Question

If we have a single phase transformer, and we keep the primary voltage constant. what is the affect of the three types of loads in the secondary side(resisitive,inductive and capacitive) on the secondary winding.

Answer 1

In the question it is asked that if we have a single phase transformer, then what will be the effect on the loads of the types given as resistive, inductive and capacitive on the secondary winding. The solution for the above problem is given below

When the resistive load is connected to secondary winding-

under this conditions the load will consume the apparent power and the voltage drop in the secondary winding will increase. Under these conditions the active and apparent power will be equal to each other and the reactive power will be equal to zero. Hence the power factor of the system is said to be the highest under these conditions. The secondary voltage and secondary current will be in phase with each other.

When the inductive load is connected to the secondary winding of the transformer -

under these conditions there will be a voltage drop in the secondary windings of the transformer and consume active power from the system and absorb it. The secondary current will lag behind the secondary voltage by an angle of 90 degrees when a pure inductive load is connected. This type of loads makes the power factor of the system very low as the secondary current lags the secondary voltage by a large angle.

When the capacitive load is connected to the secondary winding of the transformer -

under this conditions the capacitive load acts as a power factor correction device. There will be voltage drop in the secondary and almost zero voltage regulation is achieved in this conditions. The capacitive load leads the output current towards the output voltage and reduce the angle between them. The capacitive load makes the secondary current 180 degrees out of phase with the demagnetizing components and oppose the demagnetizing components of the core of the system, thus the core is magnetized by the capacitive load. The power factor of the transformer is improved of the system under this conditions.