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This paper presents an input–output linearization (IOL) control strategy to achieve PFC (power factor correction) and output voltage constant in a boost converter. The method transforms the nonlinear system to a linear one in new coordinates by the appropriate nonlinear coordinate transformation and state feedback, ultimately allowing the controller to be designed according to the classical linear control theory. An example implementation is simulated using PSIM software. The simulation results show that the phases of input voltage and input current are consistent, and the output voltage remains constant under load step changes. A set of experimental devices are set up to verify the control method, and the results are consistent with the simulation. Thus, the method is proved to be effective in achieving PFC and provides robust constant voltage output in the boost converter.

The output voltage of the traditional CUK PFC converter is negative, and an additional inverting amplifier circuit is needed, which increases the volume and cost of the converter. A new type of bridgeless CUK PFC converter topology is proposed in this paper, which makes the converter have a positive output voltage without the need of an additional inverting amplifier circuit, and has the advantages of simple control, high efficiency, and low cost. Through topology optimization, one input capacitor is reduced, and the two diodes are converted from the high-current working state of high frequency to low-current working state of power frequency, ordinary rectifier diodes can be selected instead of fast recovery diodes, thereby reducing the volume and cost of the converter. The converter works in DCM, so no current control loop is required, which simplifies the control circuit. In addition, the main switch is turned on under ZVS condition, and the output diode is turned off under ZCS condition, which reduces the switching loss and improves the efficiency of the converter. A simulation model was built in PSIM, and a prototype with a rated power of 150 W was fabricated to verify the effectiveness and superiority of the proposed converter. Experimental results show that the PF of the proposed converter is 0.995 7, and the input current THD is 3.78% under rated input conditions.

This paper performs parameter optimization of proportional-integral (PI) and repetitive controller (RC) with a new objective function by adding two degrees of freedom for a three-phase boost power factor correction (PFC) rectifier. The main objectives are to optimize the multiple control loop parameters for total harmonics distortion (THD) reduction and dynamic performance indices improvement, including overshoot, rise time, and zero steady-state error. The control parameters of the three-phase boost PFC rectifier are optimized through a standard genetic algorithm. After obtaining the optimal PI and RC parameters values, fast Fourier transform and dynamic response analysis were performed using MATLAB. Moreover, separate evaluation functions are used to validate the optimal results in terms of THD reduction and dynamic performance indices improvement. Furthermore, the results are compared with the existing objective functions to show the proposed objective function superiority. Simulation results demonstrated that our proposed objective function outperforms existing objective functions to achieve optimal PI and RC parameters value. Finally, simulation results are validated through experimental results. The experimental setup includes a 5kW three-phase PFC rectifier with DSP TMS320F28335 prototype hardware to verify controller parameter performance.

The low power factor in electrical installations results in high power losses and increased installation costs. This comes as a consequence of the high current flowing through the transmission lines due to high reactive power consumption. Most often, before the installation of renewable energy systems involving battery storage, the load demand is not evaluated in terms of the different load power factors. Because of these diversified power factors for different loads, the overall power factor of the installation will witness a decrease which puts the user at a disadvantage as more charges will be incurred. For these reasons, this paper presents the economic benefits of using an automatic power factor correction system in renewable energy installations. The Arduino microcontroller has been used in the proposal as the main automat. The power factor correction is done by installed capacitor banks connected to the loads automatically using MOSFET (Metal Oxide Semiconductor Field Effect Transistor) power electronic switches and relay blocks with control signals from the microcontroller. A small system was analyzed involving a water pump, fan, television, and a fluorescent lamp. A targeted corrected power factor of 0.99 was used and the results showed that 430.18 W of power was saved after power factor correction leading to a reduction of 58% line losses. Also, $1300 could be saved by the user on batteries and photovoltaic modules by incorporation the power factor correction system. The proposed correction algorithm was economically beneficial and is therefore strongly recommended to be employed by renewable energy users in particular and the grid-connected individuals in general.

