A review on various Smart Grid Technologies used in Power System

Electrical infrastructure is expanding day by day due to which smart grid gives better vision for electrical reliability. Various parameters like quality and quantity of power transmitted should be available with the electricity board which can be achieved using smart sensing, metering and communication technologies. If all the above requirements are met in power system then it is called smart grid (SG). SG also helps consumers to manage the load patters and also to manage their expenses. The main component of SG is the communication technology to share data between consumers and grid since grid operators requires real time data to schedule their supply. The Wireless Sensor Network (WSN) uses Aggregation Protocol with Error Detection (APED) to improve the security of data. The SG with SCADA is facilitated by data acquisitions which includes the meter reading, system conditions, etc. that are monitored and transmitted at regular intervals in real time. This paper reviews the modern technologies used in smart grid communication based on IEEE 802.15.4 standard to the SG and how it is modified to ensure effective, efficient and economical and secured communication of the huge real time data from the smart meters

Step-on versus step-off signals in time-domain controlled source electromagnetic methods using a grounded electric dipole

The time‐domain controlled source electromagnetic method is a geophysical prospecting tool applied to image the subsurface resistivity distribution on land and in the marine environment. In its most general setup, a square‐wave current is fed into a grounded horizontal electric dipole, and several electric and magnetic field receivers at defined offsets to the imposed current measure the electromagnetic response of the Earth. In the marine environment, the application often uses only inline electric field receivers that, for a 50% duty‐cycle current waveform, include both step‐on and step‐off signals. Here, forward and inverse 1D modelling is used to demonstrate limited sensitivity towards shallow resistive layers in the step‐off electric field when transmitter and receivers are surrounded by conductive seawater. This observation is explained by a masking effect of the direct current signal that flows through the seawater and primarily affects step‐off data. During a step‐off measurement, this direct current is orders of magnitude larger than the inductive response at early and intermediate times, limiting the step‐off sensitivity towards shallow resistive layers in the seafloor. Step‐on data measure the resistive layer at times preceding the arrival of the direct current signal leading to higher sensitivity compared to step‐off data. Such dichotomous behaviour between step‐on and step‐off data is less obvious in onshore experiments due to the lack of a strong overlying conductive zone and corresponding masking effect from direct current flow. Supported by synthetic 1D inversion studies, we conclude that time‐domain controlled source electromagnetic measurements on land should apply both step‐on and step‐off data in a combined inversion approach to maximise signal‐to‐noise ratios and utilise the sensitivity characteristics of each signal. In an isotropic marine environment, step‐off electric fields have inferior sensitivity towards shallow resistive layers compared to step‐on data, resulting in an increase of non‐uniqueness when interpreting step‐off data in a single or combined inversion

Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and attributable disease burden in 204 countries and territories, 1990-2019 : a systematic analysis from the Global Burden of Disease Study 2019

Background Ending the global tobacco epidemic is a defining challenge in global health. Timely and comprehensive estimates of the prevalence of smoking tobacco use and attributable disease burden are needed to guide tobacco control efforts nationally and globally. Methods We estimated the prevalence of smoking tobacco use and attributable disease burden for 204 countries and territories, by age and sex, from 1990 to 2019 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study. We modelled multiple smoking-related indicators from 3625 nationally representative surveys. We completed systematic reviews and did Bayesian meta-regressions for 36 causally linked health outcomes to estimate non-linear dose-response risk curves for current and former smokers. We used a direct estimation approach to estimate attributable burden, providing more comprehensive estimates of the health effects of smoking than previously available. Findings Globally in 2019, 1.14 billion (95% uncertainty interval 1.13-1.16) individuals were current smokers, who consumed 7.41 trillion (7.11-7.74) cigarette-equivalents of tobacco in 2019. Although prevalence of smoking had decreased significantly since 1990 among both males (27.5% [26. 5-28.5] reduction) and females (37.7% [35.4-39.9] reduction) aged 15 years and older, population growth has led to a significant increase in the total number of smokers from 0.99 billion (0.98-1.00) in 1990. Globally in 2019, smoking tobacco use accounted for 7.69 million (7.16-8.20) deaths and 200 million (185-214) disability-adjusted life-years, and was the leading risk factor for death among males (20.2% [19.3-21.1] of male deaths). 6.68 million [86.9%] of 7.69 million deaths attributable to smoking tobacco use were among current smokers. Interpretation In the absence of intervention, the annual toll of 7.69 million deaths and 200 million disability-adjusted life-years attributable to smoking will increase over the coming decades. Substantial progress in reducing the prevalence of smoking tobacco use has been observed in countries from all regions and at all stages of development, but a large implementation gap remains for tobacco control. Countries have a dear and urgent opportunity to pass strong, evidence-based policies to accelerate reductions in the prevalence of smoking and reap massive health benefits for their citizens. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

A review on different algorithms and methods used for neural spike detection

Identification of neural spike activities has been a challenging task for a researcher which is a prerequisite for understanding various types of brain function. Computing the activities of each neuron with maximum accuracy can be a tricky task since the acquired signal form neurons have large amount of noise, therefore it becomes difficult for detection. This article reviews various algorithms and different techniques used for detection and classification of neural spike sorting. The article firstly shows the challenges faced for the measurement of neural activities and preliminary issues of signal detection and classification. Further this paper reviews and demonstrates algorithms and methods that have already been applied to various spike sorting problems. Also the advantages and limitations of each algorithm and methods along with its applicability have been discussed in this paper

Protection of interconnected transmission network using phasor measurement unit scheme

The demand of load is increasing everyday but the transmission resources are very limited because of various challenges and constraints faced during power system monitoring. This insufficiency of transmission resources had lead to reduced operational margins for power system operators. Further due to this heavy loading the stability limit has reached it maximum value. Therefore this issue of deregulation has lead for the development of wide monitoring, protection and control rather than traditional scheme. This paper proposes an adaptive protection scheme which is based on phasor measurement unit (PMU) for the protection of power system network. Here positive sequence voltage and currents of transmission lines are used to identify the location of fault. The fault location is located at maximum speed and accuracy with the help of PMU’s placed over a wide area transmission network. This paper shows results of IEEE 5 bus system which is been simulated on MATLAB/SIMULINK platform for various fault conditions

Identification of low frequency oscillation disturbance with the help of phasor measurement unit

An integration of various techniques like measurement, communication, integration with computer, and control techniques forms a new method for protection and reliable operation of power system which is known as smart grid power system. Phasor Measurement Unit (PMU) is the most important and promising technology among all the technologies which are being implemented for building a smart grid power system. Presently ultra-high and high voltage buses used all over the world are all equipped with PMUs. The main contribution of the paper is to present an application of PMU for determining the source of distribution where the frequency of oscillations is less i.e. the disturbance or fault occurring in power system due to which the oscillations might be very low. These low oscillations might happen due to the resonance phenomenon; therefore, it is of utmost importance to determine the location of disturbance. There are various trial and error techniques which have been implemented but this paper proposes a unique method with the help of PMU to provide the exact response of the system. This method requires minimum time for locating the disturbance which has been validated with the help of case study