Questions tagged [power-engineering]

Power electrical engineering. Includes industrial electrical engineering (i.e. motors, switchboards), transmission and distribution (poles, wires, transformers, grids) and generation.

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3answers
2k views

How do utility companies treat voltage deviations in distribution networks?

I live in a region where nominal mains voltage is 220 volts and state standards permit deviations within 5 percent continuously and within 10 percent for short periods. So if I measure the voltage in ...
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7answers
24k views

What causes overvoltage in power grid?

In the region where I live there's a state standard that says that mains voltage deviation can be within 5 percent continuously and within 10 percent for short periods of time, so if the mains voltage ...
0
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1answer
319 views

Localized Star Network From Bulk Cap?

I was reading the Power Integrity article on Altera's website and came across the recommendation for the Bulk Capacitor (47uF to 100uF). I'm supposed to have one 47uF-100uF capacitor for every two ...
3
votes
1answer
451 views

how grid tie invertor works?

I read it somewhere that it should be a current source as grid is low impedance voltage source. ( whatever that means. ) I get the part where voltage is converted from DC to AC via Inverter. But what ...
4
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5answers
423 views

Is direct current really better for pumped-storage hydroelectricity facilities?

Currently the article equivalent to War of the Currents in Russian Wikipedia section says that direct current is beneficial to pumped-storage hydroelectricity plants and provides no reference to that ...
2
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1answer
247 views

What could be this "transient electric deviation"?

On August 7th, 2011 a lightning hit a transformer powering one of Amazon EC2 facilities in Dublin. The status report said Normally, upon dropping the utility power provided by the transformer, ...
4
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4answers
523 views

Why are power distribution systems so prone to massive faults?

Many region-wide blackouts (like this one or this one) are described as follows: some high-voltage equipment (like a generator or a transformer) fails and the grid gets overloaded and then protective ...
20
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6answers
14k views

How does earthing work when earth is dry?

Earthing is meant to provide reliable contact of an electric appliance to earth so that if there's an insulation fault current goes into earth instead of through a person's body. This requires ...
10
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3answers
10k views

Why would a power cable need copper wire shielding?

Today I witnessed burying 10 kilovolt power cable in the ground. I noted the cable mark and Googled it. The description is rather interesting. It's a single conductor cable - it takes three such ...
9
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3answers
13k views

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 ...
2
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2answers
4k views

max amperage of WAGO 222-415 connector?

Here's a really nice multi-wire splicing connector: http://www.wago.us/news/5019.htm http://www.wago.us/images/222415_PR.jpg I'm using it for power distribution for a quadcopter: http://eastbay-rc....
12
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7answers
2k views

Power grids : AC vs DC

We know that we have now 50/60Hz in our walls due to mainly historical reasons - back 100 years ago there were no ways to up/down scale DC voltage. These days we just have problems due to that - ...

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