Inductor Converter Research Articles

Position Control of a Maglev System Fed by a DC/DC Buck Power Electronic Converter

In this paper, we solve the problem of position regulation in a magnetic levitation system that is fed by a DC/DC Buck power electronic converter as a power amplifier. We present a formal asymptotic stability proof. Although this result is local, the merit of our proposal relies on the fact that this is the first time that such a control problem is solved for a magnetic levitation system, a nonlinear electromechanical plant. In this respect, we stress that most works in the literature on control of electromechanical systems actuated by power electronic converters are devoted to control brushed DC motors which are well known to have a linear model. Furthermore, despite the plant that we control in the present paper is complex, our control law is simple. It is composed by four nested loops driven by one sliding mode controller, two proportional-integral controllers, and a nonlinear proportional-integral-derivative position controller. Each one of these loops is devoted to control each one of the subsystems that compose the plant: electric current through the converter inductor, voltage at the converter capacitor, electric current through the electromagnet, and position of the ball. Thus, our proposal is consistent with the simple and intuitive idea of controlling each subsystem of the plant in order to render robust the control scheme. We stress that such a solution is complicated to derive using other control approaches such as differential flatness or backstepping. In this respect, our proposal relies on a novel passivity-based approach which, by exploiting the natural energy exchange between the mechanical and electrical dynamics, renders possible the design of a control scheme with the above cited features.

A Novel High Voltage Gain SEPIC Converter Based on Hybrid Split-Inductor for Renewable Application

ABSTRACT The modified single-ended primary inductor converter (SEPIC) reported in the literature has limitations namely, low static gain and high input current ripples. This resulted in poor efficiency with high switching losses and switching stress. Hence, in order to overcome the above-said limitations, this paper proposes a high static gain SEPIC converter with reduced input current ripple. The proposed converter resembles a split-inductor design consisting of three diodes and two inductors. The static gain of the converter is significantly improved while input current ripple gets reduced by using a split-inductor. Additionally, the low value of input current ripple causes minimal switching stress and switching losses. Hence, the efficiency of the proposed converter improves significantly. The working principle and theoretical analysis of the proposed converter is studied in detail for continuous, discontinuous and boundary conduction modes. Moreover, a small signal/transient analysis is also discussed to validate the feasibility as well as the stability of the proposed system using the transfer function approach. In order to validate the effectiveness of the proposed converter, a MATLAB/Simulink model has been designed. Further, a laboratory prototype has been developed and the experimental results obtained are in agreement with the simulated results.

Design of coupled inductors using split winding scheme for bridgeless SEPIC

A bridgeless single-ended primary inductance converter (SEPIC) is a highly preferred single-stage front-end AC–DC converter for applications requiring a wide variation of DC voltage because it also gives improved performance in terms of the quality of supply current. This study presents the design of coupled inductors for the bridgeless SEPIC using the split winding scheme. With coupling incorporated the required value of self-inductances of the input and output inductors for the same performance is reduced. Also, they can be wound on the same core, thereby resulting in a reduction in size. The conventional method of tuning the coupling coefficient by adjusting the air-gap is tedious. A split winding scheme for the distribution of windings over three limbs of E-core for obtaining the desired coupling coefficient is presented. The split winding scheme for the design of coupled inductors for bridgeless SEPIC converter rated for 500 W, 20 kHz is illustrated. The effect of coupling on the volume, weight, cost, and efficiency of the converter is compared with the conventional SEPIC converter without coupling for a similar performance. The performance of the proposed converter is evaluated using MATLAB/Simulink simulation and experimental results with a laboratory prototype rated for 500 W.

