Power Supply Interruption Research Articles

Research on False Data Injection Attack Detection of S mart Grid Based on Machine Learning

The safe and reliable operation of power systems is an important guarantee for the healthy development of the national economy. Industry and people’s lives are inseparable from electricity, so the safety and reliability of electricity supply is very important. The sudden interruption of power supply will not only bring serious economic losses, but also seriously affect people’s normal lives and even endanger social stability. False data injection attack (FDIAs) are a new type of power system network attack method. FDIAs are a new type of power system network attack method. It can successfully bypass the bad data detection mechanism, offset the power measurement data, and mislead the control center under extremely subtle conditions. Therefore, it poses a very serious threat to the stable operation of the power system. Therefore, this article first analyzes the principle of false data injection attacks, in order to provide a theoretical basis for subsequent attack detection. Then this paper constructs a detection method based on extreme learning from the perspective of optimizing learning efficiency. Based on the IEEE14-bus standard test system, the method is verified through simulation, which shows the feasibility of this method, which provides a direction for building a safe and stable smart grid.

3D Model of partial discharge in defects with different sizes and positions in power cable for distribution and transmission networks

The knowledge of partial discharge (PD) phenomena inside electrical insulation of power cables is an important issue for assessing the insulation condition and its degradation state, obtaining information about the likelihood of failure. PDs cause signals to propagate along the cable, as noise phenomena, and contribute to the insulation degradation, culminating in a disruptive fault with the interruption of power supply. Therefore, PDs are considered the best ‘early warning’ indicators of insulation degradation and their modelling, with the development of on-line PDs location methods, are important topics to increase the networks’ electricity security. In this study, a three-dimensional (3D) model of PD events using the CST STUDIO® Dassault software is proposed. PDs inside air inclusions in epoxy-resin are analysed with different shapes, positions and sizes of the defect. The electric-field distribution is evaluated with the conduction current inside the void and the apparent charges induced on the electrode. The effectiveness of the model is validated by comparing the simulation results with other published experimental results. Finally, a description of a 3D–1D hybrid model useful to describe the propagation of PD signals in power networks is given.

Communication technology of crisis management in conditions of mass disruption of power supply in the period of «ice rains»

A technology is presented for crisis management and handing reputation and image consequences for the JSC IDGC Holding power company in connection with the man-caused accident of 2010 – 2011 (the most extended and painful for power supply of the Russian population), which occurred under the impact of a natural factor in the form of "ice rain" on power transmission engineering systems. Based on the results of a comprehensive analysis of the PR situation, the nature of the crisis has been revealed, which, in terms of its geographical scale, the extent of mass outages of consumers from power supply sources, and the scope of repair and restoration work, was unprecedented in the Russian Federation over the previous 30 year period. It is estimated that the restoration of performance of the electricity network infrastructure took three months (January through March of 2011) and involved huge information and communication resources, mobilization of staff and additional pool of specialists with a total number of more than 3 thousand people. The research methodology is consistent with conventional boundaries, with a full set of approaches typical of research of a systemic social phenomenon, such as the company's communication activities and in interfacing with the essential characteristics of business reputation. As a hypothesis, a convincing and proven assumption has been put forward that mass disruptions of power supply under the influence of natural elements can become a decisive factor for a fundamental shift in public opinion in favor of the power grid company, if the crisis PR program is based on creative ideas for the involvement of journalists, experts, environmentalists, deputies, other stakeholders and opinion leaders in the process of emergency response. By way of example of analysis of communication work in conditions of mass power supply disruption in the zone of responsibility of JSC IDGC Holding, a system of recommendations is suggested for the PR service activities during the crisis period.

Prosumer site power interruption attacks: exploiting the reactive power control feature in smart inverters

Increased adoption of distributed energy resources in the form of renewable energy sources (RESs) to handle the capacity expansion in the power distribution system (PDS) is a new paradigm. RESs being intermittent in nature, present operational issues that worsen with increasing RES penetration rate. An attractive approach for handling the intermittency is coordinated reactive power control (RPC) of the RESs in the PDS. RPC leverages on the reactive power capacity of the RES inverters and hence is a significantly cheaper option than the conventional solutions such as energy storage systems. Oversizing of inverters is considered to improve the robustness of RPC, however, malicious attackers may exploit the oversized capacity to strengthen their attacks. In this study, a demonstration of data integrity attacks launched against RPC and its impact on the availability of the power supply at the prosumer premises are presented. Validation for the attack using simulations and emulated experiments in a scaled-down power system test-bed is also presented. The analytical, simulation and experimental results illustrate the feasibility of tripping the circuit breaker at the prosumer site and causing power supply interruption. Finally, a defense mechanism is proposed to minimise the impacts and it is validated using MATLAB–SIMULINK simulations.

