Proposed Power Factor Correction Converter Research Articles

A Low Voltage Stress PFC Rectifier Based on Nonoverlapping Strategy Using Resonant Switched-Capacitor Converter

In order to break limited step-down ratio range and poor regulation capacity in the conventional resonant switched-capacitor converters for rectifier application, a single-stage ac/dc rectifier based on the dual-resonance switched-capacitor converter is proposed in this article. Through utilizing a dual-resonant structure and nonoverlapping strategy to realize wide continuous voltage gain of the proposed converter, high power factor (PF) and low total harmonic distortion (THD) based on the narrow dead zone are guaranteed by operating at high step-down conversion ratio in this converter topology. Moreover, the voltage gain is concentrated between resonant frequency and double resonant frequency to achieve a narrow switching frequency range for rectifier application. Furthermore, operating at flat voltage stress curves to obtain low voltage stress character. Comprehensive mode analysis, input PF and THD, and stress analysis are given, and analysis results indicate that the proposed power factor correction converter can work with soft turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and zero-current turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> ; high efficiency is realized. Finally, an experimental prototype with 85–130 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ac</sub> input and 47 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub> /44 W output is built and tested for verifying the operation modes and PFC performance, and the comparison between different rectifiers and the proposed one is provided.

A Modified Forward PFC Converter for LED Lighting Applications

A modified forward power factor correction (PFC) converter for light-emitting-diode (LED) lighting applications is proposed in this paper. The proposed circuit topology is an integration of a forward converter and a flyback converter with a multi-windings transformer. The flyback converter is operated as an auxiliary voltage source (AVS) connected in series with the rectified ac grid voltage to achieve low harmonic current distortion and high power factor. The magnetizing inductance energy is recycled to charge the capacitor in the AVS. The commonly used constant on-time control and primary side regulation can be easily adopted to control the proposed LED driver. The operation principle of the proposed converter is presented followed by the mathematical derivation of the parameter design. An 80 W prototype converter was built and tested to verify the performance of the proposed PFC converter. Experimental results show that the proposed PFC converter can comply with the IEC 61000-3-2 standard with high efficiency, low current harmonics, and a nearly unity power factor under universal input voltage range.

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.

On‐board electric vehicle battery charger with improved power quality and reduced switching stress

Development of charging infrastructure is one of the key factors for the successful operation of electric vehicles. This study proposes a power converter for on-board electric vehicle battery charger suitable with universal input voltage (85–265 V). The proposed converter is able to make better power quality by the reduction in total harmonic distortion (THD) of supply current, power factor correction and accurate output voltage regulation. System configuration includes diode bridge rectifier followed by three-level DC–DC SEPIC converter which emphasises on the reduction of voltage stress and switching loss across switches, thereby reduces the switch rating and improves the overall efficiency of the converter. The converter employs a duty cycle feed-forward controller scheme for charging the battery at constant voltage (CV) and constant current (CC) mode. Incorporating the above-said controller scheme has benefits of low THD in supply current, make power factor unity and nearly no zero-crossing detection. The proposed power factor correction converter system analysis is executed in continuous conduction mode. The system performance is evaluated with 400 V, 48 AH battery charging under CV and CC mode through MATLAB/Simulink and experimentation. To estimate the features of power quality indices like power factor and THD is recorded under the wide range of supply variations.

Series-Capacitor-Based Buck PFC Converter With High Power Factor and Ultrahigh Step-Down Conversion Ratio

In this paper, a series-capacitor-based interleaving buck power factor correction (PFC) converter is proposed, the intermediate energy storage capacitance of which is operated at discontinuous capacitor voltage mode (DCVM), and automatic power factor (PF) correction for this converter is obtained. Moreover, the voltage across the series capacitor of the proposed PFC converter is clamped at the input voltage, and thus peak voltage stress existed in the traditional DCVM buck PFC could be relieved. By effectively regulating the charge/discharge time for the series capacitor, ultrahigh step-down conversion ratio of the proposed converter is achieved, the conversion ratio of which is independent of the duty cycle and only related to the switching frequency and circuit parameters. Therefore, high PF can be obtained due to very narrow deadtime of the input current. Meanwhile, the proposed PFC converter can realize the soft turn- on of part power switch and soft turn- off of part power diodes. In addition, comparing with the traditional discontinuous inductor current mode PFC, the input current of the proposed PFC converter is continuous so that the peak value and root-mean-square value of input current can be reduced. The operational principle, performance analysis, and parameter design principle are given in this paper. The analysis results show that the PF and total harmonic distortion are also independent of the duty cycle. Finally, a 220-Vac input, 60 W/15 V output experimental prototype is built to verify the validity of the theoretical analysis.

