Period-doubling bifurcation in two-stage power factor correction converters using the method of incremental harmonic balance and Floquet theory

In this paper, period-doubling bifurcation in a two-stage power factor correction converter is analyzed by using the method of incremental harmonic balance （IHB） and Floquet theory. A two-stage power factor correction converter typically employs a cascade configuration of a pre-regulator boost power factor correction converter with average current mode control to achieve a near unity power factor and a tightly regulated post-regulator DC-DC Buck converter with voltage feedback control to regulate the output voltage. Based on the assumption that the tightly regulated postregulator DC-DC Buck converter is represented as a constant power sink and some other assumptions, the simplified model of the two-stage power factor correction converter is derived and its approximate periodic solution is calculated by the method of IHB. And then, the stability of the system is investigated by using Floquet theory and the stable boundaries are presented on the selected parameter spaces. Finally, some experimental results are given to confirm the effectiveness of the theoretical analysis.

Performance Evaluation of a Permanent Magnet Electric-Drive- Reconfigured Onboard Charger with Active Power Factor Correction

This paper presents a comprehensive charging operation for an electric-drive-reconfigured onboard charger(EDROC)with active power factor correction(APFC).The charging topology exclusively utilizes the three-phase permanent magnet synchronous motor(PMSM)propulsion system as a three-channel boost-type converter in which only a contactor and a small diode bridge are added.First,the operation scenario of the EDROC is introduced.Second,the relationship between electromagnetic torque and rotor position is investigated.Third,the current ripple cancellation of the EDROC is discussed in detail.Moreover,to implement the single-phase APFC along with charging voltage/current regulation of propulsion battery,control strategies including current balancing and synchronous/interleaving PWM strategies are incorporated.Finally,200W proof-of-concept prototype-based tests are conducted under different operation scenarios.

New DCM Operated Single Phase Bridgeless Cuk Derived Converters for Power Factor Correction

This paper presents a power factor corrected (PFC) new bridgeless (BL) Cuk Topologies for low power applications. A BL configuration of Cuk converter is proposed which eliminates the usage of diode bridge rectifier at the front end of the PFC converter, thus reducing the switching and conduction losses coupled with it. This new BL Cuk converter has two semiconductors switches. The current flow during each switching cycle interval of the converter reduces the conduction losses compared to the conventional Cuk PFC converter. It also reduces the input current ripple and Electromagnetic Interference (EMI). The inrush current during the starting period is limited and the input, output currents of the converter are continuous with minimum current ripple. Hence it is preferred mostly compared to other PFC circuits. The proposed topology works in the Discontinuous Conduction Mode (DCM) with simple control circuitry to achieve almost a unity power factor with less distortion in the input AC current. The switching of the power switches is done under zero current. The proposed PFC topologies are theoretically investigated and performance comparisons are made with the conventional rectifiers. The proposed PFC converter is simulated in MATLAB/SIMULINK with Fuzzy Logic Controller (FLC) and results are demonstrated to evaluate the effectiveness of the controller.

A new high-performance AC/DC power factor correction switching converter based on one-cycle control technology and active floating-charge technology

A new family of converters,high-performance AC/DC power factor correction(PFC) switching converters with one-cycle control technology and active floating-charge technology,was derived and experimentally verified.The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed.Its operating prniciples and control methods were expounded.Based on these,a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein.The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.

Power Factor Correction Rectifier with a Variable Frequency Voltage Source in Vehicular Application

This paper presents a PFCVF (Power Factor Correction) rectifier that uses a variable frequency source for alternators for electric and hybrid vehicles application. In such application, the frequency of the signal in the alternator changes according to the vehicle speed, more over the loading effect on the alternator introduces harmonic currents and increases the alternator apparent power requirements. To overcome these problems and aiming more stability and better design of the alternator, a new third harmonic injection technique is proposed. This technique allows to preserve a good THD (Total Harmonic Distortion) of the input source at any frequency and to decrease losses in semiconductors switches, thereby allowing more stability and reducing the apparent power requirements. A comparative study between the standard and the new technique is made and highlights the effectiveness of the new design. A detailed analysis of the proposed topology is presented and simulations as well as experimental results are shown.

