Electrical Circuit Research Articles

Impact of Using PhET and NI Multisim Simulation on Understanding Electrical Circuit Concepts

Impact of Using PhET and NI Multisim Simulation on Understanding Electrical Circuit Concepts

Resistance distance and sharp bounds of two-mode electrical networks

Abstract Electrical networks are ubiquitous in our daily lives, ranging from small integrated circuits to large-scale power systems. These networks can be easily represented as graphs, where edges represent connections and vertices represent electric nodes. The concept of resistance distance originates from electrical networks, with this term used because of its physical interpretation, where every edge in a graph G is assumed to have a unit resistor. The applications of resistance distance extend to various fields such as electrical engineering, physics, and computer science. It is particularly useful in investigating the flow of electrical current in a network and determining the shortest path between two vertices. In this work, we have investigated seven different resistance distance-based indices of bipartite networks and derived general formulae for them; the sharp bounds with respect to these resistance distance indices are also identified. Additionally, we introduced a novel resistance distance topological index, the Multiplicative Eccentric Resistance Harary Index, and derived general formula for it. The sharp bounds with respect to this newly introduced index are also identified for bipartite networks.

Dynamic phasor model of HVDC links for linear analysis of dynamic performance

This paper presents a linearized HVDC link model, which was implemented in PacDyn software and is applicable to dynamic performance studies of power electronic equipment considering electrical network electromagnetic transients, differently from electromechanical studies where the network dynamics is usually neglected. The proposed HVDC model was developed employing equivalent switching functions concepts and dynamic phasors. Simulations and results for small and large-scale test systems are presented. Model validation is performed through comparisons between results obtained by PacDyn and PSCAD. In sequence, there are practical examples of controller tunning considering adverse dynamic interaction mitigation between HVDC Link and electrical grid. The final results on a large-scale model of the Brazilian power system demonstrate that the proposed HVDC model can be used in actual engineering studies.

Different Demand Response Programs with its Implementation in Various Countries and the Role of TOU DR in the Context of Nepal

With the increasing trend of electricity consumption worldwide, it creates a cumbersome, reliable power system and necessitates the construction of new generator companies, transmission lines, and other infrastructures. Despite investing in new infrastructures to manage occasional peaks, utilities can use the demand response concept to effectively handle demand during such peak time intervals, and in doing so, it enhance the grid stability. This assists in balancing the supply and demand for electricity, making the grid more resilient to fluctuations, and reducing the risk of blackouts. This paper delves into the diverse DR programs across different countries and comparative analysis for finding the suitable DR method to make a more reliable electric power network in Nepal.

Wind energy cost evaluation based on a techno-economic assessment in the Algerian highlands

Wind energy is an important and growing source of renewable energy. It is becoming increasingly integrated into electricity markets around the world. In Algeria in particular, the integration of wind power into the electricity grid is being developed based on a government project to achieve a high penetration rate. In this context, this study is elaborated to analyse the techno-economic assessment of the electrical energy production from four selected wind turbines: Vestas V-80; Suzlon S-82; Enercon E-58 and Gamesa G-114, installed at three sites in the Algerian highlands, namely El Beidh, Sétif and Djelfa. The three highland sites are chosen due to their good wind potential. On the other hand, the Algerian transmission electrical network DZ-114 bus presents some technical problems in the highlands related to low voltage profiles. Therefore, wind farm integration in these three sites can be beneficial as voltage magnitude support. Besides, it can be an important tool to reduce fossil fuel consumption and pollutant gases from conventional plants. Wind potential assessment and economic analysis were carried out for the three selected sites using wind speed data measured 10 m above ground level over 10 years. The results obtained confirm that the Gamesa G114 wind turbine is the most suitable for all the sites and in particular for El Bayadh, as it offers both the highest annual energy production (AEP) and capacity factor (CF) values in all the selected sites and guarantees the lowest unit energy cost (UEC) compared to other types of wind turbines.

Exploring temperature effects on raw polysaccharide in semi-diluted solution using complex conductivity: Correlation analysis of activation energies

