SEPIC Power Factor Correction Research Articles

Enriched PQ-based bridgeless isolated one-stage sepic PFC converter for power solutions

ABSTRACT This article deals with an enriched power quality (PQ) based bridgeless isolated one-stage (BIOS) Sepic PFC converter as a cost-effective power solution. The presented revamped bridgeless structure on the front-end avoids unnecessary capacitive coupling and assures less current harmonic distortions, better power factor (PF) at the AC mains to confirm the permissible power quality (PQ) metrics as per IEC 61,000-3–2 standards. This PFC circuit is modelled to be operated on discontinuous inductor current mode (DICM) to reveal the innate zero current switching (ZCS) and power factor correction (PFC) capability. The added merits of DICM and high-frequency isolation involve lesser number of sensors, part count, control complications, size and cost associated with the entire power conversion. Further, the hardware setup of 250W/48 V power solution is assembled to testify the performance of the developed circuit. From the experimental outcomes it is notable that this power solution retains the bettered PQ profile within the perceivable limits even under broad range of source voltage and load discrepancies. Finally, the extensive loss modelling of the power circuit is formulated to evaluate the actual efficiency of the entire power conversion.

Analysis of interval type-2 fuzzy controller based interleaved sepic PFC converter for PQ enhancement in power solutions

The Power solutions have become indispensable for all the devices in recent years with an appropriate power conversion circuitries and control methods to ensure good dynamic response, improved stability, reliability and efficiency. The main intent of this article is to impart the designing of interval type-2 fuzzy logic controller (IT2FLC) based interleaved Sepic power factor correction (PFC) converter. This work also involves the careful design of the robust controller with enhanced precision and good power quality (PQ) performance at the AC mains. In addition, the development of IT2FLC based power solution improves the overall power conversion with stabilized output in the perspective of its quick rise time, less overshoot and fast settling time in comparison to other traditional controllers. Further, the uncertainties and issues associated with the conventional proportional integral (PI) and fuzzy logic controllers (FLCs) are handled effectively by the proposed IT2FLC controller. Moreover, this preferred converter is modeled with an internal parasitics and its performances are evaluated and compared with other conventional Zeigler Nicholas (ZN) tuned PI controller and FLC by dint of MATLAB/Simulink platform. Finally, the experimental test bench set up of 250 W, 48 V power circuitry is devised and the test outcomes confirm the excellent transient behavior and PQ performances of the modeled power solution.

Bridgeless Modified High-Step-Up Gain SEPIC PFC Converter Based Charger for Light EVs Battery

This study presents a two-stage on-board charger for light electric vehicles (LEVs) with low voltage battery (24-72V). The front-end of the charger has characteristics of high voltage conversion ratio and unity power factor operation achieved by a bridgeless high gain modified SEPIC converter. The high voltage conversion ratio enables the front-end to operate over a wide range of input voltages. At the back-end of the charger, an isolated positive output Luo DC-DC converter is employed to regulate the charging profile of the LEV battery under constant current (CC) and constant voltage (CV) charging modes. The presented charger operates in discontinuous conduction mode (DCM), which has dual advantages of having inherent feature of power factor correction (PFC) at the supply end along with significantly reducing the complexity of control mechanism, thereby reducing the cost and effort of control implementation. The operational analysis and design of the presented charger in DCM are covered in detail in this study and the same are further validated by means of simulations. A 650 W test bench setup is developed to authenticate the theoretical performance by means of experimental results. The experimental performance of the front-end is finally compared with other PFC topologies to highlight the merits and demerits of the presented charger.

A cost‐effective switched inductor‐based bridgeless Sepic converter for PQ enrichment in power solutions

SummaryPower solutions contribute a remarkable role in all the sectors. In order to develop the sustainable and affodable power solution, the bettered power quality (PQ) based modified bridgeless switched inductor (MBSL) Sepic power factor correction (PFC) converter is introduced in this article. An added feature to an already existing traditional Sepic converter resulted in switched inductor (SL) network that reasonably improves the step‐down voltage gain with low current stress across the output inductors and diodes which restricts the utilization of transformer that ultimately reduces the overall cost of power solution. This introduced structure acts as a good choice of low‐cost power conversion solution in the perspective of improved inline PQ indices, high efficiency and good reliability. Furthermore, the discontinuous conduction mode (DCM) functioning of SL network reveals the innate zero current switching (ZCS) capability with enhanced efficiency. Besides, the effective functionality of the one‐stage PFC converter is tested on hardware prototype of 250 W/48 V, and it also adopts an appropriate control approach to stabilize the output voltage. This study also exposes small signal modeling to prove the stability of the power solution. In addition, the test outcomes reveal that the preferred PFC procure sinusoidal current from the AC mains that confirms the good enshaping attribute and low current harmonic distortions within the stipulated IEC 61000‐3‐2 standard guidelines for both standstill and fluctuating conditions.

