Three-Phase Modular PFC Converter in Continuous Conduction Mode

For most actual power applications, power-factor correction (PFC) converters usually operate in the stable continuous conduction mode (CCM), but input current distortion will occur as long as these converters operate in oscillatory condition. This distortion usually manifests itself as a local oscillation within one line cycle. Typically, a Zeta PFC converter under the general pulse-width modulated (GPWM) control possesses high performance, and requires simpler control circuitry with fewer external components. However, due to the large-signal nonlinearity of the GPWM controller, the dynamic analysis and modeling of the input current distortion in its PFC converters remains vacant. In this paper, a large-signal average SPICE model is derived to capture the time-domain waveforms of the input current and output voltage. A power-balance approach for the PFC converter operating in CCM is developed, which can predict the steady-state values of the converters by using the Fourier series expansion. Analysis of the distortion behavior is provided in terms of the proposed model and the unbalanced power transfer mode. Experimental results are presented to verify the proposed method.

Dynamic response of boost power factor correction (PFC) converter operating in continuous-conduction mode (CCM) is heavily influenced by low-bandwidth of voltage control loop. A novel tri-state boost PFC converter operating in pseudo-continuous-conduction mode (PCCM) is proposed in this paper. An additional degree of control-freedom introduced by a freewheeling switching control interval helps to achieve PFC control. A simple and fast voltage control loop can be used to maintain a constant output voltage. Furthermore, compared with boost PFC converter operating in conventional discontinuous-conduction mode (DCM), boost PFC converter operating in PCCM demonstrates greatly improved current handling capability with reduced current and voltage ripples. Analytical and simulation results of the tri-state boost PFC converter have been presented and compared with those of the boost PFC converter operating in conventional CCM and DCM. Simulation results show excellent dynamic performance of the tri-state boost PFC converter.

This paper introduces small signal modeling of the restructured boost converter (RBC) in continuous conduction mode (CCM) by using the circuit averaging technique. The averaging technique produces linear transfer functions of the converter. The transfer functions relating the duty cycle to output voltage, duty cycle to inductor current, input voltage to output voltage, and input voltage to inductor current are obtained. To validate the converter model, power simulation (PSIM) simulations are developed, and experiments are conducted. The function of RBC is similar to a conventional boost converter, i.e., to level up the input voltage. A comparative analysis between the RBC and conventional boost converter is performed. The results highlight the advantages of RBC over a conventional boost converter.

Hızlı DA şarj için elektrikli araç şarj istasyonu, araç dışında AA-DA dönüşümü gerçekleştirir. Son yıllarda, üç fazlı AA-DA güç faktörü düzelten (GFD) dönüştürücüler hızlı şarj cihazı ile birlikte ele alınmaktadır. Bu dönüştürücüler, tek yönlü ve çift yönlü güç akışı yapısı kullanılarak geliştirilmiştir. Bu çalışmada, çift yönlü güç akışı sağlayan üç fazlı AA-DA GFD dönüştürücü topolojileri performans açısından değerlendirilmiştir. Amaç, elektrikli araç hızlı şarjı için en yeni üç fazlı çift yönlü çok seviyeli AA-DA GFD dönüştürücü teknolojisini sunmaktır. Bu makale, elektrikli araçlar için hızlı şarj altyapısıyla ilgilenen araştırmacılar için kapsamlı ve pratik bir inceleme sunmaktadır.

To reduce total harmonic distortion (THD) and improve the power factor (PF) of a boost power factor correction (PFC) converter, here, the authors propose a non‐linear control algorithm that includes the feedforward correction (FC) algorithm in the continuous conduction mode (CCM) and the non‐linear frequency variation (FV) algorithm in the mixed conduction mode (MCM). The proposed FC algorithm achieves current out of distortion through zero crossing with a lower current loop bandwidth. The proposed non‐linear FV algorithm achieves high PF and low THD under minimal load conditions. The non‐linear FV algorithm comprises a third harmonic extraction algorithm, a harmonic control loop for reducing THD and a frequency production algorithm. By using this non‐linear FV algorithm, the inductor size is reduced, which leads to lower cost and also achieves better THD and PF. The proposed algorithms are verified experimentally in terms of current tracking, current THD, PF, heating and loss on a 2000‐W boost PFC converter hardware prototype.

