Power Loss Research Articles

Optimizing Grid-Dependent and Islanded Network Operations through Synergic Active-Reactive Power Integration

DG integration improves distribution network performance and also enables microgrid (MG) formation for islanded operation. However, existing studies assume an isolated operation approach for islanded mode, which is unrealistic and increases overall system costs while adding complexity to the grid. This paper presents a dual-stage methodology for the efficient operation of distributed generation (DG) and shunt capacitor banks (SCBs) in radial distribution networks (RDNs) for both grid-integrated and islanded modes. The first stage proposes an improved Jaya algorithm (IJaya) to optimize DG and SCB allocation during grid-connected operation, aiming to reduce power loss and improve voltage profiles. IJaya employs a dynamic weight-based grid search to address premature convergence. The second stage formulates a multiobjective function for the islanded operation to minimize power loss and underutilization of DG-SCB capacity. Case studies on IEEE 33- and 69-bus RDNs show IJaya reduces power loss by 38.84% and improves voltage by 3.26% in grid-connected networks compared to existing methods. The proposed analytical approach for islanded operation tunes the source power factor, reducing DG-SCB underutilization by up to 15.83% for power factors between 0.8 and 0.93. The results demonstrate that operating distributed resources near optimal capacities meets a larger portion of the island network's energy needs.

Improved binary quantum-based Elk Herd optimizer for optimal location and sizing of hybrid system in micro grid with electric vehicle charging station

In recent times, there has been increasing interest in renewable power generation and electric vehicles within the domain of smart grids. The integration of electric vehicles with hybrid systems presents several critical challenges, including increased power loss, power quality issues, and voltage deviations. To tackle these challenges, researchers have proposed various techniques. Effective management of energy systems is essential for maximizing the benefits of integrating a hybrid system with a microgrid at an electric vehicle charging station. This research specifically aims to optimize the location and sizing of such a hybrid system within the microgrid. Additionally, an improved binary quantum-based Elk Herd optimizer approach is proposed. This approach addresses for optimally managing renewable energy sources and load uncertainty. The proposed system also considers the stochastic nature of electric vehicles and operational restrictions, encompassing diverse charging control modes. The proposed technique performance is implemented in MATLAB platform and compared against existing approaches. The analysis demonstrates the effectiveness in achieving optimal location and sizing for a hybrid system with an electric vehicle charging station. Additionally, the proposed approach contributes to minimizing power loss, electricity costs, and average waiting time. Furthermore, the proposed approach reduces computing time, net present cost, and emissions are 12.5 s, 1.1×106 dollar, 2.21×108 g year−1, respectively.

Lost in the Shuffle: Testing Power in the Presence of Errorful Network Vertex Labels

Two-sample network hypothesis testing is an important inference task with applications across diverse fields such as medicine, neuroscience, and sociology. Many of these testing methodologies operate under the implicit assumption that the vertex correspondence across networks is a priori known. This assumption is often untrue, and the power of the subsequent test can degrade when there are misaligned/label-shuffled vertices across networks. This power loss due to shuffling is theoretically explored in the context of random dot product and stochastic block model networks for a pair of hypothesis tests based on Frobenius norm differences between estimated edge probability matrices or between adjacency matrices. The loss in testing power is further reinforced by numerous simulations and experiments, both in the stochastic block model and in the random dot product graph model, where the power loss across multiple recently proposed tests in the literature is considered. Lastly, the impact that shuffling can have in real-data testing is demonstrated in a pair of examples from neuroscience and from social network analysis.

Performance evaluation of different photovoltaic array configurations under partial shading

