scholarly journals CoSiWiNeT: A Clock Synchronization Algorithm for Wide Area IIoT Network

2021 ◽  
Vol 11 (24) ◽  
pp. 11985
Author(s):  
Rahul Nandkumar Gore ◽  
Elena Lisova ◽  
Johan Åkerberg ◽  
Mats Björkman
Keyword(s):  
Failure Modes ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Packet Delay ◽  
Wide Area ◽  
Monitoring And Control ◽  
Performance Measurements ◽  
Public And Private ◽  
Hardware Failure ◽  
Delay Variations

Recent advances in the industrial internet of things (IIoT) and cyber–physical systems drive Industry 4.0 and have led to remote monitoring and control applications that require factories to be connected to remote sites over wide area networks (WAN). The adequate performance of remote applications depends on the use of a clock synchronization scheme. Packet delay variations adversely impact the clock synchronization performance. This impact is significant in WAN as it comprises wired and wireless segments belonging to public and private networks, and such heterogeneity results in inconsistent delays. Highly accurate, hardware–based time synchronization solutions, global positioning system (GPS), and precision time protocol (PTP) are not preferred in WAN due to cost, environmental effects, hardware failure modes, and reliability issues. As a software–based network time protocol (NTP) overcomes these challenges but lacks accuracy, the authors propose a software–based clock synchronization method, called CoSiWiNeT, based on the random sample consensus (RANSAC) algorithm that uses an iterative technique to estimate a correct offset from observed noisy data. To evaluate the algorithm’s performance, measurements captured in a WAN deployed within two cities were used in the simulation. The results show that the performance of the new algorithm matches well with NTP and state–of–the–art methods in good network conditions; however, it outperforms them in degrading network scenarios.

scholarly journals Synchronized Phasor Measurements with GPS Time Stamping using 64 Point DFT in PMU

2020 ◽  
Vol 9 (4) ◽  
pp. 2435-2440
Keyword(s):  
Power System ◽  
Time Synchronization ◽  
Electrical Energy ◽  
Wide Area ◽  
Monitoring And Control ◽  
Wide Area Monitoring ◽  
New Energy ◽  
Accurate Comparison ◽  
Area Monitoring ◽  
System Frequency

This paper describes about the time synchronization of different locations voltage or current signals for accurate comparison of signals on single phasor graph, all the measured phasors are synchronized with Global Positioning System (GPS) time stamping. Day to day power demand increases very rapidly, to meet the growing demand of electrical energy new energy resources are required and manage them efficiently. For efficient allocation of sources there should be a good monitoring and fast control system. For better monitoring and control of the system accurately it requires “Wide Area Monitoring” of power system. In the wide area monitoring system collection of data from the power system should be at a faster level. The collection of data from the power system at faster level is possible by using “Phasor Measurement Units(PMUs)”. PMU collects the data at faster rate rates like 50-60 samples for cycle, this information is send to local Phasor Data Concentrator (PDC). Local phasor data concentrator collects the data from different PMUs which are located in different areas. This PDC helps to take the necessary action on power system. For synchronization, pulse per second(PPS) is taken from GPS module. From this 1PPS, 3200 pulses is generated for high accuracy of 64 point DFT of 50Hz signal using microcontroller. System frequency is calculated by using time period between the two consecutive raising edges or falling edges of square wave. This is in synchronous with the input sinusoidal signal.

Research on PTP Clock Synchronization in IP

2014 ◽  
Vol 1079-1080 ◽  
pp. 762-765
Author(s):  
Hai Dong Zou ◽  
Liang Qian
Keyword(s):  
Time Synchronization ◽  
Clock Synchronization ◽  
Random Noise ◽  
Packet Delay ◽  
Lms Algorithm ◽  
Least Mean Square ◽  
Delay Jitter ◽  
Lms Filter ◽  
Ip Packet ◽  
Synchronization Accuracy

A certain delay jitter will impact the time synchronization accuracy of PTP system in the IP packet switched network. Look the network delay jitters as independently distributed random noise, and use the Least Mean Square (LMS) filter to filter out the noise, that will help to relieve the delay jitter on the system synchronization accuracy. The simulation results show that, by using the LMS algorithm, the research can increase the synchronization accuracy and decrease the bad impact on master and slave time synchronization of packet delay jitter.

scholarly journals An Efficient Algorithm for Partial Discharge Localization in High-Voltage Systems Using Received Signal Strength

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4000 ◽  
Author(s):  
Umar F. Khan ◽  
Pavlos I. Lazaridis ◽  
Hamd Mohamed ◽  
Ricardo Albarracín ◽  
Zaharias D. Zaharis ◽  
...  
Keyword(s):  
High Voltage ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Human Life ◽  
Partial Discharge ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Time Of Arrival ◽  
Localization Algorithm ◽  
Require Time

The term partial discharge (PD) refers to a partial bridging of insulating material between electrodes that sustain an electric field in high-voltage (HV) systems. Long-term PD activity can lead to catastrophic failures of HV systems resulting in economic, energy and even human life losses. Such failures and losses can be avoided by continuously monitoring PD activity. Existing techniques used for PD localization including time of arrival (TOA) and time difference of arrival (TDOA), are complicated and expensive because they require time synchronization. In this paper, a novel received signal strength (RSS) based localization algorithm is proposed. The reason that RSS is favoured in this research is that it does not require clock synchronization and it only requires the energy of the received signal rather than the PD pulse itself. A comparison was made between RSS based algorithms including a proposed algorithm, the ratio and search and the least squares algorithm to locate a PD source for nine different positions. The performance of the algorithms was evaluated by using two field scenarios based on seven and eight receiving nodes, respectively. The mean localization error calculated for two-field-trial scenarios show, respectively, 1.80 m and 1.76 m for the proposed algorithm for all nine positions, which is the lowest of the three algorithms.

