Power Factor Correction Control Research Articles

A High Performance Interleaved Bridgeless PFC for Nano-grid Systems

A high performance interleaved bridgeless boost power factor correction (PFC) rectifier operating under the critical current conduction mode (CrM) is proposed in this paper to improve the efficiency and system performance of various applications, such as nano-grid systems. By combining the interleaved technique with the bridgeless topology, the circuit contains two independent branches without rectifier diodes. The branches operate in interleaved mode for each respective half-line period. Moreover, when operating in CrM, all the power switches take on soft-switching, thereby reducing switching losses and raising system efficiency. In addition, the input current flows through a minimum amount of power devices. By employing a commercial PFC controller, an effective control scheme is used for the proposed circuit. The operating principle of the proposed circuit is presented, and the design considerations are also demonstrated. Simulations and experiments have been carried out to evaluate theoretical analysis and feasibility of the proposed circuit.

CUK Converter based Power Factor Correction and speed control of PMBLDC Motor using PI controller

CUK Converter based Power Factor Correction and speed control of PMBLDC Motor using PI controller

Design and research of modular permanent‐magnet DC generator based on magnetic integrated transformer for offshore wind farms

Traditional topologies of all-DC offshore wind farm raised the voltage by making multiple generators connected in series, which would cause problems of additional enforcement insulation and complex power distribution and voltage control when situations of unbalanced wind speed and potential faults were encountered. A modular permanent-magnet DC wind generator topology based on the magnetic integrated transformer (MIT) for the offshore wind farm was proposed in this study. The combination of fractional slot concentrated winding direct-drive permanent-magnet synchronous generator and MIT directly produced high-voltage direct current at the end of a generator, which was of strong fault tolerance. Mathematical models of the generator, power electronic converters, and MIT were established. Both power factor correction control strategies of generator winding currents and voltage stability control strategy of generator inner low-voltage direct current bus were designed. Simulation results demonstrated that the designed generator can achieve smooth transitions during start, variable wind speed and fault processes, and realise the maximum power point tracking, which verify the rationality and feasibility of the proposed topology and strategy, and can provide a useful technical reference for the future all-DC offshore wind farms.

Interleaved Digital Power Factor Correction Based on the Sliding-Mode Approach

This study describes a digitally controlled power factor correction (PFC) system based on two interleaved boost converters operating with pulsewidth modulation (PWM). Both converters are independently controlled by an inner control loop based on a discrete-time sliding-mode (SM) approach that imposes loss-free resistor (LFR) behavior on each cell. The switching surface implements an average current-mode controller so that the power factor (PF) is high. The SM-based digital controller is designed to operate at a constant switching frequency so that the interleaving technique, which is recommended for ac–dc power conversion systems higher than 1 kW, can be readily applied. An outer loop regulates the output voltage by means of a discrete-time proportional–integral (PI) compensator directly obtained from a discrete-time small-signal model of the ideal sliding dynamics. The control law proposed has been validated using numerical simulations and experimental results in a 2-kW prototype.

Improved Single-Stage AC-DC LED-Drive Flyback Converter using the Transformer-Coupled Lossless Snubber

This paper presents an improved single-stage ac-dc LED-drive flyback converter using the transformer-coupled lossless (TCL) snubber. The proposed converter is derived from the integration of a full-bridge diode rectifier and a conventional flyback converter with a simple TCL snubber. The TCL snubber circuit is composed of only two diodes, a capacitor, and a transformer-coupled auxiliary winding. The TCL snubber limits the surge voltage of the switch and regenerates the energy stored in the leakage inductance of the transformer. Also, the switch of the proposed converter is turned on at a minimum voltage using a formed resonant circuit. Thus, the proposed converter achieves high efficiency. The proposed converter utilizes only one general power factor correction (PFC) control IC as its controller and performs both PFC and output power regulation, simultaneously. Therefore, the proposed converter provides a simple structure and an economic implementation and achieves a high power factor without the need for any separate PFC circuit. In this paper, the operational principle of the proposed converter is explained in detail and the design guideline of the proposed converter is briefly shown. Experimental results for a 40-W prototype are shown to validate the performance of the proposed converter.

A Digital Predictive Peak Current Control for Power Factor Correction With Low-Input Current Distortion

A digital predictive peak current control (PPCC) employing the adaptive slope compensation is proposed in this paper. The PPCC precisely predicts the peak current reference with the adaptive slope compensation according to operation regions and load conditions. Thereby, the PPCC can control the peak inductor current, and it significantly reduces the total harmonic distortion compared to that of the conventional digital average current control with duty ratio feed-forward which is widely used. In addition, parts of the PPCC are implemented by utilizing the internal high-resolution ramp generator and comparator of a digital signal processor without external components. The principle and analysis of the PPCC are presented, and the performance and feasibility are verified by experimental results with universal input ( $90\; {\rm V}_{\rm rms} \sim 260\; {\rm V}_{\rm rms}$ ) and $750\; {\rm W}-400\; {\rm V}$ output laboratory prototype.

