There is 2-machine model having losses too, with their transfer impedance being resistive. The maximum value of sending power P1max and maximum receiving end power P2max will take place with power angle ‘δ’ such that

The maximum power transfer in a system with resistive transfer impedance occurs under specific conditions relating to the power angle ‘δ’. The power angle ‘δ’ is the angle by which the voltage phasor at the sending end leads the voltage phasor at the receiving end. The relationship between the power transferred and the power angle ‘δ’ in an AC transmission line can be described by the power-angle equation.

For a system with only resistive losses and assuming a purely resistive transfer impedance, the maximum sending end power ((P_{1max})) and the maximum receiving end power ((P_{2max})) will occur when the power angle δ is 90 degrees. However, this is an ideal condition often associated with purely reactive power transfer where the sine of the power angle (sin(δ)) reaches its peak. In real-world systems, especially with resistive components, achieving this exact condition is rare and not particularly practical due to stability concerns and the possibility of leading to system instability.

In practical scenarios, especially when considering resistive losses, the angle for maximum power transfer will be less than 90 degrees due to the need to maintain system stability and the fact that real power transfer involves both resistive and reactive components. The derived maximum power will also be diminished by resistive losses in the transmission path. The actual maximum power that can be sent (P1max) or received (P2max) through a transmission line can be calculated using the formula based on line imped