorithm is used with a solar-powered system. A prototype comprising a solar panel, a SEPIC converter, a driver, and a controller circuit was created. A soft-switching SEPIC converter with an MPPT cuckoo algorithm for the PV system is implemented, as are the converter operation, converter analysis, and theoretical analysis, and a controller circuit is analysed. The PV system, MPPT controller with tracking algorithm, and PMSM load were used in the system simulation. A 60-watt SEPIC converter prototype is built, and the outcomes are also tested experimentally.

Experimental investigation on the design of a three-phase power factor corrector utilizing a SEPIC converter

A new configuration for a three-phase electric vehicle (EV) charger based on the Single-Ended Primary Inductor Converter (SEPIC) topology. The proposed charger operates as a power factor correction (PFC) converter, offering both step-up (boost) and step-down (buck) functions, enabling efficient adaptation to different input voltage levels while ensuring a stable DC output. By incorporating closed-loop current control and fast-switching regulation, the system attains unity power factor, which helps to reduce power losses and improve overall power quality. A unique control technique is proposed to regulate input current under unbalanced voltage conditions, ensuring reliable operation and high efficiency even during grid fluctuations. Simulations using MATLAB/Simulink demonstrate that, in unbalanced voltage scenarios, the control method maintain stable input current shaping, highlighting the system’s resilience. The results validate the SEPIC-based EV charger’s ability to consistently deliver efficient charging performance in both balanced and unbalanced voltage conditions, while achieving unity power factor and stable voltage regulation.

Design and implementation of Golden Eagle optimized cascaded PI and LQR controller for PFC SEPIC converter in EV charging

This research article focuses on designing and implementing a single ended primary inductor converter (SEPIC) for an AC-DC converter, followed by an electric vehicle (EV) charger. It improves the high-power factor at the AC supply with minimum harmonic distortion. The Golden Eagle optimization techniques are adapted to optimize the tuning of Proportional-Integral (PI) and Linear Quadratic Regulator (LQR) controller parameters for better converter performance. The optimization is designed based on the eagle knowledge of hunting methods at various angles of spiral trajectories in capturing the animal. The SEPIC converter is designed and derived from the state space model by state space averaging, and the reduced model is obtained through the moment matching method to reduce computational complexity. The Golden Eagle Optimize the parameters of KP and KI of the PI controller and weighing matrix Q of the linear quadratic controller. The fitness function of the proposed optimization is the sum of the Integral Absolute error (IAE) and Integral Square error (ISE). The proposed optimization is implemented using MATLAB/SIMULINK software, and the simulation outcomes demonstrate an improved settling time, fast recovery against input and output variations, Total Harmonic Distortion (THD) of 1.75 %, and enhanced stability.

DEVELOPMENT OF DUAL-SWITCHES BRIDGELESS PFC TOTEM-POLE SEPIC CONVERTER FOR LED DRIVER APPLICATION

This paper presents a Dual-Switch Bridgeless Power Factor Correction (DSBPFC) Single Ended Primary Inductor Converter (SEPIC) with Totem-Pole circuit structure for LED Driver Application. The conventional Full-Bridge Rectifier (FBR) SEPIC converter has five diodes, four in the rectifier bridge and one in the SEPIC. In addition, the FBR SEPIC converter has several drawbacks, including low power factor (PF), high current harmonics (THDi), and high output voltage ripple, due to the combination of two operation circuits in a single converter structure. The proposed DSBPFC SEPIC converter with Totem-Pole method improves PF and reduces THDi and output voltage ripple compared to the conventional FBR SEPIC. Additionally, it only requires three diodes instead of five. The optimization parameter design minimizes the THDi and output voltage ripple. In addition, to improve the quality of the AC source, the inductors are designed to operate in DCM and CCM based on the ripple-balancing concept between input and output inductors. As to reduce output voltage ripple, a high capacitance of output capacitor is used. The simulation result of the THDi is 3.8% whereas the experimental result shows that the THDi is 23.5%; which can be attributed to the parasitic elements at the passive components. Furthermore, the experimental results of the output voltage ripple are 2 V with output capacitance of 3300 μF, compared to the output voltage ripple of 4.40 V for 470 μF. Therefore, the proposed converter's design is confirmed with an output power of approximately 14.4 W.

