Energy Production, Distribution and Storage - 1
Modern tendencies in power grid development are focused on integrating renewable wind and solar energy sources in medium voltage grids. The prospects and validity of this tendency are in little doubt. However, this integration should be conducted, taking into account many factors, such as the grid’s transfer capacity and its components, mode parameters, and limitations put on them, load and power flow changes over time, etc. The developed countries’ experience shows that the significant increase of renewable sources requires either new approaches in power grid management and control or energy storage systems to be installed. It is highly necessary in order to keep the system state in the area of allowable values simultaneously with maximum power production from renewable sources. In the maximum demand mode, these storage systems near the consumers allow to supply them, avoiding additional capital investments in grid renovation to increase its transfer capacity. On the contrary, in the off-peak condition, these storage systems are charging up by the power produced at renewable source power plants, regulating thus voltage and accumulating energy to be used in further. Unfortunately, the bleeding-edge technologies of energy storage systems keep being quite expensive, which makes it essential to integrate them with the highest effectiveness. This contribution outlines an approach for optimal energy storage systems sizing and allocation based on the regression analysis and takes into account the aforementioned problems.
The aim of studies presented in this article is to determine energy efficiency of distributed generation (DG) plants in railroads power supply systems (RPSS). The study was carried out using Fazonord software application designed for power supply systems simulation in phase coordinates. The results obtained proved that the following positive results can be obtained based on DG plants: reduction in energy supply costs due to the lower cost of electricity generated at its own co-generation plants (CGP), compared with the rates of the energy supplying entity, reduction of power losses at the main sections of supplying power line on average by 53 ... 58, in traction transformers – by 18 ... 32. The use of automatic excitation controllers of CGP generators that maintain constant voltage levels on 10 kV buses allows to increase the effect of power line losses reduction by up to 80, as well as to stabilize voltages on load utilizing equipment of electric locomotives, in which case the amplitude of these voltages decreases by about 25.
All high-voltage installations are subject to a series of legislation and regulations to limit the permitted noise levels. Considering area, levels are divided into public areas, areas of increased sensitivity and occupational exposure areas. In addition, it is well known that there is a connection between load harmonics and noise in certain frequency spectrum. In order to investigate this phenomenon in more details, the in-situ field measurements of power harmonic and sound pressure levels are conducted in two high voltage substations The results showed that the noise values at all observed voltage levels are within the limits prescribed by the regulations. Moreover, dominant peaks in sound pressure level spectra typical for power transformers (fundamental, third, fifth and seventh harmonic) are visible in the corresponding current spectra. However, sound spectra peaks without obvious electrical counterpart have been detected as well, which will be subject of our future research.
Metrology for Smart Grids - 2
In this paper a case study of two network nodes interconnected over power line communication technology is provided. Standard ping utility was modified to generate timestamps corresponding to those used in SNTP. Experimental estimation of the round trip delay and clock offset was carried out utilizing ST8500 PLC-G3 modems from ST Microelectronics. It was found that uplink and downlink delays exhibit a jitter causing communication channel asymmetry which is detrimental for the accuracy of the SNTP clock synchronization. It is suspected that the reason of uplink and downlink delays jitter is mainly due to RTOS controlled software implementing communication stacks on both client and server sides. Nevertheless, the accuracy of clock adjustment may be improved by averaging a group of clock offset estimates. In particular, to achieve approximately 10 ms accuracy 100 SNTP transactions has to be completed and the mean offset used to adjust the client clock.
This paper is presenting the preliminary results of testing new AC foil resistive current transducer. Foil Resistive current transducer is development at Faculty of electrical engineering and computing in Department of electrical engineering and measurements. Foil current shunt is compared with cage shunts. The results of amplitude and phase frequency analysis are presented.
In this paper a low-budget single-phase voltage waveform simulator based on the NI PCI-6071E DAQ card and desktop PC with real-time Phar Lap operating system has been presented. Program for generating waveforms in accordance to the IEC standard 61000-4-13, with harmonics of variable frequency, amplitude and phase, has been implemented in the LabVIEW RT environment. Calibration of DAQ card internal clock has been performed to increase the accuracy of the generated voltage waveform frequency. In order to achieve consistent system operation, DAQ card internal temperature sensor has been used to compensate clock frequency drift caused by local ambient temperature variations. For verification purposes, one of algorithms for the frequency estimation based on the linear Kalman filter has been deployed to target PC. Experimental results in steady-state and dynamics have also been presented. The estimated frequency of the generated signal matches very well with the values obtained by the digital multimeter used for calibration procedure.
