Boost-type 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.

Performance Analysis of Meta-Heuristic Algorithms for Optimal PI Tuning of PFC

The popularity of the average current mode (ACM) controlled boost type power factor correction (PFC) topologies is increasing due to their suitability for power quality problems. Proportional-Integral (PI) controller method is generally used in ACM controlled boost PFC circuits which include two controllers. However, the most important complexity of ACM controlled PFC circuits is tuning the coefficients of the PI controllers optimally. Therefore, this paper proposes the optimal tuning of PI coefficients used in ACM controlled boost PFC circuits using different meta-heuristics algorithms. First, the proposed ACM controller-based boost PFC topology is analyzed in MATLAB/Simulink software by using variable loads. Then the simulation results of the Cuckoo Optimization Algorithm (COA) based ACM controlled boost PFC converter are compared with the results determined via Ziegler-Nichols (ZN), Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Imperialistic Competitive Algorithm (ICA), and Invasive Weed Optimization (IWO). Finally, the experimental verification of the topology has been done using a 600 W prototype and eZdsp F28335. As COA showed better results among other evolutionary algorithms used in this paper, we used COA parameters to observe the performance of the proposed tuning method. The experimental studies have been done under different load variations similar to the simulation studies.

Variable Output Voltage Switching Rectifier for Cathodic Protection Applications With DC–DC Variable Frequency and Duty-Cycle Full-Bridge Converter

Rectifiers used in cathodic protection (CP) applications convert ac voltage to variable dc output. This article proposes a switching converter for CP, mostly to enhance the efficiency in low to medium output powers, where the duty cycle is less than 30%. This device is composed of two parts, an ac-dc converter and a dc-dc full-bridge converter. The ac-dc converter is a single-phase boost-type power factor correction converter with emphasis on high efficiency, thus resulting in an almost unity power factor and fixed dc output voltage. The dc-dc full-bridge converter operates under pulsewidth modulation with the simultaneous change of frequency and duty-cycle (SCFD) control method responding to the user output power demand. The SCFD control strategy, in this converter, increases overall efficiency of the proposed rectifier. Finally, a 1875 W prototype is implemented and tested to verify the nearly fixed high efficiency for the converter in a wide operating range of the output power.

Study of Power Quality Phenomenon Based on Design and Simulation of Boost Type PFC Converters

This paper present design and simulation of boost type Power Factor Correction (PFC) converter which improved the power quality. With the enormous development in the usage of power converters circuits like rectifiers which is non linear loads, the current drawn by these non- linear loads will not follow the supply voltage (i.e. non simulation). This results in high Total Harmonic Distortion (THD) and poor Power Factor (PF). Hence there is a need of converter topology to improve the PF and reduce line current harmonic. Boost type PFC converters is most popular topology for improving the PF in supply AC side. Average Current Mode (ACM) control technique is employed to control the boost converter in Continuous Conduction Mode (CCM). Simulation of proposed system is carried out using MATLAB/ Simulink platform.

Single-Phase Bridgeless PFC Topology Derivation and Performance Benchmarking

This article introduces two general ways to derive single-phase bridgeless power factor correction (PFC) topologies and then, 15 accessible bridgeless topologies are derived based on the configuration of different basic types of dc–dc converter cells. Although the majority of the topologies have been previously proposed, other possible research points are reviewed. Besides, a consistent component sizing procedure with electric, thermal, and cost models is applied to conduct the performance benchmarking of these PFC topologies in terms of power loss, volume, and cost. Three boost-type PFC topologies are chosen as examples to demonstrate the procedure and the corresponding benchmarking results with both theoretical analyses and experimental verification. Finally, mission profiles of one specific application are introduced to show the material cost payback period of adopting one modified bridgeless boost topology instead of conventional one in different scenarios.

Active Bridge Rectifier With DM EMI Reduction Based on Linear Reverse Operation of MOSFETs

A new linear control scheme for operating power MOSFETs in the third quadrant (i.e., synchronous rectifier (SR) operation) is proposed and applied to electromagnetic interference (EMI) mitigation of switching converters. MOSFETs operating in the third quadrant exhibit electrical characteristics equivalent to a voltage-controlled voltage source between the gate-source and the drain-source voltages. Such operation is an alternative to typical SR mode, allowing fast control of the ac drain-source voltage. It is applied to active bridge rectifiers (ABRs) that can produce the necessary high-frequency voltage compensation signal to reduce differential-mode EMI. The ABR can then play the role of ac line rectification and EMI reduction at the same time. Its characteristics are modeled, and experimental verifications are carried out on a boost-type power factor corrector (PFC). The EMI performance of the PFC is improved with the proposed technique. The proposed technique facilitates the reduction of passive filter size and gives the potential of integrating active filtering function into the ABR as a solid-state front-end module. The idea can, thus, help increase the power density of power converters.