FOUR SWITCH THREE PHASE SEPIC INVERTER WITH FRONT END BOOST CONVERTER

In this paper, four switch sepic inverter with front end boost converter capable of producing quality three phase ac output is explained. Proposed topology is an advanced one when comparing with conventional topologies .Converter offer a design for the inverter with the combination of single-ended primary-inductance , which can obtain higher phase voltages compared to conventional four switch and six switch three phase inverters. A differential arrangement of SEPIC enables to obtained three phase balanced output voltage with only four switches. The output voltage is pure sinusoidal without the help of external filter. This proposed inverter is designed to reduce the cost, complexity and switching losses .It also improves the efficiency and reduces the harmonic distortion. Here the output of the inverters are connected deferentially across the load. The line voltage can not exceed the full value of the input dc voltage, for avoiding this a dc - dc boost converter is placed in the front end of the four switch sepic inverter, thus producing the required output voltage along with the sinusoidal nature. Due to this features, the inverter can be used for the grid integration and pv based power extraction. Proposed topology is operated in both current control algorithm and a modified sine pwm control technique. In this paper it is based on the novel sine pwm control technique. The topology is analysed, simulated using MATLAB/SIMULINK and also a prototype is accomplished to verify the feasibility of the proposed topology. Index Terms—Three-phase inverter, Bi directionl sinlge ended primary inductance converter, Novel sin pwm control, DC-DC boost converter,

Hybrid power generation system with Total Harmonic Distortion minimization using improved Rider Optimization Algorithm: Analysis on converters

Hybrid power generating system is the renowned renewable energy technology that is mainly meant for its reliable performance. This paper introduces a new phase for power quality output by analyzing three DC-DC converters. This work intends to reduce the Total Harmonic Distortion (THD) by proposing hybrid power generation system with the combination of solar-wind as well as converters and full bridge inverter. The analysis is conducted by connecting the converters like buck boost, Single Ended Primary Inductor Converter (SEPIC) and Cuk converter for DC to DC level conversion. As a major contribution, the proportional gain and the Integral gain parameters of the PI controller are optimized which, in turn minimizes THD. For this optimization, this paper introduces a new improved optimization algorithm termed as Fitness Oriented Rider Optimization Algorithm (FO-ROA), which is the improvement of Rider Optimization Algorithm (ROA). The optimized performance of the proposed control system is compared with other conventional models and the superiority of proposed work has been proved.

Performance comparison and stability analysis of ACM and ENLC controlled SEPIC PFC converter

In this study, a detailed comparison between two power factor correction (PFC) controls, viz., average current mode (ACM) control and enhanced non-linear carrier (ENLC) control for single-ended primary inductance converter (SEPIC) are made. In ACM control, a linear current reference, generated using the conventional method is compared with the inductor current. In ENLC control, a non-linear carrier current reference, generated using passive components is compared with switch current. The proposed ENLC control uses reduced components and sensors compared to ACM and conventional non-linear carrier control methods. The evolving of nonlinear phenomena during load variation is investigated along with the electromagnetic interference (EMI) study with power spectral density estimation. For stability enhancement and EMI mitigation, a detailed simulation study is performed using MATLAB/Simulink platform. Mathematical bifurcation analysis, by deriving critical phase angle is carried out to obtain a better insight of stability boundaries in order to access the system behaviour. Owing to the advantages of ENLC, an experimental setup of ENLC controlled SEPIC PFC converter was built to support the results.

Design of extended Kalman filter for SEPIC converter and comparison to Kalman filter

Single ended primary inductance converter (SEPIC) is a type of DC–DC converter whose industrial applications include maximum power point tracking and Active power factor correction. Owing to present nonlinear circuit components, SEPIC has discontinuous nonlinearity and for the mathematical model determination, state space averaging or more advanced modeling techniques are required. Once the approximated nonlinear model is obtained, the states of the plant can be estimated using a nonlinear state estimator. Nonlinear estimators are preferred mostly when the real trajectory of the states cannot be estimated accurately by a linear state estimator and the deviation from the linear behavior and nonlinear one is above what is tolerable for the applications. Extended Kalman filter (EKF), being such a state estimator is widely employed in control and fault monitoring applications where a complete or an approximated nonlinear model of the plant is available. EKF especially operates well for the plants where the nonlinearity does not cause the assumptions behind EKF to be violated. In this study, first an approximated nonlinear model for SEPIC is determined. Using the model, EKF is designed to estimate the states of the plant. The efficacy of the designed EKF is demonstrated in a series of numerical MATLAB based simulations where the both open loop and closed loop performances are analyzed, and the results are detailed in the paper.

