Reduce Transmission Losses Research Articles

A Convex–Concave Procedure-Based Method for Optimal Power Flow of Offshore Wind Farms

In recent years, offshore wind farms have boomed all over the world. It is essential to manage the energy dispatch of the offshore wind power systems to reduce transmission losses. This article proposes an optimization method for the optimal power flow of offshore wind power systems based on the convex–concave procedure. First, the nonlinear variables in the power flow constraints of the offshore wind power system are relaxed with newly defined variables. Second, the non-convex constraints are reconstructed according to the variables’ characteristics so that the optimization method satisfies all constraints at the same time. Meanwhile, by applying the Taylor series expansion, the relaxation variables’ gaps are changed dynamically, and the convex relaxation is tightened to ensure the effectiveness of the proposed method. Finally, the feasibility of the relaxation and the optimized solution is verified by the simulation to realize the power optimization in the real offshore wind system.

Transactive energy revolution: Innovative leverage for reliable operation of modern energy networks—A critical review

The electric industry is developing towards a more efficient, reliable, and resilient electric power network. In this way, utilizing distributed energy resources (DERs), especially renewable DERs (RDERs) are a paradigm change. DERs offer many advantages in power systems, including transmission loss reduction, environmental benefits of RDERs, and enhancement of security, reliability, and resiliency of the network. However, high penetration of DERs increases uncertainty and challenges the efficient and reliable operation of the power system. This paper provides a thorough review of the transactive distribution platform which is essential to address the aforementioned challenges. This distribution platform includes a transactive distribution system operator providing a seamless and coordinated control to dynamically balance supply and demand and follow uncertain generations of RDERs. Indeed, this review paper highlights the capability of transactive energy (TE) by considering its key aspect in providing energy sharing opportunities for the integration of DERs into smart grids (SGs). TE is acombination of economic and control methods that enable optimum, reliable, sustainable, and efficient operation of SGs. Furthermore, a fully transactive framework offers more choices for DERs to control and manage the energy transactions in the retail market, as well as improves the inter operability among various market players.

A micro off-grid power solution for solid oxide fuel cell waste heat reusing enabled peak load shifting by integrating compressed-air energy storage

Nowadays, the proportion of thermal power generation is still large, the waste of electricity will lead to more environmental pollution. With the continuous increase in electricity demand, how to improve the quality of power supply, reduce transmission loss and ease the burden of power grid are urgent problems to be solved. The combination of fuel cell and energy storage technology could be a good solution. In this article, a new off-grid system with peak load shifting function is proposed to solve problems of power supply in remote regions. This combined system consists of a solid oxide fuel cell, a regenerative Brayton cycle, an organic Rankine cycle and a compressed-air energy storage system. By rational utilization of waste heat in exhaust gas, the cascade utilization of energy can be realized. The results indicate that the fuel cell-waste heat recovery system can achieve higher thermal efficiency and exergy efficiency, with an improvement of 6.69% and 6.46%, respectively. The application of compressed-air energy storage system not only makes the system have the functions of energy storage and peak regulation, but also improves the economic performance. The system reaches a minimum payback time of 4 years in the case presented. In conclusion, this new combined system is clean, efficient and economical, which can provide a good solution for power supply in coteaux, suburbs and islands.

A novel design for muffler chambers by incorporating baffle plate

In many technical applications in the present era, acoustics noise is the most difficult issue for humans. Although reactive and absorptive types of mufflers are currently available for noise reduction, their performance is limited for a variety of reasons. This study involves measuring transmission loss in an automotive exhaust muffler and then adopting new design parameters to reduce transmission loss, which is important for a greener environment. The automotive mufflers chosen for this study are investigated and employed in a numerical study to compare with an experimental investigation of passive noise control for transmission loss in automobiles. The transmission losses are compared to the original muffler chamber specifications to find the change in transmission losses, and the muffler chambers are modified by integrating a baffle plate to minimise the automotive exhaust noise. The transmission loss in a muffler is experimentally controlled by a passive noise, and a numerical analysis is performed for comparison using commercial software MATLAB. The installation of the baffle plate reduces the transmission loss, both in the narrow band and octave band region, according to the experimental, numerical and theoretical data, with more reduction happening in the narrow band region than the octave band region in this passive noise control experimental work.