Research on control strategy of a buck-type harmonic injection three-phase rectifier

This paper proposes a buck-type harmonic injection three-phase rectifier to mitigate the high voltage stress of the rear switch of the conventional boost-type power factor correction (PFC) circuit. It develops a control strategy composed of improved double loop control pattern and voltage feedforward pattern. Firstly, the working principle of the buck-type harmonic injection three-phase rectifier is described. Then, it demonstrates the advantage of improved control strategy. Afterwards, the controller’s corresponding involved parameters are optimized. Finally the theoretical analysis and simulation results show that the circuit can output the stable low ripple voltage with increased power factor and decrease the harmonic content of input side current.

Maximum Efficiency Tracking of an Integrated Two-Staged AC–DC Converter Using Variable DC-Link Voltage

This paper presents an approach to achieve maximum conversion efficiency of a two-staged-cascaded ac–dc converter. In this study, the integrated ac–dc converter consists of a three-phase boost-type power factor correction rectifier and a phase-shifted full-bridge dc–dc converter. The detailed loss modeling of the integrated stage implies that the total power loss varies in a nonmonotonic fashion with intermediate dc-link voltage. In order to ensure maximum conversion efficiency, an optimum dc-link voltage level can be set depending on the load power level. A comparison between the efficiency variation under two different cases is carried out with extensive mathematical analyses: 1) fixed dc bus and 2) variable dc-bus voltage control. In addition, the experimental results obtained from a 6-kW-integrated ac–dc hardware prototype show a unity power factor along with a peak efficiency of 97.2%, which is 2.5% more than the fixed dc-link control approach.

A Single-Stage High-Power Factor Converter with Synchronized Self-Excited Technique for LED Lighting

This paper proposes a single-stage, high power-factor light-emitting diode (LED) driver with a self-excited control scheme for the power switches. The self-excited mechanism is accomplished by fetching the driving voltages from a center-tapped transformer. The frequency of the driving voltages is exactly the same as the resonant frequency of the resonant converter, thus synchronizing the resonant frequency with the switching frequency and achieving zero-voltage switching (ZVS) and zero-current switching (ZCS) of power switches. The circuit topology is mainly composed of a half-bridge LC resonant converter, along with a boost-type power-factor corrector (PFC) to fulfill the single-stage structure, meaning that the presented LED driver possesses high power-factor features and low switching loss. Finally, a 40 W prototype circuit is implemented and tested, and the experimental results exhibit a satisfactory performance.

Design and Experimental Analysis of PFC Rectifiers for Domestic Induction Heating Applications

Induction heating is nowadays a key technology due to its advantages in terms of performance and efficiency, which has boosted its adoption in industrial, domestic, and medical applications, among others. Recent developments in domestic induction heating are focused on flexible cooking surfaces with higher output power. The design requirements of this cooktops are more restrictive due to electromagnetic compatibility (EMC), power density, efficiency, control complexity, and cost. In order to overcome these issues, the use of active power factor corrector (PFC) rectifiers is proposed. This paper proposes and analyzes a complete set of modulation strategies for a single-phase boost-type PFC applied to domestic induction heating. A comparative analysis is performed taking into account the device stress, efficiency, operating frequency, control complexity, and EMC performance. This discussion reveals the advantages and disadvantages of each modulation strategy according to the final implementation requirements and the application area.

A Comprehensive Design and Optimization of the DM EMI Filter in a Boost PFC Converter

This paper presents a systematic and comprehensive approach for differential mode (DM) electromagnetic interference (EMI) filter design in a three-phase boost-type power factor correction (PFC) rectifier. Since the DM EMI filter forms a significant portion of the overall filter as well as converter volume, the reduction of DM filter component size is kept as a major objective in the filter design process in order to improve the power density. In addition to the objectives of volume optimization and conducted emission attenuation requirement to comply with the EMI standard, the filter design process also ensures a near-unity power factor operation with the optimal set of EMI filter parameters. To accomplish this, the paper analyzes the effect of EMI filter component selection on the overall lower order (1–100 kHz) frequency response, which is important for evaluating the dynamic response and stability. The results from the proposed design approach are validated through simulation, the DM Bode plot, and frequency response of the input current with and without EMI filter. As a proof-of-concept verification, the proposed EMI filter is implemented in a 4-kW three-phase boost-PFC prototype, which demonstrates minimal phase displacement (<5°) of the input current.

