Power Factor Correction Converter Research Articles

Non‐linear control of a boost PFC converter with a small inductor based on feedforward correction and frequency variation

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.

Linear Quadratic Regulator-Based PI Control of a Non-Ideal Quadratic Boost PFC Converter for Low-Power Wind Energy Conversion Systems Supplying Uninterruptible DC Power

DC–DC converters are efficient in providing a regulated power with power factor control in switch-mode power supplies and also in electric vehicle charging stations. The aim of this research work is to design an efficient DC–DC quadratic boost power factor correction converter for Wind Energy Conversion Systems (WECS) to provide uninterruptible DC power in case of one or two modules loss for low-power applications. The state-space model of the converter is derived using a state-space averaging technique through small signal modeling by considering the non-linearities. The reduced-order model is obtained using Routh-Pade's approximation method to reduce the complexity involved in the design of the controller parameters for the outer and inner loops. The outer voltage is regulated using an Internal Mode Control (IMC)-based proportional integral (PI) controller to overcome the effect of right-half plane zero (RHP) and three-phase currents are shaped by using three PI controllers. The three inner PI controllers for each phase are tuned using three methodologies like Zieglar Nichols, Skogestad and Linear Quadratic Regulator (LQR)-based PI control. The transient and steady-state performances of the closed-loop system are analyzed for variations in the load and set point using extensive computer-based simulation studies. The results reveal that the LQR-based PI controller show considerably better performance in terms of less settling time, overshoot, power factor and %THD, including parasitic parameters of the components.

Parallel Fixed Switching Frequency CRM and DCM Boost PFC Converter With High Power Factor

Critical conduction mode (CRM) or discontinuous conduction mode (DCM) boost power factor correction (PFC) converter is widely used in low power applications for its advantages of zero-current turn-on of the switch, no reverse recovery in diode and simple control. The input current of fixed switching frequency control CRM boost PFC converter and the input current of constant duty-cycle control DCM boost PFC converter mainly contain third harmonic. Moreover, the phase of the third harmonics is opposite. This paper proposes a harmonic elimination parallel control to connect these two converters in parallel. The input current third harmonic of the parallel converter can be eliminated completely so as to improve the PF to nearly unity in the whole input voltage range. This parallel method is an interesting way to extend power, and is different from the existing method of parallel DCM boost PFC converter or parallel CRM boost PFC converter. The experimental results verify the accuracy of the theoretical analysis.

Analysis of a new SEPIC AC–DC PFC converter for light emitting diode applications

Active power factor correction (PFC) converters are used to increase the power factor and improve the total harmonic distortion as a result of reducing the harmonics in the current. In this paper, a new bridgeless single-ended primary inductor converter (SEPIC) topology used in light emitting diode (LED) load is proposed to obtain near-unity power factor. By eliminating the input bridge in the bridge PFC converter, the total harmonics distortion is improved and a lower cost is obtained. The reactive power control is used to generate the reference current signal in the proposed converter to control the LED current. To demonstrate the applicability of the proposed topology and to compare its performance with the bridge SEPIC topology, PSIM circuit simulation was used, and an experimental prototype was performed. In the experimental study, 25 Vrms input voltage was applied, and 10 V DC voltage was obtained at the output. Using the proposed converter, the total harmonic distortion value was reduced from 5.722% to 1.837%, and the power factor was increased to 0.999. The experimental and simulation results showed that the total harmonic distortion value of the input current improved and that the proposed SEPIC PFC converter for low-power circuits, particularly in LED applications, is a very good option.

An Isolated Bridgeless Cuk–SEPIC Converter-Fed Electric Vehicle Charger

A single-stage electric vehicle (EV) battery charger with an isolated bridgeless (BL) Cuk–single-ended primary-inductor converter (SEPIC) converter is developed in this article. The design of proposed charger is ensured in discontinuous conduction mode with intrinsic power factor correction (PFC) at ac mains. Compared to the BL Cuk converter topology when used for both positive and negative cycles, the proposed topology has reduced number of components with improved efficiency. This is due to integration of Cuk and SEPIC converters during the individual half cycle. The presence of output inductor at Cuk converter side also smoothens the output current, as compared to SEPIC converter used for both cycles. A high power quality (PQ) operation of new BL isolated PFC converter with an EV battery load of 48 V/100 Ah is verified using single-phase PQ analyzer. A laboratory prototype of proposed charger is developed and validated to corroborate the efficient performance during two charging profiles. Test results are shown under steady state as well as over extreme load and line conditions. Different performance indices such as displacement PF, ac mains PF, and mains current distortion are recorded, which comply the IEC 61000-3-2 standard.