Buck-buck/Boost power factor correction (PFC) converter is a great choice to compensate the inherent dead zones in the input current of buck PFC converter. However, whether the converter operates with traditional constant on-time control in critical conduction mode (CRM) or with conventional constant duty-cycle control in discontinuous conduction mode (DCM), the power factor (PF) is low, especially at low input voltage. Therefore, fixed on-time ratio control (FOTRC) and fixed duty-cycle ratio control (FDCRC) are proposed for CRM/DCM buck-buck/boost PFC converter to achieve high PF, respectively. Both control methods maximize PF over wide input voltage range by adjusting on-time or duty-cycle of buck/boost mode and buck mode. Compared with the traditional controls, the proposed control methods also have advantage of increasing efficiency. Furthermore, for improving dynamic response performance, smooth and rapid dynamic response control (SRDRC) is put forward, which can reduce the regulation time and output voltage overshoot/undershoot when the load or input voltage changes abruptly. In addition, the implementation circuits combining FOTRC/FDCRC and SRDRC are designed. Two prototypes have been built and tested in the lab to demonstrate the validity of the theoretical analysis.

Power Factor Correction (PFC) converter is a key component in modern switching power supplies, while high efficiency and high power density are the main goals of PFC converter. In this paper, taking a single-phase Boost circuit as an example, a PFC converter with 300 kHz switching frequency and 1 kW output power which is based on continuous inductor current (CCM) mode is designed to reduce the volume of the core component and improve the power density of the converter. The paper includes the detailed design of the boost inductor, the analysis of the loss of the inductor at high frequency operation and the loss of the PFC converter. Finite element analysis is used to verify that the winding loss can be reduced by taking multi-strand wire winding. New semiconductor devices CoolMOS and SiC are employed which can reduce the loss effectively. The experimental results are provided which demonstrate that the employ of SiC diode and multi-strand wire winding can enable enhanced performance on efficiency.

This paper deals with the control strategy for the double boost converter in power factor correction (PFC) application, working in continuous conduction mode (CCM). This converter is based on the classic boost converter split into two parallel modules of power processing; each one of these modules process half of the nominal power of the converter. Technical literature concerning this converter does not analyze in detail some very important control aspects and it seems that it is still lacking a general control strategy for such converter. This subject is developed in the present paper. This is done by converter modeling based upon the PWM switch model. The model obtained, verified by simulations, points to a multivariable control system, since the converter output voltages and the control variables (duty cycle of the two active switches) are strongly coupled. The dynamic uncoupling technique is applied in order to overcome this undesirable characteristic and to design the voltage and current compensation loops. Each module of power processing has a current mode controlled PFC circuit with a current-regulation inner loop and a voltage-regulation outer loop and the dynamic uncoupling is performed over the former. Numerical simulation results of the behavior of the double-boost converter for power factor correction application are presented.

In more electric aircraft (MEA), three-phase power factor correction (PFC) rectifiers of several kilowatts are required. In this paper, a three-phase buck–boost derived PFC converter with three switches and with input inductors connected in delta configuration for use in MEA is presented. The proposed converter is operated in a discontinuous conduction mode to achieve PFC at ac input. This avoids the inner current control loop which further eliminates the current sensors. It requires only one output voltage sensor unlike five sensors in conventional PFC converter for its control implementation. This makes the system cost effective, more reliable, and robust. A simple voltage control loop is used to generate the gate signals. The steady state operation of the converter and detailed design calculations are presented. For each power component, the analytical expressions for calculating the average and rms current ratings are derived to facilitate the converter design. The small-signal model of the converter is presented to aid the controller design. The experimental results from a 2 kW laboratory prototype are presented to confirm the operation of the proposed converter. An input power factor of 0.999, an input current total harmonic distortion of as low as 2.76%, and a high conversion efficiency of 96% are achieved from the prototype.

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.

Electronic devices such as SMPS, UPS, rectifier and electronic ballast primarily require DC power supply. Electronic switching devices draw highly distorted input current (spikes with respect to the line voltage) for a short duration, due to their non-linear nature. This results in interference with other electrical equipment, increase in Total Harmonic Distortion (THD) and poor Power Factor (PF), which further results in poor output voltage regulation. Power factor correction (PFC) circuits are being increasingly used to mitigate the problems associated with poor power factor. This paper discusses an Active Power Factor Correction (APFC) technique using voltage feed forward and voltage feedback loop. It is based upon current wave shaping technique to get the source current in phase with the input voltage. Current wave shaping is achieved by implementing voltage control loop and current control loop. This paper explains the development of boost converter as a power factor correction controller, operating in continuous conduction mode (CCM). The boost converter is also designed to regulate the output voltage. The prototype of boost active PFC has been developed for single-phase rectifier, supplying load of 80W at 400V DC. Analysis has been carried out for different load conditions which prove that the PF can be improved from 0.6 to 0.98∼0.99 with THD reduction.