The Hardware Design of Measurement System of Transmission Lines Based on Wireless Communication

2015 ◽  
Vol 1092-1093 ◽  
pp. 366-369
Author(s):  
Shu Min Sun ◽  
Wen Juan Jiang ◽  
Yu Meng ◽  
Yan Cheng
Keyword(s):  
Wireless Communication ◽  
Data Storage ◽  
Measurement System ◽  
Transmission Lines ◽  
High Speed ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Report Generation ◽  
Test Efficiency ◽  
Synchronization Module

A set of measurement system for the testing of transmission lines, composing of wireless center station, wireless current acquisition and transmission nodes, wireless voltage acquisition and transmission node, was designed, which was based on wireless communication. The high speed wireless bridge working at 2.4GHz together with the clock synchronization module based on the IEEE1588 communicating protocol were both employed for the communication and time synchronization separately. The measurement system has data storage, waveform display, data analysis, automatic report generation and other functions. The measurement system can greatly reduced arrangement of cables, thereafter improved the test efficiency.

Digital I&C Operating Experience in the US

2008 ◽  
Author(s):  
Bruce Geddes ◽  
Ray Torok
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Failure Modes ◽  
Operating Experience ◽  
Data Set ◽  
Common Cause ◽  
Hardware Failure ◽  
Common Cause Failure ◽  
Defensive Measures

The Electric Power Research Institute (EPRI) is conducting research in cooperation with the Nuclear Energy Institute (NEI) regarding Operating Experience of digital Instrumentation and Control (I&C) systems in US nuclear power plants. The primary objective of this work is to extract insights from US nuclear power plant Operating Experience (OE) reports that can be applied to improve Diversity and Defense in Depth (D3) evaluations and methods for protecting nuclear plants against I&C related Common Cause Failures (CCF) that could disable safety functions and thereby degrade plant safety. Between 1987 and 2007, over 500 OE events involving digital equipment in US nuclear power plants were reported through various channels. OE reports for 324 of these events were found in databases maintained by the Nuclear Regulatory Commission (NRC) and the Institute of Nuclear Power Operations (INPO). A database was prepared for capturing the characteristics of each of the 324 events in terms of when, where, how, and why the event occurred, what steps were taken to correct the deficiency that caused the event, and what defensive measures could have been employed to prevent recurrence of these events. The database also captures the plant system type, its safety classification, and whether or not the event involved a common cause failure. This work has revealed the following results and insights: - 82 of the 324 “digital” events did not actually involve a digital failure. Of these 82 non-digital events, 34 might have been prevented by making full use of digital system fault tolerance features. - 242 of the 324 events did involve failures in digital systems. The leading contributors to the 242 digital failures were hardware failure modes. Software change appears as a corrective action twice as often as it appears as an event root cause. This suggests that software features are being added to avoid recurrence of hardware failures, and that adequately designed software is a strong defensive measure against hardware failure modes, preventing them from propagating into system failures and ultimately plant events. 54 of the 242 digital failures involved a Common Cause Failure (CCF). - 13 of the 54 CCF events affected safety (1E) systems, and only 2 of those were due to Inadequate Software Design. This finding suggests that software related CCFs on 1E systems are no more prevalent than other CCF mechanisms for which adherence to various regulations and standards is considered to provide adequate protection against CCF. This research provides an extensive data set that is being used to investigate many different questions related to failure modes, causes, corrective actions, and other event attributes that can be compared and contrasted to reveal useful insights. Specific considerations in this study included comparison of 1E vs. non-1E systems, active vs. potential CCFs, and possible defensive measures to prevent these events. This paper documents the dominant attributes of the evaluated events and the associated insights that can be used to improve methods for protecting against digital I&C related CCFs, applying a test of reasonable assurance.

scholarly journals Assessment of the Exposure of Turkey Farmers to Antimicrobial Resistance Associated with Working Practices

2019 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Giorgio Franceschini ◽  
Marta Bottino ◽  
Ilary Millet ◽  
Elisa Martello ◽  
Francesca Zaltron ◽  
...  
Keyword(s):  
Direct Contact ◽  
Failure Modes ◽  
Individual Therapy ◽  
Human Consumption ◽  
Structured Interviews ◽  
Public And Private ◽  
Effect Analysis ◽  
Extended Spectrum Beta Lactamase ◽  
Working Practices ◽  
The Individual

The objective of the present study was the identification of farming practices in the production of turkeys for human consumption, and their ranking in terms of the occupational probability of exposure to antimicrobial resistant (AMR) bacteria, for farm workers. We gathered evidence and data from scientific literature, on risk factors for AMR in farmers, and on the prevalence of those hazards across farming phases. We administered semi-structured interviews to public and private veterinarians in Northern Italy, to obtain detailed information on turkey farming phases, and on working practices. Data were then integrated into a semi-quantitative Failure Modes and Effect Analysis (FMEA). Those working practices, which are characterized by direct contact with numerous animals, and which are carried out frequently, with rare use of personal protection devices resulted as associated with the greatest probability of exposure to AMR. For methicillin resistant Staphylococcus aureus (MRSA), these included vaccination and administration of any individual therapy, and removal and milling of litter, given the exposure of farmers to high dust level. Indeed, levels of occupational exposure to MRSA are enhanced by its transmission routes, which include direct contact with animal, as well as airborne transmission. Level of exposure to extended spectrum beta lactamase (ESBL) is more strictly associated with direct contact and the oral-fecal route. Consequently, exposure to ESBL resulted and associated with the routinely tipping over of poults turned on their back, and with the individual administration of therapies.

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