In Partial Shading Conditions (PSCs), Photo Voltaic (PV) systems often experience notable output power and efficiency reductions due to weather variations. This study is dedicated to determining the most effective PV array configuration under partial shading. Various configurations, including Series Parallel (SP), Total Cross Tied (TCT), Bridge Linked (BL), Honey Comb (HC), Double Tied (DT), and hybrid connections, are simulated and evaluated under PSCs. Nine shading patterns, such as vertical, horizontal, centre-wise, upper triangular, cross-wise, expansive, arbitrary, L-shaped, and diagonal, are examined using a 6 × 6 array of PV Configuration. Performance analysis is based on parameters such as open circuit voltage (Voc), short circuit current (Isc), Global Maximum Power Point (GMPP), maximum voltage (Vm), maximum current (Im), Fill Factor (FF), Mismatch Loss (ML)/Power Loss (PL), and efficiency (η). Additionally, hybrid configurations like Alternate- Total Cross Tied -Bridge Linked (ALT-TCT-BL), Alternate -Total Cross Tied -Double Tied (ALT-TCT-DT), and Alternate -Total Cross Tied -Triple Tied (ALT-TCT-TT) are investigated and compared with existing configurations. Hybrid configurations with fewer cross-ties are recommended to simplify circuit complexity. MATLAB/Simulink software is employed for simulation, using a Sunpower SPR-E18-295-COM panel. Comparative analysis confirms that hybrid configurations exhibit higher efficiency for various shading patterns than existing configurations, equal or at par with the TCT connection. For eight connections and nine shading scenarios along with zero (no) shading conditions, eighty distinct combinations have been analysed, and on comparative analysis with contemporary work, the optimal output is obtained from the connections considered under PSCs. For all the shading patterns considered, the proposed work fetches maximum efficiency compared to the contemporary work, and it ranges between 13.61 % and 17.84 % for different shading patterns. The maximum value of efficiencies for horizontal, vertical, diagonal, centre-wise, expansive, arbitrary, upper triangular and L-shaped shading patterns is 13.77 %, 17.24 %, 17.84 %, 15.66 %, 13.61 %, 17.21 %,17.35 % and 15.11 % respectively. The hybrid configuration achieves higher efficiency than current methods for all shading patterns and configurations, with improvements in efficiency ranging from 2.1 % to 42.22 % across all cases.

Investigation to the vibration characteristics of ultrasonic transducer based on the number of piezoelectric ceramics

As the vibration actuator source, PZT applied on the ultrasonic transducers (UTs) plays a crucial role in the vibration characteristics of UTs. Most conventional research focus on the overall size and positional relationship of PZT stack, while the influence of PZT numbers on vibration characteristics of UTs is seldom reported. In this article, we present a comprehensive investigation between the PZT numbers and vibration characteristics of UTs with identical geometric configurations, specifically UTs with 2 (UT2), 4 (UT4) and 6 (UT6) PZT. The electromechanical equivalent circuit and finite element analysis (FEM) based on PZT numbers are established to investigate the impedance and resonant frequency. Furthermore, the dynamic displacement model of the UTs is proposed to study the influence of PZT numbers on amplitude, and the calculation results are consistent with harmonic response analysis. Finally, the experimental platform is established to test the vibration characteristics of the three types UTs. The results show that the resonant frequency of the transducer is not affected by the numbers of PZT, while the impedance and impedance stability can be improved by the increased PZT numbers. Moreover, the amplitude of UTs is negatively correlated with the numbers of PZT. Through experiments, it is verified that UT2 is suitable for the conditions as the load less than 1000g and amplitude less than 2.2µm, and UT4 is applicable to the other conditions. Although the UT6 exhibits excellent impedance stability, its output power is relatively high and is not suitable for the structure used in this article. The findings suggest that the number of PZTs should be designed based on the operational conditions to improve amplitude output and minimize the loss of power. The presented methods can effectively improve energy consumption and working life, making the UTs greener and more efficient.

Efficiency And Effectiveness Of Circuit Arrangement And Placement Of Thermoelectric For The Design Of Utilizing Zinc Roof As An Electrical Source

