ПРОБЛЕМИ УПРАВЛІННЯ В СИСТЕМАХ SMART GRID УНІВЕРСИТЕТСЬКОГО ХАБА ЕНЕРГОЕФЕКТИВНОСТІ

The article attempts to tackle the issues of enhancing the performance of university energy efficiency management systems. An emphasis is put that in modern realia, alternative and renewable energy sources are becoming increasingly important in the electric power sector, thus contributing to environmental protection and enabling active electricity consumers to have their own sources of energy generation. However, it is observed that the relationships between energy generation sources and electricity consumers are complicated by new demands for setting balancing modes due to certain volatility of energy generation by alternative sources as well as the need to connect additional energy storage facilities. To identify opportunities of using Smart Grid technologies to manage the University energy consumption, a power balance equation was used to determine an active power balance between generated power, generation sources and power consumed by electricity consumers. In addition, the indicators of the total active power loss in the electrical network associated with the technological consumption of energy for its transmission was included into this equation. The study presents the results of an in-depth critical analysis on Smart Grid methodology and provides argument for the relevance of using artificial intelligence techniques in Smart Grid management systems of the University energy efficiency hub, along with suggesting a notion of electricity generating consumer in the concept of intelligent networks with two-way flow of energy and information as subsystems of a different nature. It is argued that the developed conceptual model of the electricity generating consumer for multilevel smart grid management systems and their infrastructure within the University energy efficiency hub allows establishing relationships between its structural elements and objects of different character. The findings reveal that the specifics of the developed method in setting priorities and regulatory standards for optimal management by a generating consumer within the University energy efficiency hub is the possibility of its automatic adaptation to changes in the external environment subject to interactions between electricity generating consumers.

Identification of the flicker source in the power supply systems

THE PURPOSE. To consider issues related to the study of methods for determining the sources of violations of the quality of electrical energy in power supply systems, in particular consumers which create rapid voltage changes or voltage fluctuations that create rapid changes in the luminous flux in electric lighting installations. Show that electrical receivers with a sharply variable operating mode are sources of fluctuations in the consumed current and voltage in the electrical network of power supply systems, which in turn manifests itself in the form of unacceptable values of one of the indicators of the quality of electricity - flicker, defined as the subjective perception of fluctuations in the luminous flux of lighting devices. To study the possibilities of determining the places of occurrence of significant voltage fluctuations without the use of expensive and complex instruments for measuring flicker values in the electrical network. To develop a simplified method for determining the locations of electricity consumers that negatively affect the operation of electric lighting systems and, ultimately, the vision of personnel. Conduct a check on a computer model of a simplified method for determining the places of occurrence of voltage fluctuations that are inadmissible in their magnitude, which are expressed in the appearance of significant doses of flicker that exceed the standard values.METHODS. Solving the problem, a computer model was used, created in the Simulink extension package of the Matlab scientific and technical calculation system.RESULTS. The article describes the relevance of the problem, discusses the quality of electricity in power supply systems. It has been shown using experimental data that in electrical networks there is an excess of the standard values of flicker doses. The possibility of using interharmonic components of the mains voltage to determine the sources of unacceptable doses of flicker is considered. A simplified method for finding flicker sources based on obtaining the values of the derivatives of currents at various points of the electrical network is presented. Computer simulation of an electrical network diagram with electrical receivers, which have both calm and sharply variable nature of work, has been performed. It is shown that the use of the values of the derivatives of the current at various points of the electrical network makes it possible to identify the sources of the occurrence of unacceptable doses of flicker.CONCLUSION. The occurrence of significant rapid voltage changes in the electrical network negatively affects vision, which is inevitably accompanied by increased personnel fatigue and can lead to industrial injuries. The results obtained by the authors of the article show that it is possible to use it to determine the places of occurrence of large voltage fluctuations, which are manifested in unacceptable doses of flicker of the derivatives of currents. It should be taken into account when conducting surveys of power supply systems in order to use fairly simple hardware to identify sources of disturbance in the quality of electrical energy.

