Voltage and power characteristics in German low voltage grids: Field experience in presence of high photovoltaic installations and voltage-regulated distribution transformers (VRDT)

2016 ◽  
Author(s):  
M. Cramer ◽  
C. Matrose ◽  
M. Cremer ◽  
A. Schnettler ◽  
P. Hahulla ◽  
...  
Keyword(s):  
Field Experience ◽  
Low Voltage ◽  
Power Characteristics ◽  
Distribution Transformers

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>

Study of the Winding Temperature Distribution for Distribution Transformers

2014 ◽  
Vol 672-674 ◽  
pp. 1380-1383 ◽  
Author(s):  
Yu Sheng Quan ◽  
Lin Jie Fang ◽  
Zi Jian Wang ◽  
Pu Xin Shi
Keyword(s):  
Low Voltage ◽  
Reference Value ◽  
Simulation Software ◽  
Thermal Design ◽  
Iron Core ◽  
Point Distribution ◽  
Ansys Simulation ◽  
Heat Transfer Theory ◽  
Distribution Transformers ◽  
Fiber Optic Temperature

In this article, in order to provide a reference for determining the location of fiber optic temperature probe in saving distribution transformers,we analyze the internal transformer by the basic heat transfer theory and simulate via ANSYS simulation software, determining the location of the highest temperature separately of the high and low voltage winding and iron core. The simulation results will be as a reference value for the experimental results. Therefore, it is very significant for analyzing the hottest point distribution of distribution transformers and improving thermal design of dry type transformers and temperature monitoring that the numerical simulation of dry-type distribution transformers of temperature field.

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