Formula for active power loss in transmission lines
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In the book, the formula for the active power loss in transmission lines is △P=I^2R. Can it be calculated as △P=U^2/R instead? In the book, I’ve seen that the calculation always uses current, not voltage
It is possible, but the problem is: how can you know the voltage drop along the circuit? It’s not easy to determine the current in the wire; one still has to calculate the voltage drop along the circuit by working backwards from the current.
Voltage can only be expressed in terms of voltage drop, so current is more convenient
Voltage can only be expressed in terms of voltage drop, so current is more convenient
In principle, the flow of electrons generates an electric current; as these moving electrons do work, a voltage drop occurs whenever there is a current. The voltage drop U on the transmission line changes due to variations in the power load downstream. In terms of parameter measurement, it is convenient to measure the current in the circuit, while it is not convenient to measure the voltage drop between the transmission ends. (The resistance of a circuit can be estimated based on the data of the conductors; adding a temperature correction gives a relatively accurate value. If you want to measure the power of a device, the input signals for a power meter are U and I, with R not being taken into account.)
Formula 2 cannot be used to calculate the line voltage drop, right? Formula 1 can