Substation System Research Articles

Design and Implementation of the Rapid Debugging and Automatic Acceptance System for the Substation Integrated Automation System

This article designs a rapid debugging and automatic acceptance system for the comprehensive automation system of substations, mainly used for the automatic acceptance of information in intelligent substation monitoring systems. It achieves functions such as static verification of remote configuration, synchronous acceptance of remote information and on-site monitoring information, dynamic closed-loop verification of remote information, automatic triggering of remote information, and archiving of acceptance reports; By using computer software technology, communication technology, and other technological means to improve the automation level of the comprehensive automation system acceptance of substations, reduce the participation of various departments in the acceptance process, and reduce the workload of manual operation of primary and secondary equipment addition.

ВИЗНАЧЕННЯ ОПОРУ ЗАЗЕМЛЮВАЛЬНИХ ПРИСТРОЇВ ПІДСТАНЦІЙ 330(220) кВ

In the electric power industry of Ukraine, the main system-forming objects are power transmission lines and substations with 330(220) kV switchgear. The most powerful sources of danger at substations are short circuits on the busbars, a direct lightning strike or the operation of overvoltage limiters and arresters.The purpose of the article is to develop a method for determining the resistance of the grounding system of substations with open switchgear 330(220) kV, aimed at increasing accuracy, taking into account the most influential independent factors. The provisions of the theory of experiment planning, the theory of electric circuits, mathematical modeling in the package Grounding 1.0, LiGro and Microsoft Excel were used to conduct the research. In the paper, a comparative analysis of the known formulas for determining the resistance of the grounding system is carried out: the formula of the GOST 12.1.30-81 standard, Ohlendorf-Laurant, Laurent and Neumann, Schwartz, Sverak formulas, as well as the formula of the international standard IEEE Std 80-2013. The results of multifactorial experiments to determine the dependence of the resistance of the grounding system on its area, the size of the grid cell, the perimeter of the cross-section of the grounding, the equivalent specific resistance of the soil, the short-circuit current and the depth of the grid location are given. A graphical comparison of the results of determining the resistance according to the considered formulas was carried out. In the paper, the method of determining the parameters of grounding system of 330(220) kV substations was further developed, aimed at ensuring standardized values of the resistance of the grounding system and the ground potential rise using formulas obtained from the results of multifactorial experiments. The results obtained in the work will make it possible to reduce the probability of damage to the insulation of 6-10 kV cables, as well as cables of secondary circuits from low-frequency and high-frequency (pulse) voltages when large currents flow into the grounding system in the mode of a single-phase short-circuit to the ground in electrical grid with a grounded neutral. References 9, tables 2, figures 6.

Techno-Economic analysis of distributed generation for power system reliability and loss reduction

ABSTRACT This paper presents a techno-economic analysis of the impact of distributed generation (DG) integration for power loss reduction and reliability of two 33 kV radial outgoing feeders at the Motta distribution substation in Ethiopia. Transient earth faults and permanent short-circuits were identified to be the most common causes of interruptions. The substation's system average interruption frequency index (SAIFI) is 806 and its system average interruption duration index (SAIDI) is 1394.145 for planned outages. This necessitates the pursuit of effective methods to increase the reliability of the distribution system. The results show that the distribution system is more reliable with the SAIFI and customer average interruption frequency index (CAIFI) reduced by 97.8%, SAIDI reduced by 76%, average service availability index (ASAI) increased by 14.38%, and average service unavailability index (ASUI) reduced by 76%, resulting in a total power loss reduction of 0.32 MW. The cost analysis was performed using the Monte Carlo (MC) reliability analysis and the DG net present cost analysis results in a payback period of less than five years indicating that the system is profitable.

Analysis of the Very Fast Transient Overvoltage in a Nuclear Plant 500kV GIL-GIS System

The simulation models of the 500kV gas-insulated transmission lines (GIL) and gas-insulated substation (GIS) systems in a realistic nuclear plant are presented in the paper. The Very Fast Transient Overvoltage (VFTO) which is generated during switching operations, is analyzed. Some affecting factors on the level of the VFTO are investigated. These factors are the location of the power source, the entrance capacitance of the potential transformer (PT), and the capacitive voltage transformer (CVT). At last, some suggestions on overvoltage calculations or calculations of electromagnetic interference sources are proposed. The conclusions can be used in insulation designing and analyzing the electromagnetic interference on the secondary system in nuclear plants and substations.