Plug-and-Play Voltage Ripple Mitigator for DC Links in Hybrid AC–DC Power Grids With Local Bus-Voltage Control

In this paper, a straightforward plug-and-play voltage ripple mitigator (RM) is proposed. Unlike existing voltage ripple reduction methods, the proposed device can be attached to the dc link of a hybrid ac–dc power system without modifying the host system itself. In particular, a local bus-voltage control scheme is employed to achieve the plug-and-play operation. With the requirement of the dc-link voltage measurement only, this device can be operated as a standalone module. Theoretical analysis and experimental work on a boost-type power factor correction rectification system have been successfully performed to validate the effectiveness of the ripple-mitigating function, the hot-swap operation and the nonintrusive property of the RM. Practical results obtained from a 110-W miniature hybrid ac–dc power system comprising an ac/dc converter and two resistive loads are included to demonstrate some of the functions of the RM.

An Integrated Control Strategy for a Fast Start-Up and Wide Range Input Frequency Operation of a Three-Phase Boost-Type PFC Converter for More Electric Aircraft

This paper presents an integrated control strategy to achieve fast start-up and enable wide input frequency operation in a three-phase six-switch power factor correction (PFC) converter. Limiting the inrush current with simultaneously minimizing the start-up time is achieved by implementing a nonlinear compensator in the voltage control loop. In addition, the concerning issues regarding unity PFC operation with an accurate reference tracking in a system with wide input frequency variation (typical for more-electric-aircraft) are resolved by a second-order compensator integrated with a state-feedback controller in the current loop. For a proof-of-concept verification, a hardware prototype of 6 kW, three-phase six-switch PFC is developed and tested with the proposed integrated control strategy in a wide source frequency range (360–800 Hz) ac input that shows perfect unity power factor operation throughout. Both the start-up time and inrush current are reduced to $ of their values in conventional PI compensation.

Boost-Type Power Factor Corrector With Power Semiconductor Filter for Input Current Shaping

This paper extends the application of a solid-state input current harmonic filtering technique, named as power semiconductor filter (PSF), for boost-type power factor corrector (PFC). The filtering technique is based on connecting an active device, namely, series pass device (SPD), in series with the input of the boost converter. By adjusting the control signal to the SPD, the input current of the PFC is profiled to be in phase with the supply voltage and regulate the output voltage. The power dissipation of the SPD is maintained at a low level by operating the SPD at the boundary between the linear and saturation regions. Modeling of the static and dynamical characteristics, design, and analysis of the entire system will be given. A 100 W, 85–265 Vac/400 Vdc PFC with the boost converter operating in discontinuous conduction mode has been built and evaluated. Experimental results reveal that the PSF can reduce the input current harmonics and improve the input power factor. They are in close agreement with the theoretical predictions. Finally, the conducted electromagnetic interference under different supply voltages will also be reported.

Digital Current Sensorless Control for Dual-Boost Half-Bridge PFC Converter With Natural Capacitor Voltage Balancing

To improve the efficiency of the conventional boost-type power factor correction (PFC) converters with the diode bridge circuit, the PFC converters of bridgeless category are often used. Due to no series-connected switches and no short-through risks, the dual-boost half-bridge (DBHB) circuit is used as the PFC converter in this paper. In order to simplify the conventional two-loop control scheme and reduce the number of sensors, the behaviors of the DBHB PFC converter are studied and its equivalent single-switch model is developed. Then, the current sensorless control for the DBHB PFC converter is proposed to achieve voltage regulation and yield sinusoidal input current in phase with the input voltage without sensing any current. In addition, the proposed method is able to balance capacitor voltages naturally without adding any voltage balancing control loop. An 800-W DBHB PFC prototype is implemented to evaluate the control performance. Both simulation and experimental results are provided to demonstrate the proposed current sensorless control method.

Study on Three-phase Six-switch Buck-type Rectifier of High Power Factor

This paper proposed a three-phase six-switch buck-type APFC rectifier based on DSP28335. At present, the boost-type power factor correction rectifier has the advantages of high input current power factor and low harmonic distortion. However, it has the disadvantages of high EMI common-mode noise, and the high output voltage also produces negative effect to the DC-DC converter. This paper designed a three-phase six-switch buck-type APFC circuit, which has no shortcomings of the boost-type power factor correction rectifier, but retains the advantages of the boost-type rectifier, which has high input power factor, low harmonic distortion, low output voltage and low EMI common-mode noise. In addition, it has a high conversion efficiency. Finally a 117V input, 60V/138 watts output device is produced for verification.