This article presents the analysis and design of a resonant power factor correction (PFC) rectifier for the first stage in single-phase front-end offline converters targeting low-power applications (up to 100 W). With the addition of a charge-pump circuit comprised of a capacitor and a diode to a class-DE resonant converter, PFC functionality is achieved inherently. The operation is based on soft switching, allowing for increased switching frequencies with reduced switching losses. A 1-MHz prototype employing wide bandgap switching devices is built and tested to validate the analysis and proposed design method. The prototype achieves up to 50 W of output power with a power factor of 0.99, a total harmonic distortion of 8.6%, and an efficiency of up to 88%; with harmonic magnitudes well-within the IEC 61000-3-2 standard class-C device limits, making it suitable for use as the rectifier stage in light-emitting diode (LED) drivers. Despite the additional circuit stresses from the charge-pump operation, the proposed converter offers simplicity and low component overhead, with the potential for higher frequency operation toward higher power densities.

This paper proposes a single-stage bridgeless isolated AC-DC power factor correction (PFC) topology, and this topology can realize the function of step-up and the galvanic isolation for the AC input and DC output voltages through single-stage power conversion process. Firstly, the operation principle of the topology is analyzed in details. Then, by reasonably designing the series resonant parameters, the zero-voltage-switching (ZVS) turn-on for the power switches in the primary-side and zero-current-switching (ZCS) turn-off for the output rectifier diodes in the secondary-side of the transformer can also be achieved under wide load range, and the voltage stress of the power switches are also reduced based on the active clamping technology. The design procedure for the key components of the proposed converter is also derived. Finally, a 3 kW experimental prototype based on SiC power devices with 85 kHz switching frequency is built to verify the correctness and feasibility of the proposed topology, and the experimental results show a good performance. It can operates in a wide input grid voltage range, 95.7% of peak conversion efficiency and 3.9% of total harmonic distortion(THD) value for grid current could be obtained.

This paper proposes a novel multifunctional topology for a grid-connected voltage source inverter to control the speed and power flow of a squirrel-cage induction motor. For high-inertia loads during startup, the issues faced include a large transient current and high heat generation. However, the solutions proposed by existing startup methods are inadequate. The topology presented in this study not only addresses the problems related to these methods, i.e., creating a smooth startup, but also presents a flexible alternative for power factor correction using capacitor banks. First, the proposed technique accelerates the motor smoothly to its operating point through the sinusoidal voltage provided by an inverter with an LC filter in its output. In the second step of the control method, after achieving stability in the desired operating point, a converter with an LC filter is assigned the task of power factor correction. Thus, the proposed topology achieves a smooth startup and unity power factor. It includes a new control strategy in which the rotor field-oriented control method is employed for the speed control mode. Finally, the validity of the proposed theory is verified.

This paper presents and analyzes an AC-DC power converter structure, which is comprised of a Power Factor Correction (PFC) module and a LLC resonant DC-DC converter module. This converter only uses two switches, and requires three less diodes and one less switch compared to popular LLC resonant converter solutions. Compared to its conventional counterpart, the rectifier of interest has high energy efficiency while a smaller size, owing to the soft-switching in the LLC resonant converter. Detailed theoretical analyses are conducted in this study, followed by software simulation and hardware experimentation, which demonstrate that the single stage double-switched (DS)-LLC rectifier is able to realize unity power factor and a wide output range, indicating its effectiveness and applicability.

Due to the input power and output power do not match in real time, single-stage power factor correction converters have large double-line-frequency ripple at the output voltage. The double-line-frequency ripple voltage will cause some electronic devices to work abnormally, and limit the control loop bandwidth of power factor correction converter. In order to reduce the output double-line-frequency ripple voltage, a single-stage Flyback power factor correction converter with Buck ripple suppressor is used in this paper, the Buck ripple suppressor can generate same magnitude but 180° phase shifted voltage as Flyback power factor correction converter output voltage ripple. Adaptive on-time control is adopted in the Buck ripple suppressor benefiting with its wider bandwidth and fast dynamic response. The switching frequency range and stability of Buck ripple suppressor under constant on-time control and adaptive on-time control are discussed. By establishing the input-output audio susceptibility model, the output double-line-frequency ripple suppression performance is analyzed. Buck ripple suppressor using adaptive on-time control can suppress double-line-frequency ripple voltage effectively with the fast dynamic response and high efficiency. Simulation and experimental results are given to verify the theoretical analysis.

