Power Factor Improvement Research Articles

Enhanced thermoelectric performance of Bi2O2Se by MXene addition via liquid assisted shear exfoliation-restacking process

In this study, Bi2O2Se-x%MXene (Ti3C2Tx) composite samples were prepared using the liquid assisted shear exfoliation-restacking (LASE-R) method, and their thermoelectric properties were thoroughly examined. The findings indicate that the introduction of MXene effectively boosts the carrier concentration and mobility, thereby enhancing the electrical conductivity of the composite. Notably, the absolute Seebeck coefficient exhibited a distinct trend of increasing initially and then declining with an increase in the MXene composite content, leading to an improved Power Factor (PF). Furthermore, the inclusion of MXene suppressed the thermal conductivity of the composites, attributed to enhanced phonon scattering. Consequently, the Bi2O2Se-2 %MXene composite sample achieved a ZTmax value of 0.58 at 773 K, representing a significant enhancement of 1.66 times compared to the pristine sample.

Comprehensive benefit optimization method for photovoltaic inverters participating in distribution network loss reduction by reactive compensation

When a large number of distributed photovoltaic (PV) systems are integrated into the distribution network, power flow becomes bidirectionally fluctuating, resulting in variable line losses. In the scenario of reverse flow, the increase in line loss is particularly significant. The bidirectional reactive power regulation of photovoltaic inverters is an effective approach to reduce losses in the distribution network. However, despite the benefits of reducing losses, reactive power regulation by photovoltaic inverters also incurs additional costs. Therefore, there is a need for research into a comprehensive benefit optimization method for inverters participation in reducing reactive power losses in distribution networks. Firstly, the cost quantification models for the investment, transformation, operation, and lifespan loss of the photovoltaic inverters involved in reactive power loss reduction are established. Secondly, the benefit quantification models for loss reduction and power factor improvement are developed. Thirdly, considering various operational scenarios of both photovoltaic systems and loads, a comprehensive benefit optimization method for photovoltaic inverters participating in reactive power loss reduction in distribution networks is proposed. Finally, through example analysis, the cost and benefit are calculated and fitted in different scenarios, and the optimization calculation is carried out. Compared to the scenario where the photovoltaic inverter operates at the maximum reactive power regulation capacity, the optimized comprehensive benefit is increased by 21.20%. The proposed method is validated to effectively enhance the comprehensive benefits of inverters participation in reactive power loss reduction.

Microstructure evolution and thermoelectric behaviour of directionally solidified Bi2Te3 based multiphase thermoelectric

Thermoelectric materials are vital for sustainable energy applications, yet improving their efficiency remains a significant challenge. This study investigates the influence of unidirectional solidification on the Bi2Te3-Cu3Te2 eutectic alloy to enhance thermoelectric performance through microstructural control. Alloys of the same composition of Bi, Cu, and Te were processed using a Bridgman-type furnace under varying solidification velocities, with the resulting phases characterized as rhombohedral (Bi2Te3) and tetragonal (Cu3Te2). A distinctive eutectic columnar structure was formed at higher solidification rates, optimizing the balance between electrical and thermal transport. Alloy Solidified at 20µm/s, exhibited a peak figure of merit (zT) of 0.93 at 442K due to improved power factor and reduced thermal conductivity. This work highlights unidirectional solidification as an effective approach to advancing thermoelectric material design.

Power quality solutions for rail transport using AI-based unified power quality conditioners

This paper proposes an artificial intelligence-based Unified Power Quality Conditioner (AI-UPQC) and a unique Dynamic K-factor PI (DKPI) algorithm for PI-UPQC to address power quality issues in electrified railway systems. The widespread use of power electronic converters in modern traction drives has exacerbated problems such as harmonics, voltage fluctuations, and resonance phenomena. The proposed AI-UPQC utilizes artificial neural networks (ANNs) to generate optimal reference signals for controlling series and shunt active power filters. A detailed 25 kV, 50 Hz traction power supply system model is developed in MATLAB/Simulink to evaluate the AI-UPQC's performance. Simulation results demonstrate that the AI-UPQC significantly outperforms conventional PI-controlled UPQCs in reducing voltage and current total harmonic distortion (THD), improving power factor, and providing faster response times under varying load conditions. The AI-UPQC reduced source current THD from 25.16 to 1.12% and load voltage THD from 6.62 to 2.07%. Sensitivity analysis further validates the robustness of the proposed system across different operating parameters. The AI-UPQC shows promise as an effective solution for enhancing power quality in modern electrified railway networks.

