Feeder Network Research Articles

Optimal Sizing and Placement of Distributed Generators and Capacitors in Nepal's Sankhu Feeder Using the Water Cycle Algorithm

Minimizing power loss and improving voltage stability are crucial aspects of power systems, driven by transmission line contingencies, financial losses for utilities, and potential power system blackouts. Optimal allocation comprising the sizing and operating power factor—of Distributed Generation (DG) units and capacitor banks (CBs) significantly enhances power system efficiency. Efforts by power system operators and researchers focus on addressing issues related to power loss, energy loss, voltage profiles, and voltage stability through the strategic placement of DGs and CBs. Additionally, optimal DG and CB allocation protects the distribution system from unforeseen events and enables operators to run the system in islanding mode when necessary. The integration of DG units and CBs in distribution systems aims to enhance overall system performance. This research paper introduces a Water Cycle Algorithm (WCA) for the optimal placement and sizing of DGs and CBs. The proposed method targets both technical and economic benefits, considering multiple objective functions: minimizing power losses, reducing voltage deviation, lowering total electrical energy costs, and improving the voltage stability index. The WCA emulates the natural water cycle, from streams to rivers and rivers to the sea. Five different operational scenarios are evaluated to test the performance of this methodology. Simulations are conducted on distribution systems: the IEEE 69-bus test system and the Sankhu feeder network, a real system. The results demonstrate the superior performance of the proposed WCA compared to other optimization algorithms. The findings highlight the WCA's flexibility, efficiency, and significant improvements in economic benefits, establishing it as a promising approach for optimizing the placement of DG and CB in distribution systems.

Hub port location and routing for a single-hub feeder network: Effect of liner shipping network connectivity

For the design of feeder lines within a region, previous studies assume that the hub port is given in advance. It is necessary to investigate locating hub port together with designing feeder lines for a region. This paper proposes a hub port location and routing problem for a single-hub feeder network, which addresses feeder line design and hub port location. The proposed problem also considers liner shipping network connectivity (the connection between feeder lines and main lines via container transshipment at hub ports). It is described by a mixed integer linear program, which is solved by a genetic algorithm devised. Numerical experiments show that: i) the devised algorithm can efficiently solve our model; ii) due to considering liner shipping network connectivity, the optimal solution of hub port location and feeder line design becomes more rational, as compared with that without considering liner shipping network connectivity.

An Adaptive Droop Control for Power Sharing Between Three Phase Parallel Inverter in Autonomous Microgrid

The development of an adaptive droop controller is for power sharing between three-phase parallel inverters. Traditionally, droop controllers have been employed in conventional power systems to allocate the load among generators with varying capacities. Our approach involves the utilization of an adaptive control technique. This method is designed for a setup involving three-phase parallel inverters linked to an AC microgrid, to enhance the proportional distribution of active power despite changes in feeder network characteristics and loads. The proposed control mechanism automatically tunes the frequency droop parameter to address mismatch frequencies. The system includes two sets of three-phase inverters regulated by a combination of P-F droop control, an enhanced droop control loop, and PI controllers. The adaptive droop coefficient control is capable of addressing problems where power distribution inaccuracies arise due to different line loads as well as different inverter capacities.

Feeder bus service design under spatially heterogeneous demand

In rapidly sprawling urban areas and booming intercity express rail networks, efficiently designed feeder bus systems are more essential than ever to transport passengers to and from trunk-line rail terminals. When the feeder service region is sufficiently large, the spatial heterogeneity in demand distribution must be considered. This paper develops continuum approximation models for optimizing a heterogeneous fixed-route feeder network in a rectangular service region next to a rail terminal. Our work enhances previous studies by: (i) optimizing heterogeneous stop spacings along with line spacings and headways; (ii) accounting for passenger boarding and alighting numbers on bus dwell times and patron transfer delays at the rail terminal; and (iii) examining the advantages of asymmetric coordination between trunk and feeder schedules in both service directions. To tackle the increased modeling complexity, we introduce a semi-analytical method that combines analytically derived properties of the optimal solution with an iterative search algorithm. Local transit agencies can readily utilize this approach to design a real fixed-route feeder system.This paper reveals many findings and insights not previously reported. For instance, integrating the heterogeneous stop spacing optimization further reduces the system cost (by 4% under specific operating conditions). The cost savings increase with demand heterogeneity but decrease with the demand rate and service region size. Choosing the layout of feeder lines where buses pick up and drop off passengers along the service region’s shorter side also significantly lowers the system cost (by 6% when the service region’s aspect ratio is 1 to 2). Furthermore, coordinating trunk and feeder schedules in both service directions yields an additional cost saving of up to 20%.