This paper proposes a novel high-gain AC-DC converter based on the Cockcroft-Walton (CW) voltage multiplier which can be utilized in motor drive systems with low input voltage. In this topology, use of the voltage multiplier and boost circuit results in the increment of converter gain which has a significant impact on the cost and efficiency of the system. Moreover, in this converter, the AC voltage is directly changed to DC voltage using the switching method in high frequency and, as well, the power factor is corrected. Besides, this high-frequency converter contributes to the reduction of output ripple. On the other hand, cost efficiency, the low voltage stress on capacitors and diodes, compactness, and the high voltage ratio, are achieved from the Cockcroft-Walton circuit. Furthermore, the hysteresis method is presented for converter switching to correct the power factor. The converter is simulated in MATLAB software to demonstrate the effectiveness of the suggested method. Lastly, a laboratory prototype of the suggested converter is built, several tests are done in order to verify the theoretical analysis, and comprehensive comparison with the state-of-the-art converter is done.

Performance degradation is, in general, regarded as a power quality problem. One solution to recover grid performance is through the application of a unified power quality conditioner (UPQC). Although these devices are multi-input/multi-output (MIMO) systems, the most common control strategies consist of two decoupled controllers, which neglect the coupling effects and add uncertainty to the system. For this reason, this paper proposes a multivariable resonant observer-based control strategy of a UPQC system. This method includes all significant coupling effects between this system and the grid. This strategy results in a stability-based compensator, which differs from recently proposed strategies that are based on signal calculation and cannot assure closed-loop stability. In addition, this paper introduces a simplified controller tuning strategy based on optimal conventional methods without losing closed-loop performance. It implies that the controller can be easily tuned, despite the complexity of the MIMO dynamic model. The UPQC with the resonant observer is verified on an experimental setup for a single-phase system, obtaining three relevant results for power quality improvement: (1) harmonics compensation tested with a total harmonic distortion limit of 5%, (2) sags and swells mitigation, and (3) power factor correction, achieving a unitary value on the grid side.

The existence of nonlinear loads produces high distortion and low power factor in the power system that leads to get poor power quality. Resonance problem is occurred due to the power system inductances and the compensation capacitors which increases the harmonic distortion. Therefore, it is necessary to prevent the action of resonance even if conventional or modern methods are built to improve the power system quality. In this paper, active static compensation circuit is proposed and designed to have the features of improving power factor, reducing THD, and eliminating the harmonics resonance effect at the same time with different linear and nonlinear load conditions. These features have been performed based on a modified pulse width modulation technique to drive and control the proposed circuit. The originality designed point of this technique is to have ability to operate the active static compensation circuit as harmonics injector, power factor corrector and resonance eliminator at the same time. Simulation model results illustrate that the proposed circuit is effective for both steady-state and transient operations conditions. The THD of the supply voltage and current at firing angle (α=300) is reduced by 99% and 98.8% respectively. While the power factor is improved to stay around unity.

Power Factor Correction (PFC) single-phase AC/DC converters are used in several power electronics applications as full wave control rectifiers improving power quality and providing high standards of efficiency. Many papers dealing with the description or use of such topologies have been published in recent years, however, a review that describes and organizes their specific details has not been reported in the technical literature. Therefore, this paper presents an extensive review of PFC single-phase AC/DC converters operating with the Boost converter topology for low and medium voltage as well as and power appliances. A categorization of bridge, semi-bridgeless, and bridgeless, in accordance with the construction characteristics, was carried out in order to unify the technical terminology. Benefits and disadvantages are described and analyzed in detail. Furthermore, a comparison performance in terms of PFC, Total Harmonic Distortion (THD), power capacity, electromagnetic compatibility (EMC), number of elements, and efficiency is included.