Single-stage active clamp power factor correction AC/DC converter

A simple single-stage AC/DC converter circuit with active clamp is presented. The operation theory and state are analyzed. The experimental results show that the voltage across main switch can be clamped to a certain value,and zero voltage switching (ZVS) can be achieved. The voltage stress and switching loss are both decreased. In range of the whole load,power factors can be always more than 97%,and the highest efficiency can reach 88%.

Comparison and Evaluation of Power Factor Correction Topologies for Industrial Applications

Power factor correction is a major issue for all industries, since a typical industrial load is causing current delays, as well as higher order current harmonics. Power factor correction is often mandatory from the power companies, usually by charging the reactive power that the company consumes. Many solutions for power factor correction have been presented in the bibliography;in this paper, the most significant power factor correction topologies will be reviewed and simulated with SABER RD software. Finally, a prototype design will be presented, based on a mass/cost analysis of the selected topologies and with an aim to manufacture 10 kW modules. The main outcome of this work is the feasibility for an SME to manufacture a competitive modular power factor correction product for industrial applications.

A RESEARCH TO HIGH-PERFORMANCE MULTI-LEVEL SINGLE-PHASE AC/DC POWER FACTOR CORRECT SWITCHING CONVERTER

This letter studies and analyzes the working features of main circuit of tri-level boost Power Factor Correct(PFC) converter and the advantages of tri-level switch converter in aspects of bearing high-voltage of power components,overall system loss and magnetic component selection based upon the single-level boost PFC switch converter.Besides,relying on the application of mi-croprocessor in power converter technology and DSP(Digital Signal Processing) chip's strong cal-culating capacity,the letter presents the adoption of modified scheme of tri-level boost PFC converter under the control of predictive control algorithm.Moreover,the operating principle and control method are specified,the results of circuit test and analysis are provided and the advantages of pre-dictive control technology-based multi-level boost PFC converter is verified.

An Improved Non-isolated LED Converter with Power Factor Correction and Average Current Mode Control

A new type of high power LED drivers is proposed by adopting an improved two-stages non-isolated configuration. In order to improve power factor and achieve accurate average current control under universal input voltages ranging from 100 Vrms to 240 Vrms, the power factor correction and average current mode control methods operating in continuous current conduction mode are designed and implemented. With the LUMILEDS emitter type LEDs, a laboratory prototype is built and measured. And from the measured results, it could be concluded that the proposed driver has many better performances such as high power factor, low current harmonic, accurate average current control and switch protection.

Phase Angle Control Based Three-phase DVR with Power Factor Correction at Point of Common Coupling

This paper investigates the ability of correcting the power factor at the point of common coupling(PCC)of the source side using dynamic voltage restorer(DVR).By applying the phase angle control(PAC)method,the DVR compensating voltage will be injected with a specific phase angle and magnitude in series with the transmission line,which leads to a power factor angle shift of the resultant load voltage.As a result,the source voltage is always in phase with the source current under different load conditions,which means that the power factor correction is achieved at the PCC of the source side.A laboratorial prototype of the DVR is utilized to verify the proposed control algorithm.The experimental results validate that an approximate unity power factor can be maintained at the source side.

The Security Correction of Large Consumers Long-Term Direct Power Trading Based on DC Power Transfer Distribution Factor

The experiments of large consumers direct power trading is conducting in china nationwide, and it’s important to the reform of electricity market. To compensated efficiencies in security correction of large consumers direct power trading, a novel security correction method based on DC power transfer distribution factor was proposed. Using the presented method to comply security correction, all the transactions that satisfy the specific requirements of maximizing social welfare are able to enter security correction process, and when the power of transmission line is out of limit, this method avoid the transaction which causes this problem is abandoned directly by introducing supplement transactions. The simulation has shown that the proposed security correction method of large consumers direct power trading based on DC power transfer distribution factor is effective.

A novel arc welding inverter with unit power factor based on DSP control

A novel inverter power source is developed characterized with constant output current and unit power factor input. Digital signal processor （ DSP ） is used to realize power factor correction and control of back-stage inverter bridge of the arc welding inverter. The fore-stage adopts double closed loop proportion and integration （PI） rectifier technique and the back- stage adopts digital pulse width modulation （ PWM） technique. Simulated waves can be obtained in Matlab/Simulink and validated by experiments. Experiments of the prototype showed that the total harmonic distortion （THD） can be controlled within 10% and the power factor is approximate to 1.

