For maximum theoretical Mvar flow across a transmission line, what power angle is optimal when resistance is ignored?

The optimal power angle for achieving maximum theoretical Mvar flow across a transmission line, when resistance is ignored, is 90 degrees. In power systems, the power angle refers to the phase difference between the voltage and current.

At a power angle of 90 degrees, the power flow is purely reactive, which means that it is focused solely on the transmission of reactive power (Mvars) rather than real power (MW). This scenario represents the maximum capacity of the system to transfer reactive power, as it maximizes the sine of the power angle in the equation for power flow in an AC system.

When we consider maximum reactive power flow specifically, the relationship between reactive power and power angle is such that a 90-degree angle results in maximum Mvar transfer. This angle essentially implies that the voltage and the current are orthogonal, allowing for an optimal transfer of reactive power without the influence of real power loss due to resistance.

Thus, the answer provided does not align with this optimal condition. A deeper understanding of power transmission dynamics demonstrates that a 90-degree power angle is essential for maximizing Mvar flow without resistance considerations.