Light-Emitting Diodes (LEDs) are coming strongly into the lighting market due to their advantages over conventional lighting solutions: energy efficient, controllable in both light and color, long lifetime, lack of a warm-up period and high power density. Some of these advantages will make LED light sources to be more than just a lightbulb, being able to transmit data, control light color, hue and intensity or even detect people in indoor environments. Nevertheless, these advantages attributed to LED capabilities are, in reality, achieved thanks to the LED driver. The present work reviews the current stateof- the-art strategies to drive LEDs from ac power grids with special emphasis into removing the most limiting component from the point of view of the lifetime, which is the electrolytic capacitor, while achieving a flicker-free performance of the light output of the LED driver. Moreover, it focuses on analyzing the required regulations, challenges and applicability of LED drivers in both single-phase and three-phase ac power grids, Trabajo apoyado en parte por el Gobierno español en virtud del Proyecto MINECO-17-DPI2016-75760-R, por el Principado de Asturias bajo la subvención BP14-142 de Severo Ochoa y el Proyecto GRUPIN2018 JAVIER SEBASTIAN, y en parte por el Fondo Europeo de Desarrollo Regional (FEDER)

The pulse width prediction control technique has been widely used in AC-DC converters with power factor correction in boost topology, where satisfactory results have been reported without the need to use classic control laws. However, this technique has not been explored for other types of ACDC converters with power factor correction. In this work, the use of this technique is proposed in an AC-DC converter with power factor correction in a half-bridge boost topology. This topology presents high efficiency because it uses the least number of semiconductors compared to other topologies. In this technique the duty cycle is predicted by processing the average values of state and input variables of the converter in half bridge boost topology, using only four multiplications and five additions, which implies less complexity in its implementation. For its validation simulations were performed using MATLAB R Simulink, where it was possible to observe values of power factor and THD comparable with other control methods such as non-linear carrier control, and conventional analog control, both reported in the literature. Resumen La técnica de control de predicción de ancho de pulsos ha sido ampliamente utilizada en convertidores AC-DC con corrección de factor de potencia en topología boost, donde se han reportado resultados satisfactorios sin necesidad de usar leyes clásicas de control. Sin embargo, ésta técnica no ha sido explorada para otros tipos de convertidores AC-DC con corrección de factor de potencia. En este trabajo, proponemos el uso de ésta técnica en un convertidor AC-DC con corrección de factor de potencia en una topología de boost medio puente. Esta topología presenta una alta eficiencia dado que usa el menor número de semiconductores comparada con otras topologías. En ésta técnica el ciclo de trabajo es predicho al procesar los valores promedio de las variables de entrada y estado del convertidor en topología boost medio puente, usando únicamente cuatro multiplicaciones y cinco adiciones, lo que implica menos complejidad en su implementación. Para su validación, se realizaron simulaciones usando MATLAB R Simulink, donde fue posible observar valores de factor de potencia y THD comprables con otros métodos de control como control de portador no lineal y control convencional análogo, ambos reportados en la literatura.

This work focuses on an isolated offline driver to power LED lamps, realized with a high-power-factor quasi-resonant (Hi-PF QR) flyback converter with peak current mode control and employing constant-current primary-sensing regulation (CC-PSR). The converter is controlled with a recently introduced control technique that enables this kind of converter to ideally draw a sinusoidal current from the input source and, at the same time, to accurately regulate the dc output current using only quantities available on the primary side. The resulting absence of an optocoupler or other means crossing the isolation barrier to close a feedback loop not only reduces size and cost of the driver but also brings greater safety and reliability. The analysis addresses those factors inherent in the control method that affect the shape of the input current that have not been covered in the existing literature. The aim is to set up some design guidelines to minimize the Total Harmonic Distortion (THD) of the input current. The experimental work shows that using this technique enables the design of an LED driver for wide range mains (90 to 264 Vac) that achieves output current regulation better than ±2%, power factor close to unity and THD of the input current