Accessibility enhancement of mass transit system through GIS based modeling of feeder routes

Access and ingress to and from the metro stations plays a crucial role in elevating the efficacy of transportation systems. This study presents a novel approach to optimize and integrate feeder route network with mass transit system using GIS. An initial accessibility analysis of existing feeder routes revealed only 0.12% of the total population being served. To address the accessibility challenge a comprehensive GIS based feeder route design model based on population data and road network attributes was developed. The model efficiently identified candidate feeder stops which were further subjected to a route analysis model for optimal route design. A total of 29 feeder routes with an average length of 10.2 ​km were identified by the route analysis model. The results demonstrated that the feeder routes obtained through this method exhibited exceptional coverage across the study area effectively bridging the accessibility gaps. The effectiveness of the proposed model was validated through the service area analysis and density analysis, verifying a noticeable increase in route density and substantial population served corresponding to 0.25%. which is doubled as compared to the population served existing feeder routes. The study provides an opportunity for transit authorities to design efficient feeder networks complying with better integration and accessibility.

Two-Stage Optimal Scheduling for Urban Snow-Shaped Distribution Network Based on Coordination of Source-Network-Load-Storage

With the widespread integration of distributed resources, optimizing the operation of urban distribution networks faces challenges including uneven source-load-storage distribution, fluctuating feeder power flows, load imbalances, and network congestion. The urban snow-shaped distribution network (SDN), characterized by numerous intra-station and inter-station tie switches, serves as a robust framework to intelligently address these issues. This study focuses on enhancing the safe and efficient operation of SDNs through a two-phase optimal scheduling model that coordinates source-network-load-storage. In the day-ahead scheduling phase, an optimization model is formulated to minimize operational costs and mitigate load imbalances. This model integrates network reconfiguration, energy storage systems (ESSs), and flexible load (FL). During intra-day scheduling, a rolling optimization model based on model predictive control adjusts operations using the day-ahead plan to minimize the costs and penalties associated with power adjustments. It provides precise control over ESS and FL outputs, promptly correcting deviations caused by prediction errors. Finally, the proposed model is verified by an actual example of a snow-shaped distribution network in Tianjin. The results indicate significant improvements in leveraging coordinated interactions among source-network-load-storage, effectively reducing spatial-temporal load imbalances within feeder clusters and minimizing the impact of prediction inaccuracies.

Development of an Automatic Phase Selector for Nigerian Power Utility Customers

Power utility customers in a developing country like Nigeria have constituted a habit of changing the electricity supply line from an unavailable or unstable phase to the most available or stable phase. The category of customers involved in this character are those on single phase power supply. However, this act is being carried out manually at the meter point using the cut-out fuses. This attitude results in phase unbalances, overheating electrical equipment including feeder pillars, transformer coils, network faults, and overall system instability. Thus, this paper presents the development of an Automatic Phase Selector for Nigerian Power Utility Customers. The device automatically selects an available phase from the three-phase power supply lines. The research comprises designing an automatic phase selector circuit, simulation of the designed circuit, programming code development in C- Language for the microcontroller, construction of the designed circuit, and carrying out tests on completed work done to ascertain the effectiveness of the developed system. The system operation involved a three-phase supply from the closest distribution network of the power utility company which is connected to a three-in-one gang switch while the switching ON and OFF of their static switches represent phase-off in an ideal situation. The operational results of this system are presented in the form of the truth table which indicates that the affected customer would not have a power supply only when the 3-phases are under voltage or overvoltage or unavailable. This implies that one of the three phases that meet the three criteria would be switched ON. A pure sine wave was used as input into the Optocoupler and the output waveform of the rectified pulsating signal is separately displayed. This output waveform is very clean and noiseless. Finally, the system when practically tested with an unbalanced three-phase supply, worked perfectly enhancing the flexibility of operating an Automatic Phase selector and hence avoiding manual switching of the phase selector which has been attributed to changing of cut-out fuses and associated stress as well as having a user-friendly phase selector.

