Terms Of Power Factor Research Articles

A Comparison of Digital Constant On-Time and Variable On-Time Control in Buck/Buck-Boost PFC Converter

This study compares two frequently used control strategies in the context of completely digitally controlled critical conduction mode (CRM) buck/buck-boost converters, namely constant on-time (COT) and variable on-time (VOT). The aim of this research is to compare and assess the performance of different control systems in terms of power factor (PF) and total harmonic distortion (THD). The COT control technique employs a fixed on-time period for each switching cycle, resulting in a predictable and straightforward control scheme. On the other hand, VOT control dynamically adapts the on-time period based on the input and output voltage conditions, offering potential advantages in terms of load regulation and stability. The analysis results provide valuable insights into the strengths and limitations of each control technique. Additionally, the dynamic behavior of the converters under various operating conditions is investigated, shedding light on the stability and robustness aspects of each control scheme. The study is conducted using a fully digital setup and evaluated in Matlab/Simulink environment. The findings show that VOT control outperforms COT in terms of THD and PF under steady-state conditions. These findings offer valuable guidance for selecting the appropriate control technique for PFC converters, depending on specific requirements of their applications.

Performance Analysis of 9, 11, 13, and 15 – Level Back-to-Back Connected Modular Multilevel Converters fed Doubly Fed Induction Machine

In this paper, back-to-back Modular Multilevel Converters are used to feed the Doubly Fed Induction Machine. The MMC with 9, 11, 13, and 15 – Level output voltages are generated and fed to the DFIM and the performance of the DFIM is analyzed, when the machine is working as Doubly Fed Induction Generator (DFIG) and when the machine is working as Doubly Fed Induction Motor. The performance of the DFIG is analyzed in terms of power factor at Grid Side Converter (GSC) for different levels of operation of MMC. The results show that the power factor is maintained near to unity power factor at grid side. The performance of the Doubly Fed Induction Motor is analyzed in terms of variation of the load torque being applied to motor. The results show that there is clear variation of the speed for two different load conditions. The work is carried out by using Typhoon HIL Real-Time Simulation platform, i.e., both Software and Hardware.

Power quality improvement for 20 MW PEM water electrolysis system

Hydrogen is an important alternative as a clean fuel for industry and power-to-gas energy storage. The water electrolysis process is a promising technology in green hydrogen production where proton exchange membrane (PEM) technology has been keenly interested. Industrial large-scale PEM electrolyzers need a high current power supply. When connected to an alternating current (AC) source, high current power rectifiers are used to convert AC to DC. Currently, the most commonly used topology in large-scale PEM electrolysis systems is the thyristor-based topology due to its technology maturity and low cost. However, this topology presents several drawbacks in terms of power quality and consequently leads to higher stack-specific energy consumption (SEC) and additional losses. In the present research, we demonstrate the potential power quality improvement for a 20 MW PEM water electrolysis system by rectifier topology upgrade. Rather than traditional thyristor-based topology, a 3-phase interleaved buck rectifier topology is proposed. The new topology presents advantages on both AC and DC sides via a validated simulation model, which is built using MATLAB/Simulink and then validated with experimental data from an industrial 20 MW PEM water electrolyzer at Air Liquide's Bécancour plant. Results show a great improvement in terms of power factor, Total Harmonic Distortion (THD), and DC-current ripple reducing the total losses and the SEC of the PEM stack, especially under partial load. Towards a higher power efficiency, the proposed rectifier topology may be considered in the construction of future large-scale PEM systems.

Design and Fabrication of an Isolated Two-Stage AC–DC Power Supply with a 99.50% PF and ZVS for High-Power Density Industrial Applications

Power quality in terms of power factor (PF), efficiency, and total harmonic distortions (THDs) is an important consideration in power supplies designed for 5G telecom servers. This paper presents a different magnetic parts design and manufacturing techniques of power supplies, design and selection criteria of switching elements as well as the optimal design of control loops based on small-signal stability modeling and an appropriate stability criterion. The designed telecom power supply consists of the power factor correction (PFC) stage to increase the input power factor and the isolated phase-shift pulse width modulation (PWM) zero-voltage switching (ZVS) DC–DC converter stage to regulate the supply voltage to the specified load value while maintaining a high conversion efficiency. A two-stage outdoor telecom power supply with a power rating of 2 kW was designed and fabricated on a printed circuit board (PCB). The distinct two-stage power components of the power supply were subjected to loss analysis. Furthermore, PSIM simulation and experiments were used to demonstrate the total harmonic distortions (THDs), voltage ripples, power efficiency, and PF performance of the supply current for the proposed power supply under various operating situations. This work produces an industrial high power density power supply with a high PF, low THD and high conversion efficiency which is suitable for telecom power server applications.