Optimal Integration for DGs with EVs planning in Distribution Networks with Hybrid MC-GA Technique using Realistic Load Models

With the growing integration of Distributed Generations (DGs) and Electric Vehicles (EVs) into distribution grids, the need for efficient and intelligent management strategies has become paramount. The need for power consumption is increasing every day in accordance with the standard demand pattern. As a result, either creating a lot of electricity or minimizing losses is crucial. In order to minimize real and reactive power losses from the system's point of view, this paper presents the optimal performance index-based size and location determination of DGs, EVs and their coordination in distribution networks using realistic load models (RLMs) such as RLM-1, RLM-2, RLM-3, RLM-4, and RLM-5, respectively. Improvement of the system power factor (SPF) is defined in this analysis as the power system's performance both with and without different kinds of DGs and DGs with EVs for various RLMs. PHEVs type of EVs used in this paper. The hybrid Monte Carlo-Genetic Algorithm (MC-GA) is the basis of the simulation technique that is being suggested. Networks with IEEE-16 and 37 buses in their distribution systems have been used to test the suggested methods. Comprehensive simulations on a test distribution network are used to show that the suggested method is effective. The system's performance can be optimized in terms of grid stability, efficiency, and reliability, according to the results. By stressing the significance of employing a hybrid MC-GA technique to meet realistic load circumstances, this research advances optimal DG and EV solutions.

Fast Prediction of Characteristics in Wound Rotor Synchronous Condenser Using Subdomain Modeling

Wound rotor synchronous condensers (WRSCs) are DC-excited rotor machines that utilize rotor winding instead of permanent magnets. Their voltage regulator controls the rotor field to generate or absorb reactive power, thereby regulating grid voltage or improving power factor. A key characteristic of a WRSC is the compounding curve, which shows the required rotor current under specific stator current and voltage conditions. This paper presents an approach for quickly calculating the electromagnetic parameters of a WRSC using a mathematical method. After determining magnetic flux density, induced voltage, and inductance through analytical methods, the Park and Clarke transformations are applied to derive the dq-frame quantities, enabling prediction of active and reactive powers and compounding curve characteristics. The 60 Hz model was evaluated through comparison with finite element method (FEM) simulations. Results of flux density, induced voltage, and the compounding curve under varying rotor and stator current conditions showed that the proposed method achieved comparable performance to FEM simulation while reducing computational time by half.

Enhancing the performance of solar-powered EV charging stations using the TOSSI-based CTF technique

In this paper, the design and analysis of a novel solar-powered EV-charging system employing a third-order sinusoidal signal integrator (TOSSI) based-CTF (character of triangular function) is proposed. The TOSSI-based CTF is used to extract fundamental active components by eliminating harmonic distortions from the load currents. This control structure has the unique capability of active current separation, employing simple mathematical operations. Moreover, the response is further refined with the help of optimized gain parameters. The designed system is capable of handling various power quality issues, including harmonic mitigation, current balancing, and power factor improvement. The EV battery is primarily charged by solar-PV power employing a bidirectional DC-DC converter. Alternatively, the EV battery may be charged by the grid supply during the unavailability of sunlight by taking the power quality issues into due consideration. The suggested control topology is used to enhance the dynamic operation of solar-powered EV charging stations experiencing solar power intermittency and variation of load. Using MATLAB, the efficacy of the proposed control topology is tested for different operating scenarios. The suggested control topology is also verified and validated using prototype hardware developed in the laboratory, where the suggested controller has proven its utility over and above existing state-of-the-art controllers in the domain.