An elliptical dual-band antenna with crescent slot for 5G mmWave applications

Abstract This paper proposes a new elliptical dual-band antenna with a crescent slot with the advantages of compactness, lightweightness, low cost, and easy installation for 5G mmWave applications. The radiating element is obtained by Boolean manipulation of three ellipses of unequal length to short axis ratio, the resulting crescent slot defining its dual-band characteristics. The -10 dB impedance bandwidth of 23.8—31.6 GHz at 28 GHz and a bandwidth range of 36.8—40.6 GHz at 38 GHz are achieved, completely covering the currently applicable n257, n258, n260 and n261 mmWave bands and filtering out the unlicensed 31—36 GHz band. Dimensions of the single element are 10 mm by 7 mm. In addition, to reduce the interference caused by atmospheric attenuation, a conventional feeder network is combined with the designed antenna element to form a 1 × 4 line array to improve the gain. The antenna array with total dimensions of 20 × 25 mm2 is modeled in 0.254 mm thick Rogers 5880 substrate. As a result of the array configuration, 10.4 dBi gain and a 95% radiation efficiency are achieved in the 28 GHz band. Meanwhile, at the 38GHz band, the gain is 10.4 dBi and the radiation efficiency is 95%. The proposed antenna meets the 5G communication requirements well and can be a better candidate in the mmWave band range.

Optimal hybrid resonant current controller for microgrids connected to an unbalanced IEEE test distribution network

Microgrids (MGs) based on renewable energies have emerged as a proficient strategy for tackling power quality issues in conventional distribution networks. Nonetheless, MG systems require a suitable control scheme to supply energy optimally towards the electrical grid. This paper presents an innovative framework for designing hybrid Proportional-Resonant (PR) controllers with Linear Quadratic Regulators (LQR), PR+LQR, which merge relevant properties of PR and LQR controllers. This method simultaneously determines the MG control parameters and the current unbalanced factor generated at the distribution network. We select the traditional IEEE 13-bus test feeder network and place two MGs at strategic locations to validate our approach. Moreover, we use the Grey Wolf Optimizer (GWO) to find control parameters through a reliable fitness function that leads to high-performance microgrids. Finally, we conceive several tests to assess the efficacy of GWO for tuning the hybrid controller and compare the resulting data across distinct realistic operation conditions representing power quality events. So, we choose four case studies considering different renewable energy penetration indexes and power factors and evaluate the effects of the MGs over the distribution grid. We also compare the proposed hybrid PR+LQR controller against closely-related alternatives from the literature and validate its robustness and stability through the disk margin approach and the Nyquist criterion. Our numerical simulations prove that hybrid controllers driven by GWO are highly reliable strategies, yielding an average unbalanced current reduction of 30.03%.

Modelling and Analysis of High Performance for Solar Power Injection with Distribution Networks

Given the growing emphasis on environmental consciousness, there is a spike in the integration of solar photovoltaic energy into contemporary distribution networks. Interestingly, there is a non-linear relationship between the energy production of solar modules and changing external environmental conditions. In response, this study aims to increase the effectiveness of solar photovoltaic systems (SPVS) by putting out a careful analysis to ascertain the ideal performance criteria for the integration of renewable energy sources into distribution networks. The use of a Maximum Power Point Tracker is crucial to this assessment (MPPT). The model provides important insights into the possible increases in energy efficiency, making it a strong tool in this optimization process. In addition, the research conducts a comparison analysis, examining the distribution system properties in relation to different levels of solar PV system penetration. This aspect of the research illuminates the consequences of harmonic-induced distortions in current and voltage on the feeder networks in the distribution system. The simulation findings clearly show that as the penetration capacity of the PV system increases, so does the amount of harmonic dispersion that is introduced into the network. This suggests that it would be wise to incorporate the photovoltaic (PV) array only as far as the network can support it in order to prevent any possible performance reduction. Using MATLAB/SIMULINK as a computational tool, the research carefully examines the important characteristics from the technical data in order to examine the overall model. Further testing of the model's flexibility and resilience under a range of weather scenarios and partial shade conditions offers a thorough assessment of the model's performance dynamics. Positively, the investigation concluded with results that were satisfactory and confirmed the system's exceptional performance capabilities, which are supported by the MPPT. This result reflects a positive trend toward maximizing the integration of renewable energy sources into distribution networks, which will help to create a more sustainable and environmentally friendly energy landscape.