Энергоэффективное управление системой отопления для зданий с циклическим режимом работы

Lack of energy can be a significant factor holding back the country's economic growth. At the level of objects of energy consumption, this problem can be solved by developing systems for energy efficient management 
 of the consumption of energy resources, taking into account the peculiarities of the functioning of specific objects. There is considered a heating system of the building of the OSTROVskiy shopping center (SC) (Astrakhan). There has been made engineering evaluation analysis of energy saving and energy efficiency measures of the building. Engineering evaluation analysis of the building and the heating system of the SC as a control object was carried out, the main regulated, regulating and disturbing quantities were identified. A functional model of a SC as a thermal facility has been developed. To calculate the air temperature inside the building, a thermal model of the object was built based on the thermal characteristics of the building envelope. The correspondence of the model to the real thermal characteristics of the building is shown. A control system for the heating point of SC was developed using the Totally Integrated Automation Portal software. The interface of the control and management system for the heating point of SC has been developed. An algorithm for the heating system functioning in an energy-efficient mode is proposed, taking into account the cyclical mode of operation of SC. A comparative evaluation of the effectiveness of the proposed control system for a thermal substation in the modes of constant performance, variable performance with manual control, variable performance with automatic energy-efficient control has been carried out. It is shown that the use of the proposed method of energy efficient control makes it possible to reduce the consumption of thermal energy by 21.7% compared to the constant performance option used.

Analysis Of Modern Railway Power Quality Conditions With Inspection Methods To Mitigate Operating System Failures Referring To Regulations And Standard References

Elevated stations or commonly called elevated stations have an electric power system with a main power supply of 20KiloVolt with a nominal voltage of 750volt and a station operating facility voltage of 380volt laying station. This research uses the inspection method by making observations by work instructions and instruction manuals for railway infrastructure maintenance studies. Some were identified as related to power quality issues with progression-appropriate inspections and appropriate instruction manuals. The main objective of this study is to prevent overvoltage interference problems by recommending risk mitigation through investigative and simulation analysis methods using Electric Transient and Analysis Program (ETAP) software that can help evaluate and estimate strategic steps by paying attention to regulations and standard references and detecting losses in operating pattern disturbances due to disruption of power quality conditions caused by overvoltage surges in the station traction substation system by investigation and simulation methods using Electric Transient and Analysis Program (ETAP) software. This overvoltage is carried out in the context of research on maintaining services to the public and preventing system failures by using risk mitigation and investigation and simulation methods using Electric Transient and Analysis Program (ETAP) software that pays attention to environmental, safety, technical, and economic aspects with regulations and standard references. This research is in the form of mitigation analysis and describes the losses that have an impact by looking at a power quality condition and the follow-up provided to prevent overvoltage and components of modern railway electric facilities.

Case Studies for Supplying the Alternating Current Auxiliary Systems of Substations with a Voltage Equal to or Higher than 230 kV

This paper presents case studies for replacing diesel generators (DGs) that are used as the main and emergency power sources for alternating current (AC) auxiliary services in substations (SS) within the transmission network (voltage greater than or equal to 230 kV). The objective of this research is to present a solution that is more reliable, environmentally friendly, and financially viable than DGs. To achieve this, the proposed solutions incorporate Battery Energy Storage Systems (BESSs) with or without the integration of Photovoltaic (PV) Systems. These solutions were simulated using the HOMER PRO Version 3.14.5 software for the Messias SS /AL, and the results were analyzed and compared to the DG in terms of reliability, financial viability, and environmental impact. Based on the conducted analyses, the BESS solution with the PV system was found to be the most suitable for the main source. However, in the case of the emergency source, if one of the main sources is a DG/BESS, maintaining the emergency DG is the preferable option. If both main sources are independent, the BESS solution with the PV system is a suitable solution.

