Changes based on electromagnetic principals

[physicsgal]

Homework Statement

in a previous lesson i wrote about making an environmentally friendly "pioneer village". it consisted of a large wind turbine and each house having its own solar panels.

this question asks to discuess any changes that should be made based on my knowledge of electromagnetic principals.

The Attempt at a Solution

heres what i have so far:

All the electric currents in the town would be alternating currents. Alternating currents allow electricity to be transmitted at high current and then adjusted as needed by transformers. This makes electricity transmission more efficient.

The wind turbine creates electricity by powering a generator which consists of magnets. These magnets create a changing magnetic field which causes current to be induced.
The electricity from the turbine would be go through power lines to step-up and step-down transformers (as described in part -a-)

for part -a- i wrote quite a bit about how step-up and down transformers work.

does that somewhat hit the nail on the head? I am drawing a blank and i don't know what else to say. i want to make sure my answer is relevant to the question asked.

any help is appreciated

-Amy

 

[quickslant]

looks alright.. but you never know exactly what the teachers are asking for with these @ home courses... I've had the same problem on a few questions

 

[Kurdt]

You might want to include how to integrate the DC photovoltaic cells into the AC system.

 

[physicsgal]

quickslant; for the gr 12 course, do they specify how many marks each question is worth? they did so in the bio and math, but not physics for some reason. at least if the question is worth a lot of marks id have an idea of how detailed the answer needs to be.

kurdt; no mention of photovoltaic cells in the course (high school level). but thanks anyway for the tip.

-Amy

 

[berkeman]

kurdt; no mention of photovoltaic cells in the course (high school level). but thanks anyway for the tip.

In your original post (OP) you mentioned something about a solar panel at each house. I had the same thought as Kurdt -- integrating the DC output from the solar panels into the AC mains of the house is non-trivial, but obviously do-able. And it would deserve mention in your paper, if each house still has solar panels.

 

[marcusl]

You're connecting your transformers backwards. Power companies step up the voltage to reduce the current for transmission. That way they can use lightweight wires, and the resistive losses ("voltage drops") in the wires are low. Voltages on telephone pole-type lines range from 7 to 30 kVAC, the ones atop metal-frame towers run up to 100's of kV.

Do you see why Hi V/ Low I results in lower losses?

 

[physicsgal]

i don't think i have the transformers backwards. here's what i wrote for part -a-:

The homes in my pioneer village were powered by individual household solar panels, as well as by a wind turbine. The solar panels convert the electricity to 220 volts with no additional transformers required. The wind turbine would need first connected by power lines to a step-up transformer. This would increase the voltage and decrease to minimize power loss of a long distance (several miles) to the village. Step-up transformers work by having a square ring made of iron ore with a primary coil on one side, and a secondary coil on the other. The primary coil has less turns in it than the secondary coil. This way the induced voltage produced at the secondary coil is greater than the supplied voltage at the primary coil.


When the power lines reach the village, transforming stations with step-down transformers will reduce the voltage to 110 kV. Smaller step-down transformers within the village will reduce the voltage to 5 kV. Each house or building will have a transformer that further reduces the power to 220 V. A step-down transformer is created when the number of turns of wire in the secondary coil is less than the number of turns in the primary coil. This causes the induced voltage produced at the secondary coil is be less than the supplied voltage input at the primary coil.

In your original post (OP) you mentioned something about a solar panel at each house. I had the same thought as Kurdt -- integrating the DC output from the solar panels into the AC mains of the house is non-trivial, but obviously do-able. And it would deserve mention in your paper, if each house still has solar panels.

thanks i added:

Each home in the village has its own solar panels. This solar panels produce direct currents, so they would have to be attached to an inverter to convert the direct currents into alternating currents.

-Amy

 

[marcusl]

Your

in OP said transmit at high current, but this post looks good!