Analysis of Lightning Performance on 345 kV Transmission Lines Using Python Programming

One of main causes of interruption of electrical power supply is the lightning strike on overhead power transmission lines. The lightning performance of transmission line can be determined by value of shielding failure flashover rate (SFFOR) and back flashover rate (BFOR). The object of this study is to create a computer application to compute lightning performance on the transmission lines using Python programming. Pythons package tkinter used for program interface window. Application programming is done by using the concept of object-oriented programming (OOP) using Pythons keyword class. Validation shows that the application has applied the method correctly with a percentage error 0 % for SFFOR and 3.14 % for BFOR. The application can do analysis on the factors that affecting SFFOR and BFOR such as the effect of thunder day, tower foot resistance, and number of isolator disk. The results obtained in this study is computer application that can perform lightning performance analysis and analysis of factors that can affect it, such as thunder day, tower foot resistance and the number of isolator disk.

Об эффективности цифровой системы проактивной диагностики силовых трансформаторов

The purpose of the paper is to diagnose the state of a power transformer by determining its equivalent circuit parameters by means of synchronized vector measurements of currents and voltages in the transformer normal operation mode without shutdowns, which makes it possible to increase the reliability of relay protection operation. A cost - effective method for proactive diagnostics of power transformers is proposed. Through monitoring of additional parameters (short circuit resistance, active and inductive resistance of the positive sequence, active and inductive resistance of the negative sequence) it can increase the speed and accuracy of detecting possible internal short circuits arising due to winding damage or high-voltage transformer bushings without diagnosed transformer disconnection from the network. The method allows to estimate the transformer health index and serviceability by the difference between the calculated parameters of the equivalent circuit and the passport values of the parameters. Having conducted the damage causedependent analysis of the number of power transformer damages, the authors determined total economic losses that include the losses caused by equipment damage and losses caused by the interruptions in consumer power supply. The total economic losses for a power transformer with a rated power of 63 MVA amounted to 10687402 rubles. It is shown that the diagnostic system expands the possibilities of analyzing the transformer state in operating modes, allows to pr event the approaching of the damage moment and occurrence of sudden accidents as well as minimizes the expected damage from shutdowns and equipment failure. A hardware and software complex is proposed for the diagnostics of power transformer internal damage. The given main characteristics of the proposed hardware and software complex include the number of measuring channels, accuracy class, sampling frequency, and others. The results of the work expand the possibilities of analyzing the transformer state in the operating mode and can be used in the world practice of creating various monitoring systems designed to identify the defects developing in transformers caused by winding deformation.

Analysis on the behavior of line differential protective relaying with solar PV penetration

Power System Protection is very important in electrical power system as it minimizes power supply interruption to customers, and also prevents damages to electrical equipment. Lately, renewable energy (RE) penetration in power system helps to support and fulfil the increasing demand of electricity to customers. However, the contribution of power from RE such as solar photovoltaic (PV) will increase the fault level and lead to reverse power flow; thus, it will affect power system protection reliability. This paper focuses on evaluating the reliability of differential protection relay during steady state, internal and external faults conditions when the power system is without and with solar PV penetration. Steady state and three-phase symmetrical line fault will be simulated in IEEE 39 bus test system using Power System Simulation for Engineering (PSS<sup>®</sup>E) software.

Particle Swarm Optimization for Computing Nash and Stackelberg Equilibria in Energy Markets

Interactions among stakeholders in deregulated markets lead to complex interdependent optimization problems. The present study is motivated by load control programs in energy markets and more precisely by using the power supply interruption as a tool for reducing consumers’ demand voluntarily, also known as voluntary load curtailment programs. The problem is formulated as a Stackelberg game, specifically, as a bilevel optimization problem that belongs to the mathematical programs with equilibrium constraints. In this game, a player that acts as leader determines the actions of the players that act as followers and play a Nash game among them through a subsidy program. The corresponding equilibria need to be found and the presence of nonconvex functions makes the use of metaheuristic algorithms attractive. An extension of particle swarm optimization is proposed for solving such problems based on the unified particle swarm optimization that is a variation of the plain particle swarm optimization algorithm. The proposed algorithm is tested by solving some examples of the formulated games in order to study its efficiency and the interactions between the stakeholders of the market.