Golden eagle optimized fractional-order PI controller design for a PFC SEPIC converter in EV charging

The power factor correction converter is the function of the front-end converter, followed by the DC–DC converter of the electric vehicle charger. It improves the power factor and regulates the output voltage and current. This research article proposes the Golden Eagle optimization for fractional order PI (FOPI) controller for Single Ended Primary Inductor Converter (SEPIC) power factor correction. The Golden eagle optimization is based on its knowledge of hunting tactics at various degrees of spiral trajectories to catch the prey. The FOPI controller has a broad range of controller parameters that provide better control and performance of the converter. The tuning of the parameters of the FOPI controller is optimized in Golden Eagle Optimization, and the Integral Absolute error with Integral Square error is used for the objective function. The optimized parameters of FOPI compare with the conventional PI controller performance. The SEPIC converter is designed and derived from the state space model by state space averaging, and the reduced model is obtained through the moment matching method. This system is tested under MATLAB/SIMULINK, and simulation results show improved settling time, fast dynamic response, reduction of inrush current, less harmonic distortion, and stability.

Modified incremental conductance MPPT using SEPIC converter for PV system, simulation and arduino implementation

Photovoltaic (PV) systems are widely used in different sectors of industry. However, they have relatively low efficiency due to their dependence on temperature and solar irradiation fluctuations. Several maximum power point trackers (MPPT) have been developed to improving these PV systems’s efficiency. In this paper, a modified incremental conductance (IncCon) MPPT control technique is proposed to detect the MPP provided by the PV system that can overcome the limitations of conventional algorithms such as perturb and observe (P&O) and basic incremental conductance particularly in sudden variation of solar irradiation. To this end, we first developed and validated a model of the PV panels through numerical simulation using ISIS Proteus software, where the different characteristics curves I-V and P-V are plotted and compared to theoretical ones. Thereafter, the single ended primary inductor converter (SEPIC) part and that of the MPPT controllers are presented. Finally, a simulation in a semi-virtual environment is carried out by programming the MPPT control strategies (P&O, conventional and modified IncCon) in an Arduino allowing the control of a PV system equipped with a SEPIC converter. The obtained results, showing the effectiveness of the proposed algorithm, are presented and discussed.

Interleaved Modified SEPIC Converters with Soft Switching and High Power Factor for LED Lighting Appliance

A novel ac/dc LED driver with power factor correction and soft-switching functions is proposed. The circuit topology mainly consists of two modified single-ended primary inductance converters (SEPIC) with interleaved operation. The first half stage of SEPIC operates like a boost converter and the second half stage operates like a buck–boost converter. Each boost converter is designed to operate in discontinuous current mode (DCM) to function as a power factor corrector (PFC). The two buck–boost converters that share a commonly coupled inductor are designed to operate at near boundary conduction mode (BCM). Without using any active clamping circuit, auxiliary switch or snubber circuit, the active switches can achieve zero-voltage switching on, and all diodes achieve zero-current switching off. First, operation modes in steady state are analyzed, and the mathematical equations for design component parameters are derived. Finally, a prototype circuit of 180 W rated power was built and tested. Experimental results show satisfactory performance of the proposed circuit.

Optimization of solar energy using recurrent neural network controller with dc-dc boost, Cuk, and single-ended primary inductor converter (SEPIC) Converters

Optimization of solar energy using recurrent neural network controller with dc-dc boost, Cuk, and single-ended primary inductor converter (SEPIC) Converters

Optimization of solar energy using artificial neural network controller with dc-dc boost, cuk, and single-ended primary inductor converter (SEPIC) converters

Optimization of solar energy using artificial neural network controller with dc-dc boost, cuk, and single-ended primary inductor converter (SEPIC) converters

Averaged switch model of single-ended primary inductor converter in discontinuous conduction mode

Averaged switch model of single-ended primary inductor converter in discontinuous conduction mode

Linear Quadratic Gaussian Controller for Single-Ended Primary Inductor Converter via Integral Linear Quadratic Regulator Merged with an Offline Kalman Filter

This paper introduces a Linear Quadratic Gaussian (LQG) controller for a Single-Ended Primary Inductor Converter (SEPIC). The LQG design is based on merging an integral Linear Quadratic Regulator (LQR) with an offline Kalman Filter (commonly referred to as a Linear Quadratic Estimator (LQE)). The robustness of the LQG controller is guaranteed based on the separation principle. This manuscript addresses the need to use observer-based systems for the fourth-order SEPIC, which needs a sensor reduction as an essential requirement. This paper provides a comprehensive, yet systematic, approach to designing the LQG system. The work validates the convergences of the states in an LQG system to an actual value. Furthermore, it compares the performance of an LQG system with a benchmark Type-II industrial controller by means of a simulation of the switched converter model in the Simulink/MATLAB 2023a environment.