IMPLEMENTATION OF VIENNA RECTIFIER WITH SLIDING MODE CONTROL FOR ELECTRIC VEHICLE CHARGING STATIONS

This work recommends using an electric vehicle (EV) charging station employing a Vienna rectifier (VR) with sliding mode control. The Vienna rectifier is preferred for high-power applications due to its reduced harmonic distortion and improved power factor correction. Sliding mode control is used to regulate the rectifier's output voltage and current, allowing for reliable and efficient charging of EVs. The suggested system is modeled, and the simulation outcomes are presented to demonstrate the value of the recommended approach concerning stability, strength, and unexpected responsiveness. The proposed technology is expected to contribute to developing more dependable and effective EV charging stations.

Achieving enhanced power factor using dual substitution at Cu and S sites in tetrahedrites thermoelectric materials Cu12Sb4S13

Thermoelectric (TE) materials-based devices are valuable for translating heat into electricity, but the cost is largely driven by the use of purified metals required for efficient TE performance. This study focuses on tetrahedrite materials, which are cost-effective due to their abundance in copper ore mining waste and status as one of the most widespread sulfosalts on Earth. The research investigates the effects of co-doping and iso-valent doping on the TE properties of p-type tetrahedrite samples, specifically Cu10Mn2Sb4S11Se2 (Sample A) and Cu10MnZnSb₄S11Se2 (Sample B). These samples were synthesized using hot pressing at 773 K and compared with the existing pristine compound (Cu10Mn2Sb4S13). Doping with Mn and Zn (1:1) at the Cu site was found to optimize carrier concentration and enhance phonon scattering, leading to an improved power factor. Additionally, the Se substitution at the S site also introduced band degeneracy, further increasing the power factor. Further, sample B exhibited the highest Seebeck coefficient (∼300 μV/K) at 650 K, in comparison to Sample A (∼225 μV/K) and the pristine compound (∼250 μV/K). On the other hand, Sample A demonstrated significantly higher electrical conductivity (∼0.76 × 10⁴ S/m at 650 K), ∿ three times greater than that of the other prepared samples. Notably, the power factor of Sample A (∼0.389 mW/mK2 at 650 K) was more than twice that of Sample B (∼0.141 mW/mK2) and the pristine compound (∼0.160 mW/mK2). These findings suggest that dual-site substitution at the Cu and S positions presents a promising strategy to augment the TE performance of tetrahedrite compounds.

Double-vector based deadbeat torque control of PMSMs with power factor improvement

Double-vector based deadbeat torque control of PMSMs with power factor improvement

Design of interline hybrid continuous trans-impedance turns ratio controlled tuning power filter: New approach to suppress harmonics in energy system

Harmonic distortion (HRD) is a major issue in power and energy systems due to its effect on output, power factor and performance of entire system. Interline hybrid continuous network impedance (IL-hCONTI) tuned filter is proposed to suppress the harmonic distortion in a inter tied i.e. integrated energy system. In a proposed method, effective transformer impedance i.e. trans-impedance is utilized rather than using entire grid impedance power system. Transformer impedance control (Tf-ZPC) in the power network under testing is possess the reactive voltage drop at point of common coupling (PoC). Transformer impedance is proportional to the turns ratio and the concern voltage change and it is imposed by the proposed tuned filter. Tuned filter is designed with the Tf-ZPC along with filter circuit impedance to control the harmonic currents and PoC voltage profile. Proposed hybrid filter design utilizes the both instantaneous capacitor voltage and inductive capacitor filter (LCF) voltage component to suppress harmonic component. Hence improved power factor of energy system is assured using proposed technique. Proposed IL-hCONTI tuned filter is tested over a strong grid conditions, as well as weak grid conditions for linear, non-linear loading.