<p>The problem related to electrical power sources commonly encountered in society is the frequent occurrence of rotating power outages or sudden blackouts, which disrupt activities for both communities and industries as they heavily rely on electrical power to meet their needs, both collectively and individually. In order to meet the needs of society and industry, Indonesia requires a sufficiently large energy supply. One renewable energy source that can be utilized is solar energy due to its easy availability, cleanliness, and cost-effectiveness. In this study, an experimental method is employed, which utilizes the heat from zinc roofs and converts it into electrical energy using thermoelectric generators. Testing is conducted by varying the circuit arrangements, including series, parallel, and combined configurations, as well as the number of thermoelectric modules (20, 30, and 42 modules), and placement locations on zinc roofs and house ceilings, to observe the output results in terms of voltage and electrical current. As observed from the test results presented in the graphs, the output voltage and current vary for each type of circuit. Based on the use of various circuit arrangements, it can be concluded that combining thermoelectric generators results in higher current and voltage values. The greater the number of thermoelectric modules, the larger the output value. There is a difference in output values between placement on zinc roofs and ceilings, with higher output values observed when installed on zinc roofs. This is due to direct contact between the hot side of the thermoelectric generator and the inner part of the zinc roof. All data obtained from these variations depend on the temperature difference between the hot and cold sides of the thermoelectric generator. The greater the temperature difference produced, the larger the voltage and current output from the circuit. This temperature difference affects the overall performance of the circuit.</p>

The impact of blood viscosity modeling on computational fluid dynamic simulations of pediatric patients with Fontan circulation

For univentricular heart patients, the Fontan circulation presents a unique pathophysiology due to chronic non-pulsatile low-shear-rate pulmonary blood flow, where non-Newtonian effects are likely substantial. This study evaluates the influence of non-Newtonian behavior of blood on fluid dynamics and energetic efficiency in pediatric patient-specific models of the Fontan circulation. We used immersed boundary-lattice Boltzmann method simulations to compare Newtonian and non-Newtonian viscosity models. The study included models from twenty patients exhibiting a low cardiac output state (cardiac index of 2 L/min/m2). We quantified metrics of energy loss (indexed power loss and viscous dissipation), non-Newtonian importance factors, and hepatic flow distribution. We observed significant differences in flow structure between Newtonian and non-Newtonian models. Specifically, the non-Newtonian simulations demonstrated significantly higher local and average viscosity, corresponding to a higher non-Newtonian importance factor and larger energy loss. Hepatic flow distribution was also significantly different in a subset of patients. These findings suggest that non-Newtonian behavior contributes to flow structure and energetic inefficiency in the low cardiac output state of the Fontan circulation.

A facile strategy for customizing multifunctional magnetic‑dielectric carbon microflower superstructures deposited with carbon nanotubes

The novel fabrication of multiple components and unique heterostructure can inject infinite vitality into the electromagnetic wave (EMW) attenuation field. Herein, through the self-assembly of polyimide complexes and catalytic chemical vapor deposition, porous carbon microflowers were synthesized accompanied by carbon nanotubes (CNTs). By regulating the metal ions, the composition and structure of the as-obtained hybrids are modified correspondingly, and thus the adjustable thermal management and EMW absorption capabilities are obtained. In detail, the rich pores and huge specific surface area endow the hierarchical structures with distinguished thermal insulation ability (λ<0.07). The carbon framework and CNTs are beneficial for consuming EMWs via conductive loss and defect polarization loss while reducing the filling ratio and thickness. The doped heteroatoms and abundant heterointerfaces generate ample dipole polarization and interface polarization losses (supported by DFT calculation). The metal nanoparticles uniformly embedded in the carbon framework offer optimized impedance matching, proper defect polarization, and suitable magnetic loss. Accordingly, the synergy of magnetic-dielectric balance and flower-like superstructure enables FNCFN2 and NNCFN2 to accomplish remarkable microwave absorbing capacity with thin thickness (14 wt.%). Therefore, respectable specific reflection loss and specific effective absorption bandwidth are acquired (215.39 dB mm–1 and 22.10 GHz mm–1, 257.23 dB mm–1 and 22.12 GHz mm–1 respectively), superior to those of certain renowned carbon-based absorbers. The simulation results of electric field intensity distributions, power loss density, and radar cross section reduction (maximum value of 36.02 dBm2) also verify the prominent radar stealth capability. Moreover, the customizable approach can be applied to other metals to obtain fulfilling behaviors. Henceforth, this work provides profound insights into the relationship between structure and performance, and proposes an efficient path for mass-producing multifunctional and high-performance EMW absorbers with excellent thermal properties.