The evolution of the complex conductivity of raw polysaccharides extracted from Cystoseira myriophyloides algae exhibited significant temperature dependence in an aqueous solution. An analysis of the complex conductivity versus frequency was conducted using an appropriate electrical circuit based on our theoretical approach. This facilitated the generation of analytical functions representing the relaxation processes occurring at different temperatures. Subsequently, extrapolation and deconvolution procedures were employed to further investigate and identify all relaxation processes and their origins. These approaches revealed the presence of three relaxation processes. The first relaxation, observed at low frequency, is attributed to interfacial polarization between the electrode and the solution. The second and third relaxations, observed at medium and high frequencies, are attributed to bulk relaxation processes. Then, subtracting the low-frequency process clarified the bulk relaxation processes. Both relaxations are described by the Cole-Cole relaxation, which effectively models the well-known Maxwell-Wagner-Sillars (MWS) phenomenon typically observed in polyelectrolyte solutions. This relaxation is typically caused by interfacial polarization between molecular chains and counterions in the sample. Both relaxations were found to be thermally activated. The temperature dependence of useful parameters extracted from each relaxation, such as relaxation time (τσ) and conductivity (σdc) and (σ∞), followed Arrhenius law behavior. Furthermore, activation energy values for each relaxation process were determined, establishing a linear correlation between activation energy values related to relaxation time (τσ) and both conductivities (σdc) and (σ∞). These results confirm the origin of bulk relaxations and demonstrate a strong link between relaxation and conduction mechanisms.

Evaluation of injection current frequency on molten NaCl solidification images reconstructed by high-temperature electrical resistance tomography

Abstract The injection current frequency has been evaluated on molten NaCl solidification images reconstructed by high-temperature electrical resistance tomography (htERT). The evaluation is performed by an electrical equivalent circuit consisting of an electrical double layer (EDL), bulk solution and current-voltage path (CV path). The EDL and bulk solution are the elements to indicate electrochemical noise and bulk noise due to random thermally excited vibrations of Na+ and Cl-. The CV path compensates the measurement device errors due to low resistivity of molten NaCl. The molten NaCl solidification images were reconstructed by htERT in an alumina crucible with platinum-wire electrodes under the initial temperature air T 0= 820 ˚C and temperature drop rate γ= 6.67 ˚C/min. As a result, the solid volume fraction of molten NaCl φ was properly obtained in the appropriate injection current frequency of L f < f < H f, which is determined by the electrical equivalent circuit with EDL, bulk solution and CV path. The electrical equivalent circuit was validated by comparing the SNR and Nyquist plot obtained experimentally with an error of resistance. The best frequency range implemented into htERT for molten NaCl solidification images was determined as L f= 1.4 kHz and H f= 41 kHz.

Study of Solid-State Diffusion Impedance in Li-Ion Batteries Using Parallel-Diffusion Warburg Model

Abstract Anomalous diffusion impedance due to the solid-state Li+ diffusion in Li-ion batteries is often troublesome for the analysis. In this work, we propose a novel analytical Parallel-diffusion Warburg (PDW) model and couple it with the conventional equivalent electrical circuit model (EECM) analysis to tackle this long-standing challenge. The analytical expression of the PDW is derived from the classical Fickian diffusion framework, introducing non-unified diffusion coefficients that originate from the diverse crystalline conditions of Li+ diffusion paths, as theoretically demonstrated in the atomistic
modeling results. The proposed approach (EECM + PDW) is successfully employed to study the diffusion impedance of thin-film LiNi0.5Mn1.5O2 (LNMO) electrodes and porous LiNi0.80Co0.15Al0.05O2 (NCA) electrodes, demonstrating the applicability and robustness of this method.

Grounding resistance model considering propagation time between grounding electrodes

The velocity of electric field in the soil is sufficiently lower than that in the air. Conventional grounding resistance models based on an electric circuit theory ignore the propagation time between grounding electrodes (GEs). If the GEs are connected using an aerial lead conductor, the propagation time along the lead conductor is apparently different from that along a grounding conductor (GC) in the soil. The propagation time of mutual grounding resistance between GEs should be considered in accurate lightning surge analysis. This paper proposes a simulation model of the mutual grounding resistance considering the propagation time between GEs.

Modelling a DC Electric Railway System and Determining the Optimal Location of Wayside Energy Storage Systems for Enhancing Energy Efficiency and Energy Management