Multiple defect states engineering towards high thermoelectric performance in GeTe-based materials

GeTe is a promising material for thermoelectric (TE) applications. However, its low Seebeck coefficient and high thermal conductivity in the mid-temperature range of 298–550 K have hindered its widespread use in TE devices. In this work, we show that a combination of band engineering, Fermi level tuning, and miscibility gap exploration can significantly improve the energy conversion performance of GeTe. Bi provides the optimized carrier concentration and induces band convergence, while Ga possibly forms a resonant state. The synergistic effects of Bi and Ga significantly improve the Seebeck coefficient from 38 µVK−1 for undoped GeTe to over 120 µVK−1 for Bi and Ga-containing materials at 298 K and provide a high power factor over a wide temperature range. Phonon scattering is strengthened by optimizing the microstructure through Pb-induced spinodal decomposition and enhanced point defect scattering due to increased dopant solubility, resulting in a very low lattice thermal conductivity of about 0.5 Wm-1K−1 at 600 K for the triple-doped samples. The maximum thermoelectric figure of merit ZT was significantly increased to 2.1 at 600 K for the Ge0.87Pb0.05Bi0.06Ga0.02Te sample due to the improved power factor and reduced lattice thermal conductivity. Additionally, the average figure of merit ZTave for this sample achieved a very high value of 1.4 for Ge0.87Pb0.05Bi0.06Ga0.02Te at a temperature gradient of 475 K (Tc = 298 K). The developed material shows great potential for use in energy conversion devices, with an estimated energy conversion efficiency exceeding 17 %.

Enhanced Thermoelectric Performance of p-type AgSbTe2 via Cu Doping.

Recently, the p-type semiconductor AgSbTe2 has received a great deal of attention due to its promising thermoelectric performance in intermediate temperatures (300-700 K). However, its performance is limited by the suboptimal carrier concentration and the presence of Ag2Te impurities. Herein, we synthesized AgSb1-xCuxTe2 (x = 0, 0.02, 0.04, and 0.06) and investigated the effect of Cu doping on the thermoelectric properties of AgSbTe2. Our results indicate that Cu doping suppresses the Ag2Te impurities, raises the carrier concentration, and results in an improved power factor (PF). The calculation reveals that Cu doping downshifts the Fermi energy level, reduces the energy band gap and the difference among several valence band maximums, and thereby explains the improvement of PF. In addition, Cu doping reduces the thermal conductivity, possibly attributed to the inhibition of Ag2Te impurities and the phonon softening of the AgSb1-xCuxTe2. Overall, Cu doping improves the ZT of AgSb1-xCuxTe2. Among all samples, AgSb0.96Cu0.04Te2 has a maximum ZT of ∼1.45 at 498 K and an average ZT of ∼1.11 from 298 to 573 K.

Improvement of Power Factor and Torque of a PM Vernier Motor From Perspective of Armature and PM Field Harmonics

Improvement of Power Factor and Torque of a PM Vernier Motor From Perspective of Armature and PM Field Harmonics

Research on Power Factor Improvement of a Variable-Leakage-Flux PM Motor Based on Regulated-Flux-Barrier Topology

Research on Power Factor Improvement of a Variable-Leakage-Flux PM Motor Based on Regulated-Flux-Barrier Topology

Improved Harmonic Mitigation and Power Injection Technique for Solar-fed DG System Using GA and PSO

This paper deals with Distributed Generation (DG) system requiring power quality features such as current harmonics, reactive power compensation, and power factor improvement in grid tied operation. The motivation is to combine DG system with the capabilities of shunt active filter to perform real power injection, current harmonics mitigation and power factor improvement. The control algorithm employed in this setup utilizes a reference current generator based on p-q theory together with a pulse width modulation controller for switching pulse generation. The control strategy utilizes PI controller with Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) for finding optimal PI controller parameters. The effectiveness of the proposed method is verified using MATLAB/Simulink and experimental model developed for 3kWp inverter. The PI-PSO controller injects 0.588kW active power into the grid results in sharing 54% of load power demand and the current harmonics is reduced from 23.70% to 1.63%. The obtained results demonstrate that the grid tied inverter maintains harmonic standards in accordance with the IEEE-519 standard while injecting maximum possible active power to the line.

