Extra High Voltage Substation Research Articles

Binary Tree Algorithm-based Fault Location Method for Tripping in Ultra-high Voltage Substations

The current conventional method for fault location in substations involves using a mathematical model to convert the problem into a parameter identification problem. However, this approach often yields poor results due to the lack of characterization of fault features. To address this, a new fault location method for tripping faults in Extra High Voltage (EHV) substations is proposed. This method utilizes a binary tree algorithm to construct a fault binary tree and encode the nodes to accurately characterize the fault characteristics. Using this information, a fault location model is developed. Experimental verification confirms the effectiveness of the proposed method, with analysis showing its ability to successfully locate tripping faults in EHV substations with high convergence and superior accuracy.

Analisis Arus Gangguan Hubung Singkat Pada Feeder Tampinna Gardu Induk Tegangan Ekstra Tinggi Wotu

An electric power system is a complex system consisting of a powerplant, transmission system and distribution system that operates simultaneously in distributing electric power. In the distribution of electric power can not be separated from the occurrence of abnormal conditions of the system or disruption so that it needs a protection system to overcome the occurrence of interference. Disruption that often occurs in the electrical power system is a short circuit disruption so that a short circuit analysis is carried out as a first step in determining the right protection system. Short circuit disorder is a type of disruption that occurs in an electric power system due to an increase in excess current due to a decrease in the strength of isolation from the channel both between phases and between phases and earth. Tampinna feeder is one of the feeders in Wotu Extra High Voltage Substation. In this study will be calculated how much the current of short circuit interference in the feeder and the working time of the protection relay, namely OCR and GFR. From the calculation obtained a maximum short circuit disruption in three phases amounting to 771.86 A, two phases amounting to 668.45 A and one phase to the ground amounting to 370, 6 A.

Analisis Pengaruh Penambahan Suplai Daya 1000 MW Terhadap Performansi Jaringan Backbone 500 kV

Based on the Decree of the Minister of Energy and Mineral Resources (ESDM) Number 0074.K / 21 / MEM / 2015 concerning the Ratification of the 2016-2025 Electricity Supply Business Plan (RUPTL), the load growth every year has increased. Therefore, there will be additional Generating Units with a capacity of 1000 MW at PLTU Paiton, it is necessary to analyze the effect of additional loads in 2017 - 2022 on the 500 KV GITET system before and after the addition of a 1000 MW generator. Based on the analysis, it is known that the additional power of 1000 MW will strengthen the Paiton GITET reserve margin in bearing the load growth, it can be seen from the reserve margin value before the addition of power plants by 16% and after the addition of 29%. For the ability of the Paiton - Grati GITET transmission line until 2022, the load is 62% with a power loss of 35.41 MW (2.85%) and the load on the Paiton - Kediri GITET transmission line is 62% with a power loss of 35.41 MW (2.85%) indicates that the channel still in good shape. In addition, the load condition for the IBT transformer until 2022 is 84%, it can be concluded that the transformer is in good condition

Assessment of cortisol secretory pattern in workers chronically exposed to ELF-EMF generated by high voltage transmission lines and substations.

We investigated the effects of extremely-low frequency electromagnetic fields (ELF-EMFs; 50Hz) on the secretion of cortisol in 14 men (mean age=38.0±0.9years) working in extra-high voltage (EHV) substations. The workers dwelt in houses that were close to substations and high-voltage lines. Thus, they had long histories (1-20years) of long-yerm exposure to ELF-EMFs. Magnetic field strength was recorded using Emdex dosimeters worn by the volunteers day and night for seven days; the one-week geometric mean ranged from 0.1 to 2.6 μT. Blood samples were taken hourly from 20:00 to 08:00 the next morning. Cortisol concentrations and patterns were compared to age-matched, unexposed control subjects whose exposure level was ten times lower. The comparison of the control group (n=15) and the groups exposed to fields of 0.1-0.3 μT (n=5) and>0.3 μT (n=9), respectively, revealed a significant effect of field intensity on the cortisol secretory pattern. This study strongly suggests that chronic exposure to ELF-EMFs alters the peak-time serum cortisol levels. Studies are required on the effect of this disruption in high-risk populations such as children, elderly people, and patients with cancer.