Seismic resilience evaluation and retrofitting strategy for substation system

Electrical substation systems have always had an obvious vulnerability during earthquakes. To find an efficient retrofitting strategy at a substation’s functional network level, this paper proposes a seismic resilience evaluation framework that combines seismic simulation and function recovery. According to the structural connectivity and redundancy of substation seismic behavior, a directed acyclic graph was built. After careful consideration of the load transmission capacity of substation equipment and important coefficients of the output terminal, a structural and electrical dual-function network model was established using the Simulink module. The model was divided into four analytical steps for hierarchical simulation. Post-earthquake iterative analysis was carried out according to equipment repair efficiency. The post-earthquake repair sequence was found, and the steps to functional recovery were obtained. To quantify the seismic retrofitting efficiency of equipment, a set of seismic analytical methods for retrofitting was developed using a typical 220 kV substation. Seismic resilience analysis using the Monte Carlo method led to new optimal retrofitting strategies under different resource limitation conditions. These new strategies are presented in this paper.

Modelling and Experimental Investigation on the Differential Protection of Transmission Line

Due to the significant impact of the fault on power systems and the failure of protection devices, power system operators and researchers have given reliability a great deal of consideration. The modern IEC 61850 standard is used recently to improve communication systems in digital substations and allow signals to be shared between the devices. Differential protection is used to protect the transmission lines, cables, and transformers, as it detects the faults by comparison of the currents flowing into and out of the protected devices. In this research, MATLAB/Simulink has been utilized to simulate the differential protection by using two current transformers (CTs) and to analyze the current waveforms of CTs. A model of the transmission line has been implemented in Taylor’s University Lab to validate the simulation results and measure the differential current, which equals the current summation of two CTs. The outcomes of the research show that the phase shift in the secondary side of CTs between two terminal points is zero and the value of differential current is zero under normal operating situations. However, the differential current has increased in each of the following cases: one CT is connected to the system with the wrong polarity or under an internal fault.

Proposal of a predictive and preventive maintenance plan in electrical substations through the use of thermography

The objective of this study was to make a proposal for a predictive and preventive maintenance plan in the electrical substations La Propicia, Las Palmas, and La Pradera belonging to CNEL-EP Esmeraldas Business Unit through the use of thermography. The methodology was of a qualitative approach, under the type of documentary-bibliographical research. The search for information was carried out online in scientific and academic databases. It was found that the information on the maintenance plans in the subtransmission system of CNEL EP Esmeraldas Business Unit, is meager, preventive and predictive maintenance actions are carried out such as revision, washing, readjustment and replacement of elements in poor condition, but no information was found on the analysis technique used leading to the maintenance activities of electrical equipment and installations. The results of the consulted investigations agree that the thermographic technique and its tools such as drones, infrared cameras and software programs are very useful for the diagnosis, collection and processing of data in electrical systems to determine maintenance requirements. Finally, the investigation yielded substantial information that allowed the preparation of a maintenance plan for the aforementioned La Propicia, Las Palmas and La Pradera electrical substations of CNEL-EP Esmeraldas Business Unit through the use of infrared thermography, to assist in their better operation. and performance by allowing the evaluation of the state of the equipment that makes up the electrical system of the aforementioned substations.

Deepening research on the construction thought of intelligent substation aerial survey auxiliary system

In the construction and development of modern society, the rational use of intelligent system is the inevitable trend of the development of the world's electric power, and the comprehensive promotion of smart grid is the basic consensus of the world's innovation. Substation intelligentization belongs to a gradual in-depth development process, which will change from traditional substation to integrated automation station, and then to digital substation, and finally become smart substation. Nowadays, Chinese power grid enterprises have already realized the large-scale construction and management of digital substations, and put forward the development goals and basic plans for the construction of smart substations. In 2020, the intelligent development probability of important substations has reached 100%. Therefore, after understanding the construction scheme and development status of smart substation system, this paper mainly discusses the construction ideas and main structure of the new generation of smart substation line measurement auxiliary system, and then defines the future development direction of smart substation auxiliary system, in order to provide effective basis for the construction and operation of power system in the new era.