<div class="section abstract"><div class="htmlview paragraph">As light electric vehicles (LEVs) gain popularity, the development of efficient and compact on-board chargers (OBCs) has become a critical area of focus in power electronics. Conventional AC-DC topologies often face challenges, including high inrush currents during startup, which can stress components and affect system reliability. Furthermore, DC-DC converters often have a limited soft-switching range under light load conditions, leading to increased switching losses and reduced efficiency. This paper proposes a novel 6.6 kW on-board charger architecture comprising a bridgeless totem-pole power factor correction (PFC) stage and an isolated LLC resonant DC-DC converter. The main contribution lies in the specific focus on enhancing startup behavior and switching performance. In PFC converters, limiting inrush current during startup is crucial, especially with fast-switching wide-bandgap devices like SiC or GaN. Conventional soft-start techniques fall short in of ensuring smooth voltage transitions. Moreover, maintaining stable operation across a universal input voltage range and achieving a high-power factor under light load conditions remain persistent challenges. Although resonant converters are widely used for their natural soft-switching ability, achieving zero voltage switching (ZVS) over a wide range of loads, especially at light load conditions, is still a technical challenge. Existing solutions rely on complex control strategies or hardware modifications, which increase cost and design complexity. The proposed architecture was modeled and simulated using MATLAB/Simscape to assess dynamic and steady-state behavior under a range of operating conditions. Results demonstrated high input power factor, line/load regulation, and switch-node waveforms to confirm ZVS operation. Additionally, the proposed charger exhibits low harmonic distortion, ensuring compliance with IEC 61000-3-2 power quality standards. These findings confirm the topology’s effectiveness for high-performance LEV charging and set a strong foundation for future experimental validation and hardware development.</div></div>

This paper aims at the application of a half bridge DC-DC converter as a power factor correction (PFC) converter for a permanent magnet brushless DC motor (PMBLDCM) driven air conditioner. This PFC converter is fed from singlephase AC mains through diode bridge rectifier (DBR) and connected to a voltage source inverter (VSI) feeding the PMBLDCM. The proposed PFC half-bridge converter based PMBLDCM drive is controlled to have the variable speed operation of the compressor for efficiency improvement of the air conditioning system. The control scheme for the PFC converter based PMBLDCM drive is designed, modeled and its simulation is carried out in Matlab-Simulink environment for an air conditioner compressor driven through a 1.5 kW, 1500 rpm PMBLDC motor. The obtained results are presented to validate the effectiveness of the proposed adjustable speed drive in wide range of the speed and an AC input voltage. An improved power quality is observed with almost unity power factor and improved efficiency of the drive in a wide range of the speed and an AC input voltage.

In this paper, a bee colony optimization (BCO) algorithm is adapted to the current control strategy of power factor (PF) correction for a Sheppard-Taylor converter. The control approach is developed to eliminate the input current harmonics in the converter. The BCO algorithm is a new population-based search algorithm which is one of the metaheuristic techniques based on swarm intelligence. This algorithm depends on modeling the natural behavior of real honey bees. In this approach, duty cycles are generated by the BCO algorithm for the Sheppard-Taylor converter switch to obtain unity PF (UPF) and lower total harmonic distortion of the input current. The duty cycles for half a line period are calculated and stored in a lookup table. By synchronizing the memory with the line, near-unity PFs can be achieved in an operating point. The feedforward is also used into the control algorithm with the maximum value of the input voltage. The implementation of feedforward improves the converter performance. The input current of the converter is operated in continuous conduction mode. The simulation and experimental results show that the proposed control strategy works well and the UPF can be achieved with wide input voltage, load, and parameter variation. The results are compatible with the International Electrotechnical Commission (IEC) 61000-3-2 current harmonic standard.

This paper proposes an improved modulated carrier control method for a continuous conduction mode (CCM) power factor correction (PFC) boost converter. The proposed method allows precise sinusoidal line current shaping for a boost PFC converter operating in CCM. This is accomplished by simply comparing the compensated modulated carrier signal with the switch current information, such that the current loop compensation is eliminated and multiplier is not required. Also, the proposed control method overcomes the instability problem of conventional modulated carrier control around the zero crossings of the line voltage at light load. The performance of the proposed control method is experimentally verified on a 300 W PFC converter.