Hybrid Charging Station

A hybrid micro grid-powered charging station reduces transmission losses with better power flow control in the modern power system. However, the uncoordinated charging of battery electric vehicles (BEVs) with the hybrid micro grid results in ineffective utilization of the renewable energy sources connected to the charging station. Furthermore, planned development of upcoming charging stations includes a multiport charging facility, which will cause overloading of the utility grid. The project works on (1) the energy management strategy and converter control of multiport BEV charging from a photovoltaic (PV) source and its effective utilization; (2) maintenance of the DC bus voltage irrespective of the utility grid overloading, which is caused by either local load or the meagerness of PV power through its energy storage unit (ESU). In addition, the charge controller provides closed loop charging through constant current and voltage, and this reduces the charging time. The aim of an energy management strategy is to minimize the usage of utility grid power and store PV power when the vehicle is not connected for charging. To balance the load demand, the proposed system is connected to the grid through a three-phase bidirectional DC-AC (alternating current) inverter. The obtained results show that the proposed renewable charging mechanism is suitable for EV charging thus help creating pollution free environment.

Design and implementation of iot integrated monitoring and control system of renewable energy in smart grid for sustainable computing network

The Smart Grid (SG) is a system with a lot of controls and communications. Both local and global controls are included in these controls. One of the advantages of SG over a traditional utility grid is that it uses a two-way communication mechanism at each stage. However, challenges such as complexity, data gathering and administration, and so on are brought into the SG system as a result of this two-way communication. As a result, an SG needs connectivity, automation and device tracking. The Internet of Things is used to do this (IoT). This study presents an IoT-enabled smart grid monitoring and control system in a computer network. Here the IoT module has been used in monitoring the network which is integrated with (MLDRNN). Renewable (DER) should be combined in grids to make electricity supply more reliable and reduce transmission losses. The control system of smart grid has been enhanced using (CPCS). The suggested system is scalable, modular, and allows for the interoperability of various types of inverters, as well as data transmission over a secure communication channel. All of these characteristics, combined with its low cost, make the created control system and monitoring platform ideal for monitoring smart microgrids online. The experimental results show scalability, QoS, power consumption, efficiency of the network.

Simultaneous placement of electric vehicle charging station and DG units in urban area using novel enhanced antlion optimizer

The electric vehicle market has surged the consideration of charging station requirements in the commercial and residential areas of the urban regions. The addition of charging stations at the existing power network introduces a greater challenge on voltage stability and losses. The effect of the charging station can be addressed through the optimal integration of Distributed Generation (DG) units into the network. The improper placement of DG units can jeopardize the network stability. These issues are addressed by optimal placement of DG units and charging stations in the network to improve voltage, reduce transmission loss and maximize the charging station capacity. Here the objectives are considered as a multi-objective problem and solved using an enhanced Ant-lion optimization algorithm. The proposed method is implemented and tested over IEEE – 33, 69 and 94 radial bus system in MATLAB R2020a version. In IEEE – 33 bus system, the total loss reduction of 67.63% and the minimum voltage of 0.981 is attained with 2909.2 kW of DG and 1770.7 kW of charging station. The voltage stability index is improved to 0.92. The efficacy of the proposed method is evaluated through comparison with existing methods such as Genetic Algorithm (GA) with VRP method, Harris Hawks Optimization (HHO) and Particle Swarm Optimization (PSO). It is evident that the proposed method gives improved performance than other methods.

Performance of Various Voltage Stability Indices in a Stochastic Multiobjective Optimal Power Flow Using Mayfly Algorithm

The performance of voltage stability indices in the multiobjective optimal power flow of modern power systems is presented in this work. Six indices: the Voltage Collapse Proximity Index (VCPI), Line Voltage Stability Index (LVSI), Line Stability Index (Lmn), Fast Voltage Stability Index (FVSI), Line Stability Factor (LQP), and Novel Line Stability Index (NLSI) were considered as case studies on a modified IEEE 30-bus consisting of thermal, wind, solar and hybrid wind-hydro generators. A multiobjective evaluation using the multiobjective mayfly algorithm (MOMA) was performed in two operational scenarios: normal and contingency conditions, using the MATLAB–MATPOWER toolbox. Fuzzy Decision-Making technique was used to determine the best compromise solutions for each Pareto front. To evaluate the computational efficiency of the case studies, a preference selection index was used. The results indicate that VCPI and NLSI yielded the best-optimized system performance in minimizing generation costs, transmission loss reduction, and simulation time for normal and contingency conditions. The best-case studies also promoted the most scheduled reactive power generation from renewable energy sources (RES). On average, the VCPI index contributed the highest penetration level from RES (13.40%), while the Lmn index had the lowest. Overall, VCPI and Lmn index provided the best and worst average performance in both operating scenarios, respectively. Also, the MOMA algorithm demonstrated superior performance against the multiobjective harris hawks algorithm (MHHO), multiobjective Jaya algorithm (MOJAYA), multiobjective particle swarm algorithm (MOPSO), and nondominated sorting genetic algorithm III (NSGA-III) algorithms. In all, the proposed approach yields the lowest system cost and loss compared to other methods.