peer-reviewed This letter describes an enhancement to a previously reported single-stage transformer-leakage-inductance-based power-factor-corrected isolated power supply. An improved switch timing calculation algorithm is developed to achieve zero current switch on of the active rectifier switches. The algorithm is based on an analytical model of the system relating the gate timing to the input and output voltages and control inputs. Remarkably, a closed-form expression for the switch timing can be derived and used to calculate and apply the timings in real time without the need for high-speed measurements or resonant structures. A prototype 1.25 kW prototype power supply is implemented using the proposed technique and performance measurements presented. ACCEPTED peer-reviewed

A novel power converter system to drive medical laser equipment is proposed here, which has the major features of interleaving, external auxiliary triggering, and lighting period control. The converter system can deal with universal line input and provide instantaneous high power for medical laser equipment. This system mainly includes an interleaved-boost front end (IBFE), a lighting-period control unit (LPCU), an energy-stored capacitor bank (ESCB), an igniting and arc-sustaining circuit (IASC), external auxiliary triggering circuit (EATC), and a system controller (SC). With them, it is able to fulfil power factor correction (PFC), lower input current ripple, deal with universal line voltage, provide a larger current to xenon lamp, ignite xenon lamp at a lower voltage, and sustain lamp arc. The sustained arc will be beneficial to light the xenon lamp again. As a result, much more precise timing of laser output control can be accomplished. The operation of the converter system is discussed. In addition, a 2-kW prototype to deal with the line voltage range of 90 to 265 V ac is built and examined. Key waveforms and practical measurements have demonstrated the feasibility of the proposed converter system.

Power factor correction (PFC) converters are widely employed for ac/dc conversion to fulfill the applicable standards while ensuring high efficiency. Current-sensorless controllers in PFCs simplify the interaction between power and control circuits, improving noise immunity. This paper reviews the state-of-the-art in-line current control techniques, identifying relevant contributions that incorporate predictive algorithms and eliminate the current sensor. Furthermore, it evaluates two approaches for current-sensorless PFC. The first is applicable to converters with diode bridge and includes a high-resolution digital control loop to cancel the estimation errors. The second, valid for bridgeless PFCs, is a new current-sensorless control, which includes a fast compensation of the prediction errors with a third-harmonic-dependent function generated from a phase locked loop. This compensation modifies the duty cycle sequence obtained from the controller, ensuring the matching of the line current with the reference obtained from the line voltage. The two evaluated approaches are investigated via computer simulations and experimentally.

This study proposes an implementation based on a low-cost field-programmable gate array (FPGA) of a high-resolution pulse width modulation applied on a single-phase power factor correction (PFC) converter operating with 2 MHz switch frequency. The PFC was implemented using a half-bridge enhancement-mode Gallium Nitride (eGaN) field effect transistor with on-board gate drives (EPC9003 development board) and the MAX10 FPGA.

Active rectification of the three-phase grid nowadays is a central task of power electronics. However, as the necessary DC bus voltages vary, DC-DC converters are needed. This study presents the design and development of a three-phase power factor correction with an interleaved buck converter in the output stage. The power stage switches are equipped with silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors. A modular setup of the half-bridge modules as well as low inductive design of these modules is put into focus.

In this paper, a new control strategy for an induction motor (IM) drive system fed from three-phase pulse width modulation (PWM) ac chopper is proposed. The main objective of the proposed control scheme is to achieve input power factor correction (PFC) of the IM drive system under different operating conditions. PFC is achieved by continuously forcing the actual three-phase supply currents with the corresponding reference currents, which are generated in phase with the supply voltages, using hysteresis band current control (HBCC) technique. The proposed control strategy has two loops: the inner loop and outer loop. The output of the outer loop is the magnitude of the supply reference current resulting from either speed controller or startup controller, whereas the output of the inner loop is PWM signals of the ac chopper. The proposed ac chopper features a smaller number of active semiconductor switches, four IGBTs, with only two PWM gate signals. As a result, the proposed system is simple, reliable, highly efficient, and cost effective. Mathematical analysis of the drive system is presented. Components of the input LC filter are designed using frequency response. The IM drive system is modeled using MATLAB/SIMULINK, and a laboratory prototype was built and tested. The simulation and experimental results confirm the validity and robustness of the proposed control strategy.

