Active Power Factor Correction Research Articles

Power Loss and Temperature Distribution in Coil of PFC Inductor with Air Gap for Multimode Operation

Power converters inherently display non-linear load characteristics, resulting in a high level of mains harmonics, and hence the necessity of implementing Power Factor Correction (PFC). Active PFC circuitry typically comprises an inductor and a power switch to control and alter the input current so that it matches, in shape and phase, the input voltage. This modelling of the waveforms can be performed by means of distinct conduction modes of the PFC inductor. The digital controller implemented in the constructed and investigated boost-type PFC converter can be programmed to operate in discontinuous conduction mode (DCM), continuous conduction mode (CCM), or a combination of the two. The individual modes of operation, via distinct PFC inductor current waveforms, impact the overall efficiency of power conversion and, by extension, temperature distribution in the magnetic component. This paper investigates how the examined conduction modes bear on distinct power-loss mechanisms present in the PFC inductor, including high-frequency eddy-current-generating phenomena, and the fringing effect in particular. As demonstrated herein, the DCM operation, for the set output power level, exhibits exacerbated power dissipation in the winding of the inductor due to the somewhat increased RSM value of the current and the intensified fringing magnetic flux at an air gap. The latter assertion will undergo further, more quantitatively focused research. Finally, the construction of the coil was optimised to reduce power loss by diminishing eddy-current mechanisms.

Universal Continuous Model of Active Power Factor Correctors

The purpose of the work is to develop continuous mathematical models of power factor correctors for switch-mode power supplies. The models are designed to solve optimization problems aimed at increasing the energy efficiency of these devices. This goal was achieved by developing a universal continuous averaged model of switch-mode voltage converters, which are an integral part of any active power factor corrector. State-space averaging method was proposed for constructing such a universal model. It has been shown that such a model adequately reproduces the processes in any of the main types of DC-DC voltage converters. The possibility of constructing a mathematical model of an active power factor corrector based on the proposed universal model of a DC-DC voltage converter is substantiated. The features of the structures of active power factor correctors for switching power supplies are considered and the problems that arise when studying their energy efficiency are shown. By simulation in the time domain with using the constructed model, diagrams of transients of the power factor corrector during load and primary network voltage disturbances are obtained. The most important result is the creation of a universal continuous mathematical model of switching voltage regulators. This model, unlike previously proposed models, is suitable for use in the analysis, modeling and design of any power factor correctors without the need to modify it in each specific case. The significance of the results obtained lies in accelerating the design process of active power factor correctors built on the basis of any type of pulsed DC-DC voltage converters. The developed model is intended for use in the Micro-Cap electronic circuit analysis program. However, since it is ultimately a software module in the SPICE language, this model can be used in many circuit analysis programs that support this language.

Research of electric vehicle battery packs and charging stations based on an active three-phase rectifier

Problem. The proliferation of electric vehicles has underscored the need for the development of energy-efficient charging stations and systems. These systems must deliver high efficiency, maintain a power factor close to unity, adhere to electromagnetic compatibility standards, emit low levels of higher harmonics, and enable fast charging capabilities. Current electric vehicle charging devices encounter issues such as significant power losses, high harmonic emissions to the power grid, and challenges in implementing fast charging modes. Consequently, enhancing the energy efficiency of charging stations – by reducing power losses, minimizing harmonic emissions, ensuring a high power factor, and supporting modes for regulated current and voltage sources for fast charging – is a pressing concern. Goal. The aim of this work is to perform a comparative analysis of different types of batteries for electric vehicles, exemplified by TESLA cars, presenting comparative characteristics of lithium-ion, lithium-iron-phosphate, and lithium-titanate batteries. Methodology. The study showcases an evaluation of battery units for electric vehicles and outlines a comparative assessment of lithium-ion, lithium-iron-phosphate, and lithium-titanate batteries. The research focuses on enhancing the energy efficiency of electric vehicle charging station systems through the use of active rectifiers, with modes for active power factor correction and optimal configuration. Results. An examination of the quality of converters for electric vehicle charging stations was conducted, proposing schemes for a three-phase active voltage source rectifier and an active current source rectifier. Power circuitry and space-vector switching states for power transistors are introduced. Analysis concludes that an active current rectifier may be a more promising topology. Originality. A model of a charging station based on an active current source rectifier was developed using Matlab/Simulink. Transient processes of the converter's operation and the charging of a 60 kWh battery pack were examined. It was found that the active rectifier facilitates regulation of the battery charging current, achieves a power factor close to unity, and maintains a low level of higher harmonic emissions with a harmonic distortion factor of 2.52%. Practical value. The advancement of electric vehicles necessitates the ongoing development and enhancement of the energy indicators for electric vehicle batteries and the converters of charging stations, especially those that enable fast charging. Active progress is being made in each of these areas.

