A novel approach of a dynamic multi objective optimization of a power distribution system

A new dynamic multi objective optimization approach is covered in this paper. The technique for optimizing the power distribution system is dynamic reconfiguration. The goal is to propose an optimal dynamic reconfiguration which minimizes the active power losses and the voltage deviation of the nodes of the power distribution system according to the energy available at the source, while constantly guaranteeing the supply of the electrical energy to priority consumers. The reliability indices considered in this paper are the system average interruption frequency index (SAIFI) and the system average interruption duration index (SAIDI) and are used to check the reliability of the optimal configurations obtained. This study subdivides a day into periods. The variations in the available power of the source and the power requested by the load, cause a new optimal configuration of the network at each period. In this work, the load adapts to the source and the optimal network topology evolves according to the maximum available power of the source. A mathematical formulation of the dynamic optimization problem by period or piece is proposed. The dynamic approach consists in acquiring the power of the load and of the source by period or piece and to compare them. When the available energy is sufficient, an optimal configuration that minimizes the power losses and voltage deviation while ensuring the supply of electrical energy to all consumers in the network is proposed. On the other hand, when the available energy is insufficient, an optimal topology of the power system minimizing the power losses and voltage deviation while guaranteeing the supply of electrical energy to priority consumers of the network is proposed. The optimal solutions per period are obtained using the MIP and MINLP methods. The approach is implemented on standard IEEE 15, 33 and 69 node power distribution system. The results obtained are satisfactory and prove the effectiveness of this new vision for the conduct of the power distribution system.

An Analysis of the Operation of Distribution Networks Using Kernel Density Estimators

Efficiency in the operation of distribution networks is one of the commonly recognised goals of the Smart Grid aspect. Novel approaches are needed to assess the level of energy loss and reliability in electricity distribution. Transmission of electricity in the power system is invariably accompanied by certain physical phenomena and random events causing losses. Identifying areas where excessive energy losses or excessive grid failure occur is a key element for energy companies in resource management. The study presented in the article is based on data obtained from distribution system operators concerning 41 distribution regions in Poland for a period of 5 years. The first part of the article presents an analysis of the distribution of values for the introduced energy density and energy losses in the lines of medium- and low-voltage networks and in transformers supplying the low-voltage network. The second part of the article presents the assessment of the network reliability of the same distribution regions based on analysis of the distributions of System Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI) values for planned and unplanned outages. Data analysis is performed by non-parametric methods by means of kernel estimators.

89 Relationships Among Measures of Efficiency with Body Weight, Frame Score, and Body Volume in Lactating Multiparous Crossbred Beef Cattle

Sixty cows of varying frame scores (FS; 5.17 ± 1.38) were used to examine relationships between body size [BW, FS, and body volume (V)] and cow efficiency. Dry matter intake (DMI) and BW change were monitored over 64 days starting 1 month before bull turnout. Cows were fed a forage-based diet and DMI monitored using the Insentec system. Average BW (ABW; 662 ± 93.3 kg) was calculated by averaging 2-d beginning and end BW. Measurements (body length, hip height, hip width, and heart, mid, and flank girth) were collected at the beginning and end of the experiment and average V (628 ± 96.4 L) calculated. Calf BW was recorded at weaning (WW). Pearson partial correlations between body size characteristics and efficiency measures were determined using GLM (SAS) and the MANOVA/PRINTE statement. There was positive correlation (P < 0.001; r = 0.84, 0.74, 0.81) between DMI (kg) and ABW, FS, and V. There was a tendency for negative correlation (P = 0.08, 0.09; r = -0.24, -0.23) between DMI (% of BW) and ABW and V. There was positive correlation (P ≤ 0.05; r = 0.33, 0.28, 0.26) between WW (kg) and negative correlation (P < 0.001; r = -0.63, -0.57, -0.65) between WW (% of ABW) and ABW, FS, and V. There was positive correlation (P = 0.04; r = 0.26) between calf ADG and ABW, and a tendency for positive correlation (P = 0.09; r = 0.23) between calf ADG to weaning and FS. The observed correlations suggest that larger cows consume more kg of feed and wean heavier calves with greater ADG to weaning, whereas smaller cows tend to consume more feed as a percentage of BW and wean a greater percentage of cow BW. Further research is needed on the complex relationship between cow size and efficiency.

Application Study in the Field of Solutions for the Monitoring Distribution Transformers of the Overhead Power Grid

This paper will present the development and application of overhead transformers of the distribution grid, as well as the different technologies used for the gathering of electrical quantities, in the field of a monitoring solution. The solution reports the values of the quantities and alarms of operation remotely and almost in real-time. The development of this solution seeks to provide an electrical grid with greater reliability, proposing the reduction of KPIs (Key Performance Indicator), such as SAIDI (System Average Interruption Duration Index) and SAIFI (System Average Interruption Frequency Index), through more transparent monitoring of the behavior of the electrical distribution grid and its equipment. Through the research and development (R&D) project Urban Futurability, ENEL (Ente nazionale per l’energia elettrica) Distribution São Paulo seeks to apply the solution by implementing the concept of smart grids, an idea that has been growing each year by virtue of technological developments and the employment of new sensors in electrical distribution grids. Urban Futurability seeks to innovate the automation area, digital twin, and construction enhancement in the Vila Olímpia neighborhood of São Paulo, Brazil.

