How to calculate the reactive power,Q (VAR) in single phase controlled full wave bridge rectifier with only R-load? The sample observations of the experiment are given in the image. But I am wondering how does reactive power exist in case of pure resistive load!
It the situation described, there is no reactive power in the usual sense of reactive power. The harmonic currents cause reactive volt-amperers in the sense that little or no real power is transferred by the harmonic current. If the source voltage is a power frequency sine wave with only a little distortion, there is little or no source voltage at the harmonic frequencies. If current of one frequency is multiplied by a voltage of another frequency, there is no resulting real power. There is a periodic waveform containing both frequencies but the average of that waveform is zero.
In vector terms, if real power is on the X axis and reactive volt-amperes are on the Y axis, harmonic volt-amperes are on the Z axis. Harmonic volt-amperes are not the same as reactive-volt-amperes, the two can not be added algebraically.
I believe that the Q(VAR) data in your table is the square root of the sum of the squares of the RMS harmonic currents multiplied by the RMS voltage.