Parameters Optimized with the Pattern Search Algorithm for Fuzzy Control Based Active Power Factor Correction

In recent times, the demand for reliable and efficient power systems has intensified, necessitating the need for advanced control methodologies. This study introduces an approach to active power factor correction using Fuzzy Control theory. Unlike traditional power factor correction methods which may suffer from imprecision and slow response times, the proposed fuzzy logic controller (FLC) offers a more adaptive and resilient solution by dealing with uncertainties inherent in power systems. The FLC's inherent ability to handle imprecision makes it a suitable choice for active power systems where parameters can be non-linear and constantly changing. Furthermore, this study describes the design and simulation processes of the FLC for active power correction. Under different load and distribution conditions it demonstrates the FLC's efficacy in maintaining power quality by promptly reacting to disturbances, reducing harmonic distortions, and ensuring consistent power factor levels. Comparative analyses with conventional control methods affirm the superiority of the Fuzzy Control-based approach in terms of accuracy, robustness, and response time.

An experimental investigation of variable-step-size Affine Projection Sign based algorithm for power quality enhanced grid-interactive solar PV system

This article proposes a variable-step-size Affine Projection Sign algorithm that improves power quality ancillary services in a grid-interactive solar photovoltaic system. VSS-APS algorithm features decreased steady-state fluctuation, faster convergence, and robustness to disturbances. The VSS-APS algorithm efficiently extracts contaminated source current active and non-active fundamental weight components to estimate source current reference signals. The solar grid-integrated voltage source inverter manages solar PV unit active power and provides free multipurpose PQ-ancillary services. Harmonic current, active power, load, neutral current, reactive power, and power factor correction are the PQ indices that improved significantly with the proposed VSS-APS control. VSS-APS improves GISVSI's steady-state and dynamic performance. MATLAB®/SIMULINK and a scaled laboratory prototype developed to test the VSS-APS control approach. The DSP-dSPACE 1104 controller implements the suggested controller in real time. The proposed VSS-APS control algorithm is compared with the conventional algorithms, and test results from a laboratory experiment demonstrate its feasibility and benefits. The experimental results show that the proposed VSS-APS algorithm is effective in improving power quality while complying to IEEE 519-2014 and IEEE 1547-2003 standards for grid connections.

A fault diagnosis method for active power factor correction power supply based on seagull algorithm optimized kernel‐based extreme learning machine

AbstractTo address the issue of diagnosing hard and soft faults in active power factor correction (APFC) power supply, this study analyzes failure modes resulting from aging and malfunction of various sensitive components. The power fault waveform patterns are initially analyzed based on the circuit's THD, current ripple value, and RMS value. The inductor current signals in different fault modes are then utilized to extract and construct time–frequency fusion fault features of the APFC power supply. Finally, these feature quantities are downscaled and optimized using the RF algorithm. The SOA‐KELM model of the APFC converter is proposed, and the feature vectors under different fault modes are used to classify and diagnose faults, achieving hard and soft fault detection of the converter. The experiments show that the method achieves 100% accuracy for hard fault diagnosis and 96.36% accuracy for soft fault diagnosis of the converter, demonstrating high diagnostic accuracy.