A Novel DCM Soft-Switched SEPIC-Based High-Frequency Converter With High Step-Up Capacity

A novel discontinuous conduction mode (DCM) soft-switched single ended primary inductor converter (SEPIC)-based high-frequency converter is presented in this article with the advantages of high voltage gain and low voltage stress. In order to achieve higher voltage gain, it integrates a switched inductor with a coupled inductor–based modified SEPIC converter, and a resonant cell is built with integration of a resonant capacitor, which enables the switches to work under zero voltage switching (ZVS). Therefore, the working principle is changed and better performance is obtained. The proposed converter can operate in both continuous conduction mode (CCM) and DCM, but ZVS can only be achieved in the discontinuous mode; hence, DCM is more suitable for high-frequency applications. Mode analysis, parameter design, and boundary of the two working modes are all presented in detail. For higher efficiency, a 500-kHz/54-W DCM prototype with 15 voltage gain has been designed to demonstrate theoretical analysis. Obtained efficiency was up to 93.4% at full load. Experimental results show good accordance with theoretical analysis.

Tepe Akım Kontrol Modunda Çalışan SEPIC DA/DA Dönüştürücünün Tam Çözümlü Sembolik Zayıf Sinyal Analizi

Full order small signal analysis of peak-current controlled non-isolated Single Ended Primary Inductor Converter (SEPIC) is presented by utilizing pwm-switch model in Continuous Conduction Mode (CCM). The analysis provides control to output voltage transfer function together with its zeros and poles in symbolic form taking into account parasitic resistances of all four reactive components in the SEPIC topology. The resultant transfer function is with 4th order numerator and 5th order denominator, which necessitates approximation in deriving formulas of zeros and poles in symbolic form. Symbolically derived transfer function of the SEPIC is validated on two different numerical examples, one with operating in step down mode and another operating in step up mode, by frequency domain PSpice simulations on average circuit models and by time domain LTspice simulations on switching models. The mathematical analysis, PSpice and LTspice simulations, and measurement results of control to output voltage transfer function of SEPIC agree very well proving that the symbolic control to output voltage transfer function of SEPIC together with its zeros and poles are successfully derived.

Nonlinear Control for Positive Output Super Lift Luo Converter in Stand Alone Photovoltaic System

This paper proposes a stand-alone photovoltaic (PV) system based on a DC-DC positive output super lift Luo (POSLL) converter. A conventional sliding mode control, a sliding mode controller using a simple sign function and a linear controller using proportional integrator (PI) are used for the control of the PV panel voltage and POSLL converter inductor current and these methods are compared together. The POSLL converter is a DC-DC converter with higher voltage gain compared to other conventional DC-DC converters, and has a good voltage regulation with a simple structure. The stability and accessibility of the proposed nonlinear controls are investigated widely. The internal dynamics of the proposed closed-loop control systems are also investiged. A practical implementation of the system on a hardware setup is performed using a low cost Discovery real time digital control platform. The experimental and simulation results demonstrate the validity of the proposed control schemes over a stand-alone real photovoltaic system.

Simulation and analyses of SEPIC converter using linear PID and fuzzy logic controller

The DC-DC converter is now widely used in renewable energy conversion systems such as photovoltaic. They serve to adapt the input voltage of a system to the desired output voltage.The SEPIC converter (Single-Ended Primary Inductor Converter) is a converter that has several advantages over other converters of classical structure. The SEPIC converter is classified among the converters with complex topologies of fourth order. The state space average model is used to analyse the behaviour of DC-DC converters to design the appropriate controllers. Various techniques are commonly used to control these converters, such as linear controllers (PI, PID…) or non-linear controllers (fuzzy logic…).Our study is based on the dimensioning and modelling of a SEPIC converter in continuous conduction mode. These converter is submitted to disturbances such as the variation of input voltage, also in this study, the state space average model is established in MATLAB/Simulink environment, and The results are used to design a linear controller PID to regulate the output voltage and compare them with a nonlinear controller fuzzy logic to prove the validity and efficiency of the two models.

