Aim: To study the operation of Three Phase Variable Frequency Drive (VFD) Learning Objectives: To study speed variations of a Three phase IM To understand operation of V/F control using three phase Inverter Apparatus : Experimental kit DSO/CRO (Unearthed) Multimeter Patch cords and DSO probes Pre Test Experimental Setup Experiment Video Procedure Switch on the power supply Adjust freq. of Drive signals to 30 Hz using pot. Observe Gate Drive signals 1to6 one by one & plot timing diagram. Measure I/P of error amplifier using dc voltmeter. Due to feedback circuit they have almost same values. & o/p of error amplifier almost 0. Measure Ac voltage fed to induction motor between any to phases on terminal strip provided on back side of box. Vary the speed by varying frequency. Calculate V/F ratio. Vary freq 20Hz, 25 Hz, 35 Hz, 40 Hz & repeat step 5....