Hardware-in-the-Loop Emulation of a SEPIC Multiplier Converter in a Photovoltaic System

This article presents the development and execution of a Single-Ended Primary-Inductor Converter (SEPIC) multiplier within a Hardware-in-the-Loop (HIL) emulation environment tailored for photovoltaic (PV) applications. Utilizing the advanced capabilities of the dSPACE 1104 platform, this work establishes a dynamic data exchange mechanism between a variable voltage power supply and the SEPIC multiplier converter, enhancing the efficiency of solar energy harnessing. The proposed emulation model was crafted to simulate real-world solar energy capture, facilitating the evaluation of control strategies under laboratory conditions. By emulating realistic operational scenarios, this approach significantly accelerates the innovation cycle for PV system technologies, enabling faster validation and refinement of emerging solutions. The SEPIC multiplier converter is a new topology based on the traditional SEPIC with the capability of producing a larger output voltage in a scalable manner. This initiative sets a new benchmark for conducting PV system research, offering a blend of precision and flexibility in testing supervisory strategies, thereby streamlining the path toward technological advancements in solar energy utilization.

Enhancing power generation via an adaptive neuro-fuzzy and backstepping maximum-power-point tracking approach for photovoltaic single-ended primary inductor converter system

Abstract The distinct characteristics of photovoltaic generators related to power and current present a complex problem in terms of optimizing their power output. To tackle this, maximum-power-point tracking techniques such as the adaptive neuro-fuzzy inference system are frequently utilized for their swift adaptability and reduced fluctuations. In addition, the backstepping controller is often selected to handle both linear and non-linear systems due to its exceptional reliability. The purpose of this research is to propose an innovative method that merges the adaptive neuro-fuzzy inference system and backstepping controller to refine the tracking of the optimal power point and to bolster the stability of the photovoltaic system in the face of unpredictable scenarios, such as those presented by the Ropp irradiance examination, which utilizes a single-ended primary inductor converter as a stage for power electronics adaptation. Simulations conducted using MATLAB®/Simulink® demonstrate that the combination of adaptive neuro-fuzzy inference system and backstepping controller achieves an impressive efficiency of 99.6% and exhibits fast, robust, and accurate responses compared with other algorithms such as artificial neural networks combined with the backstepping controller and conventional perturb and observe algorithm.

Performance evaluation of bridgeless isolated SEPIC-Luo converter for EV battery charging using PI and ANN controller

Electric vehicle (EV) rechargeable battery packs that employ traditional power factor correction (PFC) circuit design have performance limitations due to their substantial conductivity loss that ensures at the input of a diode bridge rectifier (DBR). This study suggests a bridgeless (BL) isolated single ended primary inductance converter (SEPIC) - Luo converter to address the problem. As a result, the input current exhibits a power factor operation of unity throughout the charging process. DBR elimination and current conduction through a remarkably small number of circuits both significantly reduce conduction losses. The use of an artificial neural network (ANN) and proportional integral (PI) controller enhances the converter's performance with a stable DC link voltage. The suggested converter overall operation is thoroughly described in terms of variety of operating modes and simulation-based effectiveness. Here, with the assistance of the hysteresis current controller (HCC), the input current disruptions are reduced. Constant current and voltage management is used to successfully charge the EV battery, resulting in improved efficacy and inherent PFC. By utilizing simulation outcomes achieved from MATLAB, the performance of proposed BL isolated SEPIC-Luo in boosting the power quality of EV charger system is examined.