Power Factor Improvement in Modified Bridgeless Landsman Converter Fed EV Battery Charger

This work deals with the design and implementation of a new charger for a battery-operated electric vehicle (EV) with power factor improvement at the front end. In the proposed configuration, the conventional diode converter at the source end of existing EV battery charger is eliminated with the modified Landsman power factor correction (PFC) converter. The PFC converter is cascaded to a flyback isolated converter, which yields the EV battery control to charge it, first in constant current mode then switching to constant voltage mode. The proposed PFC converter is controlled using single sensed entity to achieve the robust regulation of dc-link voltage as well as to ensure the unity power factor operation. The proposed topology offers improved power quality, low device stress, and low input and output current ripple with low input current harmonics when compared to the conventional one. Moreover, to demonstrate the conformity of the proposed charger to an IEC 61000-3-2 standard, a prototype is built and tested to charge a 48 V EV battery of 100 Ah capacity, under transients in input voltage. The performance of the charger is found satisfactory for all the cases.

A Soft-Switching Step-Down PFC Converter With Output Voltage Doubler and High Power Factor

In this paper, a new soft-switching bridgeless single-phase power factor correction (PFC) converter is presented and analyzed. Employing an auxiliary switch, the input current dead angle that is the main drawback of the existing buck-type PFCs is omitted, and thus, the power factor (PF) is improved, which is the main contribution of the paper. Proposed PFC converter operates under discontinuous conduction mode (DCM) and draws sinusoidal input current from power supply inherently. All switches and diodes are turned on and off under soft switching, which leads to low switching losses and elimination of diode reverse recovery problems. Also, minimum numbers of semiconductor devices are in the power flow path that reduce the conduction losses. A 120-W laboratory prototype is implemented and experimental results verify the validity of theoretical analysis and show efficiency of 92.1%. In addition, total harmonic distortion (THD) of 3.3% is achieved and the input current harmonics complies with IEC61000-3-2 Class D requirements.

Single-Phase PFC Converter Using Switched Capacitor for High Voltage DC Applications

This paper presents a single-stage nonisolated switched capacitor ac–dc converter for power-factor correction (PFC). This converter features reduced passive components, single switch, transformerless high voltage gain, and improves the power factor, reduces total harmonic distortion, and voltage stress across the switch. The peak current mode with a dynamic resonant perturbation scheme compensates the subharmonics that exist at zero crossing of the source current is implemented for PFC. In this paper, the principle of operation, large signal modeling of the circuit, and control method for the proposed PFC converter are provided.

Development of a ZVT-PWM Buck Cascaded Buck–Boost PFC Converter of 2 kW With the Widest Range of Input Voltage

This paper describes the development of a new buck cascaded buck–boost power factor correction (PFC) converter of 2 kW with a soft-switching technique. For its wide range of input voltage, it operates in both buck and boost modes. The parameters are properly selected to endure voltage and current stress in all operating ranges. In addition, the electromagnetic interference (EMI) filter is used to reduce the EMI noise and guarantee continuous input current in buck operation. Moreover, the zero-voltage-transient pulse-width-modulation (ZVT-PWM) method is applied to improve the overall efficiency of the converter. The performance of the proposed PFC converter with the widest range of input voltage is evaluated by the hardware experimental test including harmonics analysis based on the International Electrotechnical Commission standard in all operating ranges. Also, the variations of power factor are theoretically analyzed in both buck and boost modes to determine the widest input range of the proposed PFC converter of 2 kW with an EMI filter. These are strongly required to commercialize it in practice. Finally, the efficiency of proposed PFC converter is compared with that of a conventional buck cascaded buck–boost PFC converter under various conditions.

A novel single-phase AC–DC bridgeless boost converter for PFC application

ABSTRACTA novel single-phase AC–DC bridgeless boost power factor correction (PFC) converter is proposed in this paper. This converter is constructed by paralleling a boost and a buck–boost topology. It features a solid connection between the input and output ground terminals leading to low common mode noise. Moreover, it possesses a high PFC performance which can satisfy IEC-61000-3-2 Class D Limits completely and only two semiconductors conducting in the current-flowing path. In addition, the two power switches are driven by the same control signal resulting in a simple controller. The detailed circuit operation principle in discontinuous conduction mode is presented. A simulated model established by PSIM software and a lab prototype is designed to validate the effectiveness of this proposed PFC converter.