Three-phase voltage sensitivity estimation and its application to topology identification in low-voltage distribution networks

This paper aims to estimate the three-phase voltage sensitivity matrix and the network topology of a low-voltage distribution network from smart meter data, which measures voltage magnitude, current magnitude, and power factor with a lead/lag indicator. The targeted networks are three-phase networks with single-phase loads. Understanding network sensitivity and topology is crucial for fault detection, unmetered load identification, and addressing Dynamic Operating Envelope problems. The problem is formulated as a constrained optimization problem to estimate both the three-phase voltage sensitivity and the low-voltage transformer voltage. The estimated voltage sensitivity is used to further identify the network topology, by implementing an enhanced Recursive-Grouping and Backtracking algorithm, as well as a candidate topology selection technique. The proposed method is tested on the 55-node European feeder and several synthetic networks. Compared to the state-of-the-art, the results show a four-fold improvement in the accuracy of voltage sensitivity estimation and substantially fewer mistakes in the topology estimates. The result underscores the efficacy of a three-phase network model and voltage angle approximation in enhancing estimation accuracy.

Performance improvement of radial distribution system with distributed generation and intermittent load

The distribution network's load situation is typically variable and non-uniform. Therefore, a modified Distributed Generation (DG) algorithm is proposed in this paper, which uses the analytical approach and applies to all kinds of radial distribution feeder networks. The specified parameter of the distribution network is given accurately to the programme manually or through the file uploading mode, and the power flow analysis is done by MATLAB software. The results are obtained, including the specific location of DG placement which is optimised analytically. Here, the voltage and power profiles are monitored seriously, and the minimisation of voltage drop, and power loss is obtained, which is precise of a high value. The system is implemented for the IEEE 33 bus system which is got from Panchasakha Feeder Network. In this proposed method, DGs are deployed to reduce the loss in the transmission line as well as to maintain the voltage stability in the system by an analytical algorithm approach.

A broadband circularly polarized antenna for millimeter-wave applications

Abstract This paper presents a broadband circularly polarized (CP) antenna array for millimeter-wave applications, and the antenna array has the advantages of wide impedance bandwidth (IBW), novel CP design, and low profile. The antenna unit consists of a two-layer substrate and two pairs of magnetoelectric dipoles. Stepped microstrip lines coupled by rectangular slits form a feeder network for easy integration. The axial ratio bandwidth (ARBW) is extended because a pair of parasitic patches is loaded and an elliptical perturbation is added. The simulation results show that the antenna has an ARBW of 18.6% (26.4–31.9 GHz) and an IBW of 45.5% (20.6–32.7 GHz), with a gain greater than 7.11 dBic in the IBW. To improve the gain of the antenna, a 2 × 2 antenna array is designed, fabricated, and measured. The measured results show that the array has an ARBW of 16.6% (26.42–31.21 GHz), an IBW of 41.6% (22.28–33.97 GHz), a peak gain of 13.89 dBic in the IBW, the cross-polarization levels in the xoz-plane and yoz-plane are above 20 dB, and a radiation efficiency greater than 89%.

Pengaruh Panjang Jaringan Terhadap Drop Tegangan Pada Penyulang Duku dan Kurma PT. PLN (Persero) ULP Rumbia

