Distribution Substation Research Articles

Data-driven model for calculating capacity efficiency margins for distribution substations

To solve the problem of the low recovery rate of critical loads in the capacity efficiency margin calculation model of the distribution substation area, a data-driven capacity efficiency margin calculation model for the distribution substation area is designed by identifying the data characteristics of customer-side resources in the distribution substation area, approximating the functional relationship between mechanical and electrical energy using segmentation functions, finding the equipment regulation strategies corresponding to historical load sequences from the database, designing a dynamic optimal tide framework using data-driven technology, discovering the shortcomings that limit the performance of network carrying capacity, and constructing a capacity efficiency margin calculation model. Test results: Under three different simulation scenarios, the average values of key load recovery rates of the distribution substation capacity efficiency margin calculation model and the other two models are 64.946%, 56.223%, and 55.024% respectively, indicating that the designed distribution substation capacity efficiency margin calculation model is more effective when fully combined with data-driven technology.

Impact of Charging Stations for Electric Vehicles on the Power Distribution Network

Abstract The paper describes the impact of the load increase caused by the connection of electric vehicle (EV) charging stations in the power distribution network. The power distribution network model was created using the professional software tool DIgSILENT PowerFactory (DPF). Analyses were carried out for the cases of connecting a different number of EV charging stations to 0.4 kV busbars of distribution transformer stations (TS). The results of voltage conditions and loading of the most loaded distribution substations are shown. Increasing the load results in an increase in losses in the network, which is particularly significant today since the prices of electrical energy on the market are currently at historically high levels. Distribution System Operator (DSO) should pay attention to the problem of losses increase in the network, and in addition to classic solutions in strengthening the network, the DSO should also consider modern solutions such as the flexibility of new consumers.

Pengujian Tahanan Isolasi Pada Transformator Distribusi 160 kVA Di PT. PLN (PERSERO) UP3 Bengkulu

The power transformer is a high voltage equipment that functions as a distributor of electric power from high voltage to low voltage or from low voltage to high voltage. If the transformer's isolation condition deteriorates, it can have an impact on operating failure and the most fatal is that the transformer is damaged which can cause electrical system disturbances. To overcome this it is necessary to test the insulation resistance. This test is carried out using the polarization index method to determine the feasibility of the insulation resistance in the transformer. The use of this method is the most accurate and effective way to determine the feasibility of insulation resistance in transformers at distribution substations in Indonesia. This study took data at the location of PT. PLN (Persero) UP3 Bengkulu. In the insulation resistance test, the polarity index measurement results are obtained. Based on the data that has been collected then proceed with calculations and analysis to obtain better results. The ground-primary polarization index value shows that it is in good condition with a primary-ground value of 1.25 and a secondary-ground polarization index value of 1.5 (good standard between 1.25 – 2.0).

A comprehensive review of control techniques for compensating the fault current in resonant grounded distribution networks: From the perspective of mitigating powerline bushfires

Powerline faults are responsible for major bushfires around the world where arcs provoked from ground faults are common causes for igniting such fires. The grounding techniques (mainly resonant grounding) used in distribution substations and arc suppression devices play a crucial role for compensating fault currents in order to extinguish arcs so that the likelihoods of powerline bushfires are significantly reduced. Though passive arc suppression devices (e.g. Petersen coils) are extensively used for compensating the reactive component of the fault current, the active component of this current is still large enough to ignite the fire in bushfire prone areas for which active arc suppression devices are recently used. These active arc suppression devices incorporate residual current compensation inverters and the full compensation of the fault current rely on the control scheme of these inverters. This paper comprehensively reviews different control schemes that are used for compensating the fault current in resonant grounded power distribution systems. The existing control schemes are discussed in terms of the model used during the controller design process, loop structures, control block diagrams, and performance analysis frameworks (i.e. the type of fault impedances). It is worth mentioning that faults on resonant grounded power distribution networks exhibit the characteristics of high impedance faults and it important to consider this aspect for performance analysis of the control scheme. This paper also covers a brief overview of different grounding techniques used for mitigating fault currents and finally, the challenges with the existing controllers are identified in terms of extinguishing powerline bushfires. The comprehensive review motivates and guides future research activities on developing more efficient fault compensation techniques.