Renewal Consider of Extra-High Voltage Substation in Existing Commercial Facilities

Renewal Consider of Extra-High Voltage Substation in Existing Commercial Facilities

Investigation of occupational hazard of 750 kV extra high voltage substations

Objective: To understand the current status of major occupational hazards in 750 kV extra high voltage (EHV) substations. Methods: In July 2019, through investigating and detecting the sulfur hexafluoride, power frequency electric field and noise occupational hazards of 750 kV EHV substations in substation 1, substation 2, substation 3, substation 4, substation 5, substation 6 and substation 7, the exposure intensity of the sulfur hexafluoride, power frequency electric field and noise intensity that the operators are exposed to during the inspection process were analyzed. Results: The qualified rate of 358 sulfur hexafluoride test results was 100.0% of the seven 750 kV EHV substations. The qualified rate of 8 h time-weighted average of the power frequency electric field of those 750 kV EHV substations contacted by operators was 100.0%. Among the 847 power frequency electric field detection points, the exceeding standard rate of power frequency electric field was 64.3%, and the differences in the power frequency electric field detection exceeding standard rates of different substations and inspection areas were statistically significant (χ2=87.52, 50.86, P<0.01) . The highest exceeding standard rate of power frequency electric field was the circuit breaker inspection area (94.4%, 34/36) . The noise intensity test results of the seven EHV substations were 41.1-79.7 dB (A) , and the qualified rate was 100.0%. Conclusion: The sulfur hexafluoride, power frequency electric field and noise that the operators contacted in 750 kV EHV substations meet the requirements of occupational exposure limits. The inspection areas of main transformers, capacitors, reactors, bus bars and switches have high power frequency electric field radiation, should be select equipment iand give priority to robot inspection, and reasonably adjust the inspection time to reduce the intensity level of substation operators' exposure to power frequency electric field.

ANALISIS PENGUJIAN KAPASITAS BATERAI 110 VOLT GROUP 2 (SISTEM 500 KV) GITET MANDIRANCAN

Abstract Battery is a DC system device, its existence is very important in the world of electricity to maintain the stability of the DC system. Battery function in Extra High Voltage Substation (GITET) as a backup to supply DC device components such as relays, PMS (Disconnecting Switch), PMT (Voltage Breaker), and SCADATEL telecommunication devices. In the event of blackout, the rectifier does not get a power supply whose function is to convert the AC to DC power current to meet the needs of the DC device lsitrik supply remains active and working, so that the battery that replaces the role of the rectifier to maintain the stability of the DC system until the repair is complete. To maintain the stability and feasibility of battery function, routinely conducted tests on batteries carried out once every 2 years. This paper will compare the data of test results conducted in 2018 and 2020. From the results of the comparison data obtained the function of the state of the battery. Testing the battery capacity through 4 stages, floating is a battery in a full charger does not receive and emits current under normal circumstances the battery is connected to the rectifier. Equalizing aims to equalize and level the voltage value on each battery cell. Dischaerge Battery is a battery testing process to obtain a total efficiency capacity value (Ah) of the battery. When the battery is discharged large, the next step is boosting to restore the voltage value at a normal state (floating) 1.40-1.44 volts.

Failure of 150 KV Power Transformer in Indication of Dissolved Gas Analysis Test in Total Dissolved Combustile Gas (TDCG) Method

