DEtecting Phase Angle in a PWM Recitifer

The angle can be sensed in a pwm rectifier by using CRO by measuring waveforms between two points b4 and after input choke.(pfeeesun@rediffmail.com) .. the waveform b4 the choke will give u the line voltage (keep this as reference wave) and the waveform after the choke will give u the bridge input voltage . if this bridge input voltage lags the line voltage then the bridge draws reactive power from the line . on the other hand if this bridge input voltage wave leads the linevoltage wave then it means ur bridge (IGBTs) is sourcing or injecting reactive power in to the line...