Mapping of Electrical Distribution Networks at Jampit Distribution Substations Using ArcGIS

In the Ijen sub-district, care must be taken to avoid overlapping uses of PTPN XII-owned plantations, resident fields, and the medium-voltage power distribution network. To lessen the interference factor in the distribution of electricity, the proper power distribution path must be chosen. The contact between trees and lightning is one of the variables that disturbs the distribution pathway. It is well known that the Jampit distribution substation in the Ijen district is situated in a region with plantations and private fields, making it susceptible to lightning and contact with trees. The position of distribution substations, medium-voltage overhead lines, and the location of energy users are among the issues examined in this study. In order to create a map of the electricity distribution network at Jampit distribution substations that pass through agricultural land and plantation areas, ArcGIS is used to help process spatial data including regional administration data, type of conductor, power capacity, distribution substation poles and electricity users.

Design of a Hybrid Transformer based on an Indirect Matrix Converter for Distribution Networks

This paper presents a novel hybrid transformer (HT) to regulate voltage sags/swells and to provide a unity power factor at the connection point to the medium voltage grid. The HT is a promising instrument for constructing an active distribution grid in the future. To overcome the applied design limitations concerning the converter and control system of the existing HTs, the HT structure and the control design have been proposed based on the indirect matrix converter (IMC) and Lyapunov energy function, respectively. The proposed HT topology consists of a direct power converter and a line frequency transformer. The proposed HT employs an IMC with space vector modulation that is connected to the distribution network via a series transformer. This power electronic converter increases the reliability, controllability and intelligence of the distribution substation. The Lyapunov direct control method is used to design the IMC controller that ensures tracking the input reference current and voltage. A systematic experimental and numerical investigation is performed in order to validate the effectiveness of the proposed topology. The proposed HT can compensate voltage sags/swells (more than 20% of nominal voltage). In addition, it performs properly in power factor correction and reduces the capacitor bank in the station.

Rancang Bangun REST API Aplikasi Sistem Informasi Gardu Distribusi berbasis Android dan Web

Today, the use of information systems is important, especially in archiving important data. Advances in technology have made conventional recordings begin to switch to digital. The case study in this research is to make an information system on one of the electric power systems, namely the distribution system. In this distribution system there is a substation that contains important components in the distribution of electricity from transmission to consumers. Generally, data collection at distribution substations uses manual recording on paper. This becomes less effective when it finds conditions of archiving data that have been in the past. Therefore, an application is designed that can help the authorities to record android-based data and websites. This information system is made using Rest API which facilitates communication via the internet. From the research that has been done, the performance between the mobile application and the website is good. Website performance produces applications on the web that have good results, namely 99, while Android is 93 from a maximum value of 100.

Application of LoRa Technology at Distribution Substation Using Peak Load Data

The process of monitoring and measuring transformers at PT. PLN (Persero) at the distribution substation BR 391 is done manually during peak load hours in the field, usually between 18.00-22.00 local time. Distribution substations sometimes have different peak load hours, in the morning, afternoon, evening, and sometimes during the day. Taking into account the different peak load hours at different substations, the current peak load hours are still determined by human. It is not effective, to overcome this, in this study it is planned to design a monitor and data storage using LoRa technology to monitor transformers at distribution substations all the time and has been tested at distribution substation BR 391 Jl. Wijaya Kusuma Medan. From the observations, peak load hours occur between 18.00-22.00 WIB and the highest peak load with power per phase: R=20,513,40 watts, S=15,350.06 watts, and T=21,323.91 watts. It can be seen that the highest average daily power consumption is at 20.00 WIB. More load usage occurs at night and the highest load is in the T phase. The increase in load affects the temperature increase of the cable up to 42.6℃