An Integrated Three-Phase AC–DC Wireless-Power-Transfer Converter With Active Power Factor Correction Using Three Transmitter Coils

Three-phase AC-DC converters are more commonly used for high-power applications compared to single-phase converters. For high-power wireless power transfer (WPT) applications, such as wireless electric vehicle chargers, usually a two-stage topology is applied, which consists of a three-phase AC-DC rectifier with power factor correction and a DC-DC converter for WPT. Recently, there are several studies on three-phase single-stage WPT solutions being proposed to reduce power conversion stages, and furtherly increase overall efficiency and reduce system cost. In this paper, an integrated three-phase AC-DC WPT converter topology with active power factor correction is proposed. The count of power semiconductor devices is significantly reduced compared to state-of-the-art three-phase single-stage topologies. Moreover, three transmitter coils are used to enhance the system power capacity. Topology description, operation analysis, control method, power loss analysis, and reference design guideline of the proposed topology are presented in detail. Finally, a laboratory prototype is built and evaluated. The functionalities, performances, and advantages are demonstrated by the corresponding experimental results.

Asymmetric modulation of bridgeless single‐stage full‐bridge AC–DC converter for active power factor correction and zero voltage switching

AbstractSinge‐phase single‐stage AC–DC converters exhibit the advantages of lower cost, higher efficiency, and lower power semiconductor device count compared with traditional two‐stage topologies. However, most existing single‐stage AC–DC topologies encounter some or all the following drawbacks: hard‐switching operation, bulky bus or output capacitor, uncontrolled bus voltage, not actively shaped input current, a large amount of power semiconductor devices, etc. The bridgeless single‐stage full‐bridge AC–DC converter can be considered a promising solution for high power capacity and efficiency. However, this topology still suffers from most of the drawbacks. In this paper, a new asymmetric modulation method of bridgeless single‐stage full‐bridge AC–DC converter is proposed to achieve active power factor (PF) correction and zero‐voltage switching. Topology description, the proposed modulation and control methods, theoretical analysis progress, and reference design procedure are presented in detail. Finally, a 2‐kW laboratory prototype is implemented with experimental results presented to validate the principle and design.

A Proprietary ZVS-Based Approach Delivers High Efficiencies at Light Load With Half the Components of Conventional Designs

The ac–dc power supply units providing isolated, regulated outputs operating above 100 W typically require some form of input active power factor correction (PFC) <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> . To achieve this, a popular solution is to combine a boost PFC input stage with an “LLC” converter which isolates and controls the dc output voltage. However, a new, innovative single-stage technique for delivering regulated ac–dc power with a high input power factor offers the promise of high efficiency from no-load to full-load, while halving the number of active devices (MOSFETs) when compared to the traditional approach.

Single Stage Active Power Factor Correction Circuit for Street LED Light with Battery Backup

This paper proposes a single-stage active power factor correction circuit for street LED light with battery back-up. The buck–boost converter and flyback converter are combined to achieve optimal performance. The first part of the integrated LED driver, the buck–boost converter is used to adjust the power while operating in the discontinuous conduction operation. The second part of the driver, the flyback converter provides regulated voltage to the LEDs. The battery backup circuit charges the battery when ac input power is available and provides power to LED lamp when input power supply is not available. The proposed LED driver was designed for 100 W output power and tested by PSpice simulation. The simulation results obtained are given in the paper to demonstrates the functionality of the proposed LED driver system. The result show good operation and performance of proposed LED driver.

On the Minimum DC Link Capacitance in Practical PFC Rectifiers Considering THD Requirements and Load Transients

The article presents the analytical derivation of the minimum dc link capacitance in single-phase front ends with active power factor correction (PFC) without hold-up time requirements. Such systems typically employ boost-type rectifiers; operate under restricted total harmonic distortion (THD) of the grid-side current. Moreover, PFC rectifiers must be capable of tolerating step-like zero-to-rated load power variations. It is well known that these two constraints contradict each other, posing nontrivial design challenges. The revealed value of minimum capacitance is expressed by an explicit function of grid voltage and frequency, converter rated power, dc link voltage reference, and grid current THD and voltage loop phase margin set points. Experimental results validate the proposed methodology, closely matching corresponding analytical predictions.