Voltage drops in distribution systems can occur in medium voltage networks (JTM), distribution transformers, low voltage networks (JTR) and house lines. Voltage drops in the network cause suboptimal distribution and increase power losses. PT. PLN (Persero) ULP Rumbia has two feeders with pure radial network characteristics sourced from the Seputih Banyak Main Substation. The length of the Duku Feeder network has a voltage of 96.8 KMS with a load of 150 A while the length of the Kurma Feeder network is 207.21 kV with a load of 155 A. The network reconfiguration of the Dente Teladas Substation was carried out to shorten the network length. This research aims to calculate the voltage drop that occurs at the Duku and Kurma feeders before and after network configuration. This research uses the quantity method to compare the calculation results with the voltage drop standards set by PT. PLN (Persero). After reconfiguring the Duku and Kurma feeders, there was an increase in tip voltage which indicated improvement. From the calculation results before adding the network to the Duku feeder, the voltage at the receiving end was 19.5 kV with a voltage drop of 7.1%, and at the Kurma feeder the voltage at the end of the line was 17 kV with a voltage drop of 19%. This is clearly no longer in accordance with the local TMP, and requires further study to overcome this problem. The voltage on the two feeders goes through a step up process using a Medium Voltage OLTC (On Load Tap Changer) so that the voltage on each feeder becomes between 19.86 kV to 20.16 kV.

Intraday residual transfer learning in minimally observed power distribution networks dynamic state estimation

Abstract Traditionally, electricity distribution networks were designed for unidirectional power flow without the need to accommodate generation installed at the point of use. However, with the increase in Distributed Energy Resources and other Low Carbon Technologies, the role of distribution networks is changing. This shift brings challenges, including the need for intensive metering and more frequent reconfiguration to identify threats from voltage and thermal violations. Mitigating action through reconfiguration is informed by State Estimation, which is especially challenging for low voltage distribution networks where the constraints of low observability, non-linear load relationships, and highly unbalanced systems all contribute to the difficulty of producing accurate state estimates. To counter low observability, this paper proposes the application of a novel transfer learning methodology, based upon the concept of conditional online Bayesian transfer, to make forward predictions of bus pseudo-measurements. Day ahead load forecasts at a fully observed point on the network are adjusted using the intraday residuals at other points in the network to provide them with load forecasts without the need for a complete set of forecast models at all substations. These form pseudo-measurements that then inform the state estimates at future time points. This methodology is demonstrated on both a representative IEEE Test network and on an actual GB 11 kV feeder network.

Links among genetic variants and hierarchical brain structural and functional networks for antidepressant treatment: A multivariate study

BackgroundAntidepressant treatment effects are strongly heritable and have substantial effects on brain function and structure, but the underlying mechanisms are still poorly understood. In this research, we aimed to evaluate the factors of single nucleotide polymorphisms (SNPs) and hierarchical brain structural and functional networks that were associated with antidepressant treatment. Moreover, we further explored the correlations and mediation pattern among “brain structure-brain function-gene” in major depressive disorder (MDD). MethodsWe analysed 405 SNPs and rich club/feeder/local connections of hierarchical structural and functional networks with three-way parallel independent component analysis in 179 MDD patients. The group-discriminative independent components of the three modalities between responders and non-responders of antidepressant treatment were identified. Pearson correlations and mediation analysis were further utilized to investigate the associations among SNPs and connections of the structural and functional networks. ResultsNotably, correlations with antidepressant treatment outcomes were found in structural, functional and SNP modalities simultaneously. The features of group-discriminative independent components included the shared feeder connections of hub regions with the inferior frontal orbital gyrus and amygdala in structural and functional modalities and genes enriched in circadian rhythmic processes and dopaminergic synapse pathways. The structural feeder network displayed close correlations with SNPs and the functional feeder network. Furthermore, the structural feeder network could mediate the association between SNPs and the functional feeder network, implying that genetic variants might influence brain function by affecting brain structure in MDD. ConclusionsThese findings provide potential biomarkers for antidepressant therapy and provide a better grasp of the associations among SNPs and hierarchical structural and functional networks in MDD.