Optimal Capacity Allocation Model for Integrated Energy Microgrids Considering Aggregation of Prosumers Under Multi-Market Mechanisms

Traditional energy consumers gradually change to the new form of aggregation of prosumers (AOP) in the integrated energy microgrid (IEM) on the demand side. The emergence of the AOPs has led to the IEM’s structure changes, resulting in the emergence of two major stakeholders, the integrated energy microgrid service providers (IEMSPs) and the AOPs. The primary studies of this study are to configure the capacity for devices managed by IEMSP and AOPs with minimal costs. To achieve satisfaction for both IEMSP and AOPs, the approach of the non-cooperative game is used to allocate the capacity of devices managed by IEMSP and devices of AOPs. In detail, the IEMSP acts as a leader who determines the electricity pricing to minimize the cost, while the AOPs respond with electricity purchase or sales as the followers according to the price information provided by IEMSP. Moreover, electricity trading between AOPs is considered to reduce transmission losses and promote energy consumption nearby. To investigate the application of the multi-market mechanism in the optimal capacity allocation of IEM, a coupling mechanism of green certificate trading, carbon emission trading, and the electricity market is built in the proposed model. The cases are studied to verify the effectiveness of the proposed model in terms of saving the configuration capacity, reducing carbon emissions, and increasing the environmental benefits.

Optimal Current Allocation Strategy for Hybrid Hierarchical HVDC System with Parallel Operation of High-Voltage and Low-Voltage DC Lines

For long-distance and bulk-power delivery of new energy, high-voltage direct current (HVDC) is a more effective way than high-voltage alternative current (HVAC). In view of the current capacity disparity between line commutated converter (LCC) and voltage source converter (VSC), a hybrid hierarchical HVDC topology with parallel operation of 800 kV and 400 kV DC lines is investigated. The optimal current allocation method for hybrid hierarchical HVDC is proposed distinct from the same rated current command configuration method of high-voltage and low-voltage converters in traditional topology. Considering the transmission loss reduction of the HVDC system, a multi-order fitting function of transmission loss including LCC converter stations, VSC converter stations and DC lines is established. To minimize the transmission loss and the voltage deviation of key DC nodes comprehensively, a multi-objective genetic algorithm and maximum satisfaction method are utilized to obtain the optimal allocation value of rated current command for high-voltage and low-voltage converters. Through the optimization model, an improved constant current controller based on the current allocation strategy is designed. The hybrid hierarchical HVDC system model is built in PSCAD software, and simulation results verify the effectiveness of the proposed topology and optimal current allocation strategy.

Application of Sine–Cosine Optimization Algorithm for Minimization of Transmission Loss

On recent trends, the reactive power planning problem has received a considerable amount of attention for the allocation of reactive power resources, both static and dynamic such as switchable capacitors and/or reactors, as well as Var compensators, respectively. The reactive power has a significant impact on voltage profile, stability and transmission loss in power systems. In recent years, voltage instability is recognized as a major threat to system operation due to a shortage of reactive power in an interconnected transmission line. These voltage conditions could be analyzed and improved by proper coordination of reactive sources/sink. In this article, the minimization of transmission loss and operating cost is performed by using the sine cosine algorithm (SCA) and quasi-oppositional based sine cosine algorithm (QOSCA) technique for standard IEEE 14 and IEEE 30 and IEEE 57 bus test system of the connected power network. The proposed QOSCA reduces the transmission losses by 6.38% in IEEE 14, 4.56% in IEEE 30 and 12.77% in IEEE 57 bus system. The results obtained by QOSCA and SCA are compared with other popular techniques recently reported in recent state-of-literature. It is observed that QOSCA yields better results in terms of reducing transmission loss, operating costs, and improving the voltage profile of each bus.

Phase-Independent Reactive Power Compensation Based on Four-Wire Power Converter in the Presence of Angular Asymmetry between Voltage Vectors

The paper presents the reactive power compensation method that allows for reducing the active power flow even in the presence of angular asymmetry between voltage vectors of the utility grid. Reactive power compensation ensures the reduction of power transmission losses and therefore brings significant economic benefits to electricity consumers. The concept of the alternating current/direct current (AC/DC) converter for prosumer applications operating as a local reactive power compensator has been proposed. The system is driven by a multi-resonant algorithm, allowing for independent control of the reactive power in each phase. The proposed method was validated experimentally by using a prototype of the converter, programmable AC source, and grid impedance model. The method made it possible to cover the reactive power demand without unnecessary active power generation and thus to improve the efficiency of the analyzed prototype. This solution can be implemented particularly in radial grids and non-urban areas.

