Bridgeless Single-ended Primary Inductance Converter Research Articles

Average current mode controller for bridgeless PFC SEPIC converter with second-order model reduction operated in continuous conduction mode.

This paper proposes an average current mode controller (ACMC) for a single-phase bridgeless power factor correction (PFC) circuit using a single ended primary inductor converter (SEPIC) via second-order model reduction. The superiority of the proposed controller is PFC accomplished at power up to 350 W with high efficiency via the second-order model reduction. The design and implementation of ACMC on the converter operated with continuous conduction mode (CCM) is explained in detail. ACMC forces input current to follow sinusoidal current reference at different power levels and sustain high power factor (PF). The proposed controller is designed based on the theoretical analysis operation of the circuit. For verification, MATLAB/Simulink simulations are carried out and validation through an experiment test rig for 110-220 Vrms input, 100 Vdc/ 350 W output prototype at 20 kHz switching frequency. It is proven that the proposed controller strategy accomplishes high PF, high efficiency and conformity with the simulation.

Design and Implementation of Bridgeless AC/DC PFC Sepic Converter with Valley-Fill Circuit

The continuous requirement to improve power quality has motivated the proposal of several PFC circuit topologies. The conventional AC/DC SEPIC has increased conduction loss due to the presence of bridge rectifier. In order to reduce the conduction loss and to improve the efficiency this research work deals with a bridgeless SEPIC (single ended primary inductance converter) AC/DC PFC integrated valley-fill circuit (VFC). The number of components is reduced compared to the existing topologies. The bridgeless topology results in reduced conduction loss, reduced current stress and improved system performance compared with the traditional SEPIC and the existing topologies. The circuit configuration of the suggested topology has been simulated using MATLAB/SIMULINK. The functional parameters of the projected AC/DC integrated VFC is compared with the conventional SEPIC (Con-SEPIC), con-SEPIC integrated VFC and bridgeless SEPIC in terms of passive component count, output voltage ripple, input current ripple, supply power factor, Total Harmonic Distortion. From the simulation outcomes, it is concluded that the bridgeless topology provides high power factor, reduced ripple and reduced supply current harmonics. The results are validated.

Analysis of a new SEPIC AC–DC PFC converter for light emitting diode applications

Active power factor correction (PFC) converters are used to increase the power factor and improve the total harmonic distortion as a result of reducing the harmonics in the current. In this paper, a new bridgeless single-ended primary inductor converter (SEPIC) topology used in light emitting diode (LED) load is proposed to obtain near-unity power factor. By eliminating the input bridge in the bridge PFC converter, the total harmonics distortion is improved and a lower cost is obtained. The reactive power control is used to generate the reference current signal in the proposed converter to control the LED current. To demonstrate the applicability of the proposed topology and to compare its performance with the bridge SEPIC topology, PSIM circuit simulation was used, and an experimental prototype was performed. In the experimental study, 25 Vrms input voltage was applied, and 10 V DC voltage was obtained at the output. Using the proposed converter, the total harmonic distortion value was reduced from 5.722% to 1.837%, and the power factor was increased to 0.999. The experimental and simulation results showed that the total harmonic distortion value of the input current improved and that the proposed SEPIC PFC converter for low-power circuits, particularly in LED applications, is a very good option.

Power quality improvements of arc welding power supplies by modified bridgeless SEPIC PFC converter

This paper proposes an efficient bridgeless power factor corrected (PFC) modified single ended primary inductor converter (SEPIC) for arc welding power supplies (AWPS). The overall configuration is composed of two converters: (1) a modified bridgeless SEPIC PFC converter, which is controlled by a PI controller to achieve a high power factor and fast response; and (2) a full bridge buck converter with high-frequency transformer for high-frequency isolation to ensure arc welding stability. The proposed system is simulated under different operating conditions of an AWPS. It is also tested in real time by a hardware-in-the-loop system based on a dSPACE DS1103 control board. The system performances are evaluated based on power quality indices such as power factor, total harmonic distortions of the AC grid current, and voltage regulation. The obtained results show that the proposed controller enhances the weld bead quality by keeping a constant current at the output and a stable arc, meet the international power quality standards and robustness for voltage regulation.

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.

A PFC Based EV Battery Charger Using a Bridgeless Isolated SEPIC Converter

Conventional power factor correction (PFC) circuits in electric vehicle (EV) battery chargers have the efficiency limitation due to high conduction loss associated with a diode bridge rectifier (DBR) at the input. To mitigate this issue, a bridgeless (BL) single ended primary inductance converter (SEPIC) with improved power quality, is presented in this article. The input current shows a unity power factor operation over the entire charging duration. Due to elimination of DBR and the current conduction through relatively less number of devices, conduction losses are significantly reduced. This, in turn, improvises the charger efficiency as compared to conventional BL SEPIC converter. The overall performance of proposed charger is illustrated with the help of various operating modes, design equations, simulation-based performance and experimental validation under steady state as well as over wide fluctuations in ac mains voltage. The EV battery is charged at constant current/ constant voltage control mode, which provides satisfactory results for improved efficiency and inherent PFC, thus, improving overall performance of the charger.