Studi Pendekatan Formula Jogja Pada Jaringan Distribusi PT PLN UP3 Pondok Gede

<em><span lang="EN-US">PT. PLN (Persero) at the Customer Service Implementing Unit (Unit Pelaksana Pelayanan Pelanggan, UP3) Pondok Gede, in order to make the loss reduction program more effective, first find out whether the biggest contribution to shrinkage in Pondok Gede UP3 is technical or non-technical. By using the shrink formula method, Jogja has several mechanisms to perform the analysis. The results of the Jogja Formula Shrinkage are presented in the Dupont Chart which divides losses into two parts, namely non-technical losses and technical losses, while technical losses are divided into four parts, namely medium voltage network losses, distribution substation losses, low voltage network losses, and house connection losses. So that we can evaluate and analyze these losses and the program's efforts to reduce losses are on target. In the calculation of the cumulative loss of UP3 Pondok Gede globally in the first quarter of 2020, it is 58,403,338 kWh or 12.27%. After performing a calculation simulation using the Jogja Formula, it was obtained with a technical loss composition of a total of 34,813,582 kWh or 7.31% (this technical loss cannot be avoided or eliminated because it is a shrinkage caused by the components of the equipment used), and non-technical losses. engineering of 23,589,757 kWh or 4.95%.</span></em>

Study of Low Frequency Magnetic Field of Indoor Distribution Substations

Abstract In this paper we presented some measurements of the low frequency magnetic field from indoor distribution substation. Using two automatic measuring instruments we made both spot measurement and automatic long-term survey presenting the spatial and temporal variability of the magnetic field in five areas with indoor distribution substation. Correlating the time of spot measurement, with that of automatic survey we estimate the magnetic field values to reduce the errors due to the temporal variation. With the values obtained after estimating the field, we draw maps for the entire zone of an indoor distribution substation. The results were compared with the maximum permissible limits by national and international standards and we found that they were not exceeded. However, in all five areas the values of the magnetic field were above the threshold of 400 nT taking into account long-term exposure, which can lead to biological effects on health, especially for children.

Analisis Kebocaran Gas SF6 Terhadap Kecepatan Busur Api dan Tegangan Tembus pada PMT di GISTET Saguling

Gas Insulated Switchgear Extra High Voltage (GISTET) is a power system component that has a function as a distribution center (transmission) that connects the extra high voltage transmission system through distribution channels or substations. 
 
 Based on the installation of GISTET equipment, relying on hexafluoride gas (SF_6) as an insulating medium on the equpment. Equipment at GISTET is not always in good condition, GISTET also often experiences problems. One of the distrubances that GISTET often experiences is the leakage of SF6 gas at the PMT (circuit breaker). This requires a treatment called a GISTET overhaul. So in this paper the author will analyze the SSF_6 gas leak as insulation on the PMT (circuir breaker) at GISTET Saguling.
 
 According to the results of the calculations in this final project, the gas pressure of SF_6 and the breakdown voltage of PMT are interrelated. At the pressure when the gas leak occurs is at a value below 5kgf/cm2it is able to with stand the voltage. Penetrating with a high value so it is very effective to reduce arc fire. In addition, the SF_6 gas pressure is also related to the arc speed because the lower the pressure value at the time of gas leakage, the arc speed decreases, so the arc will be slow to muffle.
 

High impedance fault arc analysis on 11 kV distribution networks

This paper presents a study of high impedance fault (HIF) arc analysis on 6 km 11 kV distribution network from New Haven to New NNPC, Enugu State. These HIF currents have low fault current ratings and are not readily detected by the distribution sub-station relays and protective equipment. This was realized with the aid of MATLAB. Firstly, the HIF was modelled based on the electric arc theory method for single line-to-ground and double line-to-ground faults, when the 11 kV New-haven to New NNPC Enugu distribution line interfaces with a dry asphalt ground surface. The HIF was incident on the midpoint of the distribution line between the switching times of the circuit breaker from 0.02 to 0.05 seconds. The results showed that for single line-to-ground and double line-to-ground faults, a peak current magnitude of 12.4 A and 2280 A were seen respectively and initial spikes due to arcing in the system voltages at the initial switching times of 0.02 seconds. The corresponding residual currents Ib and Ic are very small with a peak spike of 0.3 A and 1.9 A for double line-to-ground fault (BC-G). These spikes are because of the impact of the initial transients caused by the arc flames as its quenches and re-ignites.