Regenerative Mode of Charging Capability with Power Factor Correction and Speed Control using Current Source Converter for SRM Drive

Regenerative Mode of Charging Capability with Power Factor Correction and Speed Control using Current Source Converter for SRM Drive

Power quality improvement in a low‐voltage DC ceiling grid powered system

Power quality is an important issue in low-voltage DC (LVDC) grids which drives light-emitting diode lighting system and many other DC loads in residential applications. The requirement of high-quality power to the lighting system necessitates power factor correction (PFC). This study presents a three-phase modular AC-to-DC converter with a simple controller for PFC in LVDC grids under balanced and unbalanced supply voltage conditions. The proposed circuit consists of three separate single-phase boost converter modules. Each module includes a diode rectifier at the front end, followed by a boost converter. The main advantage of this converter is module loss operation where the DC supply given to the lighting system and other DC loads will be continued even in case of failure of one module. The 24 V DC output voltage is regulated using an outer proportional-integral controller and the input current wave shape in each phase is improved by three individual hysteresis controllers. The controller works successfully in tracking the reference voltage changes in order to vary the regulated DC output voltage. The effectiveness of the controller has been verified by the results obtained through MATLAB/SIMULINK. A prototype model has been developed to validate this system and tested using dSPACE1104 processor.

An Interleaved Boost Converter Based PFC Control Strategy for BLDC motor

<p>In this paper, interleaved power factor correction (PFC) boost converter based control strategy for BLDC motor has been Proposed. The converter exhibits the characteristics of voltage doublers for duty greater than 0.5. The switching losses and losses during reverse recovery operation are considerably reduced in this proposed topology. This is due reduction in switching voltages due to voltage doubler mode. The proposed topology has high efficiency compared to conventional counterpart due to slight increase in conduction losses. In this paper, the proposed PFC control Strategy has been applied to a six switch and four switch VSI fed BLDC Motor drive for effective torque ripple minimization. A comparison is also made between the six switch and Four Switch VSI fed PMBLDC Motor drive.</p><br />

Simulation and Practical Analysis on Power Factor Correction Techniques for Welding Applications

The most of the industrial welding applications involving of electronic circuits such as AC-DC, and DC-AC and AC-DC converters. The input power factor of such a system is reduced due to the presence of more harmonics due to the non-linear devices within the converters which leads to creates more adverse effects. There by a need of suitable AC-DC converter with power factor correction technique to condition the supply current. The power factor correction rectifier that requires best current control from i) Peak current control ii) Average current control and iii) Hysteresis current control. This paper presents a comparative analysis from above mentioned power factor correction control topologies. The simulation of these control techniques are carried out using “Plecs” with “MATLAB/SIMULINK”. The simulation results shows that Hysteresis control has low THD, good DC link voltage regulation and better performance than other control techniques. The same control technique is implemented in TMS320F2812 DSP and results are proved.

The Three-Level Sine-Wave Inverter with Power Factor Correction (PFC)

Nowadays, the uninterruptible power supply (UPS) is important in reliability for electric device. The UPS need high quality electricity. Therefore, the simulation of the three-level sine-wave inverter with power factor correction (PFC) is proposed in this paper. Moreover, the circuit’s guidelines of the active PFC controller in the active PFC and the sinusoidal output voltage are also presented. Validity of the proposed the three-level sine-wave inverter with the active PFC is confirmed by simulation. The simulation results show the very small current harmonics, the input power factor most nearly unity and constant output voltage when the suddenly step-load changed.

A Novel Control Algorithm for Conversion ofAC-DC with Improved Power Factor andEfficiency

A Single power-conversion ac–dc converter with high power factor and high efficiency. The proposed converter is derived by integrating a full-bridge diode rectifier and a series-resonant active-clamp dc–dc converter. To obtain a high power factor without a power factor correction circuit, this paper proposes a novel control algorithm. The proposed converter provides single power-conversion by using the novel control algorithm for both power factor correction and output control. Also, the active-clamp circuit clamps the surge voltage of switches and recycles the energy stored in the leakage inductance of the transformer. Moreover, it provides zero-voltage turn-on switching of the switches. Also, a series-resonant circuit of the output-voltage doubler removes the reverse-recovery problem of the output diodes. The proposed converter provides maximum power factor 0.995 and maximum efficiency of 95.1% at the full load.