A PFC Modified Landsman Converter-Based PWM-Dimmable RGB HB-LED Driver for Large Area Projection Applications

In this paper for power factor correction (PFC), a modified Landsman converter is introduced. The application is targeted for high-brightness (HB) projection application with brightness control for HB red–green–blue (HB-RGB) light-emitting diode (LED). A pulse-width modulation (PWM) technique is used for intensity control to achieve brightness control of the LED driver. The proposed PFC converter is used to feed a dual output flyback dc–dc converter that supplies power to the forced cooling unit and the LED module with galvanic isolation. The brightness control of LED is performed by synchronous buck converter. The modified Landsman converter operates in discontinuous output inductor current mode for PFC at universal ac mains. A prototype of the proposed LED driver is experimentally verified. The performance of proposed driver is evaluated at full and light-load condition for universal ac mains (90–265 V) over a full range of brightness. The power quality parameters are found within the acceptable limits of harmonic standard IEC 61000-3-2 for universal ac mains.

Soft‐Switching Interleaved PFC Converter with Lossless Snubber

SUMMARYThis paper describes a soft‐switching interleaved power factor correction (PFC) converter with a lossless snubber. AC–DC converters require a unity input power factor characteristic with highly efficient operation to prevent the inflow of harmonic current to the power source. The proposed PFC converter improves the input current ripple with interleave control. The converter realizes a high efficiency by the soft‐switching operation of all switching devices without a large auxiliary resonant circuit. This paper introduces the soft‐switching operation of the converter. In order to confirm the validity of the proposed converter, experiments with a prototype of the PFC converter have been performed. The experimental results indicate that the proposed converter can realize the soft‐switching operation of all switching devices, a reduction in the input current ripple, a unity power factor of 98% or more, a sinusoidal input current, and constant output voltage control. The efficiency of the proposed PFC converter with a lossless snubber is higher than that without the lossless snubber. The results presented in this paper confirm the validity of the proposed converter.

High power factor and low total harmonics distortion using critical conduction mode boost converter-fed light-emitting diode driver

Summary This article presents a critical conduction mode (CRM)–based power factor correction (PFC) converter for multistring light-emitting diode (LED) driver. The application is targeted for high power projection application with brightness control of red-green-blue LED module. A pulse width modulation (PWM) technique is used for lighting control to achieve required brightness without compromising the efficiency (overall 82%) and power quality. The CRM boost PFC converter is used to feed a dual output flyback DC-DC converter, which supplies power to the forced cooling unit and the LED modules with galvanic isolation. The brightness control of LED is performed by synchronous buck converter using current PWM modulation. The CRM boost converter–based PFC converter is designed to operate in critical inductor current mode at universal AC mains. A prototype of proposed PFC converter–based LED driver is developed and experimentally verified. The power quality parameters of the proposed LED driver are evaluated at rated and light load conditions for universal AC mains (90–265 V) with brightness control. The power quality parameters are found within acceptable ranges of international harmonic standard IEC 61000-3-2 Class C for lighting systems.

Analysis, design and realisation of a zero‐current transition pulse‐width modulation interleaved boost power factor correction converter with a zero‐current transition auxiliary circuit

A zero-current transition (ZCT) pulse-width modulation (PWM) interleaved boost power factor correction (PFC) converter with a ZCT auxiliary circuit is presented to achieve ripple current cancelation and ZCT for power switches. The proposed PFC converter adopts a ZCT auxiliary circuit to realise ZCT for power switches and diodes . Thus, the switching losses of active power switches are reduced and the reverse recovery losses of power diodes are eliminated. The interleaved PWM control scheme with constant frequency and constant duty cycle is used in it. Thus, the control circuit is simple and the circuit cost can be reduced. It shapes a close sinusoidal input current waveform, so that an input current waveform with low harmonic can be obtained. The operational principle and design consideration are discussed in detail. Finally, experimental results taken from a 1000 W prototype are presented to confirm the effectiveness of the proposed PFC converter.

Design and realisation of a zero‐voltage transition pulse‐width modulation interleaved boost power factor correction converter

A zero-voltage transition pulse-width modulation (ZVT-PWM) interleaved boost power factor correction (PFC) converter with an active snubber circuit is presented to achieve ripple current cancellation and soft-switching for power switches. The proposed PFC converter adopts an active snubber circuit to realise ZVT for active power switches and zero-current transition for power diodes. Thus, the switching losses of active power switches can be reduced and the reverse recovery losses of power diodes can be eliminated. It also uses an interleaved PWM control scheme to reduce the input ripple current and size of output capacitor. Moreover, it also adopts the average-current-control method to shape a close sinusoidal input current waveform, so that an input current waveform with low harmonic and low total harmonic distortion can be obtained. The operational principle and design consideration are discussed in detail. Finally, experimental results taken from a 1000 W prototype are presented to confirm the effectiveness of the proposed PFC converter.