Control of Dstatcom in Distribution System by Artificial Intelligence Based Controller

Issues linked to power quality are currently of the utmost importance. The utilization of non-linear loads is the cause of the power quality issues. All of these loads cause disruptions in the force of power services, system effectiveness, power factor decrease, etc. because of their nonlinearity. In order to increase power quality in grid connections, this research proposes an adaptive neuro fuzzy conclusion system (ANFIS) based control method for a three- phase DSTATCOM. In addition to improving power factor and balancing power between active and reactive components, the primary function of the DSTATCOM is to compensate for current harmonics introduced into the supply current due to non-linear loads. Matlab software is used to carry out the simulation.

Enhanced thermoelectric properties of Se-doped quasi-one-dimensional van der Waals crystal Ta2PdS6

Recently, quasi-one-dimensional van der Waals crystal Ta2PdS6 has been reported as a promising thermoelectric material with an extraordinarily high power factor. However, element doping to tune the thermoelectric properties has not been studied yet. Here, we systematically investigated the effect of Se doping on the phase composition, charge transport properties and thermoelectric performance of Se-doped Ta2Pd(S1−xSex)6 (x = 0, 0.02, 0.05, and 0.07) polycrystalline bulk materials. Upon doping Se at the S sites to increase the carrier concentration and mobility, the electrical conductivity of Ta2Pd(S0.93Se0.07)6 is dramatically enhanced, while the S is slightly reduced, yielding a significantly improved power factor compared to that of pristine Ta2PdS6. Consequently, Ta2Pd(S0.93Se0.07)6 exhibits a peak ZT of 0.29 at 700 K when the doping content x = 0.07, which is more than twice that of pristine Ta2PdS6.

Design and Development of a Wireless Energy Meter with Automatic Cos phi Corrector Feature Based on Internet of Things

The increasing need for energy efficiency and more accurate monitoring of energy consumption has driven the development of intelligent energy metering systems. This Final Project discusses the development of Wireless Energy Meter that integrates sensor technology and data analysis for better monitoring and prediction of energy consumption. The main objective of this research is to improve understanding of household energy consumption patterns and develop power factor improvement algorithms that can provide better use of energy efficiency in the future. At the first stage, the system is implemented using energy sensors connected to the household electrical network. The data obtained from this sensor is sent to the Thingspeak application for later monitoring. The second stage involves developing an algorithm to automatically correct the power factor that the capacitor will later embed to correct cos phi if the existing power factor is less than a predetermined set point. The results of this study show that the system that has been developed is able to provide real-time monitoring of energy consumption and improve electricity quality for better energy efficiency in the future. This can help users to be more efficient in energy use, identify potential savings, and reduce environmental impact. In addition, this system can be used by equipment in households whose purpose is to optimize the use of daily electricity loads.

Stochastic optimal PV placement and command based power control for voltage and power factor correction using MOPSO algorithm

This paper addresses a multi-objective particle swarm optimization (MOPSO) algorithm to locate the best position at which a single distributed generator (DG) with optimum voltage amplitude and phase can be installed. The objective is to maximize the power factor and voltage in IEEE 9-Bus system and voltage in IEEE 15-Bus system using MATLAB/SIMULINK software. Systematic simulations revealed that a single DG at Bus-5 with voltage amplitude/phase of 230 kV/-13∘ caused highest objective function value of 1.9919 with an improvement in power factor and voltage of 1.39% and 1.15% respectively. In IEEE 15-Bus system, DG at Bus-3 caused the highest objective function (0.8828) with DG voltage amplitude/phase of 10.735 kV/23.12∘ and 11.89% voltage improvement. Finally, a robust control program in dq0 domain is developed to achieve calculated powers from photovoltaic generator at DG bus whose effect is validated to be the same at all buses as given by the MOPSO algorithm.