Smart Grid Technology Prospect of Implementation in Bangladesh

The term "smart grid" refers to the transformation of the traditional electric power grid into a modern grid. Modernization of the present electric power system is an important step to implement the Smart Grid technology. The structure of the existing power sector in Bangladesh is almost a hundred years old. Due to which the power sector of Bangladesh facing huge power wastage. A Smart Grid also ensures the efficient transmission and distribution of electric power. This paper gives a brief description of Smart Grid, the latest trends, challenges, prospects, cost analysis of smart grid equipment, and its facility. The spotlight of this paper is to implement the Smart Grid's perspective to Bangladesh. That’s included to have new distributed generation technology, smart meter, a pilot project, etc. Also, the main objective of this paper is the comprehensive development of transmission and distribution loss reduction, which will be saving a big amount of capital every year. And that will play a huge role in the economy of Bangladesh to move forward in global progress.

Vibro-acoustic modelling and analysis of segmented aluminum fuselage of transport aircraft with blankets

Vibroacoustic phenomenon is of prime importance in aviation industry as it is the driving cause for the annoyance to the passengers inside the aircraft. The great deal of effort has been put into studying the method of reducing high frequency noise inside the cabin of aircraft and the same has been achieved to acceptable level. In present work, vibroacoustic modeling and analysis of segmented aluminum fuselage with blankets made up of porous material was carried out. The surface model of segmented aluminum fuselage created using CATIA V5 R11 and meshing carried by HYPERMESH 10 followed by analysis in ABAQUS 6.10. The sound transmission loss analysis from exterior to interior cabin of segmented fuselage was carried out using finite element analysis for vibroacoustic phenomenon and it is compared with fuselage skin embedded with blanket. The sound transmission loss characteristics of various foams as blankets were studied and simulated of varius foams such as melamine, polyester, polyurethane and plastic foams. The results revealed that reduction of sound transmission loss in noise achieved at maximum excitation frequency of 159 Hz inside the fuselage cabin. The overall noise reduction inside the fuselage cabin for Melamine, polyester, polyurethane and plastic foams achieved to 10 dB, 11.5 dB, 8 dB and 14 dB respectively.

Use of Energy Storage to Reduce Transmission Losses in Meshed Power Distribution Networks

One of the challenges which the electrical power industry has been facing nowadays is the adaptation of the power system to the energy transition which has been taking place before our very eyes. With the increasing share of Renewable Energy Sources (RES) in energy production, the development of electromobility and the increasing environmental awareness of the society, the power system must constantly evolve to meet its expectations regarding a reliable electricity supply. This paper presents the issue of deploying energy storage facilities in the meshed power distribution network in order to reduce transmission losses. The presented multi-objective approach provides an opportunity to solve this issue using multi-objective optimisation methods such as Non-dominated Sorting Genetic Algorithm II (NSGA-II), Multiobjective Particle Swarm Optimization (MPSO) and Biased Random Keys Genetic Algorithm (BRKGA). In order to increase the efficiency optimisation process, the Pareto Adaptive ϵ-dominance (paϵ-dominance) was used. It was demonstrated that the use of energy storages that cooperate with RES can significantly reduce transmission losses.

Reactive power management by using a modified differential evolution algorithm

AbstractIn this article, a modified differential evolution (MDE) algorithm is proposed and applied to provide the solution for reactive power management by incorporating the flexible alternating current transmission systems (FACTS) controllers. The proper siting of FACTS controller has been achieved with an objective to minimize the losses and to improve the loading capability. The power flow analysis is performed to determine the optimal position for FACTS controllers. These controllers are incorporated in the most heavily loaded lines and hence controls the power flow in that particular line and allow more power to be transmitted in the remaining lines. The proposed MDE algorithm uses a novel DE/best3/1/bin mutation operator to produce three temporary mutant vectors which are averaged to obtain the mutant vector. Hence, the decision vectors of a generation simultaneously move toward the three best decision vectors of the population thereby maintains a better trade between exploration and exploitation. The proposed MDE algorithm is applied on different standard test bus (i.e., IEEE30, IEEE57, and IEEE118) systems with varying active and reactive loading (i.e., 100%, 110%, and 120%). The proposed method's performance is compared to those obtained from some well‐known meta‐heuristic algorithms. The proposed MDE algorithm optimized FACTS controllers reduce transmission loss by 60.90% in IEEE30 bus, 49.72% in IEEE57 bus and 8.37% in IEEE118 bus test system under base loading. The statistical analysis of the obtained results is carried out using the Wilcoxon signed rank test and the Friedman and Nemenyi hypothesis test, which ensures the reliability and robustness of the proposed method.