Quick and seamless transition method for I‐f to sensorless vector control changeover and on‐the‐fly start of PMSM drives

A smooth changeover from the I-f method to closed-loop sensorless vector control is a critical requirement for permanent magnet synchronous motor (PMSM) drives using a back-emf based sensorless algorithm for medium- to high-speed range control. The existing methods provide a smooth transition by aligning the angle generated by I-f control to the sensorless estimated angle. However, the overall start-up time increases due to the additional transition interval, which limits the usability of these methods for applications requiring a quick start-up. Furthermore, the use of a direct transition method to reduce the changeover time results in speed and current oscillation if the estimated position using sensorless algorithm is having an error. In the proposed method, the inverter pulses are disabled for a short duration and the machine back-emf is measured after the stator current falls to zero. Therefore, a quick and seamless transition is achieved in the proposed method by accurately estimating the rotor position from the sensed back-emf. The proposed method is also extended to perform on-the-fly start for power failure ride through during short time power supply interruption. The performance of the proposed method is verified using simulation and experiment on a 25 kW PMSM drive.

Town Massive Garbage –To - Energy for Maputo City in Mozambique Thesis

The growing development nowadays on Mozambique is directly associated to the crescent industrialization and the increasing number of the population on enormous cities of the Nation, what needs more electrical energy and produce more garbage; uncontrolled and putting it in a challenge to face this scenario. Maputo City is facing huge problem with the Town Massive Garbage (TMG), without the structure to treat it, which deposited in the open dumpsite out of normal conditions, contributing for many diseases and environment impact, when it is burnt or it burns spontaneously, the subterranean water body is contaminated with leachate (methane); and proximately 72% of population or citizens have not electrical energy. The intention of this task is principally to turn the Town Massive Garbage into electrical energy in Maputo City the capital of the country, taking on the different technologies according to the garbage’s conditions and increase the capacity of energy which is approximately to 20% on the Country and to reduce the impact of environment from the landfill and, the number of landfill and dumpsites, working and attempting to achieve the sustainable development goals. The country has been recording constant interruptions of power supply due to increased energy demand resulting from the development of their Citizen, construction of new industrial, hotel and Office building together with housing. The motivations is to apply garbage as other innocuous source of power or energy, knowing that in the country mainly hydropower and solar, wind, biomass in a small quantity, coal, fuel are vanishing; reduce the impact of environment, global warm and ailments caused by it. The methodologies used to achieve the objectives are thermodynamics, heat transfer expressions and the COCO-OPEN simulation methodology to predate the energy generate from the composition and quantity of MSW. The results illustrates the possibility to enforce Town massive Garbage as source of energy or power, clearly taking in account the track conditions, as the heating value of it is nearly equal to the coal value which has been used to generate energy in many plants around the world. Municipal solid waste should be the future source of electricity to many developing countries if they create the structure to deal with it, treating, separating in different categories, controllin

Методика оценки выбора периодичности и продолжительности плановых ремонтов основного оборудования теплоэлектроцентрали с учетом особенностей комбинированной выработки энергии и участия на рынке на сутки вперед

The study is aimed at developing a methodology for assessing the impact of schedule and volume of planned repair work - as well as reliability indicators of the main generating units - at combined heat and power plants on the efficiency and reliability of their operation. The described methodology is complemented by the creation of a software and computing complex for its implementation. For the development of the software and computing complex, mathematical modelling and optimisation methods were used. These were then implemented by the software and "System of Computerised Program Construction" computing complex created earlier by the employees of the Melentiev Energy Systems Institute Siberian Branch of the Russian Academy of Sciences. Optimisation calculations were carried out according to the criterion of maximum possible profit from the sale of electricity on the day-ahead market taking into account the optimal unit commitment according to the algorithm for the formation of optimisation tasks to minimise non-delivered energy production. By means of the software computing complex for selecting the frequency and duration of scheduled repairs, two calculation options were carried out differing in the calendar periods of operation between two consecutive complete, intermediate and current repairs. Under the operating mode of the CHP plant according to the option with longer periods of operation between repairs, the possible profit of the power plant from the sale of electricity in the day-ahead market is determined to be 169.8 million RUB, which is 1.2% more than the profit under the operation mode with shorter repairing periods. The losses from the non-delivered electricity for the adopted options were determined to be 10.5 and 10.64 million RUB, respectively, while, for the non-delivered heat energy, the losses comprised 37.3 and 37.7 million RUB, respectively. For the considered options, the difference in the amount of losses from non-delivered electricity and heat energy was 1.3 and 1%, respectively. The economic assessment of losses from possible emergency interruptions in power supply to consumers estimated on the example of an industrial CHP plant supports a conclusion concerning the applicability of the developed methodology for selecting the schedule and volume of planned repair work at the main generating units.