Non-Isolated Power Factor Corrected AC/DC Converter with High Step-Down Voltage Ratio for Low-Power Applications

This paper proposes a high step-down ratio AC-DC converter employing a quadratic buck converter with power factor correction. Conventional active power factor correction topologies employ boost-based correction schemes for unity power factor operation. This will require a steeper step-down ratio and higher switch voltage stress apart from complexity in the control scheme with sensors. The structure of the proposed topology is developed by combining the power factor correction stage with a high step-down stage. The passive input filter is split up into two for the purpose of reducing the thermal heating apart from offering a higher power factor. A single switch operation reduces the complexity of the control scheme. In addition, the number of conducting devices during the current path is also the same as the conventional buck converter due to cascading and hence offers lower conduction losses. The need for the converter to operate at an extremely low duty cycle is reduced due to the quadratic stage structure. The proposed converter operates at a moderate duty cycle, offering higher step-down voltage apart from reducing filtering requirements. MATLAB R2020b is used for carrying out simulation studies. Xilinx FPGA-based controller using system generator is implemented for the generation of pulses of appropriate duty cycle. Simulation and experimental results for a 150 W prototype are presented. An investigation and comparative evaluation of the conventional bridgeless buck system with the quadratic buck converter are carried out. The proposed structure offers the benefit of a higher step-down voltage ratio incorporating an inherent power factor correction stage along with the AC/DC stage.

Simulation of a double-circuit subordinated coordinate regulation system of the active po wer factor corrector for the electric locomotive auxiliary electric drive

Introduction. The object of this study is an auxiliary frequency-controlled electric drive of an AC locomotive, or more specifically, the structure and parameters of the system for regulating the coordinates of the active power factor corrector, which is a part of the electric drive and a unit that ensures the energy efficiency of the electric drive as well as its electromagnetic compatibility with other equipment on board the electric locomotive and the power network. The purpose of the study is to substantiate the structure of the system for regulating the coordinates of an active power factor corrector, the choice of types of regulators and the calculation of their parameters.Materials and methods. The author has chosen as the research method the calculation of transfer functions of regulators of the subordinated regulation system, followed by computer simulation of the processes in electrical circuits using the OrCAD computer-aided design system.Results. The author made a conclusion about the expediency of using a two-circuit system of subordinated coordinate regulation containing a voltage control circuit and a current control circuit. The researcher presented and analytically compares the results of modelling of a two-circuit coordinate regulation system for the active power factor corrector for various types of regulators. The models with an aperiodic current regulator and a proportional-integral voltage regulator showed the best results.Discussion and conclusion. The obtained data serve as the basis for further improvement of the active power factor corrector operation by improving and optimising the settings, structure and algorithms of the control system, which, with the selected hardware components of the power unit, will enable it to perform its functions with a high degree of reliability in the entire range of disturbing and controlling actions on board of an electric locomotive.

An Active Power Factor Correction Technology for Aircraft

This paper analyzes the influence of harmonics on the system and the importance of power factor correction. According to the requirements of aircraft use, an active power factor correction system based on three phase six switch topology is designed. The article analyzes the working process and control method of the system, then designs a rectifier to convert 220V/400Hz AC power provided by the aircraft to DC power and the power factor of the rectifier is high. Moreover, the performance of the system is tested.

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.

Improved Power Quality Charging System Based on High Step-Down Gain Bridgeless SEPIC APFC for Light Electric Vehicles

The limited voltage gain characteristic of the mainstream dc&#x2013;dc converter restricts the application in single-stage light electric vehicles&#x2019; (LEVs) chargers. Typically, the battery voltage of an LEV is in the range from 24 to 72&#x00A0;V. Thus, while implementing the single-stage LEVs&#x2019; chargers, a line- or high-frequency transformer is essentially required. The utilization of transformer, however, compromises the overall cost, size, and efficiency of LEV chargers. Therefore, a transformerless single-stage bridgeless charger topology is presented in this article, aiming to realize a simple, reliable, efficient, and low-cost charger for the LEVs. The presented topology utilizes a switched inductor single ended primary inductance converter (SISEPIC) to achieve a high step-down dc voltage gain. Furthermore, the active power factor correction is incorporated to ensure enhanced power quality (low total harmonics distortion and unity power factor) at the ac supply side during constant current and constant voltage state charging. Additionally, this charger is controlled by employing reduced sensing devices and control complexities. Both simulation and experimental validations are provided to manifest the effectiveness of this SISEPIC charger topology for LEVs.