Coordinated control of DSTATCOM with switchable capacitor bank in a secondary radial distribution system for power factor improvement

This paper exhibits the coordinated control of 30 kVAr Distribution STATic synchronous COMpensator (DSTATCOM) with 125 kVAr Switchable Capacitor Banks for compensation of reactive power in a 750 kVA secondary radial distribution system. With the control of reactive power in a radial distribution system, the power factor can be improved near to unity. The selected radial distribution system mainly feeding power to vital loads of an Educational Institution. In this paper, the study of 750 kVA secondary radial distribution system is analyzed in terms of electrical power system of institute, power consumption pattern and tariff related issues. Some conclusions to improve the system performance in terms of power factor and reduction in tariff were drawn. The coordinated control of switchable capacitor bank and DSTATCOM performance depends on the calculation of the reference source currents that generates the gating pulses of the voltage source converter-based DSTATCOM. For this purpose, the control strategy adopted is Real and Reactive power (PQ) control, Synchronous Reference Frame theory, Back Propagation Control algorithm and Adaptive Linear (ADALINE) control is implemented in this system using MATLAB/SIMULINK software. Generation of the PWM pulses triggers the IGBT of the VSI-based DSTATCOM. This is achieved using DSP TMS 320 F 2812, a 32-bit processor that is programmed with CCS V3.3 and C2000 embedded code generation tool using MATLAB/Simulink, and the same is being executed with code composer studio V 6.0.1. The performance of the selected secondary radial distribution system is analyzed experimentally in a hardware prototype to evaluate the effect of DSTATCOM and switchable capacitor bank.

Impact of photovoltaic grid-tied systems on national grid power factor in Palestine

<abstract> <p>Residential photovoltaic systems are a cost-effective solution for Palestinians to reduce their power costs while improving the environment. Despite their numerous advantages, these systems have several negative effects on the entire electric grid infrastructure. Increased penetration of photovoltaic (PV) systems, for example, may result in a fall in the power factor of the distribution grid. When the power factor is low, heat production and switch failures are more likely to occur. Even though comparable research has been published in the past, this is the first time PV systems have been investigated in terms of power factors in Palestine. This research serves as a resource for people interested in how photovoltaics (PVs) impact their systems' total power factor. To begin, the researchers in this study presented an intuitive power factor selection criterion for photovoltaic (PV) systems. Second, the article included a proposal for an auxiliary power factor controller. This article's conclusions may be utilized by municipalities, grid operators, and legislators to aid them in planning, forecasting, and accommodating new PV systems in their grids in terms of total power factor, as demonstrated by the results of this study. However, even though the data in this study is drawn from Palestinian sources, it may be applied to other regions because the data sets used are worldwide in scope.</p> </abstract>

AI Based system Performance Enhancement Fed by BESS with grid Integration

The electric lattice should have the generation ability to satisfy the needs of power consumers. The point of this examination is to research how the force limit and situation of a battery energy stockpiling framework influence the force quality in a frail force lattice with variable loads. The system performance is expected to be improved by designing a compensator in line with the variable loads and whose control system is guided by artificial intelligence (AI) based techniques and algorithms. The grid performance enhancement shall be done in terms of power factor and active power improvement with stable outputs. The analysis has been focused on the low tension line (local loads) after the grid connection where the system is also driving the electric drive and reactive loads at the high tension line. The effect has been studied on of 400V phase to phase load line. The infers that the BESS framework is made effective for driving the heaps having improved dynamic force yield at its terminal. The voltage accessible has been made less mutilated to 3.07% and the THD level in current yield has also come down to 2.93%.

Comparative review of disk type and unconventional transverse flux machines: performance analysis

Transverse flux machines (TFM) can be designed with high pole numbers, so they are very useful in directdrive systems with high torque density. Although many TFM models have been proposed to date, no detailed classification and comparison has been made before. Conventional TFMs have a high power and torque density, but low power factors and high cogging torques have prevented them from being widely used. However, especially with the new disk type TFMs proposed in recent years and the methods developed, these drawbacks have been reduced. In this paper, the TFMs proposed in recent years have been classified and their performances in terms of power factor, cogging torque, torque density, and efficiency have been examined. According to the results of this review, the performances of the new generation TFMs are competitive. Especially double-sided disk type TFMs are seen as an important topology with their high magnet utilization and flexibility in design.