A SiC-Based High-Efficiency Isolated Onboard PEV Charger With Ultrawide DC-Link Voltage Range

In LLC-based onboard battery charging architectures used in plug-in electric vehicles (PEV), the dc link voltage can be actively regulated to follow the battery pack voltage so that the LLC converter can operate in proximity of resonant frequency and achieve high efficiencies over the wide range of battery pack voltage. However, conventional boost-type power factor correction (PFC) converters are unable to provide ultrawide dc link voltages since their output voltages should always be larger than their input voltages. This paper proposes a Silicon Carbide (SiC)-based onboard PEV charger using single-ended primary-inductor converter (SEPIC) PFC converter followed by an isolated LLC resonant converter. With the proposed charger architecture, the SEPIC PFC converter is able to provide an ultrawide range for dc link voltage, and consequently enhance the efficiency of the LLC stage by ensuring operation in proximity of resonant frequency. A 1-kW SiC-based prototype is designed to validate the proposed idea. The experimental result shows that the SEPIC PFC converter achieves unity power factor, 2.72% total harmonic distortion, and 95.3% peak conversion efficiency. The LLC converter achieves 97.1% peak efficiency and always demonstrates a very high efficiency across the ultrawide dc-link voltage range. The overall efficiency of the charger is 88.5% to 93.5% from 20% of the rated load to full load.

A Polynomial Current Controller for a Third-Harmonic Modulated Power Factor Correction Rectifier Feeding a Vector Controlled Induction Motor Drive

This paper presents the analysis, design, and hardware implementation of a digital polynomial Regulation, Steady-State Error and Tracking (RST) current controller-based third-harmonic modulated boost-type power factor correction (PFC) rectifier. The proposed rectifier is used at the front end of a vector controlled induction motor drive (VCIMD) to eliminate harmonics at the input AC supply. The proposed PFC rectifier modifies the input current to a sinusoid with unity power factor apart from offering DC bus voltage regulation. In this paper, a digital proportional-integral (PI) and RST current controllers are compared in terms of total harmonic distortion (THD) and power factor (PF) at the point of common coupling for different loading conditions. The RST current controller tracks the set-point accurately with zero steady-state error and offers good disturbance rejection that enables further reduction of supply current THD as compared to a conventional PI current controller. The control algorithm for the PFC front end rectifier along with vector control technique is implemented using a digital signal processor, and the dynamic performance is analyzed for step changes in reference speed and load torques, demonstrating significant improvement in the performance indices.

Thermal analysis and improvement of cascode GaN device package for totem-pole bridgeless PFC rectifier

The totem-pole bridgeless power factor correction (PFC) rectifier has a simpler topology and higher efficiency than other boost-type bridgeless PFC rectifiers. Its promising performance is enabled by using high-voltage gallium nitride (GaN) high-electron-mobility transistors, which have considerably better figures of merit (e.g., lower reverse recovery charges and less switching losses) than the state-of-the-art silicon metal-oxide-semiconductor field-effect transistors. Cascode GaN devices in traditional packages, i.e., the TO-220 and power quad flat no-lead, are used in the totem-pole PFC boost rectifier. But the parasitic inductances induced by the traditional packages not only significantly deteriorate the switching characteristics of the discrete GaN device but also adversely affect the performance of the built PFC rectifier. A new stack-die packaging structure with an embedded capacitor has been introduced and proven to be efficient in reducing parasitic ringing at the turn-off transition and achieving true zero-voltage-switching turn-on. However, the thermal dissipation capability of the device packaged in this configuration becomes a limitation on further pushing the operating frequency and the output current level for high-efficiency power conversion. This paper focuses on the thermal analysis of the cascode GaN devices in different packages and the GaN-based multichip module used in a two-phase totem-pole bridgeless PFC boost rectifier. A series of thermal models are built based on the actual structures and materials of the packaged devices to evaluate their thermal performance. Finite element analysis (FEA) simulation results of the cascode GaN device in a flip-chip format demonstrate the possibility of increasing the device switching speed while maintaining the peak temperature of the device below 125 °C. Thermal analysis of the GaN-based power module in a very similar structure is also conducted using the FEA method. Experimental data measured using the fabricated devices and modules validate the simulation results. The developed new package in a flip-chip configuration enhances the thermal dissipation capability of the cascode GaN device in the stack-die format. The GaN-based power module built using the same packaging structure also demonstrates desirable thermal performance.

A Stepping On-Time Adjustment Method for Interleaved Multichannel PFC Converters

A simple and effective stepping on-time adjustment (SOTA) method with status judgment for interleaved multichannel critical mode (CRM) boost-type power factor correction (PFC) converters is proposed. The boost-type PFC converter with CRM operation is commonly used for ac-dc conversion because of its circuit simplicity and high efficiency. The interleaved multichannel PFC converter becomes the trend for high-power applications. However, conventional interleaved methods are complicated and difficult to implement when more than two channels are required. Also, noise disturbances or on-time mismatching can easily lead to continuous conduction mode operation which will increase current distortion, reduce power conversion efficiency, or even damage the converter. The proposed SOTA method with status judgment can greatly simplify the control complexity of the interleaved multichannel operation. A prototype 600-W three-channel interleaved CRM boost PFC converter is built to verify the performance of the proposed SOTA method.