A Step-by-Step Design for Low-Pass Input Filter of the Single-Stage Converter

Active power factor correction converters are often introduced as the front stage of power electronic equipment to improve the power factor and eliminate higher harmonics. A Boost or Buck-Boost converter operating in discontinuous current mode is always adopted to achieve high power factor correction. In addition, the input current contains a large amount of higher harmonics, and a low-pass input filter is commonly adopted to filter it out. In this paper, a single-stage high-frequency AC/AC converter is taken as an example to demonstrate the design method of a passive low-pass filter. Firstly, the input side of the grid needs to meet the power factor and harmonic requirements. The preset parameters are set to a range to characterize the performance of the LC filter. The quantitative design method of input filter is proposed and summarized. Moreover, the sensitivity of the filter parameters is analyzed, providing a direction in practical applications. Preset parameters are all proved to conform to the preset range through PSIM simulation. Finally, a 130-W prototype is established to verify the correction of proposed design method. The power factor is around 0.935 and harmonic content in the input current is about 26.4%. All requirements can be satisfied.

Cascaded Multilevel Rectifier with Common High Voltage Direct Current (HVDC) Bus and Its Control Method

In order to realize the voltage equalization and minimize the total harmonic distortion rate of current of cascaded multilevel rectifier with common high voltage Direct Current (HVDC) bus, the cascaded multilevel rectifier with common high voltage DC bus and its control method are studied. The output side DC voltage of the cascade multilevel rectifier with common high voltage DC bus is sampled, and the output DC current signal amplitude is obtained according to the calculated output side DC voltage signal. On this basis, the AC side voltage corresponding to the applied switching state and the switching state corresponding to the rectifier in the sampling period are solved. The driving signal of the switch device is generated and sent to the corresponding switch device to realize the active power factor correction and sinusoidal input current, so as to realize the balanced control of output DC capacitor voltage of cascaded multilevel rectifier with common High-Voltage Direct Current (HVDC) bus. The test results show that this method can effectively control the three-phase output current of the rectifier and ensure the maximum output of the current. The lowest total harmonic distortion rate of the output phase voltage is about 40%, which can effectively ensure the stability of the output phase voltage after control.

A Review on Quadratic Boost Topology-Based PFC Techniques

Electronic devices require DC voltage for their operation so rectification (AC to DC conversion) is needed to convert AC voltage from the mains to DC. During this conversion, harmonics are generated in the system as well as power factor (PF) gets poor hence degrading power quality. Power factor correction (PFC) converters are being commonly used to increase PF and reduce harmonics. Boost PFC Converter is the mostly used topology for active power factor correction because of several benefits like series input inductor, high PF, but its voltage gain is not that good and it has output voltage ripple. Quadratic Boost PFC Converter can be used to overcome these two drawbacks by providing high voltage gain and less outputvoltage ripples. This paper represents applications and topologies of Quadratic Boost Converter, latest control techniques to achieve high voltage gain, regulated output and, high PF. Also, comparison is made between Boost Converter and Quadratic Boost PFC Converter. Finally, conclusion is made of this survey

Evaluation of the Perspective Power Transistor Structures on Efficiency Performance of PFC Circuit

The aim of this work is to investigate the influence of circuit elements on the properties of the selected power factor correction (PFC) topology. Active or passive PFC serves to increase the power factor (PF) and reduce the total harmonic distortion (THD) of the mains current. As a result, the distribution network is lightened due to its interference caused by connected electronic devices. An important indicator of all electronic converters is efficiency. Therefore, the work deals with the analysis of possible efficiency improvements in conjunction with the use of technologically new active components. Detailed experimental analyses and optimization procedures are performed in terms of the influence of transistor structures (SiC and GaN) on the qualitative indicators of the proposed PFC converter for a wide operating spectrum. The synthesis of the obtained results is given, together with recommendations for optimal selection and optimal design of PFC main circuit elements with regard to achieving peak efficiency values.