Lightning Surges Transferred to Low-voltage AC Power Lines through Distribution Transformers

2003 ◽  
Vol 17 (4) ◽  
pp. 94-99
Keyword(s):  
Low Voltage ◽  
Power Lines ◽  
Distribution Transformers ◽  
Ac Power

scholarly journals Control of Fan Blade Vibrations Using Piezoelectrics and Bi-Directional Telemetry

2011 ◽  
Author(s):  
Andrew J. Provenza ◽  
Carlos R. Morrison
Keyword(s):  
Low Voltage ◽  
Radio Telemetry ◽  
Magnetic Bearing ◽  
Test Facility ◽  
Test Results ◽  
Novel Device ◽  
Ac Power ◽  
Dynamic Spin ◽  
Wireless Device ◽  
Fan Blade

A novel wireless device which transfers supply power through induction to rotating operational amplifiers and transmits low voltage AC signals to and from a rotating body by way of radio telemetry has been successfully demonstrated in the NASA Glenn Research Center (GRC) Dynamic Spin Test Facility. In the demonstration described herein, a rotating operational amplifier provides controllable AC power to a piezoelectric patch epoxied to the surface of a rotating Ti plate. The amplitude and phase of the sinusoidal voltage command signal, transmitted wirelessly to the amplifier, was tuned to completely suppress the 3rd bending resonant vibration of the plate. The plate’s 3rd bending resonance was excited using rotating magnetic bearing excitation while it spun at slow speed in a vacuum chamber. A second patch on the opposite side of the plate was used as a sensor. This paper discusses the characteristics of this novel device, the details of a spin test, results from a preliminary demonstration, and future plans.

Influence of wind speed on the reliability of low-voltage overhead power lines

2019 ◽  
Author(s):  
Kornelia Banasik ◽  
Andrzej L. Chojnacki ◽  
Katarzyna Gebczyk ◽  
Lukasz Grakowski
Keyword(s):  
Wind Speed ◽  
Low Voltage ◽  
Power Lines ◽  
Overhead Power Lines

scholarly journals MITIGATION OF CURRENT HARMONIC DISTORTIONS STREAMING FROM DOMESTIC NON-LINEAR LOADS USING SINGLE PHASE ACTIVE POWER FILTER.

2018 ◽  
Keyword(s):  
Single Phase ◽  
Low Voltage ◽  
Power Grid ◽  
Power Supplies ◽  
Sleep Mode ◽  
Premature Failure ◽  
Current Harmonic ◽  
Distribution Transformers ◽  
Non Linear ◽  
Harmonic Distortions

This study investigated current harmonic distortions emanating from domestic non-linear loads which have adverse deleterious effects on installed low voltage switchgears such as transformers and conductors. The study examined harmonic distortions emanating from dominant domestic nonlinear loads such as microwave, TV set, radio, fridge, video player and compacted fluorescence bulbs (CFLs) using a power quality equipment. From the results obtained, it was noted that there is need to mitigate harmonic distortions generated by domestic loads at point of common coupling (PCC). It is pertinent to mention that the recent study on supplied loads carried out in Kenya power grid shows that above 67% of power end users are domestic consumers. Under current last mile initiative and Global Partnership on Output Based Aid (GPOBA), unprecedented increase of domestic loads connected to the power grid is predicted. It is worth pointing out that most of these domestic loads have switch mode power supplies (SMPS) which have inherent characteristics of distorting current waveform which causes voltage distortions, over-heating of neutral conductors and premature failure of distribution transformers. Further, most of these loads have two modes; standby/sleep mode and operating mode. Results shows that the two modes generate current harmonic distortions which stream back to power utility network through the service cable. Recently, engineers have designed electronic devices that consume less power. These devices draw current in pulses rather than sinusoidal waveform. As a result, the quality of power supplies continues to deteriorate hence adversely affecting the installed low voltage switchgears such as distribution transformers. Although various mitigation measures exist to reduce the effects of harmonic distortions, this paper proposes a single phase active filter as an optimal solution for attenuating the harmonics emanating from domestic non-linear loads.

scholarly journals Towards a Smart Low Voltage Distribution System: An Indian Experience

2021 ◽  
Author(s):  
Ramanuja Panigrahi ◽  
Santanu Mishra ◽  
Suresh C. Srivastava ◽  
Prasad Enjeti
Keyword(s):  
Distribution System ◽  
Smart Home ◽  
Architectural Design ◽  
Low Voltage ◽  
Voltage Distribution ◽  
Solid State Transformers ◽  
Power Exchange ◽  
Distribution Transformers ◽  
Operational Issues ◽  
Distribution Grids