Decoupling controller design for Z‐source inverter

With the state-space averaging model and the proposed pulse-width modulation switching scheme, the Z-source inverter has been decoupled into a primary boosting stage and a secondary bucking stage. Two double-loop controllers are designed to handle the voltage regulation as well as the current regulation for the DC/DC and DC/AC conversion processes. The proposed scheme demands for two separate duty ratios and novel switching scheme has been derived to realise the combined duty ratios in one switching cycle. Power regulation, harmonics elimination and power factor correction control algorithms have also been derived for the Z-inverter when it is connected to the supply grid. Finally, experimental results are included to demonstrate the effectiveness of the proposed switching and control schemes.

Direct AC–AC grid interface converter for ocean wave energy system

Ocean wave energy is very promising. However, existing systems are using rectifying circuits to convert variable voltage and variable frequency output of electric generator into DC voltage and then use grid-tied inverter to connect to the power grid. Such arrangement will not only reduce the overall efficient but also increase the cost of the system. A direct AC–AC converter is a desirable solution. In this paper, a six-switch AC–AC converter has been proposed as a single phase grid-connected interface. New switching scheme has been derived for the converter such that the virtual input AC–DC conversion and the output DC–AC conversion can be decoupled. State-space averaging model and pulse width modulation scheme have been derived for the converter. As the input and the output operations can be decoupled, two independent controllers have been designed to handle the input AC–DC regulation and the output DC–AC regulation. The proposed scheme demands for two separate duty ratios and novel switching scheme has been derived to realize the combined duty ratios in one switching cycle. Power regulation, harmonics elimination and power factor correction control algorithms have also been derived for the converter when it is connected to the supply grid. Experimental results of a small scale model are included to demonstrate the effectiveness of the proposed switching and control schemes.

Power Factor Correction of Three PhaseRectifier with Interleaved Boost Converter

This paper proposes a method of improving the power factor of a three phase rectifier by using a interleaved boost Converter with Power Factor Correction Controller. When compared to Power Factor Correction and THD minimizations of three phase rectifier with single phase rectifier , Power Factor Correction of three phase rectifier with interleaved boost converter Method is good because here THD is very low . Average Current Control technique has been discussed in this paper. Modelling of the PFC Controller using MATLAB/ Simulink is carried out and the results are verified.

A new PWM approach for digital boost power factor correction controller

A new PWM approach for digital boost power factor correction controller

Average Current Mode Controlled Power Factor Correction Converter

This paper explains the simulation of Boost Power Factor Correction (PFC) Converter. The DC-DC boost converter circuit is analyzed, designed with feedback controller. The closed loop operation of boost converter is made to work in average current mode. Design is such a way that unity power factor is achieved. Design equations are derived and it is modeled in MATLAB. Extensive simulation is carried out and results are compared.

A Novel Single-Phase AC–AC Converter for Circuit Breaker Testing Application

This paper presents a novel single-phase ac-ac converter with power factor correction and output current control for circuit-breaker testing according to the IEC 60898 standard. The important advantages of the proposed circuit are low component count and fast responses for the standard requirement, especially a current step at the beginning of the test. The proposed single-phase ac-ac converter can operate in either buck or boost mode to accommodate the need for a wide range of output current while satisfying the ramping and step current requirements in the standard. The control circuits consist of two parts, dc voltage control of dc-link capacitors and ac output current controls operating simultaneously. The proposed circuit is verified through both computer simulation and hardware experiment. An example of a 50 A circuit breaker testing according to the IEC 60898 is demonstrated in the paper.

English

Harmonic resonance has become a major hurdle for performing power factor compensation in commercial power systems, due to the proliferation of harmonic producing-loads. This paper presents an intelligent controller for power factor compensation that can perform power factor correction under varying demand conditions without exciting harmonic resonance. Practical and robust control algorithms are proposed using micro-controller. The controller relies on common low cost sensing devices and hence can be constructed as a retrofitting device to replace existing power factor correction controllers.

Single Power-Conversion AC--DC Converter With High Power Factor and High Efficiency

This paper proposes a single power-conversion ac-dc converter with high power factor and high efficiency. The proposed converter is derived by integrating a full-bridge diode rectifier and a series-resonant active-clamp dc-dc converter. To obtain a high power factor without a power factor correction circuit, this paper proposes a novel control algorithm. The proposed converter provides single power-conversion by using the novel control algorithm for both power factor correction and output control. Also, the active-clamp circuit clamps the surge voltage of switches and recycles the energy stored in the leakage inductance of the transformer. Moreover, it provides zero-voltage turn-on switching of the switches. Also, a series-resonant circuit of the output-voltage doubler removes the reverse-recovery problem of the output diodes. The proposed converter provides maximum power factor 0.995 and maximum efficiency of 95.1% at the full load. The operation principle of the converter is analyzed and verified. Experimental results for a 400 W ac-dc converter at a constant switching frequency of 50 kHz are obtained to show the performance of the proposed converter.