Short circuit fire risk assessment in investigating and examining fires caused by emergency modes in overhead transmission lines

Emergency modes (short circuits) in electric power system and equipment are the main technical cause of fires. However, it is not always possible to prove the involvement of a particular operating mode in a fire. The fire hazard can be due to three components: a fuel load, an oxidizer and an ignition source. Since overhead transmission lines are used in an open space, they are oxidized. The presence of a fuel load is confirmed by a fire. The source of ignition should be identified. The aim of the study is to develop an algorithm for assessing the fire hazard for short circuits in overhead transmission lines with 1000 V. The study was conducted using scientific analysis, physical experiment and simulation. The ignition source is due to the appearance of an energy source with parameters sufficient to ignite a fuel load. The probability of ignition in overhead line wires depends on the probability of occurrence of the short circuit itself ( Qi (v1) ) , the probability of failure of protection devices ( Qi (v2) ), and the probability that the electric current value in the event of a fault is in the range of fire hazard values (Qi(z)). The values of the first two components are determined on the basis of statistical data, taking into account the theory of reliability. The third component is based on the experiment results. The experimental studies made it possible to establish the ranges of fire hazard values for uninsulated aluminum wires of various cross-sections, thereby providing the possibility of calculating ( Qi (z). Using the data obtained and information about the nature of changes in short-circuit currents and performance characteristics of protection devices, depending on the line length, an algorithm for assessing the fire hazard for a short circuit was developed. The results make it possible to assess the fire hazard for short circuits in various sections of the electrical network, made by overhead transmission lines, and to establish the involvement of sparks generated by short circuits in a fire

Forecasting of Wind and Solar Farm Output in the Australian National Electricity Market: A Review

Accurately forecasting the output of grid connected wind and solar systems is critical to increasing the overall penetration of renewables on the electrical network. This is especially the case in Australia, where there has been a massive increase in solar and wind farms in the last 15 years, as well as in roof top solar, both domestic and commercial. For example, in 2020, 27% of the electricity in Australia was from renewable sources, and in South Australia almost 60% was from wind and solar. In the literature, there has been extensive research reported on solar and wind resource, entailing both point and interval forecasts, but there has been much less focus on the forecasting of output from wind and solar systems. In this review, we canvass both what has been reported and also what gaps remain. In the case of the latter topic, there are numerous aspects that are not well dealt with in the literature. We have added discussion on the value of forecasts, rather than just focusing on forecast skill. Further, we present a section on how to deal with conditionally changing variance, a topic that has little focus in the literature. One other topic may be particularly important in Australia at the moment, but may become more widespread. This is how to deal with the concept of a clear sky output from a solar farm when the field is oversized compared to the inverter capacity, resulting in a plateau for the output.

A Comparison Between Half and Full Fins at Nanofluids in Transformers

Power transformers characterize the biggest section of capital investment within the distribution substations as well as transmission. Additionally, outages of those transformers have a substantial economic influence on the functioning of an electrical network due to the fact that the power transformers are one of the utmost overpriced constituents in an electricity structure. A suggested thermal model for a distribution transformer is investigated. The temperature distribution in the three-phase transformer (250 KVA 11/.416 KV core type, mineral oil) was obtained using “COMSOL PROGRAM” after a 3D simulation utilizing a transient analysis in light of the Finite Element Method (FEM). Meanwhile, the suggested model is being used to examine the impacts of different types of oil on HOST. To test the effect of nanoparticles on heat transfer process, the insulation oil was changed with Nanofluids and hybrid nanofluids; For present work, can be concluded when add nanofluids (Al2O3, CuO, SiC) for oil of transformer under different concentration ratio (0.3,0.5,0.8,1,1.2,1.4 % wt) and add hybrid nanofluids (oil+ Al2O3+CuO), (oil+ Al2O3+SiC), (oil+ SiC +CuO) at different concentration ratio (1,1.2,1.4 % wt). The concentration of nanofluids show a direct influence on the temperature reduction for the studied cases. Finally it can be said, the proposed model was succeeded in simulating the distribution transformer, which is in good agreement with the experimental tests adopted for this work, and it could be used as a design tool with assist of COMSOL Multiphysics Package. The present model successfully accomplished for expecting the temperature distribution at any locations in the transformer when compared with practical measurement.