Thermoelectric Energy Harvesting from Single-Walled Carbon Nanotube Alkali-Activated Nanocomposites Produced from Industrial Waste Materials.

A waste-originated one-part alkali-activated nanocomposite is introduced herein as a novel thermoelectric material. For this purpose, single-walled carbon nanotubes (SWCNTs) were utilized as nanoinclusions to create an electrically conductive network within the investigated alkali-activated construction material. Thermoelectric and microstructure characteristics of SWCNT-alkali-activated nanocomposites were assessed after 28 days. Nanocomposites with 1.0 wt.% SWCNTs exhibited a multifunctional behavior, a combination of structural load-bearing, electrical conductivity, and thermoelectric response. These nanocomposites (1.0 wt.%) achieved the highest thermoelectric performance in terms of power factor (PF), compared to the lower SWCNTs’ incorporations, namely 0.1 and 0.5 wt.%. The measured electrical conductivity (σ) and Seebeck coefficient (S) were 1660 S·m−1 and 15.8 µV·K−1, respectively, which led to a power factor of 0.414 μW·m−1·K−2. Consequently, they have been utilized as the building block of a thermoelectric generator (TEG) device, which demonstrated a maximum power output (Pout) of 0.695 µW, with a power density (PD) of 372 nW·m−2, upon exposure to a temperature gradient of 60 K. The presented SWCNT-alkali-activated nanocomposites could establish the pathway towards waste thermal energy harvesting and future sustainable civil engineering structures.

Dynamic ambient HetNet for hybrid data communication and transmission in IoT networks

In this manuscript, the Dynamic ambient HetNet for hybrid data communication and transmission in IoT networks is proposed. The lodging of colossal devices and their linkages in and beyond 5th generations (5G) has obtained a great deal of studies from academia and business. In the macro hotspot field, the uses of emerging Device-to-device (D2D), Light Fidelity (LiFi), Unmanned Aerial Vehicle (UAV) and Drones can’t simply cross the paths of transient network support prerequisites. Environmental interaction is an optional way to efficiently reduce this problem through the provision of urgent connections among limited-power servers. In addition, the effectiveness of transmission relies on parameters and range from factors like signal form, Radio frequency (RF) origin and the atmosphere, i.e. indoor or outdoor. The proposed Dynamic Ambient HetNet architecture both indoors and outdoors, where a source node is connected to the target node via radio frequency-powered relays to increases network coverage and enhance the efficiency of mobile devices either within the macro hot spot region or during the disaster area like hurricanes. This method can exploit the Wireless interweave down-convert up-convert protocol with energy-collection capacity for simultaneous information and power transfer. During the propagation from the origin node, radio frequency-powered relay can monitor hybrid data broadcasts, owing to its full duplex features. The efficiency assessment in MATLAB demonstrates the traditional models for radio frequency relay in hybrid communication. Moreover, we endow with the challenges in relation to the ambient backscatter communication network. The experimental results proved that the proposed method is better in terms of power factor and throughput gives 90%, ratio for the uplink and down link in terms of cell load has obtained 75%, and packet throughput in terms of speed has the value of 93%.

Enhancement of cascaded multi-level VSC STATCOM performance using ANN in the presence of faults

A system can be disturbed in terms of stability when connected to a number of loads at the distribution ends or when subjected to faults. To reverse such systems to a stable state, FACTS devices such as static synchronous compensator (STATCOM) are used. In this paper, a cascaded multi-level voltage source converter (VSC) STATCOM was designed and implemented with a novel space vector pulse width modulation (SVPWM) scheme. Artificial neural network (ANN) controller was used instead of instead of Proportional-Integral (PI) controller in the proposed scheme to improve the response time (RT) and performance of STATCOM in terms of power factor (PF) and voltage amplitude during periods of voltage sag. During the implementation, two fault sources (single-line-to-ground (SLG) and line-to- line (LL) faults) were used to create voltage sag. STATCOM was subjected to performance evaluation in the presence of these disturbances via MATLAB simulation in IEEE 3-bus system. The outcome of the simulation studies showed the ANN controller to perform better than PI as it was able to rapidly recover voltage value (<1 cycle) with unity PF.

