Question

1. Consider the single-phase VSI inverter shown below dc VR(t) iz(t) a) If your input voltage Vdc - 100V2 V and switching frequency is 60 Hz with zero delay angle. Then, sketch the square wave output. Mark the peak values [10 marks] b) Sketch the fundamental output on the top of the above waveform. Mark the peak value По marksl c) The above A VSI is used to create a square wave output with 100v2 V at 60 Hz. This waveform is delivered to a 60 Hz ac utility voltage at 120 VRMS, through a series inductor of 50 mH(after removing the resistor R and connect to the grid). How much active power is transferred, when inverter fundamental has a phase shift of 40 degrees leading with respect to the grid voltage 40 marks] d) If you decide to introduce a delay to the switching, what will be the fundamental amplitude when the delay angle 6 30 degrees, with input voltage of 100V2 V [20 marks] e) Suppose you are interested on cancelling the fifth harmonic in the output. What is the delay angle do you select in this case and what is the corresponding fundamental amplitude in this case [20 marks]

Answer 1

a) → output wqvefmn 6. 66 ms Peak valuz (180.56 V. 01 R. 9.941

9. 32 13watt 2オ oh เวา o)