<em>Realizing a smart Low Voltage Distribution System (LVDS) is essential to realize a smart grid. Restructuring the existing distribution system into microgrids is one important requirement to achieve a smart LVDS. The realization of microgrids in LVDS can take different shapes in different countries. This article discusses the challenges and practical solutions to realize a smart LVDS for radial distribution grids, which are common in India. The network following a distribution transformer can be distinguished as a microgrid for radial low voltage distribution grids. However, this leads to many operational issues. Therefore, this article envisions replacing the Low Voltage distribution transformers with <a>Solid-State Transformers </a>(SSTs). This will enable the LVDS to control the power exchange between the phases within a microgrid as well as power exchange between different microgrids. The architectural design of a smart home in smart LVDS is outlined to complete the discussion. Various unique features required for smart inverters in a smart home and existing grid codes to make them compatible with smart LVDS are also reviewed.</em><i></i>

scholarly journals BASIC EQUATIONS OF THE MULTI-CIRCUIT, MULTI-PHASE AC POWER LINES

2019 ◽  
Vol 31 (107) ◽  
pp. 63-78
Author(s):  
V. M. Postolati ◽  
◽  
O. Kh. Chalbash
Keyword(s):  
Power Lines ◽  
Ac Power ◽  
Basic Equations ◽  
Multi Phase

scholarly journals Endpoint Use Efficiency Comparison for AC and DC Power Distribution in Commercial Buildings

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5863
Author(s):  
Arthur Santos ◽  
Gerald Duggan ◽  
Stephen Frank ◽  
Daniel Gerber ◽  
Daniel Zimmerle
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Low Voltage ◽  
Data Sheet ◽  
Or Efficiency ◽  
Dc Power ◽  
Ac Power ◽  
Use Efficiency ◽  
Efficiency Comparison ◽  
Electric Loads

Advances in power electronics and their use in Miscellaneous Electric Loads (MELs) in buildings have resulted in increased interest in using low-voltage direct current (DC) power distribution as a replacement for the standard alternating current (AC) power distribution in buildings. Both systems require an endpoint converter to convert the distribution system voltage to the MELs voltage requirements. This study focused on the efficiency of these endpoint converters by testing pairs of AC/DC and DC/DC power converters powering the same load profile. In contrast to prior studies, which estimated losses based on data sheet efficiency and rated loads, in this study, we used part load data derived from real-world time-series load measurements of MELs and experimentally characterized efficiency curves for all converters. The measurements performed for this study showed no systematic efficiency advantage for commercially available DC/DC endpoint converters relative to comparable, commercially available AC/DC endpoint converters. For the eight appliances analyzed with the pair of converters tested, in 50%, the weighted energy efficiency of the DC/DC converter was higher, while, for the other 50%, the AC/DC converter was. Additionally, the measurements indicated that the common assumption of using either data sheet efficiency values or efficiency at full load may result in substantial mis-estimates of the system efficiency.

Development of Remote Control System for Residential AC Power Supply Based on GSM Technology

2016 ◽  
Vol 818 ◽  
pp. 169-173
Author(s):  
Muhamad Syukri Md Noh ◽  
Yanuar Z. Arief ◽  
Nor Asiah Muhamad
Keyword(s):  
Control System ◽  
Remote Control ◽  
Mobile Phone ◽  
Power Supply ◽  
Low Voltage ◽  
Assembly Language ◽  
Remote Control System ◽  
Ac Power ◽  
Message Service ◽  
The Status

The present study deals with the development of remote control system based on the Global System for Mobile Communication (GSM) technology for switching the low voltage AC power supply system at residential consumer. Function of this system is to disconnect and reconnect the electricity supply to consumers. The introduction of the GSM technology and particularly the use of hand-held mobile phones has brought the innovative distance communication to remote locations. This utilization of this technology for the remote control of systems and appliances will make life easier, safe and quick from anywhere. GSM module was used for receiving short message service (SMS) from user’s mobile phone that automatically enable the controller to take any further action such as to switch on and off the consumer load at the incoming power supply. The system was integrated with microcontroller and GSM network interface using assembly language. AVR Studio 4 software was utilized to accomplish the integration. The system is activated when user sends the SMS to GSM controller circuit at electric meter consumption panel board. Upon receiving the SMS command, the microcontroller unit then automatically controls the incoming power supply by switching on or off the device according to the user command. In other words, the developed system reads message from the mobile phone and responds to control the devices according to the received message. The system can also give feedback to the user to inform the status of switching operation if such command is received.

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