Fast Charging of an Electric Bus Fleet and Its Impact on the Power Quality Based on On-Site Measurements

The subject of this study was a distribution substation that feeds 14 fast DC chargers (80 kW) located at the bus depot in Lublin, Poland. The voltage variations were determined to be within the PN-EN 50160 standard limit values (±10% Un). There were several events registered when 4th, 6th, 8th, and 10th voltage harmonics were above the PN-EN 50160 limit during the charging of the electric buses. The obtained maximum 10 min average values of the total voltage harmonic distortion (THD) were 3.36%, 2.27%, and 2.89% for the first, second, and third phase, respectively, i.e., below the limit value of 8% required by PN-EN 50160. Due to the exceedance of the 6th voltage harmonic, the PN-EN 50160 requirements were not met.

Bi-level planning and scheduling of electric vehicle charging stations for peak shaving and congestion management in low voltage distribution networks

Most existing algorithms for electric vehicle charging station (EVCS) planning and scheduling of electric vehicles (EVs) do not consider the uncertain behavior of EVs and distribution networks, including the EV arrival and departure times, user driving needs, and realistic residential load and generation profiles. This paper proposes a bi-level planning and operation framework that determines the optimal locations of EVCS and scheduling of EVs to reduce peak load and network congestion in low voltage distribution networks by considering uncertain EV and distribution network behavior. Planning of EVCS is performed to minimize voltage deviations and distribution network losses. The priority-based scheduling algorithm uses the vehicle-to-grid (V2G) and grid-to-vehicle (G2V) technology to charge the EVs during high priority periods to meet the user requirements and discharge during low or medium priority periods to reduce the peak load and thermal overloading in distribution feeders. Based on an Australian scenario, the proposed method has been tested on the IEEE low voltage test feeder. Uncoordinated scheduling of EVs is also implemented and compared with the proposed strategy. The results show that installing EVCS at the optimal locations can reduce the network losses and voltage deviations by 39.38 per cent and 15.32 per cent, respectively. It is also shown that the proposed scheduling of EVs can reduce the peak load of distribution substations and lower the network congestion without affecting the EV charging requirements. With a 55 percent penetration of EVs, the peak load and thermal overload in distribution lines are reduced by 20.53 per cent and 5.88 per cent, respectively.

Improving the Grounding System in 33/11 kV Distribution Substations

Improving the Grounding System in 33/11 kV Distribution Substations

Real-Time Estimation Frameworks for Feeder-Level Load Disaggregation and PEVs’ Charging Behavior Characteristics Extraction

In this article, a model-based real-time approach is proposed to disaggregate a feeder-level load and estimate the total energy of plug-in electric vehicles (PEVs), considering the controlled charging mode and the vehicle-to-grid capability of PEVs. To this end, aggregate demand of load categories participating at the feeder-head as well as the total energy of PEVs are analytically modeled. Then, the state-space representation of the system according to the mentioned models and their relations is proposed. Finally, a Kalman filter-based method is applied to disaggregate the feeder-level load into the aggregate demand of load categories and estimate the total energy of PEVs in real time. The accuracy and complexity of the proposed method are compared with two model-free methods, i.e., a nonlinear autoregressive with exogenous inputs-based shallow learning model and a long short-term memory-based deep learning approach, by using real data. They employ distribution substation measurements along with charging data of a very small subset of PEVs. The comparison results indicate that although the artificial neural network-based methods can effectively represent the nonlinear behavior of the feeder-level load and its components, the Kalman filter-based method significantly improves the PEVs’ total energy estimation by taking into account modeling and measurement uncertainties.

Seismic risk analysis of electrical substations based on the network analysis method

AbstractElectrical substations are critical elements of a power grid, enabling the transmission and distribution of electric power from power generators to the end‐users. Experiences from previous earthquakes have shown that electrical substations can be damaged due to ground shaking, reducing their functionality and potentially preventing the generated electric power from reaching end‐users. To assess the seismic vulnerability of a substation, a modular quantitative assessment method is proposed. In this method, the relation between the functionality state of a substation and the damage state of its components was established through the connection matrix technique. A substation is viewed as a network system, whose topology is defined by the connections among various pieces of electrical equipment (i.e., the components), represented in the connection matrix. The maximum allowable power transmission capacity of the substation after an earthquake is adopted as the system functionality metric, which is jointly determined by the power input, transform, and output capacity of the substation. The seismic vulnerability of an electrical substation is quantified by probabilistically calculating its postearthquake functionality when exposed to various earthquake intensities using Monte Carlo sampling. Finally, the risk of substation functionality loss is quantified by integrating the seismic hazard curve with the seismic vulnerability model of the substation. Two realistic case studies on a distribution substation and a transmission substation, with the same equipment configuration but different power delivery paths, were performed using the proposed method. Furthermore, a sensitivity analysis regarding the equipment fragility parameters is conducted, providing a risk‐informed basis for improving the seismic performance of the substation system.