New Single Phase Bridgeless CUK Converter Topology for Power Factor Enhancement Based on Fuzzy Logic Control

A new single phase bridgeless power factor correction (PFC) converter derived from CUK topology is proposed. In this new CUK converter, the absence of the front end diode bridge results in the less switching and conduction losses compared to the conventional PFC converter. The current flow in the proposed converter configuration has only two semiconductor switches and it results in less conduction loss during each interval of the switching cycle. It offers less input current ripple, less electromagnetic interference (EMI) and also protection against the starting inrush current. It is mostly preferred compared to the other PFC topologies since it has both continuous input and output currents with a reduced current ripple. The proposed converter uses the simple control strategy and is made to work in the discontinuous conduction mode (DCM) to achieve almost a unity power factor. It also offers zero current turn ON and turn OFF for power switches. The performance of the proposed PFC converter is tested in MATLAB/SIMULINK environment with fuzzy logic controller (FLC). The simulation results of the proposed new CUK PFC converter validate the effectiveness of FLC in power factor enhancement.

An FPGA-based Fully Digital Controller for Boost PFC Converter

This paper introduces a novel digital one cycle control (DOCC) boost power factor correction (PFC) converter. The proposed PFC converter realizes the FPGA-based DOCC control approach for single-phase PFC rectifiers without input voltage sensing or a complicated two-loop compensation design. It can also achieve a high power factor and the operation of low harmonic input current ingredients over universal loads in continuous conduction mode. The trailing triangle modulation adopted in this approach makes the acquisition of the average input current an easy process. The controller implementation is based on a boost topology power circuit with low speed, low-resolution A/D converters, and economical FPGA development board. Experimental results demonstrate that the proposed PFC rectifier can obtain a PF value of up to 0.999 and a minimum THD of at least 1.9% using a 120W prototype.

A Three-Level Quasi-Two-Stage Single-Phase PFC Converter with Flexible Output Voltage and Improved Conversion Efficiency

This paper presents a three-level quasi-two-stage single-phase power factor correction (PFC) converter that has flexible output voltage and improved conversion efficiency. The proposed PFC converter features sinusoidal input current, three-level output characteristic, and a wide range of output dc voltages, and it will be very suitable for high-power applications where the output voltage can be either lower or higher than the peak ac input voltage, e.g., plug-in hybrid electric vehicle charging systems. Moreover, the involved dc/dc buck conversion stage may only need to process partial input power rather than full scale of the input power, and therefore the system overall efficiency can be much improved. Through proper control of the buck converter, it is also possible to mitigate the double-line frequency ripple power that is inherent in a single-phase ac/dc system, and the resulting load end voltage will be fairly constant. The dynamic response of this regulation loop is also very fast and the system is therefore insensitive to external disturbances. Both simulation and experimental results are presented to show the effectiveness of this converter as well as its efficiency improvement against a conventional two-stage solution.

Dead Angle Reduction of Single-Stage PFC Using Controllable Coupled Inductors

This paper presents a new structure of single-stage flyback power factor correction (PFC) converter with a controllable coupled negative magnetic feedback (NMF) winding. NMF winding is used to reduce the bulk capacitor voltage at high line voltages and light loads. However, it would cause line current distortion at zero crossing condition. In the proposed circuit, a series winding is used with NMF inductor to eliminate the NMF inductor at low line voltages. As a result, the dead angle of the input current, near zero voltage crossing, is eliminated and the power factor is increased. The presented experimental results of the proposed PFC converter confirm the integrity of the new idea and the theoretical analysis.

Modified current‐fed full‐bridge isolated power factor correction converter with low‐voltage stress

One drawback of the conventional current-fed full-bridge (CFFB) power factor correction (PFC) converters is extremely high-voltage spikes on metal oxide semiconductor field effect transistors (MOSFETs), which cause many problems such as high-voltage high-cost devices used, unreliability and burdensome magnetising components imposed. To overcome above shortcomings, a new isolated CFFB PFC converter featuring efficiency improvement, high input current quality and good common mode (CM) noise performance is proposed in this study. The voltage spikes are effectively eliminated by using a non-dissipative clamping structure resulting of no-loss consumption and low-voltage MOSFETs used. Additionally, to evaluate the conducted electromagnetic interference behaviour, the differential mode loop and CM loop models are also presented. Two testing hardware systems with 180–240 V input, 380 V/1 kW output of the conventional CFFB PFC and proposed PFC were built and inspected to compare their performances. The experimental results showed that the proposed topology completely eliminated the voltage spike on MOSFETs. The efficiency was largely improved by utilising of high-performance MOSFETs. In consequence, the experimental results reveal the preponderance of the proposed PFC converter to the previous researches on this topic.