Electrical Engineering ⇒ Topic : Relation between line current and phase current

Daniel
 
Relation between line current and phase current. In Yconnected supply system, each line conductor is connected in series to a separate phase as shown in Fig.(a). Therefore, current in a line conductor is the same as that in the phase to which the line conductor is connected. Line current, I_{L} = I_{ph } .........in magnitude (a) (b) figure For a balanced load, all the phase currents are equal in magnitude but displaced 120° from one another. Fig. (b) shows the phasor diagram for a balanced lagging load ; the phase angle being (Φ).Note that (Φ) is the angle between phase voltage and the corresponding phase current. However, the angle between the line current and the corresponding line voltage (say I_{R }and V_{RY}) is 30° + Φ. If the balanced load has a leading power factor of cos Φ, then the angle between the line current and the corresponding line voltage will be 30° Φ. Hence in a balanced 3phase Yconnected supply system (1) Line current, I_{L}= I_{ph} (2) All the line currents are equal in magnitude (i.e.= I_{ph}) but displaced 120° from one another (3) The angle between the line currents and the corresponding line voltages is 30^{0 }+ Φ ; + if pf is lagging and  if it is leading.  
 
!! OOPS Login [Click here] is required for more results / answer