Model of Noise Source for HF Interference Calculation in a Converter Station

2007 ◽  
Vol 8 (6) ◽  
Author(s):  
Quanrui Hao ◽  
Zheng Xu
Keyword(s):  
Empirical Model ◽  
Noise Source ◽  
Equivalent Model ◽  
Basic Principles ◽  
Operating Modes ◽  
Snubber Circuit ◽  
Power Line Carrier ◽  
Actual Spectrum ◽  
Physical Quantities ◽  
Fft Analysis

For high-frequency (HF) interference in an HVDC converter station, the modeling of the noise source which causes interference with the power line carrier (PLC) remains a problem. Based on the profound analysis of the basic principles on which HF noise in PLC band is produced during the commutation process, the equivalent model of the HVDC valve with a snubber circuit is applied to the simulation of the GUI-GUANG HVDC project in PSCAD/EMTDC. Then spectrum plots of the noise source in the frequency domain are obtained by FFT analysis of the voltage waveforms gained from the simulation. Through analyzing the spectrum characteristics of the noise source in various operating modes, the main factors influencing the level of HF noise are found. Furthermore, a modified empirical model used to calculate the level of the noise source is introduced, with particular explanation of the physical quantities used in the model. The spectra of the noise source gained from the modified empirical model and from the simulation are compared with an actual spectrum based on the GUI-GUANG HVDC project. The results show that the modified empirical model can meet the requirement of HF interference calculation.

Power Line Carrier-Based Networking Technology of the Internet of Things

2012 ◽  
Vol 516-517 ◽  
pp. 1414-1418 ◽  
Author(s):  
Hua Yin ◽  
Bin Fa Long ◽  
Nai Zhou Wang
Keyword(s):  
Internet Of Things ◽  
Radio Frequency ◽  
Power Line ◽  
The Internet ◽  
Application Technology ◽  
Basic Principles ◽  
Power Line Carrier ◽  
Networking Technology ◽  
The Internet Of Things

This article discussed the basic principles of the power line carrier application technology and an example scheme, The unique advantage of the power line carrier networking technology is applied in the Internet of things. The advantage of the application of the power line carrier in the difficult environment of radio frequency application and layout is pointed out.

Research on Setting Calculation Dynamic Partitioning Based on Data Center

2013 ◽  
Vol 373-375 ◽  
pp. 1318-1323
Author(s):  
Xiao Bo Wang ◽  
Wei Song ◽  
Ren Min Gong ◽  
De Jun He
Keyword(s):  
Data Center ◽  
Operation Mode ◽  
Equivalent Model ◽  
Common Information ◽  
Operating Modes ◽  
Dynamic Partitioning ◽  
Common Information Model ◽  
Improve Calculation ◽  
Minimum Operating ◽  
Setting Calculation

This paper deals with the setting calculation data center (SCDC), which is based on Common Information Model (CIM). The construction consists of data splicing and graphics stitching. The splicing method of the information related to setting calculation gains more attention, especially the operation mode. Further more, it brings up a method called dynamic partitioning to improve calculation efficiency. It gives a proper element range relying on the maximum and the minimum operating modes provided by the grid. We only need to consider the network elements in this range to involve in setting calculation. Out of this range we use a simplified equivalent model. At last, the effectiveness and accuracy of the algorithm are verified by the result of the practical example and it is reasonable and effective in its application in engineering.

Study on Acoustic Model of Transformer

2014 ◽  
Vol 1008-1009 ◽  
pp. 571-575
Author(s):  
Jing Zhu Hu ◽  
Di Chen Liu ◽  
Qing Fen Liao ◽  
Su Wei ◽  
Lei Yu
Keyword(s):  
Noise Level ◽  
Noise Control ◽  
Noise Source ◽  
Sound Field ◽  
Point Sources ◽  
Equivalent Model ◽  
Noise Prediction ◽  
Acoustic Model ◽  
Plane Source ◽  
Equivalent Source

The model of transformer as a noise source is very critical for substation noise prediction. The transformer is equivalent to several point sources on the basis of regarding the transformer as a combination of several planar sources. This equivalent model is based on equivalent source method and it is convenient and easy. The model of 9 equivalent point sources is simulated to verify that the rebuilt sound field is roughly the same as the actual sound field generated by the plane source. Moreover, the accuracy of the model with different settings was discussed. The acoustic model is accurate and feasible to calculate the noise level radiated by transformer and it is meaningful for substation noise control.

scholarly journals Using Arduino GPS modules for navigation control and monitoring

2020 ◽  
pp. 96-105
Author(s):  
P.V. Gaisky ◽  
Keyword(s):  
Measurement Errors ◽  
Large Scale ◽  
Low Power Consumption ◽  
Monitoring Systems ◽  
Mountainous Terrain ◽  
Operating Modes ◽  
Active Antennas ◽  
Time Signals ◽  
The Moment ◽  
Physical Quantities

The paper evaluates the possibilities of connecting and using publicly available Arduino GPS Gy-GPSV3 modules based on the Ublox NEO-M8N chip and GPS/GLONAS ATGM336H with the NMEA 0183 Protocol. Both modules are equipped with active antennas, are configured for GPS (USA), GLONASS (Russia) and Beidou (China) satellites and are close in terms of their declared technical characteristics. They perform their functions of tracking coordinates and calculating the primary parameters of the carrier’s movement quite satisfactorily, both in conditions of a favorable landscape, and in conditions of mountainous terrain and urban development. Relatively low power consumption (25-30 mA) and dimensions, easy connection allow them to be used in Autonomous monitoring systems. However, a stable accuracy of more than 10 m is achieved only if there is simultaneous communication with 10 satellites or more, and signal reception inside premises and other shielded objects is not provided. A real cold start lasts more than a minute. Setting the operating modes of the modules provides mainly only filtering of measurement errors in a given range of heights and speeds. Of these modules, GPS/GLONAS ATGM336H is in clear priority, since it is significantly ahead in accuracy, availability of command control, and cost (at the moment it is 3 times cheaper) at standard settings when using the same type of antenna, power supply, and dimensions. No significant impact of visible environment phenomena on the operation of GPS receivers used (communication with satellites) was recorded. At the same time, closely located or relatively powerful household radio frequency transmitters affect accuracy, reducing it by 2-3 times. Signal communication can be improved by using or adding a more powerful overall antenna, which in certain conditions will also allow you to capture satellites that are closer to the horizon. As a result, with such characteristics and capabilities, the considered GPS modules can be successfully used only for navigation purposes and for receiving accurate time signals (synchronization of measurements). Using them for the purpose of measuring physical quantities (for example, parameters of surface waves, level, flow velocity, etc.) with modern requirements for accuracy makes sense only for large-scale processes.

Current Issues: Evidence-Based Practice for the Real World: Thoughts on Clinical Education in Communication Disorders

2010 ◽  
Vol 20 (3) ◽  
pp. 100-105 ◽  
Author(s):  
Anne K. Bothe
Keyword(s):  
Clinical Education ◽  
Real World ◽  
Evidence Based Practice ◽  
Communication Disorders ◽  
University Faculty ◽  
Evidence Based ◽  
Speech Language Pathology ◽  
Basic Principles ◽  
The Real ◽  
Language Pathology

This article presents some streamlined and intentionally oversimplified ideas about educating future communication disorders professionals to use some of the most basic principles of evidence-based practice. Working from a popular five-step approach, modifications are suggested that may make the ideas more accessible, and therefore more useful, for university faculty, other supervisors, and future professionals in speech-language pathology, audiology, and related fields.

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