Isolated single stage high power factor AC/DC converter

The problem of harmonic pollution has brought wide attention with the increase of power customers. The adoption of the technology of active power factor correction (APFC) with advanced high frequency power converter is a more efficient solution to the problem of harmonic pollution. A single stage isolated high power factor AC/DC converter, which features wide range DC output, high power factor, lower harmonic pollution in input current, and phase shift PWM full bridge circuit can achieve soft switching. The principle of the circuit topology and the reasons of voltage surges across the power switch are analyzed. Experiment results illustrate that this circuit has the advantages of high power factor and lower harmonic distortion.

Intelligent power factor compensation equipment of three phase low voltage loads

An intelligent power factor correction scheme is presented for three phase low power factor loads. This new scheme is able to perform individual phase sensing of parameters by monitoring at all times to sense a change in system parameters and affects individual phase correction by applying the exact amount of reactive components needed for each phase, and can also reduce negative sequence current caused by the load to improve system balance. An optimization criterion is used for the proper calculation of reactive power steps in a power compensation installation of capacitor banks. The criterion is enabled by sampling measurements performed on the electrical plant examined within specific interval of time.

Single-phase Three-level Rectifier with High Power Factor

Based on a neutral point diode clamped eight-switch configuration, a general mathematical model of single phase bi-directional three-level (TL) rectifiers is built by proposing two equivalent TL arms for topology derivation. A series of TL rectifiers are derived by using double TL and multi TL methods, and their characteristics are compared at the same time. A novel seven-switch double TL rectifier is constructed, and its operational principle and control algorithm are illustrated as well. Lastly, its waveform and harmonic spectrum are compared to those of multi TL rectifiers, and the adopted rectifier gains better performance and unit PF.

A High Power Factor Rectifier Based on Buck Converter Operating in Discontinuous Inductor Current Mode

By adding a suitable LC filter to the input of a Buck converter, a high-power-factor buck converter is proposed. The converter can operate in the discontinuous-output-current mode operation. A Buck converter in this operation mode features simple control as the constant duty cycle PWM used. The operation condition of the converter is studied. The validity of analysis is verified by Simulation and Experimental results.

一类三电平伪图腾柱无桥PFC变换器

针对传统二极管钳位型三电平整流器在单相电源前级功率校正(power factor correction,PFC)电路应用场景下全控开关器件数量多的问题,该文基于3种传统无桥PFC电路进行三电平电路拓扑设计,提出一类三电平伪图腾柱PFC电路(single-phase three-level pseudo totem-pole PFC circuit,STPT-PFC),该类三电平PFC具有双电感支路桥臂,两者相互配合工作为输入电流提供路径,在正负半周两电感支路桥臂工作于不同模态可有效降低分别流过两电感的电流;基于该类PFC的一个代表性电路,从工作电流路径过程、关键波形和调制脉冲分配等方面对其进行工作原理分析,并对其它电路进行电路特性总结,推导桥臂对地电压电平特性与开关脉冲分配的数学关系式。另外,该类STPT-PFC共有5种结构,结合该类STPT-PFC结构特点,提出统一区间判断条件的双层载波调制技术,该类STPT-PFC具有相同开关器件不同拓扑结构可采用同一调制方案的特点,便于该类调制技术移植。最后,基于STPT-PFC-I电路设计1台额定功率1 kW、直流输出电压400 V的实验样机,从稳态及动态两方面进行实验分析,实验结果验证所提出一类三电平伪图腾柱PFC电路的可行性和三电平统一双层调制方法的有效性。

基于MATLAB的功率因数可控的AC-DC变换电路研究

为解决谐波信号过多可能会导致电网的传输效率降低的问题,对功率因数可控的AC-DC变换电路进行了研究.基于Boost型单级有源功率因数校正变换器,控制电路中采用了外电压环和内电流环双闭环控制系统,利用滞环电流控制提高交流端功率因数,电压环稳定输出电压.采取小信号分析法,建立小信号模型并设计了控制电路.通过MATLAB仿真实验可得,双环控制的功率因数校正电路能够实现高功率因数,同时能够稳定输出电压.