Improved Control Strategies of Electric Vehicles Charging Station based on Grid Tied PV/Battery System

In this paper, improved control strategies of a smart topology of EVs charging station (CS) based on grid tied PV/Battery system are designed and analyzed. The proposed strategies consist of three operating modes i.e. Pv2B; charging a battery storage buffer (BSB) of the CS from solar energy, V2G; discharging an EV battery via grid, and Pv2G; injecting the produced power from PV system into the energy distribution system. However, the BSB is connected to the PV system through a single ended primary inductor converter, the V2G operating mode is emulated by an EV lithium-ion battery tied to the grid via a high frequency full bridge inverter and a bidirectional dc/dc converter. The aim of this work is to improve the energy efficiency of the CS by using a hybrid energy system. Simulation studies are performed in Matlab/Simulink in order to operate the proposed solar CS with multiple control strategies of each case scenario based on a CS management algorithm (CSMA). To provide credible findings of this research, a low power prototype is developed in order to validate the proposed CSMA and its associated controls.

Design of Adaptive Neuro-Fuzzy Inference Control Based One-Axis Solar Tracker on Battery Charging System

The photovoltaic (PV) panel can produce electrical energy that is very environmentally friendly and easy to use. The use of PV panels is suitable for supplying peak loads or at night using batteries as energy storage. However, the battery needs to manage for control, and the battery can last long. The solution to battery management problems is through research about the battery charging system. The DC-DC converter used is the Single Ended Primary Inductance Converter (SEPIC) type. Voltage Control of the battery charging using Adaptive Neuro-Fuzzy Inference System (ANFIS). In the simulation of bright conditions, ANFIS controls can track the charging point set point and obtain a voltage response with a rise time of 0.0028 s, a maximum overshoot of 0.027 %, a peak time of 0.008 s, and a settling time of 0.0193 s. When charging a solar tracker, PV battery gets a 0.25 % increase compared to a fixed PV panel. PV solar tracker can follow the direction of the sun’s position. The irradiation value and maximum temperature affect the input voltage and input current that enters the converter.

Electric power generation from heat energy using thermo electric generator and single ended primary induction converter

Electric power generation from heat energy using thermo electric generator and single ended primary induction converter

Evaluation and Comparison of DC-DC Power Converter Variations in Solar Panel Systems Using Maximum Power Point Tracking (MPPT) Flower Pollination Algorithm (FPA) Control

Maximum Power Point Tracking (MPPT) is a method that can be used to optimize the electrical power output from solar panels. The performance of the MPPT method on solar panel systems can be influenced by many variables. One of them is the selection of a DC-DC power converter. DC-DC-DC Converter is a component that is used to optimize the performance of solar panels. Several types of DC-DC Converter are Buck, Buck-Boost, Single Ended Primary Inductance Converter (SEPIC), and CUK. Each converter has a different effect on solar panels output power. In order to observe and make a comprehensive analysis, simulations are performed through PSIM (Power Simulator) software on the performance of several DC-DC Converters that use Flower Pollination Algorithm (FPA) as the MPPT algorithm. Variables that observed are the output power characteristic, the response of the voltage-current ripple signal, and the accuracy of the converter in the process of reaching the maximum power point condition. As a result, CUK converter can obtain the highest value of solar panel output power, 145.02 W. A low ripple level with a stable power value response is entirely generated by CUK and SEPIC Converter. Overall, for this system, the CUK converter has better performance than the other converters.

Binary Hybrid Multilevel Inverter-Based Grid Integrated Solar Energy Conversion System With Damped SOGI Control

This paper presents a binary hybrid multilevel inverter (BHMLI) based grid-connected solar energy conversion system (SECS), controlled by damped second-order generalized integral (DSOGI). The BHMLI architect has a cascaded half-bridge array, which modifies the DC-link of the H-bridge of the voltage source inverter, and results in approximate reference waveform. It reduces the dV/dt of the H-bridge switches and improves output waveform quality. The DSOGI control damps the oscillations and overshoots and provides longer service period of low power switches at transient conditions. It is implemented in the multilevel inverter application for the first time in literature. The SECS is designed to inject active power to the grid, and also mitigates the harmonic and reactive power demands of the load. The cascading of n' half-bridges and one H-bridge generate (2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(nC1)</sup> - 1) output voltage levels. The maximum power extraction from solar photovoltaic (PV) array is achieved through incremental conductance (IC) algorithm based maximum point tracking (MPPT) operation of the DC-DC converter. An isolated single-input multiple-output single-ended primary inductance converter (SIMO-SEPIC) realizes it. SECS with 15-level BHMLI is analyzed with extensive simulation as well as with a hardware prototype. Moreover, the shunt active filter functionality of the system at various load conditions are verified and maintained the grid power quality within the IEEE-519 standard throughout the operation. The laboratory developed setup is tested for 5 kW, 400 V, three-phase system, and the experimental analysis at steady-state and dynamic variations of load-side and insolation variations validate the theoretical claims.