Bridgeless isolated sepic PFC for EV battery charging using ANN controller

The power quality of an Electric Vehicle (EV) battery charger is improved in this work using a bridgeless isolated single ended primary inductance converter (SEPIC). Owing to the excessive amount of conduction losses associated with the conventional Diode Bridge Rectifier (DBR) based Power Factor Correction (PFC) circuit; a Bridgeless circuit model is preferred in this work. The safe functioning of the PFC circuit is further ensured by selecting an isolated topology over a non-isolated converter topology. With the use of an artificial neural network (ANN) controller, the converter's operation is improved in terms of rising time, overshoot, steady state error and settling time. Distortions in the input current are curtailed with the aid of Hysteresis Current Controller (HCC). The entire work of the proposed converter in terms of design equations and several operating modes is detailed elaborately. The input current displays functioning with a unity power factor for the full charging period. The proposed Bridgeless Isolated SEPIC PFC's efficacy in improving the power quality of the EV charger system is determined using simulation results from MATLAB and hardware implementation utilising a DSP30F411 controller.

Modified Bridgeless PFC-Based Cuk-Sepic Converter With Improved Power Quality for Arc Welding Applications

The novel single-phase Cuk and Sepic power factor correction converter attracted toward arc welding application is highlighted in this paper. The preferred converter is outlined to function in DCM concealed by variations in load voltage and supply voltage to ensure better performance. The control strategy includes a voltage loop, which ensures arc welding process stability and improved input power quality. The designed system is validated with a hardware prototype of 100 W, 48 V, and Matlab/Simulink is used to simulate the arc welding power supply under different working conditions. The reduced input line total harmonic distortion of 1.527% with unity power factor is attained for the rated load in the investigational study. The experimental performance of the propounded converter is bestowed with operating conditions of AC mains (90–270 V) to cohere to the limits delineated by the IEC61000-3-2 standards.

Three-phase SEPIC PFC for three-phase IM drive under unbalanced and distorted voltage supply

This paper proposes a three-phase power factor correction (PFC) for a three-phase induction motor (IM) drive under normal and abnormal supply voltage conditions. A new technique of PFC based on a positive sequence components method is introduced. The PFC circuit uses a SEPIC converter with a single switch, which needs only one control signal. The PFC control method with the proposed technique provides nearly sinusoidal supply currents maintaining a high power factor under different supply voltage conditions. Furthermore, the PFC method maintains DC bus voltage at the desired value. The regulated DC voltage feeds a four-switch inverter of the three-phase IM drive system. Mathematical analysis of the equivalent circuits based on operation modes of the SEPIC converter is introduced. The performance of the proposed technique is evaluated under ideal and non-ideal supply voltage conditions. The results are analyzed in terms of reduction in the THD of supply currents and improvement of power factor. System validation performed in simulation and experiment has shown the effectiveness of the proposed system under different supply voltage conditions.

Single-Phase Hybrid Switched-Capacitor Voltage-Doubler SEPIC PFC Rectifiers

In this paper, the switched-capacitor concept is extended to the voltage-doubler discontinuous conduction mode SEPIC rectifier. As a result, a set of single-phase hybrid SEPIC power factor correction rectifiers able to provide lower voltage stress on the semiconductors and/or higher static gain, which can be easily increased with additional switched-capacitor cells, is proposed. Hence, these rectifiers could be employed in applications that require higher output voltage. In addition, the converters provide a high power factor and a reduced total harmonic distortion in the input current. The topology employs a three-state switch, and three different implementations are described, two being bridgeless versions, which can provide gains in relation to efficiency. The structures and the topological states, a theoretical analysis in steady state, a dynamic model for control, and a design example are reported herein. Furthermore, a prototype with specifications of 1000-W output power, 220-V input voltage, 800-V output voltage, and 50-kHz switching frequency was designed in order to verify the theoretical analysis.

New Bridgeless DCM Sepic and Cuk PFC Rectifiers With Low Conduction and Switching Losses

New bridgeless single-phase ac-dc power factor correction (PFC) rectifiers based on Sepic and Cuk topologies are proposed. The absence of an input diode bridge and the presence of only two semiconductor switches in the current flowing path during each switching cycle result in less conduction losses and improved thermal management compared to the conventional Sepic and Cuk PFC converters. The proposed topologies are designed to work in discontinuous conduction mode (DCM) to achieve almost unity power factor in a simple and effective manner. The DCM operation gives additional advantages such as zero-current turn-on in the power switches, zero-current turn-off in the output diode and reduces the complexity of the control circuitry. The proposed rectifiers are theoretically investigated. Performance comparisons between the proposed and conventional Sepic PFC rectifiers are performed. Simulation and experimental results are provided for a design example of a 65-W/48-V at 100- V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> line voltage to evaluate the performance of the proposed PFC rectifier.