Application embodiment of civil construction technology of electric power system substation

In the rapid development of social economy, the power system as a guarantee of residents' normal life and work infrastructure, substation belongs to the overall system operation of the transfer station, practical project construction level affects the overall power system engineering operation quality, determines the social development of electricity safety and operation efficiency. From the perspective of overall development, the civil engineering construction of power engineering substation is the focus of the construction unit. In order to give full play to the application role of the power system and ensure the safety of the normal life of social residents, the technical personnel of the enterprise should fully grasp the key points of the civil engineering construction of the substation, pay attention to the actual situation, and determine the basic project construction scheme. Therefore, on the basis of understanding the current status of power system and substation civil construction, according to the construction technology applied in the construction of practical projects, taking the substation project of a regional power system as an example, this paper mainly discusses the application of civil construction technology of power system substation.

Desain Pemasangan Sistem Pembumian pada Gardu Induk Baru di Gardu Induk Kota Cane 1 x 30MVA Aceh Tenggara

ABSTRACT The presence of reliable and continuous electrical energy is very important to support modern human life, therefore its necessary to build a transmission network that connect to each other between substations. One of the important components to maintain the availability of reliable electric power in addition to the electric power protection system is the grounding system at the substation. The grounding system is useful for minimizing electric power disturbances due to overvoltage originating from the operation of existing equipment in the substation system as well as due to other factors external is a lightning impulse. In this paper, we will describe how to design and install a grounding system in substations. The type of installation of the grounding system selected is the mesh or grid method. The making of this grounding system refers to the work plan and working contract conditions, formulas commonly use in electric power engineering theory, the applicable rules and regulation of electric power system. The most important standards and variables in this design are the type and resistivity of ground resistance, step voltage, touch voltage and the length of conductor used. The result of this design after working for one month in the new substation area and measured using an Earth tester showed good result of ≤ 0.19 ohm as required by the owner is 0.3 ohm. The result of this measurement mean that the result of the grounding system design has been successfully implemented is 0.19< 0.3 ohm.

Perbaikan Tegangan dengan Menggunakan Kapasitor Bank 25 MVAR pada Gardu Induk Banda Aceh

The Nagan Raya coal-fired power plant in Aceh, Indonesia, serves as a major supplier of electricity to the region's power grid. However, the power generation unit of the plant, which supplies reactive power to the subsystem, often experiences disturbances that cause voltage values in the Banda Aceh substation system to decrease. This decrease in voltage can be detrimental to the quality of power supplied to the consumers. To address this issue, a capacitor bank with a capacity of 25 Mvar was installed at the end of 2016. The capacitor bank was successful in increasing the voltage value at the substation and proved to be an effective solution. However, with the anticipated growth in load in the coming years and the possibility of future disturbances in the power generation unit, it has been proposed that an additional capacitor bank unit with the same capacity be installed to further enhance the voltage quality at the Banda Aceh substation. To assess the feasibility of this proposal, simulations were carried out using ETAP 12.6.0 software. The simulation results show that the addition of a 25 Mvar capacitor bank unit would lead to an increase in the substation voltage value of around 5-6 KV. This increase in voltage would help to maintain the quality of power supplied to the consumers and ensure that the power grid remains stable even in the event of disturbances in the power generation unit. Overall, the proposed installation of an additional capacitor bank unit would be a cost-effective solution to enhance the voltage quality at the Banda Aceh substation and ensure the stability of the power grid. This solution could be adopted by other power plants facing similar issues in maintaining voltage quality in their power grid systems.

Analysis on Network Information Security Protection Technology of Intelligent Terminal Power Monitoring System of Substation under the Support of Multimodal Multimedia Information

According to the perspective of multimode multimedia data, the protection technology of network information security is mainly discussed. The theoretical basic research is outlined, its meaning, level, reasons, and consequences are expounded, and the future research content and development trend are discussed. With the rapid development of online services and mobile technology, the world has entered the era of multimedia big data. There have been a large number of scientific studies in the multimedia industry, which explain the various fields of big data, including the capture, storage, reference, excavation, and search of multimedia big data. The article expounds the specific concept of power monitoring system network information security, establishes the safety regulations of electric power monitoring system, formulates the corresponding ideas for the safety guarantee level of electric power monitoring system, and promotes the long-term development of China’s electric power enterprises. The safe operation of the power monitoring system is directly related to the stable operation of all power supply systems and even the social economy. At this stage, the situation of network security management in China’s power monitoring system is still not optimistic. We take the multimode multimedia data, organize the research dynamics of the network security protection technology, and discuss the future research trend.