A technique to improve the performance of grid-connected induction motors by exploiting an auxiliary winding set is proposed in this paper. This auxiliary winding features the same distribution of the main winding, although with a reduced number of turns and it is fed by an inverter a fraction of the power in comparison with the rated size of the induction motor. As shown in the paper, through the auxiliary winding, it is possible to set the machine power factor, increasing the efficiency of the power conversion system and mitigating speed oscillations due to torque disturbances. A mitigation of the grid current peaks due to motor start-up is obtainable. First, the proposed technique is theoretically introduced, then a feasibility assessment is accomplished by simulations.

In this paper, an intelligent digital low voltage power factor optimizer has been built. This power factor optimizer operates according to the measurement the value of phase shift angle between both of current and voltage, thus the power factor has been measured. It is simply that it will improve the power factor through connecting a set of shunt capacitors in order to reach to an optimal value of the power factor (close to unity). The proposed intelligent digital power factor optimizer for low voltage is built and simulated using the software which is called electronic work bench package (EWB) Multisim. Finally, this optimizer presents a good result when applied to different loads and variable currents. This optimizer is feasible, affordable and ready to be implemented especially in countries that suffer from higher prices of electrical power.

This paper proposes a new sliding surface for controlling a Semi-Bridgeless Boost Converter (SBBC) which simultaneously performs Power Factor Correction (PFC) and DC bus regulation. The proposed sliding surface is composed of three terms: First, a normalized DC voltage error term controls the DC bus and rejects DC voltage disturbances. In this case, the normalization was performed for increasing system robustness during start-up and large disturbances. Second, an AC current error term implements a PFC scheme and guarantees fast current stabilization during disturbances. Third, an integral of the AC current error term increases stability of the overall system. In addition, an Adaptive Hysteresis Band (AHB) is implemented for keeping the switching frequency constant and reducing the distortion in zero crossings. Previous papers usually include the first and/or the second terms of the proposed sliding surface, and none consider the AHB. To be best of the author’s knowledge, the proposed Sliding Mode Control (SMC) is the first control strategy for SBBCs that does not require a cascade PI or a hybrid PI-Sliding Mode Control (PI-SMC) for simultaneously controlling AC voltage and DC current, which gives the best dynamic behavior removing DC overvoltages and responding fast to DC voltage changes or DC load current perturbations. Several simulations were carried out to compare the performance of the proposed surface with a cascade PI control, a hybrid PI-SMC and the proposed SMC. Furthermore, a stability analysis of the proposed surface in start-up and under large perturbations was performed. Experimental results for PI-SMC and SMC implemented in a SBBC prototype are also presented.

Power quality is a critical issue in power systems. This paper proposes a bridgeless boost converter to increase the power factor of power systems using a utility line source for raising power quality. To reduce input and output current ripple, an interleaving manner is adopted in the proposed power system. When the interleaving bridgeless boost converter is used to implement power factor correction (PFC), it needs two bridgeless boost converters to process power during one switching cycle. In order to simplify the proposed bridgeless boost converter, two sets of switches in the conventional bridgeless boost one are integrated to reduce component counts. With this approach, the proposed bridgeless boost converter uses four switches to implement PFC features. Therefore, the proposed boost converter can increase conversion efficiency and decrease component counts, resulting in a higher conversion efficiency, lower cost and more simplicity for driving circuits. Finally, a prototype with a universal input voltage source (AC 90 V~265 V) under an output voltage of 400 V and a maximum output power of 1 kW has been implemented to verify the feasibility of the proposed bridgeless boost converter.