In this age of climate crisis, stakeholders are recognizing the need to integrate larger quantities of advanced energy technologies, from renewable generation to electrified transportation. Electric utilities the world over are challenged to integrate new technologies while limiting impacts to grid reliability. Further, the expectation of more frequent and intense weather events will drive the need for smart grid investments that provide greater energy resilience. Commonwealth Edison (ComEd) is developing and deploying technologies that enable increased penetration of low-carbon technologies, mitigate the effects of climate change, and enable higher levels of resilience, helping the communities in the utility’s service territory adapt to a changing environment. Many of these technologies are being demonstrated in Chicago where ComEd is installing the Bronzeville Community Microgrid (BCM). Within the BCM ComEd is deploying the first utility-operated microgrid cluster, serving 7 MW of load, that is being used as a living laboratory to demonstrate advanced technologies that support the integration of distributed energy resources (DERs). Together, these technologies ensure that ComEd can provide clean power, supporting communities to meet their goals. With support from the Department of Energy (DOE), ComEd developed and is demonstrating a microgrid master controller that can operate two or more connected microgrids. Also in partnership with the DOE, ComEd developed a microgrid-integrated solar storage technology that uses smart inverters, energy storage, and a microgrid controller that enables solar PV to operate as a controllable resource. This technology is being demonstrated with 750 kW of solar PV and 500 kW/2MWh of energy storage. Finally, ComEd is demonstrating a distributed linear estimation capability that supports the integration of DER. ComEd is deploying such technologies to enable higher penetration of renewable generation that can increase the grid’s sustainably, foster resiliency, and mitigate the effects of energy-disruptive events. These innovations support efforts to make communities even more sustainable, by embracing electrification. Doing this requires rich partnerships with community stakeholders to maximize the impact of these innovations, by identifying which technological solution can meet the needs of an individual community, and how it can be best leveraged. In the neighborhood of Bronzeville, Chicago, ComEd is doing just this as part of a broader community of the future initiative, which deploys technologies from an electric vehicle mobility program to STEM education opportunities, all built on the foundation of a community microgrid. The community-level approach pursued by ComEd will drive meaningful change on a local level that can be replicated regionally, nationally or globally.
Customer Based Applications 1
This work presents an IoT-based smart grid system implementation as proof of concept to examine the emerging business and technological needs in smart grids and analyze the efficiency of smart grid communications. As part of the work, we describe the smart grid system architecture consisting of a physical photovoltaic-powered microgrid laboratory, communication subsystem, and cloud-based smart grid management system along with the implementation details. Next, we discuss the obtained results in terms of messaging service quality and system availability, flexibility, and robustness. We show that our system can exchange telemetry and control messages in less than 1 s, depending on message size. Finally, lessons learned and future challenges are outlined, including communication transparency and efficiency, scalability of management and communication subsystems, characterization of message severity associated with quality of service requirements, and other non-technical considerations.
This article is dedicated to the creation of a biometric system of the identification by facial image. The conceptual model and the mathematical model based on image processing methods (Gabor and Daubechies wavelet transform) were developed, also steps of image processing in the program and the forming of the feature vector by calculating the image statistical characteristics were described during the analysis. Considering that the primary efficiency outcome of the system is the identification accuracy, which is performed by the system, it became necessary to carry out the experiments to determine these parameters, specifically the methods that are appropriate to use in the system. The results of the experimentation indicated that the system performs the most accurate identification outcome with the use of Daubechies wavelet transform for the image processing, the standard deviation and the variance for the feature vector forming, and Euclidean distance, the squared Euclidean distance or the Canberra distance as a metric of the image classification. Using these parameters, the created system performed the 92,5 accuracy of identification.
The practical application of satellite interferometric SAR images for determining the vertical displacement of the soil after a strong earthquake in Zagreb in 2020 is presented. The area affected by the terrain displacements was compared with the tracks of transmission lines for a rapid assessment of their endangering and placing them properly on the list of priorities for in-situ damage checking. In addition to the possibility of using open source satellite imagery, such as ESA Copernicus, it is proposed to use dedicated commercial fine time resolution satellite imagery that can be used operationally during earthquake rescue and remediation actions.