Power electrical engineering. Includes industrial electrical engineering (i.e. motors, switchboards), transmission and distribution (poles, wires, transformers, grids) and generation.
Questions tagged [power-engineering]
480 questions
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Why the delay between transformer failure and power outage?
A friend witnessed the explosion of the 14th street substation. I believe these transformers, about 1 city block in extent, delivered power to most of lower Manhattan. I am guessing the flood water obstructed cooling, and they overheated and…
Bobbi Bennett
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How does the Electrical Grid React to Large Changes in Supply or Demand?
Background
I'm performing some research for a software project that monitors power generation and consumption for a large fictional spaceship. My rationale is I'd like to first understand how real-world power generation works before starting to make…
gate_engineer
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How would an electric company detect wireless theft of electricity?
As legend goes it is maybe possible to steal electricity from power lines in a wireless way (also see this and this related questions). The legend continues that once someone does that he gets caught by the electric company.
Suppose I actually do it…
sharptooth
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Why is the earth a viable return path for power distribution?
I'm having trouble understanding why the earth is a viable fault path for electricity brought into my home. Isn't there really high resistance? I mean, it's dirt?
Also, let's say I connect the hot wire coming into my house directly to the ground…
ensnare
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Comparison between AC and DC power flow analyses
Consider a power flow problem. Injected real and reactive power at a bus are functions of voltage magnitudes and voltage angles and are given by
\begin{align*}
P_i = \sum_{k=1}^N|V_i||V_k|(G_{ik}\cos(\theta_{i}-\theta_k) +…
Erik M
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Why are twisted pair cables used in electric power distribution systems?
I'm an Electrical Engineer, and understand how a twisted pair of wires can be used to reduce noise in the presence of magnetic fields.
However, I recently noticed the power company replacing the cables on a high voltage transmission system with a…
user5108_Dan
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Is it practically possible to transfer electrical power around the world by wires?
Assume that we installed plenty of solar cells in all continents; mainly in Asia, Africa and America. Can we transfer the electrical power harvested from them around the world through wires, so that the continent(s) in daytime will feed the one(s)…
hkBattousai
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How are power flows between multiple power systems (tie-line flows) determined?
In Europe, for example, there are multiple transmission system operators (TSOs), which are responsible for their own region of the grid. These TSOs must exchange power to ensure reliable operation of the whole system.
Does anyone know how the…
Erik M
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How do ceramic disk insulators support the weight of transmission lines?
I know that the transmission lines are held a certain distance away from tranmission towers using those ceramic disk insulation arms and the number of disks is proportional to the voltage of the lines, but I've always wondered what provides the…
Cool Pontiac
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How to step-down voltage without a transformer?
Say I am running a line from a transformer to a distribution panel that doesn't quite need 240V but less. How do you go about creating the required voltage drop?
I was asked this in a interview for my internship and he told me the answer to that is…
Infamous_Shenanigan
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Modelling of dynamic behavior of a weak power grid?
I'm modelling the dynamic behavior of a weak power grid. I know the voltage level and short circuit capacity, and that's about it.
Short circuit max = 400A, 3-P
Voltage level = 66000 V
My problem is as follows:
I want to see the dynamic response…
Stewie Griffin
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Connections in load flow analysis
I have a very theoretical doubt. I'm trying to fully understand the load flow analysis and its application. So I have a network with about 300 nodes (AC transmission network). Inside every node I have load and generation. Also the nodes are…
zom-pro
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Zero resistance transmission lines?
I am using the IEEE 14 bus test system for a simulation and was wondering why some of the resistances of lines are set to zero, e.g. see lines (4,7), (4,9), (5,6) below (only part of the full data is shown below).
From To R X …
Erik M
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Parallel Transmission Lines
I am studying the RTS 96 test system for a power system simulation in Matlab. I have noticed that under the Branch Data file, there are some buses which have two lines connecting them. For example (from Table-12.txt) between buses 115 and 121
ID# …
Erik M
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A confusion about radial schemes in power distribution
My lecture notes about distribution systems/radial schemes say the following:
•In this scheme, feeders radiate from a substation in all
directions and feed distributors at one end only.
• SA is the feeder which feeds the distributor BC at its end…
Amr
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