Investigation of a power factor correction converter utilizing SEPIC topology with input current switching

The single-ended primary-inductor converter (SEPIC) is a popular converter topology that can be employed in diverse application fields where the needed output voltage is greater or lesser than the input voltage. The non-inverted output voltage of a SEPIC converter provides additional advantages when compared to a buck-boost or Ćuk converter. Furthermore, the position of the capacitor in the SEPIC converter provides inherent isolation and circuit safety. One drawback in the conventional bridge-diode SEPIC AC-DC converter is the lack of controllability which can be overcome by adding extra active switch(es) or by replacing the passive diode(s) with active switch(es). However, introducing more active switches increases the control complexity and may increase the requirement for additional driver circuits. To address this trade-off, this article proposes a single-phase AC to DC modified SEPIC converter with input current-switching capability without adding any extra active switch(es). The existing active switch of the DC-DC SEPIC converter was shifted towards the input side and thus no additional switch has been introduced. This allows the option of input-current switching without any additional complexity in the control or driver circuit. The circuit topology, principles of operation, and ideal voltage gain equations for the suggested circuit have been derived and included in this research work. The proposed circuit has been simulated in both open-loop conditions and closed-loop control with varying duty cycles and output load. Results from the simulation show that the proposed converter provides better efficiency (∼90 %) and lower total harmonic distortion (THD) (10 %) for varying duty cycles when compared to a conventional converter. The converter also shows good dynamic response. A low-power 15V hardware prototype has been built to experimentally validate the performance of the proposed converter. Experimental results illustrate that the suggested converter can improve the power factor by up to 0.968 while operating at an efficiency above 75 %. This converter topology can be suitable for applications where high output voltage gain, high power factor, and lower THD are needed without isolation requirements.

Optimized virtual impedance solar restoration droop emulated SEPIC controller under low irradiation

This paper is focused on PV-based reduced order pade’s approximation SEPIC (single-ended primary inductor converter) virtual Impedance, restoration controller with parallel impedance emulation condition. However, the complexity of the higher-order SEPIC controller has been reduced and compared using Pade’s approximation with different reduction techniques. It covers the time response, oscillation, overshoot, dynamic performance, and controller stability. The computational time and need of the sensor are less, and better responses occur compared to the other reduction technique under the solar irradiance variation. However, in PV, the dynamic resistance is generalized by a nonlinear solar I–V (current–voltage) curve dependent on the operating point, such as irradiance, temperature, and its I–V curve. The nonlinearity effect affects the stability of the system. The SEPIC outer voltage and inner current controller with virtual impedance controller enhance the stability, and comparative response is demonstrated through the bode plot. A virtual impedance controller (VIC) cascaded with voltage restoration minimizes the voltage notching and oscillations under variation of inertia coefficients. The transient and dynamic performance of reduced order using a genetic algorithm controller has been used to demonstrate and discuss the PV-SEPIC system’s stability.

Approaches for Maximizing Maximum Power Point Tracking and Evaluating Operational Constraints in Photovoltaic Systems

Abstract: Optimization techniques have broad utility in multiple engineering fields, including activities such as modeling, system identification, parameter estimation, forecasting, and control of intricate systems. This innovation emphasizes the use of optimization approaches to control the performance of Photo-voltaic (PV) array systems. The main difficulty lies in the nonlinear correlation between current and voltage (I-V) characteristics of PV arrays, resulting in variations in the location of the Maximum Power Point under varied climatic circumstances. It is crucial to track this Maximum electricity Point efficiently in order to collect the highest amount of electricity possible from the photovoltaic devices. Maximum Power Point Tracking is a tracking procedure that optimizes power generation by dynamically altering the operating voltage to coincide with the MPP. In order to tackle this difficulty, the paper suggests a unique two-stage Maximum Power Point Tracking technique. The initial phase applies the Weightless Swarm Algorithm to evaluate the Maximum Power Point in an offline manner. The subsequent phase employs an online Adaptive Perturb & Observe technique to continuously track the MPP in real-time. In addition, an Approximate Single Diode Model is created to quickly assess the output power. In order to verify the suggested method, computer simulations are performed utilizing a Maximum Power Point Tracking system that is combined with a Single-Ended PrimaryInductor Converter

Nonlinear controller for SEPIC with single variable to tune

This work proposes a systematic approach to designing a novel integral sliding mode controller (ISMC) for a single-ended primary-inductor converter (SEPIC) with only one tunable parameter where the upper and lower bounds are derived. The designed surface results in minimal chattering behaviour at the output voltage as well as at the duty cycle and allows for operating the SEPIC at a fixed switching frequency. The proposed controller can withstand up to a 70% variation in the input voltage and 100% variation on the load side, in addition to superior performance for a cold start. The proposed controller and the corresponding mathematical formulation were simulated in a Simulink environment and experimentally tested via a scaled prototype. The proposed controller performance is also compared to Type II and integral Linear-Quadratic Regulators (LQR).