A transformer is an electrical device to change the voltage from one level to a certain level with the same frequency that is generated from the generator. This transformer is used in a power plant to increase the voltage from the generator to be supplied to extra high voltage substations. By knowing the type and amount of gas in the transformer oil, it can be seen that the failure occurred. Preventive steps can be taken before the transformer is more severely damaged or a breakdown which will result in disrupted and detrimental electrical energy supply. The method used in this research is data collection methods used are observation, interviews and participation conducted at PT. Krakatau, Serang Banten. The method used to determine the failure of the transformer is the Dissolved Gas Analysis (DGA) method. The DGA test uses several methods to interpret the data, these methods are Total Dissolved Combustile Gas (TDCG), Key Gasses, Doernenburg Ratio, Roger's Ratio, IEC Ratio and Duval's Triangel. The method used in this research is direct observation of the process of taking transformer oil samples and testing transformer oil samples with the Transport-X tool. The result of this research is that the transformer condition is still in normal condition, because the appearance of CO2 gas has almost crossed the condition limit, so other supporting methods are needed to find the cause of the gas. Key gasses indicate the presence of overheating of paper insulation, IEC Ratio diagnoses transformer failure caused by heat failure at temperatures of 300o-700o C, Duval's Triangel diagnoses transformer failure caused by temperatures over 700o and this method supports the previous analysis. With this method, overheating occurs at certain points (hotspots) in the internal transformer. Preventive maintenance is needed to conform to the standard of the transformer. A transformer is an electrical device to change the voltage from one level to a certain level with the same frequency that is generated from the generator. This transformer is used in a power plant to increase the voltage from the generator to be supplied to extra high voltage substations. By knowing the type and amount of gas in the transformer oil, it can be seen that the failure occurred. Preventive steps can be taken before the transformer is more severely damaged or a breakdown which will result in disrupted and detrimental electrical energy supply. The method used in this research is data collection methods used are observation, interviews and participation conducted at PT. Krakatau, Serang Banten. The method used to determine the failure of the transformer is the Dissolved Gas Analysis (DGA) method. The DGA test uses several methods to interpret the data, these methods are Total Dissolved Combustile Gas (TDCG), Key Gasses, Doernenburg Ratio, Roger's Ratio, IEC Ratio and Duval's Triangel. The method used in this research is direct observation of the process of taking transformer oil samples and testing transformer oil samples with the Transport-X tool. The result of this research is that the transformer condition is still in normal condition, because the appearance of CO 2 gas has almost crossed the condition limit, so other supporting methods are needed to find the cause of the gas. Key gasses indicate the presence of overheating of paper insulation, IEC Ratio diagnoses transformer failure caused by heat failure at temperatures of 300 o -700 o C, Duval's Triangel diagnoses transformer failure caused by temperatures over 700 o and this method supports the previous analysis. With this method, overheating occurs at certain points (hotspots) in the internal transformer. Preventive maintenance is needed to conform to the standard of the transformer.

Research of electric field strength on surface of conductor and its splitting type used in extra high voltage substation

Extra high voltage substation is an important part of the whole project locates in high altitude area, so corona audible noise exists around the operation equipment, mainly concentrated in the bundle conductor in the power station. This research on the split form and surface electric field intensity distribution of bundle conductor has a certain degree of theoretical and practical engineering application value. In this paper, an analysis of the classic formula illuminates the conductor split form, conductor diameter, bundle spacing and other factors how to affect the largest surface electric field intensity of the conductor. On this basis, we take a typical extra high voltage substation conductor as the research object. The three-dimensional model of the actual power station has been established with application of finite element simulation method in accordance with actual structure, and a preliminary calculation of surface electric field intensity also been obtained. According to the results, we analyze the reasons cause the serious corona. Then we design three-split conductor instead of two-split one, and make a comparative analysis between the two different forms. According to the three-split form mentioned above, the conductor diameter and bundle spacing are optimized. The research on the electrical field calculation and split form of bundle conductor provides references for the design of substation, and has practical value for the reduction of corona noise.

Simulation Design of Ungaran 500kv Substation Operation System Using Microcontroller

Extra High Voltage Substation 500 kV is one part of the backbone of the electrical system in Indonesia, this happens because it supplies so many areas. In terms of these benefits it can be seen that the equipment in the substation must have high reliability so that the quality of electric power reaches the consumer optimally and consumers will not feel disadvantaged. Operation of a switching device at the substation to make changes to the system is called maneuvering. In the implementation of the substation maneuver, it must be in accordance with the Standing Operating Procedure (SOP), if a switching error occurs when the maneuver will be fatal for the electric power system and can cause harm to the company and consumers. Therefore we need a safety in the substation maneuvering process called interlock. In this final project, a simulation tool is made to apply the working principle of the interlock system to CB and DS in maneuvering voltage relief, voltage delivery maneuvers and load-based maneuvers based on the Arduino Mega 2560 as the central controller for the entire system circuit. This simulator tool has a fairly high level of work accuracy in accordance with SOP (Standing Operating Procedure). It is hoped that this tool can provide knowledge to the general public about the existing maneuvering system in the GI in maintaining electric power transmission systems well and easily understood.

Modeling the 10,000-Year Geomagnetic Disturbance Scenarios Based on Extreme Value Analysis

Modeling the extreme geomagnetic disturbance (GMD) scenarios is of great significance for risk assessment of the power system. In this letter, we model the 10,000-year GMD scenarios using the extreme value analysis to complement the classical 100-year and 200-year events. The 10,000-year GMD event is required for safety-critical nodes such as the ultra-high voltage (UHV)/extra-high voltage (EHV) substations and nuclear power plants, etc. The return level of geomagnetic variation is estimated using the geomagnetic observations based on extreme value theory, which is then combined with the theoretical upper limit of the disturbance storm time (Dst) index to establish the 10,000-year GMD scenarios. Finally, we present an application example of 10,000-year geomagnetically induced currents (GICs) in the Sanhua UHV power grid.