In a high-power factor quasi-resonant Flyback, an ideal zero current detection (ZCD) circuit and control circuitry enable the power switch turn-on in the exact instant a zero ringing current is reached after demagnetization. A nonzero current at the turn-on instant affects the input current shape and; consequently, affects its Total Harmonic Distortion (THD). This paper firstly deeply analyzes the effect on the distortion due to a nonideal ZCD circuit. After, some typical implementations of the ZCD circuit and their effect on the THD are analyzed, identifying their pros and cons. Finally, some experimental results are obtained to validate the analytical investigation.

A discontinuous conduction mode (DCM) three-phase single-ended primary-inductor converter (SEPIC) is presented in this article. The analyzed converter operates as a high-power factor stage in AC–DC conversion systems. As its main features, it presents three controlled switches and a single control signal with simple implementation and low-current harmonic distortion. The converter topology, its design equations, and its operation modes are presented as well as a simulation analysis considering a 3 kW–220 V three-phase input to 400 V DC output converter. The experimental results are included, considering as an application the rectifier stage in low-power wind energy conversion systems (WECS) based on a 1 kW permanent magnet synchronous generator (PMSG) with variable voltage frequencies. From the analysis performed in the paper and the simulation and experimental results revealed, it is concluded that the converter is indicated to be employed in any AC–DC low-power conversion system, such as DC distribution systems, and distributed generation or hybrid systems containing variable-frequency generation.

This study is about an improved high-quality light-emitting diode (LED) converter for a T8 LED tube. The converter is separated into the AC driving circuit and DC driving circuit. Also, the LED tube was applied with an output ripple eliminator for the optical performance. The AC driving circuit and DC driving circuit are assembled at the end of the LED tube in a G13 base and a G13 base dummy, respectively, and the output ripple eliminator is located on an LED PCB. The proposed LED converter is founded on a SSBB (single-stage buck-boost) converter topology and was designed for 10 W operation for a 600 mm T8 LED tube. The light waveform of the LED tube was measured by a photosensor. The waveform had almost no ripple and was the same as a straight line. The average calculated percent flicker of the proposed LED converter was an average of 1.9% at 100 and 240 VAC, 50 and 60 Hz. The proposed converter has lower power efficiency than a conventional converter by 2.7% at 100&ndash, 240 VAC, but it still has high power efficiency (&gt, 87%). The measurement results represent that the LED output current regulation is below 0.92% at 100&ndash, 240 VAC and the converter obtains the power factor more than 0.84 and the total harmonic distortion is less than 14.3%. All of the current harmonics reach the IEC 61,000-3-2 Class D standards for high-quality LED converters.

This paper investigates the use of the class-E inverter for power factor correction (PFC) applications. Analytical and state-space models are derived showing the class-E inverter’s capability of achieving inherent PFC operation with a constant duty cycle. The inherent PFC operation limits the controller responsibility to the regulation of the output voltage, which is key for resonant converters with challenging control. A converter incorporating a diode bridge, a class-E inverter, and a class-D rectifier is presented for the PFC stage in single-phase offline converters. A prototype is designed to validate the analysis and presented design method. The prototype operates with zero-voltage switching (ZVS) across the load range and achieves up to 211 W of output power at an efficiency of 88%, with an inherent power factor of 0.99 and a total harmonic distortion (THD) of 8.8 %. Frequency modulation is used to achieve lower output power down to 25 W, with a power factor of 0.95, THD of 28 %, and an efficiency of 88 %.

