Power Transmission
How can we transport power from power stations to homes? Why do we use “high tension” lines?
- At home, the AC voltage obtained from outlets in this country is 120V at 60Hz.
- Transmission of power is typically at very high voltages ( eg ~500 kV)
- Transformers are used to raise the voltage for transmission and lower the voltage for use. We’ll describe these next.
But why?
- Calculate ohmic losses in the transmission lines:
- Define efficiency of transmission:
- Note for fixed input power and line resistance, the inefficiency µ 1/V2
Example: Quebec to Montreal
The efficiency goes to zero quickly if Vin were lowered!