Global demand for fossil fuels is highly increasing, necessitating energy efficiency to be enhanced in transitioning to low-carbon energy systems. Electric railways are highly efficient in reducing the transportation demand for fossil fuels as they are lightweight and their energy demand can be fed by renewable energy resources. Further, the regenerative braking energy of decelerating trains can be fed to accelerating trains and stored in onboard energy storage systems (ESSs) and stationary ESSs. It is fundamental to model electric railways accurately before investigating approaches to enhancing their energy efficiency. However, electric railways are challenging to model as they are nonlinear, resulting from the rectifier substations, overvoltage protection circuits, and the unpredictability and uncertainty of the load according to the train position. There have been few studies that have examined the ESS location’s impact on improving the energy efficiency of electric railways while using specialised simulation tools in electric railways. However, no single study exists that has studied the location impact of stationary ESSs on the energy efficiency of electric railways while the trains are supported by onboard ESSs. Given these goals and challenges, the main objective of this work is to develop a model using commercial software used by industry practitioners. Further, the energy saving is aimed to be maximised using stationary ESSs installed in optimal locations while trains are supported by onboard ESSs. The model includes trains, onboard ESSs, rail tracks, passenger stations, stationary ESSs, and traction power systems involving power lines, connectors, switches, sectioning, and isolators. In this article, a test scenario is presented comprising two trains running on a 20 km with three passenger stations and two substations. The trains and track are modelled in OpenTrack simulation software (Version 1.9) while the power system is modelled in OpenPowerNet simulation software (Version 1.11). The two simulation tools are used in the railway industry and can produce realistic results by taking into account the entire electrical network structure. A stationary ESS is added on the wayside and moved in steps of 1 km to obtain the optimal location before investigating the impact of stationary ESSs on the performance and energy management of onboard ESSs. It is found that the energy saving when installing a stationary ESS at the optimal location is 56.05%, the peak-power reduction of Substation 1 is 4.37%, and the peak-power reduction of Substation 2 is 18.67%.

Synthesis of modeling and optimal management of smart grids

Smart grids may be characterized as the amalgamation of electrical grids, communication networks, specialized hardware, and computational intelligence (algorithms). This integration aims to oversee, regulate, and coordinate the generation, distribution, storage, and utilization of energy. Indeed, smart grid technologies have the potential to facilitate the distribution of substantial quantities of power generated from renewable sources. For this purpose, a comprehensive modeling approach is employed to simplify and enhance the feasibility of the task. It introduces a highly intricate system where modeling the components and relationships between entities proves challenging. Optimal energy management is necessary in this case. This paper provides a summary of an investigation into the modeling and optimal management of smart grids. In fact, this work allows a discussion of a hybrid system. Then we briefly introduce the domain of conceptual modeling within the enterprise.

Mitigation of Harmonics Due to Electric Vehicle Charging

The increasing adoption of electric vehicles (EVs) has led to an increase in demand for charging infrastructure. However, EV charging can introduce harmonic distortion into the electrical distribution network, causing power losses, reduced efficiency, and equipment damage. This project developed an EV charging system with harmonic reduction to ensure a stable and efficient charging process. The research methodology allowed the team to develop an EV charging system with harmonic reduction that was effective in reducing the total harmonic distortion (THD) level from 56.3% to 1%. The system was also found to be stable and efficient during charging. The findings of this project have the potential to make a significant contribution to the development of EV charging infrastructure. The proposed system can help to mitigate the negative impacts of EV charging on the electrical distribution network, while also ensuring a stable and efficient charging process.

Opportunities to use textile waste for the production of acoustic panels

There are many indoor and outdoor areas where one encounters acoustic discomfort. In this study, the design possibilities of a passive acoustic panel with macro-openings are investigated. An acoustic panel which absorbs a defined frequency of sound can be created when a suitable combination of acoustic absorption affecting parameters is found. These optimum parameters for a panel with macro holes were sought by means of experimental research regarding: the type of raw material suitable for the production of the components of the acoustic panel, the optimal hole shapes, their size and positioning on the panel lid, the possibility of using shredded textile from unsorted textile waste. The experiments in which the influence of the hole size and placement on the acoustic absorption was investigated were verified using a theoretical electrical equivalent circuit model created in the MathCad programming environment. The study found that the commonly used perforated panels made of Plexiglas can be fully replaced by panels made of shredded unsorted textile waste. It has also been shown that the shapes of the holes which can act as a design element can have various combinations, i.e. as long as the same percentage of perforation is maintained, the size of the circular holes or the shape of the slotted holes do not matter, as their acoustic absorption is within approximately the same range. The findings published in the study can help in the design of passive panels for both interiors and exterior use.

Detection of Salt Content in Canned Tuna by Impedance Spectroscopy: A Feasibility Study for Distinguishing Salt Levels.

The electrical impedance of dilute aqueous solutions containing extracts from five brands of canned tuna is analyzed using impedance spectroscopy in order to analyze their salt content and detect the potential presence of other salts beyond the well-stated NaCl. A complex electrical impedance is modeled with an equivalent electrical circuit, demonstrating good agreement with experimental data. This circuit accounts for the contribution of ions in the bulk solution, as well as those contributing to electrode polarization. The parameters describing the equivalent circuits, obtained through fitting data to the electrical impedance, are discussed in terms of the various ion contributions to both the electrical double layer at the electrode interface and the electrical conductivity of each solution. The ionic contribution to the electrical impedance is compared with that of a pure NaCl solution at the same concentration range. This comparison, when extended to real samples, allows for the development of a model to estimate the electrical conductivity of canned tuna samples, thereby determining the salt concentration in tuna. The model enables differentiation among the various samples of tuna studied. Subsequently, the potential presence of other ions besides Na+ and Cl- and their contribution to the electrical properties of each canned tuna extract is considered, especially for samples with a higher ratio of the sum of K+ and phosphates to Na+ concentration. This analysis shows the potential of impedance spectroscopy for on-site and rapid analysis of salt content and/or detection of additives in canned tuna fish.

