Power Factor Improvement Research Articles

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.

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

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

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.

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.

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.

Enhancing thermoelectric performance with perpendicular anisotropic magnetic domain arrays

In recent years, the incorporation of magnetic nanoparticles into thermoelectric materials has been introduced to enhance their performance. However, understanding the impact of dispersed magnetic substances in the matrix on thermoelectric properties, considering different domain directions, is crucial for performance improvement. In this study, we have designed and fabricated high-quality epitaxial single crystal thin films consisting of FePt arrays with varying magnetic domain directions embedded in an Sb2Te3 matrix. Our findings reveal that the electrical transport behavior of the films responds differently to magnetic materials with distinct domain directions, especially in the case of discontinuous arrays. The FePt array oriented perpendicular to the carrier flow direction effectively regulates the direction of carrier movement and local low-energy carriers, functioning as an "energy supplier" to enhance material performance. Simultaneously, the quantum dots formed between the Sb2Te3 and the metal film play the role of carrier channels, further regulating the carrier concentration. Therefore, the perpendicular magnetic anisotropy array synergistically modulates the electrical transport behavior through carriers, resulting in a significant improvement in the thermoelectric power factor. By increasing the S value at the measurement temperature, we achieved a maximum power factor (PFmax) of 3.35 mWm-1K-2 and an average power factor (PFave) of 3.14 mWm-1K-2.

Rational Design of Cu Vacancies and Antisite Defects for Boosting the Thermoelectric Properties of CuGaTe2-Based Compounds.

CuGaTe2-based compounds show great promise in the application for high-temperature thermoelectric power generation; however, its wide bandgap feature poses a great challenge for enhancing thermoelectric performance via structural defects modulation and doping the system. Herein, it is discovered that the presence of GaCu antisite defects in the CuGaTe2 compound promotes the formation of Cu vacancies, and vice versa, which tends to form the charge-neutral structure defects combination with one GaCu antisite defect and two Cu vacancies. The accumulation of Cu vacancies in the structure of the (Cu2Te)x(Ga2Te3)1-x compounds evolves into twins and stacking faults. This in conjunction with GaCu antisite defects intensify the point defects phonon scattering, yielding a dramatic reduction on lattice thermal conductivity from 6.95 W m-1 K-1 for the pristine CuGaTe2 sample to 2.98 W m-1 K-1 for the (Cu2Te)0.45(Ga2Te3)0.55 sample at room temperature. Furthermore, the high concentration of charge-neutral defects combination narrows the band gap and increases the carrier concentration, leading to an improved power factor of 1.58 mW/mK2 at 600 K for the (Cu2Te)0.49(Ga2Te3)0.51 sample, which is 41% higher than for the pristine CuGaTe2 sample. Consequently, the highest ZT value of 0.82 is achieved at 915 K for Cu0.015(Cu2Te)0.48(Ga2Te3)0.52, which represents an enhancement of about 22% over that of the pristine CuGaTe2 compound.

Enhanced thermoelectric performance of MoSe2 under high pressure and high temperature by suppressing bipolar effect

The electrical transport property of layered MoSe2 has a strong response to high pressure by enhancing the inter-layer interaction. However, the narrowed bandgap under high pressure will cause the bipolar effect (i.e., the thermally excited minority carriers contribute to a Seebeck coefficient with the opposite sign to the majority carriers) at high temperatures to degrade the thermoelectric (TE) performance. Hence, suppressing the bipolar effect is important to optimize the TE performance of MoSe2 under high pressure and high temperature (HPHT). In this study, the degradation of TE performance caused by the bipolar effect under HPHT in MoSe2 is investigated. It is found that in MoSe2, the electrical conductivity was improved significantly by pressure; however, the bipolar effect led to a significantly degraded Seebeck coefficient at high temperatures. By injecting massive carriers beforehand, the bipolar effect was suppressed to make a dominant type of p-type charge carries, achieving an increased Seebeck coefficient with increasing temperature, resulting in an improved power factor from 29.3 μW m−1 K−2 in MoSe2 to 285.7 μW m−1 K−2 in Mo0.98Nb0.02Se2 at 5.5 GPa, 1110 K. Combined with the reduced thermal conductivity by point defect scattering on phonons, a maximum ZT value of 0.11 at 5.5 GPa, 1110 K. This work highlights the significance of suppressing the bipolar effect under HPHT for optimizing TE performance in such layered semiconductors.

Constrained Maximum Power Extraction in PMVG Wind Turbine System With Predictive Rotor Position Bias-Based Current Angle Control for Power Factor Improvement

Constrained Maximum Power Extraction in PMVG Wind Turbine System With Predictive Rotor Position Bias-Based Current Angle Control for Power Factor Improvement

Detuned reactor for harmonic reduction on 20 kv distribution network Pocut Baren feeder in Banda Aceh

Abstract Nonlinear loads in distribution network have adverse impacts in the form of harmonic distortion. When the harmonic frequency is close to resonance, the harmonic will be amplified and overloading capacitor bank. Here detuned reactor is inserted in series to avoid from that risk. In this study, the impact of detuned reactor on suppressing the harmonics and power factor improvement are investigated, evaluated and analyzed. The Pocut Baren feeder is chosen as the case of the study. It is a radial distribution network with 28 distribution transformers where the starting point is connected to substation transformers and capacitor banks. Simulation is used to verify the efficacy of detuned reactor. The results shown that detuned reactor is able to reduce voltage harmonics and improve power factor across the distribution line. Although the efficacy wane at the distribution end, it can be compensated from adjusting the detuned reactor value to meet the 5% total voltage harmonic distortion (THDv) threshold at the end of the line. Simulation results confirmed that detuned reactor is able to reduce harmonics from 12% to meet the threshold. Power factors have also been improved beyond 0,9 from previously arround 0,8.

STUDI PERANCANGAN KAPASITOR BANK 1200 KVAR DI PT. RAYA SINERGI ELEKTRIKAL

Electricity is a vital necessity for human life, and one aspect related to electricity is the electrical panel, which functions as the distributor of electrical energy. PT. Raya Sinergi Elektrikal is a company engaged in the manufacturing of electrical panels, with one of its products being the Capacitor Bank Panel, which serves to improve power factor. The production of capacitor bank panels involves design considerations, including the components to be used, panel construction, wiring diagrams, single-line diagrams, and calculations of Capacitor Bank Panel requirements. The Capacitor Bank Panel can be operated manually or automatically. This research was conducted through direct observation and interviews at PT. Raya Sinergi Elektrikal to gather data related to the topic. This study adds new knowledge and understanding regarding the design of 1200KVAR Capacitor Bank Panels, which are widely used in industries and offices to minimize power factor losses.

High electrical conductivity and enhanced thermoelectric properties in La-Nb co-doped (Sr1/3Ba1/3Ca1/3)TiO3-based oxides

Here, we report a series of (Sr1/3Ba1/3Ca1/3)TiO3-based oxides with different La-Nb doping levels synthesized by solid-state reaction and graphite-burial sintering method. The results indicate that La-Nb co-doping significantly enhances the electrical conductivity by increasing carrier concentration, leading to a remarkable improvement in power factor (∼1665 μW/(m·K2) at 773 K). Additionally, the lattice thermal conductivity is reduced due to the enhanced phonon scattering caused by point defects and pores. As a result, a peak ZT value of 0.36 at 773 K is achieved for the 5% La-10% Nb co-doped sample, 200% higher compared to the un-doped sample. This work highlights the promising potential of the (Sr1/3Ba1/3Ca1/3)TiO3-based oxides as environmentally-friendly thermoelectric materials.