A Novel Development of Soft Computing based Hybrid Power Point Tracking Controllers for Hydrogen Vehicle Application with New Wide Source DC-DC Converter

From the present power generation scenario, most of the power production companies are focusing on renewable energy systems because their merits are easy to install, more reliable power sources, free from atmospheric pollution, and better adaptable to all weather conditions. In this article, a Polymer Electrolyte Membrane Fuel Cell (PEMFC) module is selected in the first objective to produce constant and continuous power to the hydrogen-based electrical vehicle systems. This fuel module provides fast power production and gives good energy density. However, the demerits of this module are more current production and low-level voltage generation. A new single-switch DC-DC circuit is introduced in the second objective of this work for optimizing the current levels of the fuel module thereby reducing the source power loss of the proposed system. Here, another problem of the fuel module is nonlinear power production which is linearized by proposing the Cuckoo Search Optimization (CSO)-based Adaptive Network-based Fuzzy Inference System (ANFIS) in the third objective to extract the maximum voltage from the fuel module. The merits of this introduced Maximum Power Point Tracking (MPPT) Controller are better tracking speed, low-level disturbances in the consumer load power, high robustness, more sustainability, and easy operation. The entire proposed system is investigated by selecting the MATLAB Simulink tool. The introduced converter circuit is analyzed by selecting the programmed DC supply.

Improved Switching Technique to Mitigate THD and Power Loss of NPC Inverters

Improved Switching Technique to Mitigate THD and Power Loss of NPC Inverters

Stability analysis and voltage improvement in DG-integrated distribution networks using VCPI-based critical buses and lines detection considering uncertain power factor

Voltage stability ensures reliable and efficient power transmission to end-users, making it essential for power system efficiency. Dynamic load changes and rising power requirements might cause voltage instability and strain performance. This paper investigates the voltage stability Indicators of distribution systems to address the voltage stability issue in power systems. The uncertain power factor and other numerous technical parameters that affect the voltage drop or voltage collapse are involved in predicting the system’s voltage stability. First, the analysis uses the voltage collapse proximity index (VCPI) technique, which considers bus voltage, impedance, uncertain power factor of load buses, and transmission line impedance at both ends. The applied technique correctly predicts and detects weak buses and transmission lines using different voltage stability indices since technical parameters are correlated with the VCP index. The index and line impedance correspond; consequently, the recommended indication compensates for voltage loss owing to impedance. Therefore, the VCPI is a better index for anticipating voltage collapse and finding network weak busses and lines. The implemented approach is simple, precise, and economical; the index technique detects weak buses and forecasts system collapse. Second, this work introduces EMFO-FPSO, a hybrid metaheuristic that improves voltage stability by combining Fractional-order particle swarm optimization (PSO) and Entropy design mouth flame optimization (MFO). The proposed approach is validated on the IEEE 33 bus system by identifying weak buses and optimizing distributed generation placement in the distribution system. The implemented solution approach based on VCPI and EMFO-FPSO optimization achieves a significant power loss reduction of 71.5% compared to the base case, whereas the reductions for ABC, ACO-ABC, and PSO are 57.3%, 60.7%, and 64.4%, respectively. Moreover, the proposed method attains a stable VCPI Index of 0.90, indicating a 10% enhancement in voltage stability relative to the base case. The study’s results, key findings, and comparisons show the relevance of the proposed method for voltage stability enhancement.

Simulation of unsteady ice accretion on horizontal axis wind turbine blade sections in turbulent wind shear condition

This study presents a comprehensive simulation approach to quantify power losses in horizontal axis wind turbines under environmental icing conditions. It investigates how wind shear and turbulence affect a 2.5 MW wind turbine's performance, particularly under ice accretion. Turbulence intensity, ranging from 1% to 20%, impacts the relative flow fluctuations and angle of attack on the blade sections, influencing the aerodynamic penalty ratio. The incoming wind speed and the flow angle at various blade sections were determined using the unsteady blade element momentum method, considering vortex induction effects and Prandtl and Glauert corrections. For ice accretion analysis, a fully unsteady simulation of computational grid motion due to ice accretion was performed, along with the solution of the multiphase flow of water dispersed particles in cold air, derived from the psychrometric chart. The findings highlight the significant impact of the incoming turbulent wind fluctuations on the dispersion of the ice shape formed at sections corresponding to their radial position on the blade according to the momentary angle of attack fluctuations. The formation of ice profiles along the blade has led to a subsequent degradation in the aerodynamic efficiency of the blade sections, which is directly proportional to the escalation in turbulence intensity. This phenomenon leads to a continual reduction in the power output of the wind turbine. This research provides valuable insights into the performance of wind turbines under icing conditions in real wind fluctuations.