Switching and Heat-dissipation Performance Analysis of an LTCC-based Leadless Surface Mount Package

A leadless surface mount package was developed to enhance the switching and heat-dissipation properties of a power semiconductor. The package was implemented through a low-temperature co-fired ceramic (LTCC)-based multilayer circuit substrate that could form embedded cavities. A silicon carbide (SiC) Schottky barrier diode (SBD) bare die was attached to the cavity in the LTCC substrate. Chip interconnection was realized using a wide and thick copper (Cu) clip with a low parasitic inductance and electrical resistance compared to those of a conventional wire. Silver-filled multiple vias and wide metal planes were used to reduce the electrical parasitic effects and enhance the heat-dissipation of the package. The DC and dynamic characteristics of the 600 V/10 A-class SiC SBD package involving the proposed technologies were evaluated. The dynamic test results indicated that the reverse recovery charge (Qrr) was 18.7% lower than that of a traditional TO-220 packaged product with the same bare die. Furthermore, two leadless commercial products and he proposed package prototype were applied to a power factor correction (PFC) converter, and the power loss and heat-dissipation performances were compared. The proposed package exhibited a lower loss and higher heat dissipation than those of the commercial products.

Analysis of Non-Minimum Phase System for AC/DC Battery Charger Power Factor Correction Converter

Electric mobility is nowadays one of the more important trends regarding pollution reduction and global warming due to fuel consumption. Big efforts are done in order to develop efficient and reliable power electronic systems for electric vehicles. In two stage on board-battery chargers, one way of improving efficiency is by means of ensuring the DC-DC isolated converter always operates in the nominal input/output voltage ratio, that could be achieved with a variable DC-link operation. In this paper, a four-switch buck-boost based AC/DC converter is deeply analyzed in order to improve its dynamic performance, the power factor and the total harmonic distortion. The converter suffers from a non-minimum phase characteristic in different input–output transfer functions, which reduces the closed-loop bandwidth of the system. Therefore, after a deep converter analysis has been done, different solutions have been evaluated and tested. Finally, a control to different output transfer functions of the converter become minimum phase, which allows us to increase the system bandwidth and, consequently, high power factor, low harmonics distortion, single control structure and fast dynamics for wide output voltage range are achieved.

A Review of Three Phase AC-DC Power Factor Correction Converters for Electric Vehicle Fast Charging

Electric vehicle charging station for fast DC charging performs AC-DC conversion at off-board. In recent years, three-phase AC-DC power factor correction (PFC) converters are dealt with fast charger. These converters are developed using unidirectional and bidirectional power flow structure. In this study, three-phase AC-DC PFC converter topologies, providing bidirectional power flow, are evaluated in terms of performance. The aim is to present the latest technology of bidirectional multilevel AC-DC PFC converters for EV fast charging. This paper provides a comprehensive and practical review for researchers interested in fast charging infrastructure for electric vehicles.

Review on State-of-the-Art Unidirectional Non-Isolated Power Factor Correction Converters for Short-/Long-Distance Electric Vehicles

Electrification of the transportation sector has originated a worldwide demand towards green-based refueling infrastructure modernization. Global researches and efforts have been pondered to promote optimal Electric Vehicle (EV) charging stations. The EV power electronic systems can be classified into three main divisions: power charging station configuration (e.g., Level 1 (i.e., slow-speed charger), Level 2 (i.e., fast-speed charger), and Level 3 (i.e., ultra-fast speed charger)), the electric drive system, and the auxiliary EV loads. This paper emphasizes the recent development in Power Factor Correction (PFC) converters in the on-board charger system for short-distance EVs (e.g., e-bikes, e-trikes, e-rickshaw, and golf carts) and long-distance EVs (passenger e-cars, e-trucks, and e-buses). The EV battery voltage mainly ranges between 36 V and 900 V based on the EV application. The on-board battery charger consists of either a single-stage converter (a PFC converter that meets the demands of both the supply-side and the battery-side) or a two-stage converter (a PFC converter that meets the supply-side requirements and a DC-DC converter that meets the battery-side requirements). This paper focuses on the single-phase unidirectional non-isolated PFC converters for on-board battery chargers (i.e., Level 1 and Level 2 charging infrastructure). A comprehensive classification is provided for the PFC converters with two main categories: (1) the fundamental PFC topologies (i.e., Buck, Boost, Buck-Boost, SEPIC, Ćuk, and Zeta converters) and (2) the modified PFC topologies (i.e., improved power quality PFC converters derived from the fundamental topologies). This paper provides a review of up-to-date publications for PFC converters in short-/long-distance EV applications.