Advanced Metering Infrastructure—Towards a Reliable Network

In order to ensure continuous energy supply, Distribution System Operators (DSOs) have to monitor and analyze the condition of the power grid, especially checking for random events, such as breakdowns or other disturbances. Still, relatively little information is available on the operation of the Low Voltage (LV) grid. This can be improved thanks to digital tools, offering online processing of data, which ultimately increases effectiveness of the power grid. Among those tools, the use of the Advanced Metering Infrastructure (AMI) is especially conducive for improving reliability. AMI is one of the elements of the system Supervisory Control and Data Acquisition (SCADA) for the LV grid. Exact knowledge of the reliability conditions of a power grid is also indispensable for optimizing investment. AMI is also key in providing operational capacity for carrying out energy balance in virtual power plants (VPPs). This paper deals with methodology of identification and location of faults in the AMI-supervised LV grid and with calculating the System Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI) on the basis of the recorded events. The results presented in the paper are based on data obtained from seven MV/LV transformer stations that supply over 2000 customers.

Stochastic Approach of Parsing Bengali Sentences

The parsing technique based on associate grammar rules as well as probability is called stochastic parsing. This paper suggested a probabilistic method to eliminate the uncertainty from the sentences of Bangla. The technique of Binarization is applied to increase the precision of the parsing. CYK algorithm is used in this paper. The work mainly focused on intonation-based sentences, for these reasons PCFGs (Probabilistic Context-Free Grammars) is based on proposed. About 30324 words are used to test the proposed system; average 93% accuracy is achieved. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 7, Dec 2020 P 51-56

AN ANALYSES ON PATIENTS’ QUEUING SYSTEM AT MUHAMMAD ABDULLAHI WASE SPECIALIST HOSPITAL, KANO

A major cause for concern in hospitals is congestion, which brings about untoward hardship to patients due to long queues and delay in service delivery. This paper seeks to minimize the waiting time of patients by comparing the performance indicators of a single server and multi-server model at the Paediatrics Department of Muhammad Abdullahi Wase Specialist Hospital Kano (MAWSHK). In order to achieve this, primary data was obtained through direct observation which in turn is subjected to the test of goodness of fit to ascertain the distribution that best describes the data. The performance indicators comprising utilization factor, average number of patients in the queue, average number of patients in the system, average waiting time in queue and average waiting time in system for a single server and multi-server model were computed and analyzed respectively. Our findings indicate that the G/G/4 model performs better compared to the G/G/1 model as it minimizes the waiting time of patients

Distributed Generation Impact on Distribution System Reliability

Reliability is the most important factor of distribution system and this system should be operated economically with low customer loads interruption. This is because that the distribution system gives supply to customers from transmission system. There are some power quality issues due to the failures of components in distribution system. Researchers are going on to assess the reliability of the power system. In the power system, reliability evaluation is an important aspect in complete electric distribution system planning and operation. Due to the extreme scale of problem, it is not possible to conduct reliability on complete power system, it is performed independently. Hence, In this paper, the reliability of distribution system is evaluated by using an analytical method is described and is applied to the IEEE RBTS BUS-6. Development of reliability model of distribution system using Electrical Transient Analyzer Program (ETAP) software is developed. And the Distributed Generation is introduced for the improvement of reliability. Reliability indices are such as System Average Interruption Frequency Indices (SAIFI), System Average Interruption Duration Indices (SAIDI), Customer Average Interruption Frequency Indices (CAIFI), Customer Average Interruption Duration Indices (CAIDI), Energy Not Supplied (ENS), Average Service Availability Indices (ASAI), etc. The performance of reliability of the system is shown by these indices

Battery Energy Storage System for Emergency Supply and Improved Reliability of Power Networks

This paper introduces the concept of a battery energy storage system as an emergency power supply for a separated power network, with the possibility of island operation for a power substation with one-side supply. This system, with an appropriately sized energy storage capacity, allows improvement in the continuity of the power supply and increases the reliability of the separated network at a specified time during the limitation of power transmission as a result of damage or disconnection of the main power line. This paper presents and describes a specific method of energy storage system dimensioning based on real measurement data. Based on the obtained parameters, an analysis of the reliability improvement of the considered network was performed. The implementation of the battery energy storage system will contribute to a more than 5-fold reduction in the occurrence of power outages in the time interval from 3 min to 1.5 h, which will clearly reduce the System Average Interruption Frequency Index and System Average Interruption Duration Index factors. In this paper, the network conditions for operational normality and failure are presented and the cost for implementation of an energy storage system (about EUR 1 million) is compared with the possible implementation of an additional power line (about EUR 5 million) to a specific power substation.