Power Factor Correction Inductor 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.

Multi-objective optimization of two-stage AC–DC power supply for reliability and efficiency using NSGA-II and meta-heuristic honey bee algorithms

This paper introduces a novel approach to simultaneously optimize the reliability and efficiency of a switching power supply (SPS) using the Non-dominated Sorting Genetic Algorithm (NSGA-II) and Honey Bee Algorithm (HBA). The proposed method uses a Markov model to evaluate the reliability of the converter and maximizes objective functions, including efficiency and reliability, using optimization algorithms to identify the optimum values of the converter parameters. The optimization algorithm determines the optimal values for converter parameters, such as switching frequency, transformer turn ratio, and DC-link voltage. It also fine-tunes circuit components, such as the power factor correction inductor, DC-link capacitor, and output filter components. A sensitivity analysis is carried out to assess the impact of various parameters on the multi-objective functions of the converter. The converter’s reliability and mean time to failure (MTTF) are evaluated using the Markov reliability model, considering all components’ short and open circuit faults. The failure rates of converter components are calculated using the MIL-HDBK-217 methodology. The results obtained from the NSGA-II and HBA are compared to identify the superior algorithm with the best-optimized parameters. Simulation results indicate that the proposed optimization technique enhances the converter’s reliability performance while maintaining its efficiency. Furthermore, this paper presents comprehensive analyses, comparisons, and experimental findings to demonstrate the converter’s fault-tolerant capability. The multi-objective optimization approach offers a practical and effective strategy for optimizing switching power supplies for efficiency and reliability

PFC Inductor Design Considering Suppression of the Negative Effects of Fringing Flux

In this paper, the main aim of the study was the investigation of the possibilities of power inductor design, reflecting the performance of the component itself, as well as the operational efficiency of the power factor correction (PFC) converter. PFC inductors represent a key component of the converter, while within the design of any magnetic component, several design rules must be considered to provide proper operational performance. Here we discuss skin-effect, while the proximity effect and formation of fringing flux pose a more serious problem in terms of mitigating their negative impact. Therefore, in this study, the space is devoted exclusively to the analysis of the impact of the fringing flux of the PFC inductor and subsequently to the possibilities of its suppression. The resulting optimizations are reflected in the investigation of the operational efficiency of the PFC converter.

Accurate Operating Analysis of Boundary Mode Totem-Pole Boost PFC Converter Considering the Reverse Recovery of mosfet

The boundary conduction mode (BCM) totem-pole boost power factor correction (PFC) topology is becoming popular in high-efficiency and high power density applications because of its advantages of fewer devices and low conduction losses. The ideal design methodology for the BCM boost converter ignores the reverse recovery of mosfet s’ body diode and the resonance between the inductance and output junction capacitances of switches. However, as the switching frequency increases, these two factors affect the peak value of the inductance current and the switching frequency significantly, which are critical parameters for the boost PFC inductor design. In order to calculate the practical peak current and switching frequency range accurately, this letter proposes an analytical reverse recovery model of the body diode and presents accurate switching cycle operating modes. Either the predicted inductance peak current or the switching frequency range matches the measured result on a 600-W totem-pole boost PFC prototype.

AC-Side CCM CS–CP–PFC Electronic Ballast

This paper proposes a bridgeless-type ac-side continuous-conduction-mode (CCM) current-source (CS) charge-pump (CP) power-factor-correction (PFC) electronic ballast. The drawbacks of conventional dc-side discontinuous-conduction-mode (DCM) electronic ballasts include high di/dt, high current stress, and high switching losses. As a result, conventional dc-side DCM CS-CP-PFC electronic ballasts have low efficiency, due to the DCM operation, and the ballasts require a large input electromagnetic interference filter. Conventional dc-side CCM CS-CP-PFC electronic ballasts are able to solve these problems, but still require a higher component count. To efficiently reduce the cost of electronic components, a bridgeless-type ac-side CCM CS-CP-PFC electronic ballast is proposed. A 32-W rated power electronic ballast prototype circuit is designed and implemented. Experimental results verify that the input-current harmonics meet the IEC 61000-3-2 Class-C Standard, and the CP capacitor helps the PFC inductor current to achieve CCM and high power factor

Single-stage single-switch power factor correction AC∕DC converter

A single-stage single-switch power factor correction AC/DC converter is proposed in which the power factor correction (PFC) inductor is connedted to a tap on the primary winding of the DC/DC flyback converter stage; there is direct energy transfer of a part of the input energy to the output and theDC-bus voltage feedback. The additional discharge path in the PFC inductor and DC-bus voltage feedback effectively suppresses the DC-bus voltage and increases the overall efficiency. Experimental results for a 60 W converter at a constant switching frequency of 70 kHz are obtained to show the performance of the proposed converter. It is shown that the voltage across the DC-bus capacitor can be held below 405 V even though the converter operates in a wide range of input voltages (90∼265 V AC) and the measured input current harmonics satisfy the IEC 61000-3-2 Class D requirements.

Comparison of Realization Techniques for PFC Inductor Operating in Discontinuous Conduction Mode

Several design techniques are compared for producing a power factor correction (PFC) boost inductor operating in discontinuous conduction mode. In this application, fringing fields associated with high frequency current pulses cause problems of winding loss in the vicinity of an air gap, in particular with planar core shapes. For this reason, a planar inductor in which a lumped gap is replaced by a distributed air gap material is described and investigated. The consequences of lumped versus distributed air gap for the losses of the boost inductor are investigated. A significant reduction in AC winding loss of the planar structure with the composite core is demonstrated. However, the trade-off between reduced winding loss and increased core loss for this technique has to be considered along with the selection of proper winding technology. Four boost inductor design realizations are built and compared. Presented winding loss models are verified with measurements on prototypes operating in an 80 W PFC converter.