Data compression techniques for Phasor Measurement Unit (PMU) applications in smart transmission grid

Abstract The advances in Wide Area Measurement Systems (WAMS) and deployment of a huge number of phasor measurement units (PMUs) in the grid are generating big data volume. This data can be used for a variety of applications related to grid monitoring, management, operation, protection, and control. With the increase in this data size, the respective storage capacity needs to be enhanced. Also, communication infrastructure readiness remains bottleneck to transfer this big data. One of the probable solutions could be transmitting compressed data. This paper presents techniques for data compression in the smart transmission system using singular values decomposition (SVD) and the eigenvalues decomposition (EVD). The SVD and EVD based principal component analysis (PCA) techniques are applied to the real-time PMU data collected from extra-high voltage (EHV) substations of transmission utility in the western regional grid of India. Adequacy of data is checked by Kaiser-Meyer-Olkin (KMO) test in order to have the satisfactory performance of these techniques towards achieving the objective of efficient data compression. Results are found satisfactory gives compression more than 80% using real time data.

Analisa Hasil Pengujian Uprating Peralatan Pemutus Tenaga (PMT) 500 kV 7a3 Di Gardu Induk Tegangan Ekstra Tinggi New Balaraja

In meeting customer needs while maintaining the stability of the power system, PT. PLN (Persero) conducted an acceleration program carried out on the generation system which was followed by upgrading of the main technical material (MTU) found in several substations both on 500 kV and 150 kV systems. One of the MTUs conducted by Uprating is a Circuit Breaker (CB) equipment 500 kV located in the New Balaraja Extra High Voltage Substation (GITET). The difference in manufacturer's brand is an obstacle to the Uprating process so that it needs to be done Wiring Modification. The test equipment performed is the quality of SF6 gas, insulation and contact resistance, CB opening and closing time, minimum coil voltage and capacitance testing that refers to applicable standards and then analyzed the results of tests with existing theories.

Optimal Surge Arrester Placement for Extra High Voltage Substation

Lighting Phenomena is one of the important considerations during the design of Extra High Voltage and Ultra High Voltage Transmission Lines. Most of the authors have discussed regarding the benefits of using Surge Arresters as a way to improve the performance. In this paper, simulation analysis is done on 400kV/220kV Gwaka Substation, AP, India for optimal, cost effective placement of surge arresters. The most difficult configuration has been identified. A new method of “Voltage-Distance curve” is proposed to evaluate different Surge Arrester installation configurations. Finally the way to determine the optimal surge arrester configuration for each line section is then introduced in this paper.

Detection and Cause Analysis of Structural Defects in Lead Clamp Weld of Transformer

In this paper, the causes analysis of the cracking accident at the lead clamp weld-fusion line of transformer in the extra-high voltage substation was conducted.On-site non-destructive detection of weld defects was carried out to determine the size and location of the defects. An anatomical analysis of the clamp sample revealed that there was serious incomplete penetration and incomplete fusion in the internal structure of the weld, which seriously affected the structural strength of the weld. The causes of welding defects were further analyzed, and suggestions for improving product quality and strengthening inspection supervision were put forward.

Анализ сенсорных элементов схемы и выявление слабых мест в сетях генераторного напряжения

Large industrial enterprises use own electrical and thermal energy sources in addition to external power systems. Therefore, ensuring the stable operation of both the auxiliary power plants supply mechanisms and the main technological equipment of an enterprise is an important task in the electric networks design and reconstruction. The reliability of the power supply system can be carried out in various ways, one of which is the identification and analysis of sensory (sensitive) circuit elements in order to further eliminate weak units. Thus, the paper considers a complex generator voltage network of an industrial enterprise that is connected to the system through high and extra high voltage substations. This network features thermal power plants with auxi­liary and high-voltage industrial consumers of the enterprise and pumping stations. A series of electromechanical transients calculations was performed in the simulation of short circuits in the network using KATRAN 10.0 software package to identify the sensory elements of the circuit. Based on the results of the calculation, the stability of synchronous and asynchronous motors is estimated by determining the level of their operational parameters deviation. Based on the calculation results, it is concluded that the power plant mechanisms of auxiliary needs have the highest sensitivity, and the maximum deviation of the mode parameters is achieved during short circuits at high voltage levels. Analyzing the sensor elements of the system allows for the higher reliability of the industrial enterprise power supply system with strong disturbances in the network.