Design of smart wireless changeover for continuous electric current feeding from power sources of variable capacities

Electric power has become a vital element for life today. Despite this importance, electric power consumers in Iraq suffer from the problem of noncontinuity and daily electric power supply interruption. This problem led to the use of various sources of electric power as an alternative to compensate for the shortage of electric power provided by the Iraqi national grid. In this work, a smart wireless changeover device is designed using wireless sensor networks technology aiming to solve problem caused by the multiplicity of power sources received at home and governmental buildings in Iraq by controlling operation of some electrical devices (which consume high current) in the home or workplace automatically when changing source of electricity from one to another. This solution will help to ensure the continuity of electric current feeding from power sources of variable capacities, also, to rationalize power consumption by assigning an operation priority to electric devices. Furthermore, a statistical measurement as a case study was performed in a building with a total power consumption of 160.8 KW/h. The result showed that the device functions effectively and it is capable of achieving an average saving in power of about 50% to 86% depending on the applied priorities and case study scenario.

Cause of Electricity Supply Disruption Casuistic Assessment

The port has a big role as a means of transportation in supporting the mobility of goods and people. The port is a meeting point between land and sea so that makes the port very important in the economic growth of a region. So that the operation of ports for loading and unloading must not stop or be interrupted. In many cases, one of the most frequent disruptions experienced by ports is disruptions due to electricity supply. The purpose of this study is to find the main cause of power supply disruptions in one of the container terminals as research objects. There are two factors that influence electrical supply disruption, namely external factors and internal factors. Within these factors there are several categories such as weather based, flow of transmission line, lack of maintenance, electrical current stability and lack of human resources or standard operating procedures. By analyzing the flow of electricity supply distribution in the power plants to the terminal, author can find out the main agents that cause disruption of electricity supply and the impact to the terminal. This research is expected to be used as a reference to open up insights to see all the agent that have the potential to cause disruption to the electricity supply in the terminal, so that later they can take further action.

A Novel Methodology to Incorporate Circuit Breaker Active Failure in Reliability Evaluation of Electrical Distribution Networks

The random failure of components in a distribution network leads to power supply interruptions to electricity customers. Among different failure modes in the distribution network components, active failure is more frequent and requires the circuit breaker operations to isolate faulty segments. Active failure of a breaker causes the operation of a backup breaker, thus, exposing the larger segment of the network to outages. This paper proposes a new analytical methodology to identify breaker active failure events involving different order of contingencies. This methodology introduces an active breaker incidence (ABI) matrix to capture the active failure of breakers leading to load point failures. The ABI matrix is concatenated to the incidence matrix of the minimal path to form a new incidence matrix which reflects the information of all failure events including active failure of circuit breakers. These failure events are then utilized to evaluate the reliability indices. The proposed methodology is illustrated in a test distribution network. A study conducted on the IEEE Gold Book Standard Network shows that that the methodology effectively identifies and includes breaker failure events to evaluate the reliability performance, and that the proposed methodology can be utilized to make investment decisions in modern industrial distribution systems.

A Strategic and Significant Method for the Optimal Placement of Phasor Measurement Unit for Power System Network

Currently the new state of power system relies on a precise monitoring of electrical quantities such as voltage and current phasors. Occasionally, its operation gets disturbed because of the flicking in load and generation which may result in the interruption of power supply or may cause catastrophic failure. The advanced technology of phasor measurement unit (PMU) is introduced in the late 1990s to measure the behavior of power system more symmetrically, accurately, and precisely. However, the implementation of this device at every busbar in a grid station is not an easy task because of its expensive installation and manufacturing cost. As a result, an optimum placement of PMU is much needed in this case. Therefore, this paper proposes a new symmetry approach of multiple objectives for the optimum placement of PMU problem (OPPP) in order to minimize the installed number of PMUs and maximize the measurement redundancy of the network. To overcome the drawbacks of traditional techniques in the proposed work a reduction and exclusion of pure transit node technique is used in the placement set. In which only the strategic, significant, and the most desirable buses are selected without considering zero injection buses (ZIBs). The fundamental novelty of the proposed work considers most importantly the reduction technique of ZIBs from the optimum PMU locations, as far as the prior approaches concern almost every algorithm have taken ZIBs as their optimal placement sets. Furthermore, a PMUs channel limits and an alternative symmetry location for the PMUs placement are considered when there is an outage or PMUs failure may occur. The performance of the proposed method is verified on different IEEE-standard such as: IEEE-9, IEEE-14, IEEE-24, IEEE-30, IEEE-57, IEEE-118, and a New England-39 bus system. The success of the proposed work was compared with the existing techniques’ outcomes from the literature.