STUDI TENTANG PERBAIKAN JATUH TEGANGAN DI TIANG UJUNG JARINGAN TEGANGAN RENDAH PADA PT.PLN UP3 AREA SAMARINDA

Abstract— Electric power distribution system is one of the systems in electric power that has an important role that is directly related to the user of electric energy. In the distribution system must have the appropriate reliability of the standards applied but in reality the distribution of electric power distribution is not appropriate, such as falling voltage commonly called drop voltage that reaches the consumer. This is caused by several factors so that the quality of existing electricity is not optimally beneficial and can even cause damage to electrical equipment. In phase S, from the analysis of calculations and measurements made by the author based on basic theory, conclusions can be drawn as follows. In calculations and measurements in phaseS R and T the voltage fall is caused by the length of the delivery. In phase S, when viewed from the calculation and measurement of voltage fall due to the length of the delivery and other factors, namely the cable connection is not perfect. From the data obtained by the author of the voltage fall at the GNK 383 Distribution Substation is not constant because the load changes the use of electrical energy by different consumers The voltage fall at the GNK 383 Distribution Substation occurs at night because the load usage activity by consumers is very high.

ANALISIS DAMPAK OVERLOAD TRANSFORMATOR TERHADAP KUALITAS DAYA GARDU K622 PENYULANG PELANGI PT. PLN ( PERSERO ) ULP KARANG

Transformer overload occurs in one of the distribution transformers in PT. PLN (Persero) ULP Karang,namely the K622 Distribution Transformer at the Rainbow Feeder with a load of 110.16% exceeding the standard set by SPLN, which is 80%. This study aims to find out how to overcome the Overload problem in the K622 distribution substation transformer on The Rainbow and get the size of the K622 distribution substation transformer load before and after the Uprating Transformer. From the results of uprating, the percentage of transformer loading value before uprating transformers was carried out by 110.16% and after uprating transformers by 26.38% so that it decreased by 83.78%. This means that the uprating transformer is one of the methods that can be used to overcome excess loads.

Optimal location and sizing of various DG units in real distribution substation using heuristic approach

PurposeThe purpose of the study is distributed generation planning in a radial delivery framework to identify an appropriate location with a suitable rating of DG units energized by renewable energy resources to scale back the power loss and to recover the voltage levels. Though several algorithms have already been proposed through the target of power loss reduction and voltage stability enhancement, further optimization of the objectives is improved by using a combination of heuristic algorithms like DE and particle swarm optimization (PSO).Design/methodology/approachThe identification of the candidate buses for the location of DG units and optimal rating of DG units is found by a combined differential evolution (DE) and PSO algorithm. In the combined strategy of DE and PSO, the key merits of both algorithms are combined. The DE algorithm prevents the individuals from getting trapped into the local optimum, thereby providing efficient global optimization. At the same time, PSO provides a fast convergence rate by providing the best particle among the entire iteration to obtain the best fitness value.FindingsThe proposed DE-PSO takes advantage of the global optimization of DE and the convergence rate of PSO. The different case studies of multiple DG types are carried out for the suggested procedure for the 33- and 69-bus radial delivery frameworks and a real 16-bus distribution substation in Tamil Nadu to show the effectiveness of the proposed methodology and distribution system performance. From the obtained results, there is a substantial decrease in the power loss and an improvement of voltage levels across all the buses of the system, thereby maintaining the distribution system within the framework of system operation and safety constraints.Originality/valueA comparison of an equivalent system with the DE, PSO algorithm when used separately and other algorithms available in literature shows that the proposed method results in an improved performance in terms of the convergence rate and objective function values. Finally, an economic benefit analysis is performed if a photo-voltaic based DG unit is allocated in the considered test systems.