Design and Selection of Power Circuit and Control Parameters for DSTATCOM

This paper presents the proper design and selection of power circuit and control parameters of VSI based DSTATCOM for compensation of reactive power in a radial distribution systems, feeding power to crucial loads of an industrial, commercial and residential systems. The study of radial distribution system is analyzed in terms of electrical power system of institute, power consumption pattern and tariff related issues. Some conclusions were made to improve the system performance in terms of power factor and reduction in tariff. The DSTATCOM performance depends on the calculation of the reference source currents that generate the gating pulses of the VSI.

Input switched closed-loop single phase ĈUK AC to DC converter with improved power quality

<span lang="EN-US">A new closed loop AC to DC ĈUK converter is presented in this paper. The conventional ĈUK AC to DC converter has no feedback circuit. Thereby, the output voltage of the converter changes while changing the load. The proposed closed loop converter can regulate voltage with the variation of load over a wide range. Moreover, the power factor and Total Harmonic Distortion (THD) of the supply side current found quite satisfactory from this closed loop ĈUK converter. The converter operates in four steps with a different combination of voltage polarities and switching states. The feedback path consists of a voltage control loop and a current control loop. The closed loop ĈUK converter in this study is compared with the open loop version. Additionally, the comparison is made with the conventional converter of the same topology. The effectiveness in terms of power factor and THD of the proposed converter is verified using simulation results.</span>

Conjugated Polymer Blends for Organic Thermoelectrics

AbstractA major attraction of organic conjugated semiconductors is that materials with new, emergent functionality can be designed and made by simple blending, as is extensively used in, e.g., bulk heterojunction organic solar cells. Herein doped blends based on organic semiconductors (OSCs) for thermoelectric applications are critically reviewed. Several experimental strategies to improve thermoelectric performance, measured in terms of power factor (PF) or figure‐of‐merit ZT, have been demonstrated in recent literature. Specifically, density‐of‐states design in blends of two OSCs can be used to obtain electronic Seebeck coefficients up to ≈2000 µV K−1. Alternatively, blending with (high‐dielectric constant) insulating polymers can improve doping efficiency and thereby conductivity, as well as induce more favorable morphologies that improve conductivity while hardly affecting thermopower. In the PEDOT:polystyrene‐sulfonate (PEDOT:PSS) blend system, processing schemes to either improve conductivity via morphology or via (partial) removal of the electronically isolating PSS, or both, have been demonstrated. Although a range of experiments have at least quasi‐quantitatively been explained by analytical or numerical models, a comprehensive model for organic thermoelectrics is lacking so far.

Integrated Stage Dual Buck -Boost Fly Back Converter LED Driver

This paper presents a novel integrated stage converter configuration being applied as a LED driver. In order to prove the betterment of the topology, its performance is compared in terms of power factor, output voltage and settling time with three other randomly selected topologies: A single switch AC-DC LED driver based on boost fly back power factor correction converter with a lossless snubber, Integrated stage double buck- boost converter LED driver, Integrated stage LED driver based on buck-boost and class E resonant converter. As a consequence of relevant simulations of all the chosen topologies with resistance as the load, it is understood that Integrated buck boost fly back converter based LED Driver is beneficial as a compromise between all circuits. Hence the same is translated into an experimental prototype which is capable of a yield rated 45 V, 84.6 W and 1.88 A for a LED string load.

Facile Optimization of Thermoelectric Properties in PEDOT:PSS Thin Films through Acido-Base and Redox Dedoping Using Readily Available Salts

Poly(ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has emerged as a promising candidate for renewable, clean, and reliable energy generation from waste heat due to its thermoelectric properties. This largely stems from its tunable and potentially high electrical conductivity. However, the resulting small Seebeck coefficients diminish the thermoelectric efficiency. We employ dedoping methods making use of acido-base and redox dedoping in order to optimize its properties. In order to tune the charge carrier concentration in PEDOT:PSS thin films, aqueous solutions of readily available inorganic salts, namely, sodium hydrogen carbonate (NaHCO3), sodium sulfite (Na2SO3), and sodium borohydride (NaBH4), are introduced in different concentrations into PEDOT:PSS solutions before thin film fabrication. This yields optimized thermoelectric properties in terms of power factors up to 100 μW/K2 m. Changes in the electronic structure are characterized using UV–vis spectroscopy and XPS, while changes in th...