Evaluation of Measured Power Quality Results of a Wind Farm Connected to Taiwan Power System

This paper presents the power quality measurement results of a commercial wind farm (WF) connected to Taiwan Power System. This 46-MW Jang-Bin WF with 23 2-MW doubly fed induction generators is connected to the Jang-Bin extra high-voltage substation of Taiwan Power Company (TPC) through six feeders and a step-up main transformer. The measured data were recorded from October 2 to November 6, 2013, for a total of 35 days. The recorded results include three-phase voltages, currents, active power, reactive power, apparent power, power factor, frequency, current harmonics, voltage flickers, and voltage variations. According to the measured results, it can be clearly observed that the power quality of the studied Jang-Bin WF during the measurement period can meet the grid code of TPC.

A novel distributed unit transient protection algorithm using support vector machines

Based on fault initial angle and transition resistance, a novel ultra-high-speed distributed unit transient protection algorithm is established to protect a busbar and a connected transmission line simultaneously for EHV (extra high voltage) substation through analysing the direction and instantaneous amplitude of the fault-generated high-frequency transient current by utilizing SVM (support vector machine). The fault direction was first judged during the process, and then the fault location was determined by employing different trained SVMs. In addition, the fault initial angle and transition resistance are imported into the input vector of SVMs, through which their adverse effects on the protection performance can be significantly eliminated. Moreover, the proposed algorithm extracts the fault transient information just relying on one transmission line connected to the busbar rather than overall feeders, thus simplifying the process while ensuring high reliability. Further, only typical fault samples instead of all samples are needed during the SVM training procedure, which makes it quite appropriate for practical projects. According to massive simulation results on a typical EHV transmission system on ATPDraw platform, the proposed algorithm can precisely determine whether the fault occurs within the protected busbar or on the protected line or outside the protected area.

Ensuring Grid Code Harmonic Compliance of Wind Farms

The prevalence of cabled infrastructure associated with wind farms, combined with the increase in power-electronic interfaces in wind turbines and reactive power plant, has highlighted the pervasive nature of harmonics on electricity networks. Insufficient consideration is given to the effects of harmonics through the low prioritisation of power quality in the Front-End Engineering and Design stage and a lack of awareness of the obligations of the respective parties involved. The resulting designs are incompatible with the requirements of the relevant Grid Codes. This can lead to delays, commercial exposure, restricted network access and subsequent loss of revenue. The obligations of the Transmission Owner (TO), System Operator (SO) and wind farm developer are discussed with respect to Grid Code requirements and the responsibilities of each party in ensuring compliance. The technical aspects of assessing harmonic compliance are described in the context of the design considerations which are made at the various stages of the project development. These include the shift in resonances within the host network, the modification of existing harmonic distortion and the propagation of injected harmonics into the network and through to the extra high voltage, high voltage and medium voltage substations. The ensuing challenges associated with ensuring compliance through filter design are discussed in the context of relevant international standards, including UK ER G5/4-1, IEEE 519, EN 50160 and IEC 61000-3-6. The results indicate that shifts in resonances are more problematic to resolve, compared to the propagation of injected harmonics: injected harmonics are readily absorbed through local filtering and thus the emissions are typically low; in contrast, the effects of shifts in resonances must be transferred back to the point of common coupling, resulting in complex local filtering. Early selection by the developer of appropriate transmission infrastructure and technology can lower the filtering requirement necessary to meet the harmonic specification issued by the host TO.

Determination of the corona inception voltage in an extra high voltage substation connector

Substation connectors play a key role in the reliability of power transmission systems. Despite this fact, their behavior has been rarely studied, especially in regard to electric stress. In this study the corona inception voltage of a complex-shaped 765 kV substation connector is calculated by using a three-dimensional finite-element approach combined with the semi-empirical Pedersen approach. The method proposed was previously validated by using available experimental data obtained from sphere-to-plane, concentric cylinders and point-to-plane non-uniform air gaps. To further validate the accuracy of this method, the corona inception voltage of the analyzed substation connector was obtained by making comparisons with experimental tests conducted in a high voltage laboratory. Results show the need to calculate the corona inception voltage for complex geometries and large air gaps. Using this proposed approach allows us to identify peak or stress points of the connector surface. Hence, this system strongly appears to be a valuable tool to assist the design process of substation connectors and other high voltage devices for minimizing corona activity.