MCMS submersibles: A safe undersea adventure

Abstract. Maritime Cruises Mini-Submarines (MCMS), a company based in Greece, aims to offer safe and deep-sea exploratory experiences to tourists. This paper discusses the primary challenges involved in ensuring tourist safety, particularly focusing on maintaining security in scenarios of mechanical failures or lost communication with the main vessel. We propose comprehensive safety protocols and technological solutions tailored for deep-sea tourist submersibles. The analysis begins with a detailed study of the forces acting on a submersible, considering both operational modes and the impact of ocean currents, utilizing a rigid-body coordinate system and Eulerian angular coordinate transformations to describe the submersibles motion comprehensively. We derive motion and safety parameters by solving the force differential equations, allowing the host ship to predict the submersibles position accurately. In addressing the recovery of lost submersibles, our approach evaluates power loss scenarios and search efficiency, recommending an optimal combination of hydroacoustic and frequency-hopping communication technologies for reliable, low-loss data transmission. We further enhance search methodologies by integrating motion parameters and ocean current dynamics to pinpoint probable locations, adjusting search strategies dynamically based on real-time data, and employing probabilistic models to optimize resource allocation during search operations. A case study in the Caribbean Sea exemplifies applying these methodologies, incorporating localized flow regimes and cooperative communication strategies among multiple submersibles to improve operational efficiency and safety.

Improved PWM Switching Scheme to Mitigate Power Loss and Switch Temperature of CHB Inverters

Improved PWM Switching Scheme to Mitigate Power Loss and Switch Temperature of CHB Inverters

Cervical Myeloradiculopathy With Bilateral Foraminal Stenosis Treated by Unilateral Biportal Endoscopic Decompression with Alternating Hemilaminectomy and Bilateral foraminotomy: A Case Report and Technical Note

Cervical myeloradiculopathy is a debilitating condition characterized by progressive spinal cord dysfunction commonly caused by degenerative changes in the cervical spine. It typically exhibits an insidious onset and progressive functional decline, along with multiple exiting nerve root entrapments bilaterally in some patients. Traditional surgical interventions, such as discectomy and fusion, are associated with some complications and limitations. Unilateral biportal endoscopic (UBE) decompression can have significant advantages over traditional techniques when cervical central and bilateral foraminal decompression is required. In this case report and technical note, we describe our experience with this novel surgical technique for the treatment of cervical myelopathy. A 67-year-old patient presented with progressive neck pain; bilateral upper extremity radiculopathy; loss of power and sensation in the C5, C6, and C7 nerve root distribution; gait imbalance, and spasticity. Magnetic resonance imaging revealed multilevel cervical spondylosis with central canal and bilateral foraminal stenosis. The patient underwent UBE central and bilateral foraminal decompression. At a 9-month follow-up visit, he was able to walk unassisted, his reflexes had returned to normal, no spasticity was observed, and he had good grip strength in both hands. This is a novel technique of UBE decompression with bilateral foraminotomy at the C4–5, C5–6, and C6–7 levels and laminectomy named “the floating tip technique.” The procedure involved bilateral 3-level lamino-foraminotomy and hemilaminotomy on both C5 and C6. A hemilamina was removed on the opposite sides, and flavectomy was performed. Postoperative computed tomography findings showed an intact, complete muscular mass with an intact central spinous process. Therefore, this method was labelled the “floating tip technique.”

Underground Cable Fault Detection

Underground cables play a crucial role in delivering electricity, ensuring a dependable power supply in both urban and industrial regions. However, detecting and resolving faults in these cables can be difficult due to their hidden placement. This project aims to develop an effective underground cable fault detection system that accurately identifies fault locations, reducing downtime. The system will combine electrical principles with modern sensing technologies to detect faults such as short circuits, open circuits, and insulation issues. By injecting a small current into the cable and analyzing the resulting voltage drop, the system will calculate the distance to the fault from the measurement point. Using a microcontroller along with sensors and signal processing units, it will determine and display the fault location in kilometers. Real-time fault detection will significantly decrease maintenance time and costs by quickly locating problem areas, enabling faster repairs and reducing power outages. This project aims to improve the efficiency and reliability of power transmission systems. Additionally, the system can be integrated with communication technologies for remote monitoring, allowing utility companies to detect and manage faults from centralized control centers.