Analysis and design of single phase power factor correction with DC–DC SEPIC Converter for fast dynamic response using genetic algorithm optimised PI controller

This study presents the analysis and design of a single phase power factor correction (PFC) scheme using a DC–DC single ended primary inductance converter with genetic algorithm (GA)-tuned proportional integral (PI) controllers. A systematic off-line design approach using GA for optimising the parameters of the PI controller is proposed and the performance is compared with the conventional Z–N tuned PI controller. The steady-state and transient responses of the converter subjected to a change in the load, set point and line variations are investigated. The performance analysis of the proposed converter in continuous conduction mode is made for the above-mentioned methods using Matlab/Simulink-based simulation studies and experimental set up. Results reveal that the GA-tuned PI controller yields superior performance to the Z–N tuned PI controller in terms of power factor, percentage total harmonic distortion, regulated output voltage for the variations in line, load and efficient tracking of output voltage for a change in the reference voltage.

A Novel RRR-SVPWM-Based Speed Controlling Mechanism for Brushless DC Motor

Brushless DC motor (BLDCM) is a synchronous motor that contains a permanent magnet on the rotor and armature windings on the stator. It consists of the following characteristics, such as compact form, high efficient, silent operations and low maintenance. The existing BLDCM control systems have some drawbacks such as, it needs higher requirements for control algorithms, it uses more complicated electronics, it holds high noise and the initial rotor movement is not predictable. In order to overcome these issues, a new control mechanism, namely, carrier frequency rate, duty cycle ratio and pulse position range-space vector pulse width modulation (RRR-SVPWM) technique is proposed in this paper to control the speed of BLDCM. Initially, the unregulated AC from the wind turbine system is given to the input of six-legs insulated gate bipolar transistor (IGBT) circuit for converting the unregulated AC to regulated DC. Here, the pulse generator is used to generate the pulses based on certain parameters, such as input three-phase voltage, phase current and DC voltage. Hence, the proposed RRR-SVPWM technique is applied to reduce the noise and maintain a harmonics in a controlled level by placing a high-speed switches in a circuit. Finally, the speed of the BLDCM is increased and controlled by giving an output regulated AC to the motor. The experimental results evaluate the performance of the proposed system in terms of power factor (PF), displacement PF (DPF) and total harmonic distortion (THD).

Improved Power Quality Bridgeless Converter-Based SMPS for Arc Welding

This paper proposes a power-factor-corrected bridgeless (BL) switched-mode power supply (SMPS) for welding applications that possesses output voltage control and current limiting feature even during extreme overloading conditions at the output terminals. Eliminating an input diode bridge rectifier minimizes conduction losses and improves thermal utilization of semiconductor devices. The front-end of the proposed SMPS consists of a BL boost converter operating in a continuous conduction mode to attain unity power factor, while at the rear end a pulse width modulation isolated full bridge dc–dc converter is used to regulate the output voltage. The design and implementation of this BL arc welding power supply (AWPS) is presented showing its fast dynamic response to supply voltage and load variations. The performance of the proposed AWPS is examined in terms of power factor, total harmonic distortion of the supply current, efficiency, and output current limit over a wide range of line/load variations. Test results confirm the effectiveness of the proposed AWPS in maintaining an impeccable power quality at utility interface apart from achieving an excellent output voltage regulation and current limiting capability.

A Comparative Performance Investigation of Single-Stage Dimmable Electronic Ballasts for Electrodeless Fluorescent Lamp Applications

This paper presents a comparative investigation, design and development issues about six different single-stage topologies, applied as electronic ballasts, for electrodeless fluorescent lamps. The ballast is intended to feed a 100 W lamp at 250 kHz, with dimming feature. The proposed topologies use different converters for the power factor correction (PFC) stage: Buck-Boost, SEPIC, Zeta, Cúk, Flyback, and Boost. All of them operate in discontinuous conduction mode. A resonant half-bridge inverter is used as lamp power control (PC) stage. The integration of both stages (PFC and PC) is proposed in this paper. In this way, it is possible to reduce the number of active switches, as well as simplify the required driving and control circuitry. Experimental results demonstrate the feasibility of the proposed dimming technique that achieved around 56% lamp power dimming, from 100 W down to 44 W. The implemented topologies attained high average power factor (>0.98), and low line current average total harmonic distortion (<;15.3%). A comparison among all the proposed topologies in terms of power factor, harmonic distortion, efficiency and number of components is presented. Finally, a comparison between an integrated and a nonintegrated SEPIC half-bridge converter is also performed.