Обоснование параметров преобразователя постоянного тока для источника автономного электроснабжения

As the Smart Grid concept has become a part of the electric power industry development, DC/DC conver­ters have turned into a matter of increased interest. This is due to their effective coordination in the DC-bus system operating different types of power sources, including renewable ones and energy storage devices (batteries, supercapacitor modules), and various loads. The article analyzes switch mode power supply DC/DC converters for autonomous power supply systems. The application of the SEPIC (Single Ended Primary Inductance Converter) type converter is substantiated. The techniques of determining the parameters of the converter are presented. The active phase at the duty cycle operation has been demonstrated, and justified in accordance with the theoretical behavior in response to an input voltage change above and below the desired output value. A simulation of the converter's operation in the buck and boost modes in order to stabilize the output voltage at a set level has been performed in the MATLAB / Simulink package. The obtained simulation results show the effectiveness of the suggested solution for an autonomous power supply source.

Hybrid PV and Wind Energy for Grid Connected System using SEPIC Converter

A hybrid generator is designed for both wind energy and photovoltaic system (PV) based on permanent magnet synchronous generator to maintain dc link voltage. In this paper, both the sources are connected with grid through a single ended primary inductor converter (SEPIC) and three phase inverter is followed by SEPIC converter. The fuzzy logic controller used to provide gate pulses for the converter and model predictive controller is providing pulses to three phase inverter which tracking the highest power from the wind and PV system. In the PV system the maximum power point tracking (MPPT) method is used to get higher power from the source. This new hybrid system operation is done by both the effective controllers and system steady is achieved. The integrated energy with high efficiency is directed to grid for distribution and the system is verified in Matlab/Simulink and simulation results are given with model.

On the Equivalence of the Switched Inductor and the Tapped Inductor Converters and its Application to Small Signal Modelling

Switched inductor (SI) converters are popular in applications requiring a steeper conversion ratio. However, these converters operate a twin inductor switching cell, which complicates the small-signal modeling. This paper proposes an expeditious small-signal analysis method to model the SI converters. The offered modeling approach is hinged on the analogy existing between the SI converters and certain Tapped Inductor (TI) converters. It is suggested here that by virtue of the analogy of the SI converters and TI converters the small-signal model of the SI converter is identical to that of its ideal TI counterpart. Hence, the recently developed Tapped Inductor Switcher (TIS) methodology can be applied to the modeling of the SI converters as well. As an example, the small-signal model of the Switched Inductor Buck converter is obtained. Theoretical analysis was confirmed by simulation and experimental results. In addition, several other SI converters and their TI counterparts are identified.

Experimental evaluation of global maximum power point techniques under partial shading conditions

Shading plays an important role in the operation of photovoltaic (PV) systems, especially when one of the cells or modules in the string is submitted to lower irradiance levels due to partial shading (PS). As a result of this condition, the cells or modules absorb the power generated by the unshaded parts, thus causing hot spots that can irreversibly damage the device. In order to mitigate this problem, bypass diodes (BDs) are often connected in parallel with the cells or modules to limit the reverse voltage and the power loss as a consequence. However, the occurrence of multiple peaks in the power versus voltage (P-V) curve is observed. Although conventional maximum power point tracking (MPPT) algorithms are successfully used when PV arrays operate under uniform irradiance conditions, they may fail to determine the global maximum power point (GMPP) if PS comes to occur. Considering that several MPPT algorithms for the operation under PS have been proposed during the last few years, this work presents a detailed analysis of some techniques dedicated to global maximum power tracking (GMPPT), aiming at defining which one presents the best performance. A dc-dc single-ended primary inductance converter (SEPIC) associated with microprocessor ATmega328P is employed to track the GMPP and assess the operation of each technique experimentally. The performance of the well-known perturb and observe (P&O) algorithm is also evaluated under PS condition for comparison purposes.