# Power Flow Diagram & Power Developed by Synchronous Motor

## Power Developed by Motor :

#### The mechanical power developed / phase is,

= Back emf * Armature current * Cosine of the angle between Eb and Ia
= Eb Ia Cos (α - Φ) for lagging PF
= Eb Ia Cos (α + Φ) for leading PF

#### The copper loss in a synchronous motor takes place in the armature windings. Therefore,

Armature copper loss per phase = Ia2 Ra
Total copper loss = 3 Ia2 Ra

Pm = P - Pcu

#### For three-phase,

Pm = √3 IL IL Cos Φ – 3 Ia2 Ra

## Power Output of the Motor :

To obtain the power output we subtract the iron, friction, and excitation losses from the power developed. Therefore, net output power, Pout = Pm - iron, friction, and excitation losses. The above two stages can be shown diagrammatically called as Power Flow Diagram of a Synchronous Motor.

## Net Power Developed by a Synchronous Motor :

#### If Ra is neglected, then Zs ≈ Xs and θ = 90°. substituting these values in the above equation.

Do not enter any spam links and messages