Automated classification of electrical network high-voltage tower insulator cleanliness using deep neural networks

Automated classification of electrical network high-voltage tower insulator cleanliness using deep neural networks

J-A Approach to Simulations of HTS Tapes: How to Couple With Electric Circuits

J-A Approach to Simulations of HTS Tapes: How to Couple With Electric Circuits

Increase the operational reliability of the electric drive of the weaving machine

The main purpose of this research work is to analyze malfunctions, power consumption, engine overheating and vibrations based on the loadings of electrical circuits through artificial neural networks. The reliability of artificial intelligence systems was proven on the basis of a model-based system depending on the task, and the obtained values were experimentally compared in the electrical operation of existing equipment in general industrial enterprises. An imitation model of the real object was developed. A concept of increasing productivity was set up to identify malfunctions, in contrast to the existing annular method. The article developed an algorithm for increasing the operational reliability of the electrical operation of the weaving machine on the basis of integrated indicators of excitation to determine the probability of failure of electrical operation. The article proposes the possibility of directly processing the diagnostic energy parameters through artificial neural networks. An experimental combination of signals resulted in a model based on input power and torque, and was based on an asynchronous motorized electrical circuit. It has been proven that intellectual reliability can be increased by 3-5% compared to operational reliability in traditional methods.

Voltage differences as functions of a matrix eigensystem

We firstly consider an electrical network that consists of multiple subnetworks. We refer to some basic definitions which relate net current flows and voltages, the edges and nodes respectively of each subnetwork, and define matrix G, as the direct sum of the admittance matrices that correspond to each subnetwork. Then, we prove that any voltage difference at two arbitrary nodes can be explicitly written as a function only of the eigensystem of G, namely its eigenvalues and their corresponding eigenvectors. Next, we consider a DC/AC circuit network and by using duality properties of a matrix pencil related to the network, we obtain expressions for voltage differences as functions of the pencil’s eigenvalues and their corresponding eigenvectors. To validate our findings, we present illustrative numerical examples.

Development of stability charts for double salience reluctance machine modeled using hill’s equation

The paper presents a novel algorithm for the development of stability charts. The second-order differential homogeneous equation describing a double salient reluctance machine with a capacitance connected to its stator winding is transformed into hill’s equation. The circuit components are the stator coil time-varying inductance of a double salient reluctance machine, capacitance and resistance. All these are modeled by hill’s equation. The double salient reluctance machine acts as an energy conversion system. The maximum and minimum inductance of the energy conversion system is measured in laboratory by inductance, capacitance, and resistance (LCR) meter. These values help to determine the inductance modulation index. The inductance modulation indetx, the characteristic constant and the characteristic parameter obtained from modeling equations are used in the MATLAB/Simulink model. The MATLAB/Simulink simulations generate stable and unstable oscillations to form stability charts. The proposed stability charts are in good agreement with the Ince-Stritt stability chart, which is widely applied in physics, mechanics and in electrical engineering, especially where the state of stability of a system or an electric oscillatory circuit is to be determined.

Optimizing smart grid performance: A stochastic approach to renewable energy integration

Smart grids offer numerous possibilities for developing and executing sustainable and efficient electricity supply chains that exhibit increased resilience to disturbances. The exploration of the Electric Supply Chain Network (ESCND) design problem using smart grids has been limited. This article aims to tackle this challenge through the application of a robust multi-objective optimization approach, encompassing three economic goals (maximizing profit), environmental goals (minimizing greenhouse gas emissions), and resilience goals (maximizing network resilience). Additionally, the optimization process takes into account the dual objectives of maximizing efficiency and minimizing energy loss by incorporating relevant cost considerations. The proposed methodology incorporates distinctive features of smart grids, such as demandside management programs, microgrid structures, bidirectional distribution lines, and consumer–supplier nodes. It addresses various interconnected decisions, including location placement, capacity expansion, load allocation, and pricing. To solve the formulated model, a potent combination of multi-objective optimization methods based on cutting-plane algorithms and AUGMECON2 is introduced. Subsequently, the proposed model and solution approach are applied to a practical case study, and the obtained results are comprehensively examined. The findings suggest that, despite potential contradictions between economic and environmental objectives, the implementation of smart grids can concurrently improve environmental performance and network flexibility.