A Modified Forward PFC Converter for LED Lighting Applications

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

Second Harmonic Current Reduction Schemes for DC–DC Converter in Two-Stage PFC Converters

For the two-stage single-phase power factor correction (PFC) converter, its instantaneous input power pulsates at twice the line frequency, generating the second harmonic current (SHC) at the dc-bus port. The dc–dc stage is used to regulate the output voltage or the dc bus voltage in different applications, and the SHC reduction schemes for the dc–dc stage with different control objectives are discussed in this article. When the dc–dc stage regulates the output voltage, it is pointed out that the control bandwidth of the dc–dc stage is required to be high enough and the dc bus capacitor should be large enough to suppress the SHC, and the design of the dc bus capacitor is given. When the dc–dc stage regulates the dc bus voltage, a virtual impedance is added in series with the input/output of the dc–dc stage to suppress the SHC, and a virtual impedance is added in parallel with the dc bus to improve the dynamic performance. The selection and design of the virtual impedances are also given. Based on that, three specific control schemes are proposed for the dc–dc stage to suppress the SHC, and the parameters design method is also presented. Finally, a 3.3-kW two-stage single-phase PFC converter is fabricated and tested in the lab to verify the effectiveness of the proposed SHC reduction schemes.

Interleaved Boost Integrated Flyback Converter for Power Factor Correction in Brushless DC Motor Drive

The scope of this research is to manage the speed of Permanent Magnet Brushless DC Motor Drive (PMBLDCMD) for various less capacity applications. In the circuit, a 1ϕ AC power is given to Diode Rectifier and the converted DC supply is given to condenser, which leads to abnormal pulsating current. Because of this pulsating current, the power quality disturbances arise at the supply point. Hence, the PMBLDCMD requires Power Factor Correction (PFC) converter for many household and profitable applications. The rotors of PMBLDCMD are driven by 3ϕ voltage source inverter (VSI), which performs electronic commutation. The range of PFC converter for feeding PMBLDCMD has high emphasis on the power quality (PQ) norms, cost and performance of controllers. The proposed converter requires very less components, which imposes less stress, low ripple and less power loss with positive voltage polarity. The chopper is used to correct the power factor. Various chopper layouts like buck boost Converters and boost converters with single switch are used. The mostly used regulated structures for PFC converters govern the current with continuous conduction technique and to govern the potential differential tracker using discontinuous conduction method (DCM). The processes like examining, modelling and governing of PFC converters are applied for upgrading the quality of power in AC supply.

Differential Mode Noise Prediction and Analysis in Single-Phase Boost PFC for the New Frequency Range of 9–150 kHz

High penetration of power electronics due to the concentration of switching frequency in the range of 9–150 kHz may create new challenging issues. Currently, regarding the recent version standard (IEC 61000-6-3), there is a lack of enough insight and fundamental studies despite reported electromagnetic interference (EMI) noise problems in this frequency range. Hence, this article proposes a time-frequency analytical modeling method for characterizing differential mode (DM) noise in a single-phase power factor correction (PFC) converter in this new frequency range. Provided comparative simulation analysis shows the proposed method's ability to estimate DM noise with a 9–150 kHz frequency range at high accuracy utilizing the double Fourier analysis method. Moreover, the obtained experimental results on a 1-kW single-phase boost PFC converter validate the proposed EMI modeling approach's effectiveness, demonstrating an error of less than 1.8 dB for the considered experimental case studies.

Review of the CM noise mitigation methods for the single-phase power factor correction converter

Several techniques to mitigate conducted electromagnetic interference (EMI) in single-phase power factor correction (PFC) converters have been reported in literatures. This paper mainly focuses on the review and classifications of the common-mode (CM) noise mitigation methods based on the novel structures, balance concept, novel modulation methods and so on. Through eliminating the noise generation or cut off the propagation path, those methods can mitigate the CM noise caused by the single-phase PFC converter. Besides, the comparisons and limitations are also discussed. It is believed that this review will be helpful to the design of the EMI filter for the switch-mode power system, which includes the PFC stages.

High Efficiency Common Mode Coupled Inductor Bridgeless Power Factor Correction Converter With Improved Conducted EMI Noise

