How does changing power angles primarily affect power in the system?

Changing power angles primarily affects active power in the system due to the relationship defined by the power transfer equation, which states that the active power (P) transmitted between two points in an electrical grid is directly proportional to the sine of the difference in power angles (δ) between those points and inversely proportional to the impedance (Z) of the line. As the power angle increases, the sine of that angle increases, leading to a higher power transfer capability.

This relationship indicates that even small changes in the power angle can result in significant variations in the amount of active power that can be transferred across the system. Consequently, engineers can manipulate power angles intentionally to optimize power flow and system stability. Therefore, the strong impact of power angle changes on active power is a critical factor in managing and operating electrical grids efficiently.

In contrast, while reactive power is also influenced by system conditions and power angles, the primary focus of this question is on active power, making 'strongly impacts active power' the most accurate choice in this context.