Sliding Mode Control of the Isolated Bridgeless SEPIC High Power Factor Rectifier Interfacing an AC Source with a LVDC Distribution Bus

This paper deals with the analysis and design of a sliding mode-based controller to obtain high power factor (HPF) in the bridgeless isolated version of the single ended primary inductor converter (SEPIC) operating as a single-phase rectifier. In the work reported here, the converter is used as a unidirectional isolated interface between an AC source and a low voltage direct current (LVDC) distribution bus. The sliding-mode control is used to ensure the tracking of a high quality current reference at the input side, which is obtained from a sine waveform generator synchronized with the grid. The feasibility of the proposal is validated using simulation and experimental results, both of them confirming a reliable operation and showing good static and dynamic performances.

Bridgeless PFC single ended primary inductance converter in continuous current mode

This paper presents bridgeless single ended primary inductor (SEPIC) converter operated in continuous conduction mode (CCM). The converter used in the study offers a lesser conduction loss compared to the other bridgeless SEPIC converter. In order to regulate the required output current and output voltage with high efficiency while achieving high power factor correction (PFC) at the input side, average current mode control (ACMC) is applied. The model is simulated using MATLAB/Simulink and it is found that the converter and the proposed control strategy provide a promising result. The preliminary results obtained from the experimental test-rig shows a good agreement as in simulation. The theoretical analysis of the proposed controller is verified on an output 100V to 300W prototype.

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.

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.

Modified Bridgeless SEPIC Rectifier for Power Factor Correction with Reduced Switch Stress Operating in Continuous Conduction Mode

In this paper, a high performance single-phase modified bridgeless AC–DC converter with reduced switch voltage stress for power factor correction (PFC) is introduced. The proposed converter is based on a single-ended primary-inductance converter (SEPIC) to meet the demands of PFC to unity and output voltage regulation. To reduce the number of components, the input bridge is combined with the SEPIC converter since the conventional SEPIC PFC is suffering with high conduction losses. It offers many advantages, such as fewer semiconductor devices in current flowing path which lead to improve the thermal management, low stress on each component, improved efficiency, high power factor compared to classical converter. Detailed analysis and design equations of the converter are presented. Simulation and experimental results are discussed for a 300[Formula: see text]W prototypeunder the universal input voltage (85–235[Formula: see text]V) to validate the performance of the converter.

A Power Quality Improved Bridgeless Converter-Based Computer Power Supply

Poor power quality, slow dynamic response, high device stress, harmonic rich, periodically dense, peaky, distorted input current are the major problems that are frequently encountered in conventional switched mode power supplies (SMPSs) used in computers. To mitigate these problems, it is proposed here to use a nonisolated bridgeless buck-boost single-ended primary inductance converter (SEPIC) in discontinuous conduction mode at the front end of an SMPS. The bridgeless SEPIC at the front end provides stiffly regulated output dc voltage even under frequent input voltage and load variations. The output of the front end converter is connected to a half-bridge dc–dc converter for isolation and also for obtaining different dc voltage levels at the load end that are needed in a personal computer. Controlling a single output voltage is able to regulate all the other dc output voltages as well. The design and simulation of the proposed power supply are carried out for obtaining an improved power quality that is verified through the experimental results.

Closed Loop Analysis of Bridgeless SEPIC Converter for Drive Application

In this paper closed loop analysis of Single phase AC-DC Bridgeless Single Ended Primary Inductance Converter (SEPIC) for Power Factor Correction (PFC) rectifier is analyzed. In this topology the absence of an input diode bridge and the due to presence of two semiconductor switches in the current flowing path during each switching cycle which will results in lesser conduction losses and improved thermal management compared to the conventional converters. In this paper the operational principles, Frequency analysis, and design equations of the proposed converter are described in detail. Performance of the proposed SEPIC PFC rectifier are carried out using Matlab Simulink software and results are presented.