The conventional power factor correction (CPFC) converter suffers from excessive heat generation due to high conduction loss from the input bridge diode. Various bridgeless PFCs (BPFCs) have been proposed to overcome this drawback. Among them, the conventional BPFC (CBPFC) features the significantly reduced conduction loss but has very poor conducted electromagnetic interference (EMI) noise. Further, the semi-BPFC features the reduced input diode loss and good EMI, but the input diode loss is too significant to ignore. Although another solution, totem-pole BPFC, features high efficiency and good EMI, it usually requires expensive current sensors and microprocessor. A BPFC with the integrated magnetics common mode coupled inductor (ICC) is proposed to overcome the drawbacks of traditional BPFCs. The ICC can significantly reduce the system size by integrating three inductive components into a single magnetic core. Moreover, the small magnetizing current of the ICC, not the main input current, flows through input diodes; thus, experimental results from a 600 W rated prototype prove that the input diode loss can be significantly reduced by about 10 W compared to the CPFC, and the input diode exhibits a low heat generation of 49.8 °C despite the absence of a heat sink. In particular, with the help of input diodes, the EMI noise spectra of the ICC BPFC can meet the EMI standard with a sufficient margin. The detailed analysis, design guide and experimental results from a 600 W rated prototype are provided to confirm the validity of the ICC BPFC.

Adaptive Observer Design for a Bidirectional AC/DC totem pole PFC Power Converter

In this paper, we propose a nonlinear observer for a single-phase bidirectional AC/DC totem-pole power factor correction (PFC) converter intended to be used in wireless power transfer (WPT) chargers for electric vehicles (EVs). This converter is gaining a lot of interest recently as it entails power losses reduction which is a key desirable factor in WPT chargers. Secondly after introduction, its operating principle during grid to vehicle (G2V) and vehicle to grid (V2G) power transfer modes is presented. Thirdly, an overall mathematical model governing all the operating modes of the converter is elaborated. Fourthly, a nonlinear observer-based Kalman Like technique is designed for estimating the involved state variables and also the converter's parameters. Finally, it was shown, using simulation results, that the estimated state variables match well the measured ones which verify the accuracy of the proposed observer. It is worth noting that the designed observer is a cost-effective solution since it requires only one measurement which is chosen as the grid current.

Design of a GaN Totem-Pole PFC Converter Using DC-Link Voltage Control Strategy for Data Center Applications

In today’s power industry, a compact and highly efficient power converter is the main component for server power applications. The objective of this paper is to propose a totem-pole power factor correction (PFC) converter with DC-link voltage control strategies for data center applications. Gallium Nitride High Electron Mobility Transistors (GaN HEMTs) are also used to increase power density and conversion efficiency without the reverse recovery loss. With the derived equations of the converter loss, the dc-bus voltage control strategy is proposed to improve the conversion efficiency. Furthermore, this paper proposes the hold-up time extension method to increase the DC bus voltage under heavy load conditions. The reduction of the DC link capacitor capacitance is achievable, and the power factor can be improved in a wide range. A 2.9-kW GaN totem-pole PFC prototype is developed and fabricated to verify this paper’s theoretical analysis. As demonstrated in the prototype’s experimental results, the tested peak efficiency is 98.5% and the tested total harmonic distortion (THD) is less than 3%.

Peak and Valley Current Control for Cuk PFC Converter to Reduce Capacitance

Traditional power factor correction (PFC) converters usually employ a large electrolytic capacitor to ensure a stiff output voltage. However, the electrolytic capacitor is not expected in terms of the reliability and the size of the system. This article proposes a peak and valley current control for Cuk PFC converter to remove the bulky electrolytic capacitor. The proposed control is realized by a combination of analog and digital circuits. The analog circuits are used to accomplish the real-time comparison between the actual currents and their reference values. And the digital circuits are employed to deal with simple logical judgement. Different from the existing full digital control technique, which needs a high-quality digital signal processor (DSP) to process complex arithmetic operation, the proposed control concept even can only require a low performance microcontroller unit. Besides, the control delay is avoided. This article first analyzes the operation stages of the Cuk PFC converter. Then, design considerations of main circuit and control circuit are introduced. Finally, the experimental results from 200W Cuk PFC converter are presented to verify the effectiveness of the proposed control.

A Statistical Feature-Based Anomaly Detection Method for PFC Using Canonical Correlation Analysis

Power factor correction (PFC) converters are widely used in power systems. The anomalous state of a PFC converter can develop into the complete or partial loss of the electric system. In some industrial applications, such as wind power generation and photovoltaic power generation, there is a fluctuation in the input voltage of the PFC converter, which brings great obstacles in anomaly detection. In order to effectively recognize an anomalous state, especially when the input voltage is unstable, a statistical feature-based anomaly detection method using canonical correlation analysis (CCA) is proposed. Firstly, statistical features are used to enhance the difference between the normal state and anomalous state. Then, the proposed anomaly detection method focuses on the correlation between the input voltage and the output voltage, so even if there is a fluctuation in the input voltage, the anomaly states can be detected precisely. The experimental results show the effectiveness of the method.

Review of the CM noise mitigation methods for the single-phase power factor correction converter

Review of the CM noise mitigation methods for the single-phase power factor correction converter