Optimal Overcurrent protection for industrial medium voltage network (Dept. E)

Abnormal condition and faults in power systems can cause power supply interruption and sometimes equipment damage. Hence, there is an increasing need for an effective protection scheme. In order to obtain a secure and reliable protection system, an effective coordination has to be satisfied between backup and primary protection devices. The main objective of this paper is to select the optimal settings of overcurrent relays that achieve the minimum operating time for relays when subjected to abnormal conditions or faults. The coordination process between overcurrent relays inside the network is accomplished considering detecting the fault and tripping the nearest circuit breaker to disconnect the affected area without affecting other areas. This paper investigates the protection requirement of switchgears in a practical power plant and design a coordination set for all circuit breakers and overcurrent relays in the low and medium voltage areas. In addition, both linear programming and genetic-algorithm methodologies are used to optimize the values of time dial setting for different operating scenarios of power plants so as to achieve the minimum operating times of overcurrent relays.

Combining DVR and UPS Techniques for an Uninterruptable Supply of Ultra-Sensitive Non-Linear Appliances

The paper deals with an application of combined techniques of dynamical voltage restorer (DVR) and uninterruptible power supply (UPS) that make possible both the short voltage sags compensation, as well as longer power supply interruptions, under the simultaneous operation of equipment and network. This is enabled mainly by an instantaneous voltage sag detection, quick bidirectional over-switches, and an instantaneous control method of the output voltage. This needs a fast control method, which can provide a voltage recovery for phase-sensitive loads during several calculation steps, so the dead-beat regulator is used. Such a system even compensates for the influence of non-linear loads on the power supply network without a change of a phase and amplitude of the supply voltage. The simulation results in Matlab/Simulink, as well as real experiments and their comparison results, are given in the paper.

Adjusting Electricity Cost Depending on Power Supply Outages

During the functioning of power supply system, there can be situations where the culprit in interruptions of power supply to consumers and a power quality violation is a power supply company or a consumer himself. Therefore, the economic incentive for power supply companies and consumers to increase power supply reliability and power quality is an urgent task. To implement such incentives, it is necessary to control the facts and time of power supply outages and their values as well as cases and time of non-compliance of power quality with the requirements of standards. It is possible with the use of a monitoring system for power supply reliability and power quality. (Research purpose) The research purpose is in developing a technical and economic method for stimulating power supply companies and consumers to increase efficiency of power supply system. (Materials and methods) The article provides a review of the structural diagram of a system for monitoring power supply reliability and power quality including devices for monitoring the number and duration of power outages and voltage deviations. (Results and discussion). An economic method has been developed to stimulate power supply companies and consumers to increase power supply system efficiency. The essence of the method is to control the parameters of power supply reliability and power quality, identify the violation of these parameters, determine the culprit of the violation, determine the time characteristics of the violation, summarize the duration of violations for the reporting period, compare the actual amount of duration with the allowable one, determine the amount of compensation for the violation and impose sanctions on payment compensation by the perpetrators of violations of these parameters. The article presents an algorithm for adjusting the cost of electricity supplied to consumers depending on the number and duration of voltage deviations and the number and duration of outages. The algorithm serves to ensure the operation of the specified technical and economic method. (Conclusions) The algorithm works in conjunction with a system for monitoring power supply reliability and power quality based on signals from devices that control the number and duration of outages and voltage deviations.

Research on thermal load classification and safeguard implementation

Under the current economic development, the contradiction between the shortage of energy and the increasing energy demand of the society becomes more and more prominent, which brings great hidden danger to the energy security of our country. In order to reduce the loss caused by the interruption of power supply, energy management measures corresponding to the importance of user load need to be developed. However, the existing load classification system only involves electric power and does not clearly distinguish the importance of thermal and cooling loads, making it difficult to guarantee the safety of power supply of important cooling and thermal loads in emergency situations. With reference to the principle of classified safeguard of electric load, this paper proposed the idea of thermal load classification with the analysis of the personal injury, economic loss and political significance. It provides important ideas and methods for the construction of comprehensive classification and classification of energy and complete standard system of energy security.

A Conceptual Framework for Intelligent Power Distribution Transformers

With the agenda of developing smart cities there is huge demand for continuous power supply. Power distribution transformers play avital role in providing a reliable power supply. Failure of a transformer will lead to interruptions in power supply. Many parameters lead to transformer failures. Health monitoring of transformer using IoT technology may help take proactive maintenance steps instead of reactive maintenance. When we combine IoT with AI it will more effective and IoT devices will take decision on their own. This paper presents a conceptual framework of this concept which makes the IoT devices in the transformers to make real-time decisions with the use of AI.