Enhancing MPPT performance for partially shaded photovoltaic arrays through backstepping control with Genetic Algorithm-optimized gains

As the significance and complexity of solar panel performance, particularly at their maximum power point (MPP), continue to grow, there is a demand for improved monitoring systems. The presence of variable weather conditions in Maroua, including potential partial shadowing caused by cloud cover or urban buildings, poses challenges to the efficiency of solar systems. This study introduces a new approach to tracking the Global Maximum Power Point (GMPP) in photovoltaic systems within the context of solar research conducted in Cameroon. The system utilizes Genetic Algorithm (GA) and Backstepping Controller (BSC) methodologies. The Backstepping Controller (BSC) dynamically adjusts the duty cycle of the Single Ended Primary Inductor Converter (SEPIC) to align with the reference voltage of the Genetic Algorithm (GA) in Maroua’s dynamic environment. This environment, characterized by intermittent sunlight and the impact of local factors and urban shadowing, affects the production of energy. The Genetic Algorithm is employed to enhance the efficiency of BSC gains in Maroua’s solar environment. This optimization technique expedites the tracking process and minimizes oscillations in the GMPP. The adaptability of the learning algorithm to specific conditions improves energy generation, even in the challenging environment of Maroua. This study introduces a novel approach to enhance the efficiency of photovoltaic systems in Maroua, Cameroon, by tailoring them to the specific solar dynamics of the region. In terms of performance, our approach surpasses the INC-BSC, P&O-BSC, GA-BSC, and PSO-BSC methodologies. In practice, the stabilization period following shadowing typically requires fewer than three iterations. Additionally, our Maximum Power Point Tracking (MPPT) technology is based on the Global Maximum Power Point (GMPP) methodology, contrasting with alternative technologies that prioritize the Local Maximum Power Point (LMPP). This differentiation is particularly relevant in areas with partial shading, such as Maroua, where the use of LMPP-based technologies can result in power losses. The proposed method demonstrates significant performance by achieving a minimum 33% reduction in power losses.

Analysis and circuit design of isolated forward SEPIC converter with minimum-phase stability

PurposeConventional isolated dc–dc converters offer an efficient solution for performing voltage conversion with a large improved voltage gain. However, the small-signal analysis of these converters shows that a right-half-plane (RHP) zero appears in their control-to-output transfer function, exhibiting a nonminimum-phase stability. This RHP zero can limit the frequency response and dynamic specifications of the converters; therefore, the output voltage response is sluggish. To overcome these problems, the purpose of this study is to analyze, model and design a new isolated forward single-ended primary-inductor converter (IFSEPIC) through RHP zero alleviation.Design/methodology/approachAt first, the normal operation of the suggested IFSEPIC is studied. Then, its average model and control-to-output transfer function are derived. Based on the obtained model and Routh–Hurwitz criterion, the components are suitably designed for the proposed IFSEPIC, such that the derived dynamic model can eliminate the RHP zero.FindingsThe advantages of the proposed IFSEPIC can be summarized as: This converter can provide conditions to achieve fast dynamic behavior and minimum-phase stability, owing to the RHP zero cancellation; with respect to conventional isolated converters, a larger gain can be realized using the proposed topology; thus, it is possible to attain a smaller operating duty cycle; for conventional isolated converters, transformer core saturation is a major concern, owing to a large magnetizing current. However, the average value of the magnetizing current becomes zero for the proposed IFSEPIC, thereby avoiding core saturation, particularly at high frequencies; and the input current of the proposed converter is continuous, reducing input current ripple.Originality/valueThe key benefits of the proposed IFSEPIC are shown via comparisons. To validate the design method and theoretical findings, a practical implementation is presented.