Investigation and Simulation of Technical Power Losses on 33/11kv Distribution Feeders Based on Gauss-Seidel Iterative Approach

Loss of technical performance is one of the main causes of energy shortages and inefficient operation of electrical machines in energy systems. In this study, an analysis of power losses for six selected 33/11 kV distribution feeders was presented. (Kakoba, Ntare, Karamurani, Ishaka MbararaNorth1 and Mbarara North 2) at Mbarara Central Substation Network of UMEME Electricity Distribution Company in Uganda. Data such as cable type, conductor resistance, conductor reactance, and route length were obtained from energy suppliers. From this data, the Gauss-Seidel method was used to determine the total active power and associated reactive power of the entire substation system. The findings showed that the substation is profitable due to the small calculated total power losses. Although it is possible to reduce the total loss to at least 9-12%. Losses were due to old substations, overloaded transformers, and copper losses core losses in lengthy feeder routes. To improve the performance of power distribution networks, it was recommended to replace old conductors to reduce losses.

In Situ Calibration of Transmission System Power Grid Energy Meters Using Energy Measurements and Kalman Filter

Correct energy measurement is vital for electric energy trading. There are often stringent legal demands on the revenue metering that require periodic in situ substation verification. Traditional energy metering testing methods are not possible in IEC 61850 digital stations using a process bus. In this article, we will show that it is possible to use data analysis to verify the accuracy of energy measurement systems in substations. Our algorithms can be used as a part of the legal verification and runs remotely on-line. As a consequence, some of the periodic accuracy verification including substation visits can be abandoned. The on-line algorithms makes it possible to decrease the errors in both revenue metering systems and in other energy measurements systems in the Swedish transmission system. Measurement errors are now detected and amended much faster which reduces incorrect billing. The estimated value of incorrect billing is decreased by more than a million EUR annually. Our algorithms also provide a solution to bridge the problem to verify measurements in future fully digital substations.

Research on automatic correlation technology of virtual circuit in secondary system of intelligent substation

In this paper, an automatic connection method of virtual terminals based on the distance weight vector optimization model is proposed to realize the automatic connection of virtual terminals. The method defines the similarity of virtual terminal connections based on the edit distance, establishes an optimization model based on the sample data of virtual connections, and uses the particle swarm optimization to calculate the distance weight vector, so that the edit distance similarity can be adapted to the equipment produced by various manufacturers. Finally, the dummy terminals in the two pending IEDs (Intelligent Electronic Devices) are matched based on the similarity, and the matching reliability is given. The calculation example results show that this method can accurately realize the automatic connection of virtual terminals, effectively reduce the workload of substation construction, and improve the design quality of virtual terminals.

전력계통 네트워크 통신방식 변화에 따른 사이버위협 분석 및 대응방안 제시

The Energy Management System (EMS) communicates with power plants and substations, monitors the substations and plant operational status of the transmission and substation system for stability, continuity, real-time, and economy of power supply, and controls power plants and substations. Currently, the power exchange EMS communicates with power plants and substations based on the serial communication-based Distributed Network Protocol (DNP) 3.0 protocol. However, problems such as the difficulty of supply and demand of serial communication equipment and the lack of installation space for serial ports and modems are raised due to the continuous increase in new facilities to perform communication, including renewable power generation facilities. Therefore, this paper presents a TCP/IP-based communication method instead of the existing serial communication method of the power exchange EMS, and presents a security risk analysis that may occur due to changes in the communication method and a countermeasure to the security risk.

Experimental Study of District Heating Substations in a Hardware-in-the-Loop Test Rig

This study compares two district heating substation systems for implementation in rural district heating networks with non-retrofitted single- and two-family houses. The aim is to determine which system has the potential to provide lower return temperatures and/or lower power peak demand. A hardware-in-the-loop-test rig was utilized to measure the two district heating substations under real operation conditions. This experimental study demonstrates that load balancing of the district heating network is attainable with the district heating substation with storage. This is especially advantageous when there is a high demand for domestic hot water. Overall, both systems yield comparable return temperatures.