With the widespread use of electric vehicles (EVs), the design of a highly quality and efficient battery charger has become an important research topic. In this study, an efficient AC-DC power factor corrected (PFC) boost converter with active snubber cell (ASC) is proposed for the battery charger. ASC integrated into the AC-DC PFC boost converter turns on the main switch with zero voltage transition (ZVT) and turns off with zero current transition (ZCT), which among soft switching techniques for eliminating the switching losses. In addition, it has been provided that other switching elements are operated with soft switching. Soft switching conditions and unity power factor (PF) are achieved from light load to full load conditions. Unlike the soft-switched PFC converter circuits in the current literature, no current and voltage stresses have been observed on any component in the main converter and ASC circuits. The paper also presents the steady-state operating principles and design guidelines of the proposed converter in detail. The efficiency improvement between the hard switched counterpart has been verified by making detailed loss analysis. The proposed converter has been constructed as 3.3 kW and tested according to European efficiency standards with various case studies. The total harmonic distortion (THD) of input current has been measured as less than 5% in compliance with EN 6100-3-2 Class D Limits (A) standards.

This paper proposes an approach to estimate the parameters of an AC-DC boost power factor corrector converter which includes an EMI filter. To this end, once the topology is known, measurements at the input and output terminals of the converter are done to identify the values of the passive elements. The proposed methodology is based on the trust-region nonlinear least squares algorithm to identify the parameters of the converter. The steady-state and the transient signals of the converter at the input/output terminals are acquired non-intrusively without any internal modification of the circuitry. The accuracy of the parameter identification carried out is determined by comparing the estimated values with the actual values provided by the manufacturer, and by contrasting the measured signals with the ones obtained with a simulation model with the estimated values of the parameters. The results presented in this paper prove the accuracy of the proposed approach, which can be extended to other power converters and filters.

This paper presents the design and implementation of a resonant LED driver. The driver structure comprises a charge-pump-based power factor correction (PFC) converter and a class-DE dc-dc converter. The PFC converter employs a charge-pump circuit that achieves PFC inherently. The class-DE converter comprises a series-resonant tank and a high-frequency transformer. Both converters share the same half-bridge and gate-driving circuit, resulting in an integrated-stage architecture. The inherent PFC operation limits the controller responsibility to the regulation of the output current. The overall converter operates with zero-voltage switching (ZVS) across the entire load range, allowing for increased switching frequencies with reduced switching losses. A 1-MHz prototype employing wide bandgap (WBG) switching devices is built and tested. The prototype delivers up to 42 W of output power, with a power density of 1.8 W/cm3. A power factor of 0.99 and a total harmonic distortion (THD) of 6 % are achieved, with an efficiency of 90 % at full load. The input current harmonic magnitudes are well-within the IEC 61000-3-2 standard limits for class-C devices. Burst-mode (on/off) modulation is used for output current regulation between 20 and 900 mA for dimming functionality.

The Objective of this project is to remove all power quality problems using unified power quality conditioner which is a combination of DVR and DSTATCOM linked by a DC link capacitors. This project is a combination of voltage source inverter and current source inverter. Voltage source inverter solve voltage related problems like voltage sag, swell, fluctuations, imbalance. Current source inverter maintains power factor and mitigation of harmonics from a power system including source and load harmonics and by converters fed to the load.

Power Factor (PF) correction is a major power quality function in electrical distribution systems. This paper proposes a low-cost Automatic Power Factor Correction (APFC) system to increase the PF of both lagging and leading single-phase loads. The Arduino Mega 2560 microcontroller was used to calculate the PF and activate the relays that connect the capacitor/inductor banks to the load in parallel. Thus, the required capacitive or inductive reactive power was produced by the APFC system by automatically connecting the capacitor/inductor banks to the load in parallel. The APFC system can also measure and display many electrical parameters of the load such as the rms voltage, the rms current, PF, and the real, reactive, and apparent power on an LCD display. Two zero-crossing detector circuits are used to find the phase angle difference between voltage and current waveforms of the load. The measurement ability of the APFC system was tested for resistive, inductive, and capacitive loads with two different sizes. The measurement results were compared with the measurements of a commercial digital power meter and a measurement error of less than 8.0% was observed. The PF correction ability of the APFC system was verified for inductive and capacitive loads with two different sizes. The experiments show that the PF increased to close to unity for both lagging and leading loads.