Reliability evaluation method for distribution network with distributed generations considering feeder fault recovery and network reconfiguration

AbstractThis paper presents a reliability evaluation method for distribution network with distributed generations considering feeder fault recovery and network reconfiguration, and mainly addresses issues: 1) insufficient consideration of the characteristics for the components and distributed generations (DGs) of distribution network such as time sequences, randomness and intermittency; 2) changes in the feeder area of the distribution network after the access of DGs; and 3) multi‐dimensional reliability index for distribution network with DGs has not been formed perfectly. Firstly, Markov reliability model for distribution network components/DGs is established in our study. Then, considering the fault recovery and network reconfiguration of the feeder area, island partitioning method of distribution network with DGs is also proposed. Moreover, a reliability evaluation model is presented for distribution network with DGs based on sequential Monte Carlo method. Case study is performed on the improved IEEE RBTS BUS6 F4 feeder system, and the research results indicate the validity and effectiveness of the proposed method. In addition, the system reliability indicators, such as system average interruption frequency index (SAIFI), system average interruption duration index (SAIDI), customer average interruption duration index (CAIDI), and average system availability index (ASAI), are studied and discussed in detail from three dimensions: the access of DGs, the types of DGs, and the capacity of DGs.

Distribution networks power loss allocation with various power factors

The users of power distribution and transmission networks are generally guided to sustain advanced power factor (PF) of load as it is affecting the power loss of a feeder network where it separately owns major influence on electric charges layout. Therefore, some cautious loss allotment schemes are to be incorporated and an acceptable satisfying/penalizing policy for advanced/less PF users, independently. Keeping this in view, the mentioned article proposed a new scheme, i.e., the active power loss allocation (APLA) procedure which allows power loss to the system distributors by considering the load demands, topographical localities, and PFs. A newly modified procedure assigns inducements hardly to all the involved utilizers against change in load PF continuously, where it is evaluated via proper mathematical and statistical study. The efficiency of the newly modified APLA scheme is explored in two dissimilar frameworks of low PF using 33 bus system radially distributed network (RDN). The interpretation is in favor of examined transmitted, distributed, and allows generated PF to be verified subsequently. Comparatively, the results achieved highlight the originality of the present method compared with different standard schemes/frameworks.

SHORT CIRCUIT FAULT ANALYSIS IN THE ELECTRIC POWER DISTRIBUTION SYSTEM AT PT PLN (Persero) UP3 SOUTH MAKASSAR ULP KALEBAJENG USING ETAP

Short circuit fault analysis is needed to determine the amount of short circuit current flowing in a system. This study discusses the single-phase short-circuit current to the ground at the point where the disturbance occurs from the base of the network to the end of the Malewang feeder network. The purpose of this study was to determine the amount of short circuit fault current in the Electric Power Distribution System at PT PLN (Persero) UP3 South Makassar ULP Kalebajeng. This study used the ETAP program and manual calculations. The results of the study found that the contribution of the largest single-phase short-circuit fault current to the ground in the Malewang feeder occurred on Buses located at the base of the network close to the Substation, namely Bus 1 (Exim-Rec Kalaserena) of 0.311 kA, while thesmallest Buscontribution occurred on Buses located at the end of the network far from the Substation, namely Buses 14 (Bilonga) of 0.292 kA. From the results of the study, it can be concluded that the farther the interference bus is from the Substation, the greater the channel impedance. The greater the impedance, the smaller the short-circuit current.

Studi Rekonfigurasi Jaringan Distribusi 20 kV pada Penyulang DPRD ULP Cianjur Kota Menggunakan ETAP

In the distribution of electricity from electric power sources to consumers who are located far apart, they always experience losses, namely in the form of voltage drops and power losses. However, the voltage loss that occurs in the process of distributing electrical energy is a waste of energy if it is not controlled optimally. Concerning the quality of service, the main factor which becomes the benchmark is the continuity of service and the quality of service voltage. The impact of these losses results in low levels of service quality to customers. Analysis of voltage drop and power loss is needed to determine the size of the voltage drop at the end of the DPRD feeder network. The calculation of voltage drops and power loss uses simulation results of ETAP method. The results of mathematical calculations and simulations are analyzed to determine the factors that cause the voltage quality at the end of the DPRD feeder network to be below the standard service voltage of 20 kV. The results of the analysis and simulation show that the factors that cause the voltage quality at the end of the DPRD feeder to be below the standard of service quality level are the transformer loading system, the type of conductor, and the distance of the substation to the far end of the feeder network. Then the problem was resolved by changing the type of conductor and reconfiguring it by shifting part of the load to the Lampegan feeder so that the voltage profile at the end of the DPRD Feeder was initially 17.527 kV after reconfiguration increased to 18.137 kV.