Photonics-inspired terahertz whispering gallery mode resonator waveguide on silicon platform

Terahertz (THz) photonic waveguides are of great importance in THz integrated technology, especially for versatile signal processing. However, in THz photonics, very few fundamental “building blocks” equivalent to those used in muti-functional electronics circuits exist. This study proposes a photonics-inspired micro-ring whispering gallery mode resonator (WGMR) waveguide with a standard waveguide-compatible package on silicon platform. A gradual taper is integrated on the same chip to improve the coupling efficiency and reduce transmission loss. The packaged WGMR waveguide with an operating range of 0.360 to 0.440 THz had a maximum measured extinction ratio of 32 dB at 0.390 THz, with a Q factor of 385 and an insertion loss of 2.6 dB. The compact and standard waveguide-compatible packaged WGMR can easily be integrated into practical terahertz application systems for THz signal processing and as a tool for the study of fundamental THz science.

Pressure-Based Energy Storage in Natural Gas Transmission Networks: Proof-of-Concept Analysis

Abstract This paper presents the possibility of energy storage in natural gas transmission networks using two strategies. Proof-of-concept calculations were performed under a steady-state assumption, and the more promising option was additionally modeled in a transient approach. The first strategy is based on a dedicated compressor–expander system installed at two ends of a pipeline. An electric-driven compressor increases the gas pressure in periods of peak electricity generation, while a gas expander allows energy recovery at a later stage. The compressor–expander distance determined by the inlet flow velocity of 5 m/s and a 4–5 h time shift ranges from approx. 75 to 120 km. The system provides a synergy effect, which allows to exceed 100% storage efficiency by reducing transmission losses. Storage efficiency obtained from the simplified model ranges from 70% to 128% for the performed case study. The second option uses existing compressors and pressure letdown stations expanding the gas to the distribution pressure. Here, gas pre-heating required prior to the expansion reduces the storage efficiency to about 30–40%. The dedicated machinery option was also evaluated using a transient model, which reports a lower efficiency if applied to the same assumptions. The system redesigned with the transient model is characterized by a longer storage duration (about 12 h) and a promising efficiency of 103.5%. Further research is needed to find the optimum design system parameters and to solve the detected problem of simultaneous compressor–expander operation which introduces idle work to the designed system.

Investigation of organic additives to regulate growth and signal transmission loss of copper interconnection structure

<p indent=0mm>Signal integrity is severely limited by the copper roughness. Plating solution containing different organic additives could influence the roughness of electroplating copper growth. Molecular simulation and electrochemical tests were used to regulate the competitive adsorption behavior of organic additives on the copper surface and understand the possible mechanism on the difference of copper growth. The results show that the plating solution system containing bis-(sodium sulfopropyl)-disulfide (SPS), ethylene oxide-propylene oxide copolymer (EO/PO) and Janus Green B (JGB) can contribute to the copper growth with smooth surface, leading to insertion loss of <sc>−8.9 dB@20 GHz.</sc> Therefore, organic additives could be used to regulate the low-profile growth of copper interconnection structure and reduce transmission loss to effectively ensure the integrity of high-frequency signal transmission.

Adaptive Differential Protection System for Microgrid

Microgrids are the small version of power system which grants us the integration of distributed generation resources to insure the facilities to the remotely located electric loads as well as have so many advantages over traditional power system like reduced transmission loss, green energy solution and proper use of renewable energy resources. However the resilience offered by microgrid is inconvenient if it is not be able to protect properly in case of any disturbance occurs which is very common in microgrid due to load dynamics. Protective devices used in traditional power grid cannot actually protect microgrid due to variable loads and different fault levels at grid connected modes and islanded modes. The available research about this concern has not been very successful, therefore options like distance, directional over current and differential relay remains effective protection scheme from present standard. Even though these relays are very useful in power system but their effectiveness for microgrid is yet to be analyzed. This paper is presenting the MATLAB simulation based analysis for differential relay type adaptive protection system by taking a complex microgrid model and generating various fault and generation capacities and analyzing it. In this paper different scenarios has been discussed where differential relay seems to be better than distance and directional over current relay protection scheme.