A Compressive Compilation of Cyber Security for Internet of Energy (IoE)

Internet of energy (IoE) is the natural evolution of Smart Grid incorporating the paradigm of internet of things (IoT). This complicated environment has a lot of threats and vulnerabilities, so the security challenges are very complex and specialized. This chapter contains a compilation of the main threats, vulnerabilities, and attacks that can occur in the IoE environment and the critical structure of the electrical grid. The objective is to show the best cybersecurity practices that can support maintaining a safe, reliable, and available electrical network complying with the requirements of availability, integrity, and confidentially of the information. The study includes review of countermeasures, standards, and specialized intrusion detection systems, as mechanisms to solve security problems in IoE. Better understanding of security challenges and solutions in the IoE can be the light on future research work for IoE security.

Operation and Startup of Three-Phase Grid-Connected PWM Inverter for an Experimental Test Bench With DSPACE Real-Time Implementation of PQ Control

The main objective of this chapter is the experimental validation of active and reactive power control at the connection point for a three-phase grid connected inverter. It gives an overview on the adopted vector control strategy, regulation of the angle of orientation of the blades (pitch control), synchronization grid side converter to the power network using phase closed loop (PLL). Once the experimental test bench is described, the authors devote a first part to the design of the block circuit diagram of the experimental platform and the control strategy implemented in the DSPace DS1104, and they suggest some steps to associate the inverter to the electrical network. Subsequently, they discuss the experimental results validating the proposed power control. The purpose of this experimental results is the DSPACE real-time implementation of PQ control using three-phase inverter and development of a startup algorithm of the experimental test bench.

Green technologies use in the smart grid construction in rural power supply systems

The article considers the using intelligent controls possibility in low-voltage rural electric networks to minimize the unbalance modes consequences. The proposed technology includes the digital data transmission compilation on the electrical energy parameters with a new balancing technical means the electrical network operating mode. Digital feedback is provided for changes the balancing device (BD) parameters by the unbalancing power consumption changing level. Based on the developed methods compilation, software for calculating unbalancing modes has been created, which makes it possible to assess the currents and voltages unbalancing effect on the power quality and its additional losses change. The “green” technology proposed version, which increases the economic and the electric energy environmental safety use in the rural electric power industry, contains a new constructive solution for the balancing device implementation. The proposed technology was tested on the measurement data basis in existing electrical networks. Based on the MALAB technologies use, changes studied indicators visualization in the before and after BD integration in the electrical network was carried out and its analysis was makes. Used on the “neural networks” MALAB technology, a preventive assessment of the unbalancing power consumption events development in the investigated operating electrical network is presented, as well as the proposed technology effectiveness assessment was carried out.

Perancangan Sistem Otomatisasi Penyalaan Lampu, Kipas Angin, dan Proyektor Dalam Ruang Kelas

In general, the control of using electronic equipment in the classroom manually. Sometimes lecturers or students forget to turn off electronic equipment after the class so that there is a waste of electrical energy use. Application of automation of using electronic equipment is one solution to overcome these problems so that electrical energy becomes more efficient. This study designed a prototype of an automation system for electrical equipment in the classroom, namely lights, fans, and projectors. This system was also to turn off the electricity when nobody was in the class. The automation system controls the use of electrical energy in devices in the classroom through on-off control of the electrical network components connected to each device. In this design, the PIR sensor can detect the presence of people up to a distance of 7 meters. The Arduino Uno controller activates the lights in the class when the LDR Sensor detects a light intensity of less than 200 Lux. Then, the fan is active when the LM35 sensor detects the temperature in the class above 28oC. The FC-04 sensor detects the sound of clapping for control of projector ignition by the controller.

PI CONTROLLER FOR CONTROLLING A THREE-PHASE INVERTER OF A PV SYSTEM CONNECTED TO THE ELECTRICAL NETWORK

In order to improve the efficiency of photovoltaic panels it is necessary to introduce the technique of Maximum Power Point (the technique of the MPPT). In the literature, several strategies are mentioned, among which the perturbation and observation (P&O) algorithm. The aim of this work is to a simulation study in MATLAB of a photovoltaic panel connected to the network using DC-DC and DC-AC converters. DC Boost converter is checked by the MPPT command to adjust the output voltage of the photovoltaic panel and maximize the power produced by the photovoltaic panel. The PI controller is used to control the inverter three-phase to make the connection of the photovoltaic panel to a three-phase electrical network.