Investigation and Countermeasures for Power Blackout in the Domestic Power System

Investigation and Countermeasures for Power Blackout in the Domestic Power System

A Cross-Scale Electrothermal Co-Simulation Approach for Power MOSFETs at Device–Package–Heatsink–Board Levels

This paper proposes a cross-scale simulation approach for evaluating the steady-state electrothermal performance of power MOSFETs at the device–package–heatsink–board (DPHB) level. A co-simulation framework is designed by employing the iterative process of power loss and chip temperature to bridge the device and package–heatsink–board (PHB) level simulators. As a result, the cross-scale electrothermal coupling effect within multilevel settings is considered. Correspondingly, variation values in chip temperature and temperature-dependent drain current can be obtained at various voltage biases, level settings, and DPHB structural parameters, incorporating cross-level physical insights. The simulation results are compared with existing methods, and their features and limitations are discussed. Additionally, this paper also derives an empirical equation from the co-simulations to characterize the relationship between the drain current and the chip temperature under different operations exactly. A commercial MOSFET with TO-220F packaging is implemented in experiments to extract the chip temperature and drain current in electrothermal equilibrium. The method comparisons and fair agreement among simulations, equations, and measurements presents the proposed approach as generalized and powerful for describing variations in chip temperature and drain current considering from micrometer devices to millimeter packages–heatsinks–PCB boards, thus providing effective support for DPHB-level co-design.

Power Quality Analysis of Electrical Installation at Commercial Center

For many years, power quality analysis has constantly been carried out at the power stations or sub-stations using the data collected at the data Centre of the power plant. However, this practice has proven to be erroneous and tedious to determine the exactly power quality problem especially when it comes to commercial facilities. Therefore, a revised approach of analysis for the power quality problems at the sites where they occur has been used in this research. This is because of the sensitivity of modern electronic equipment used in commercial facilities and also the need for accuracy of the data measurements carried out at the sites henceforth, with accurate data measurement, we can easily identify the power quality issues. Through-out this research, load unbalance of 28% was found. The solution to load unbalance was to balance the loads to 3,3% among the three phases and power losses caused by this unbalance current were calculated. Although the neutral conductor remained unchanged, harmonics especially triplen-harmonics was found to be more 10% recommended by IEC standards, therefore active harmonic filter of 200A was installed at the main panel board to reduce the losses caused by harmonics at the facility.

An Enhanced Multiscale Retinex, Oriented FAST and Rotated BRIEF (ORB), and Scale-Invariant Feature Transform (SIFT) Pipeline for Robust Key Point Matching in 3D Monitoring of Power Transmission Line Icing with Binocular Vision

Power transmission line icing (PTLI) poses significant threats to the reliability and safety of electrical power systems, particularly in cold regions. Accumulation of ice on power lines can lead to severe consequences, such as line breaks, tower collapses, and widespread power outages, resulting in economic losses and infrastructure damage. This study proposes an enhanced image processing pipeline to accurately detect and match key points in PTLI images for 3D monitoring of ice thickness using binocular vision. The pipeline integrates established techniques such as multiscale retinex (MSR), oriented FAST and rotated BRIEF (ORB) and scale-invariant feature transform (SIFT) algorithms, further refined with m-estimator sample consensus (MAGSAC)-based random sampling consensus (RANSAC) optimization. The image processing steps include automatic cropping, image enhancement, feature detection, and robust key point matching, all designed to operate in challenging environments with poor lighting and noise. Experiments demonstrate that the proposed method significantly improves key point matching accuracy and computational efficiency, reducing processing time to make it suitable for real-time applications. The effectiveness of the pipeline is validated through 3D ice thickness measurements, with results showing high precision and low error rates, making it a valuable tool for monitoring power transmission lines in harsh conditions.