An Approach of PFC in BLDC Motor Drives Using BLSEPIC Converter

This paper presents the analysis and design of on front end bridgeless single-ended primary-inductance converter (BLSEPIC) based power factor rectification, with output voltage regulation and high frequency isolation working in discontinuous conduction mode. The switching loss in VSI is minimized by an electronic commutation of Brushless DC motor (BLDCM) is used to operate in a low-frequency operation. To improve the efficiency, the diode bridge rectifier is replaced with the alternate bridgeless topologies which offers less conduction losses, advised by the international power quality standards, a wide range of speed control is obtained with improved power quality BLDC motor drive is proposed and simulated in MATLAB/SIMULINK. DOI: http://dx.doi.org/10.11591/telkomnika.v14i2.7404

Zero‐voltage transition bridgeless single‐ended primary inductance converter power factor correction rectifier

In this study, a new zero-voltage transition (ZVT) bridgeless single-ended primary inductance converter power factor correction converter is introduced. The proposed converter has only two semiconductor elements in the current path at any time. Therefore the conduction losses in this converter are reduced in comparison with conventional SEPIC PFC rectifier. Also, in the proposed converter, ZVT soft switching technique is applied to improve the efficiency. The principle of the operation, design procedure and simulation results are presented. A 450 W prototype of this converter is implemented and the experimental results are presented to demonstrate the feasibility of the proposed technique.

High-efficiency isolated SEPIC converter with reduced conduction losses for LED displays

This paper proposes a high-efficiency isolated bridgeless single-ended primary inductor converter (SEPIC) for light-emitting-diode (LED) displays. The proposed isolated SEPIC converter can supply LED back-light power with reduced conduction losses. Switching power losses as well as conduction losses are reduced. The proposed converter is theoretically analysed. Experimental results based on a 28 V, 300 W back-light power are discussed to verify the performance of the proposed converter.

A Bridgeless SEPIC PFC Rectifier with Reduced Conduction Losses

A bridgeless single-ended primary inductor converter (SEPIC) power factor correction (PFC) rectifier is introduced in this paper. In order to maximize its efficiency more than a conventional bridgeless SEPIC PFC Rectifier, a new driving scheme is proposed. In the proposed converter, conduction losses are reduced by eliminating bridge diodes. In addition, the impedance of the return current paths is lowered and conduction losses are reduced by applying a gate-on signal which is maintained during half line cycle to inactive switches. Consequently, the conduction losses of the proposed converter are significantly reduced and high efficiency is achieved. Besides high efficiency, the proposed converter provides high power factor (PF) and a continuous input current. Input current ripple can be easily removed by a simple filter capacitor. The operational principles, steady-state analysis and design equations of the proposed converter are described in detail. Experimental results from a 130 W prototype at a constant switching frequency of 100 kHz are presented to verify the performance of the proposed converter.

Bridgeless SEPIC Converter With a Ripple-Free Input Current

Conventional power factor correction (PFC) single-ended primary inductor converter (SEPIC) suffers from high conduction loss at the input bridge diode. To solve this problem, a bridgeless SEPIC converter with ripple-free input current is proposed. In the proposed converter, the input bridge diode is removed and the conduction loss is reduced. In addition, the input current ripple is significantly reduced by utilizing an additional winding of the input inductor and an auxiliary capacitor. Similar to the conventional PFC SEPIC converter, the input current in a switching period is proportional to the input voltage and near unity power is achieved. The operational principles, steady-state analysis, and design equations of the proposed converter are described in detail. Experimental results from a 130 W prototype at a constant switching frequency of 100 kHz are presented to verify the performance of the proposed converter.

Power-Quality Improvement in PFC Bridgeless SEPIC-Fed BLDC Motor Drive

Abstract This article presents a design of a power factor correction (PFC)-based brushless DC (BLDC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the voltage source inverter (VSI) feeding BLDC motor using a single voltage sensor. A front-end bridgeless single-ended primary inductance converter (SEPIC) is used for DC link voltage control and PFC operation. A bridgeless SEPIC is designed to operate in discontinuous inductor current mode (DICM) thus utilizing a simple control scheme of voltage follower. An electronic commutation of BLDC motor is used for VSI to operate in a low-frequency operation for reduced switching losses in the VSI. Moreover, a bridgeless topology offers less conduction losses due to absence of diode bridge rectifier for further increasing the efficiency. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power-quality at the AC mains under the recommended international power-quality standards such as IEC 61000–3-2.

Bridgeless SEPIC PFC Rectifier With Reduced Components and Conduction Losses

In this paper, a new bridgeless single-ended primary inductance converter power-factor-correction rectifier is introduced. The proposed circuit provides lower conduction losses with reduced components simultaneously. In conventional PFC converters (continuous-conduction-mode boost converter), a voltage loop and a current loop are required for PFC. In the proposed converter, the control circuit is simplified, and no current loop is required while the converter operates in discontinuous conduction mode. Theoretical analysis and simulation results are provided to explain circuit operation. A prototype of the proposed converter is realized, and the results are presented. The measured efficiency shows 1% improvement in comparison to conventional SEPIC rectifier.