Pulsewidth modulation is used to provide a 50 Hz voltage acr

Pulse-width modulation is used to provide a 50 Hz voltage across a series RL load with R= 12 ohm and L=20 mH. The DC supply voltage is 150 V. The amplitude of the 50 Hz voltage is tube 120 V. Determine the Fourier Series quantities and the RMS current of the inverter for (i) bipolar PWM with mf= 21, (ii) bipolar PWM with mi=41, (iii) unipolar PWM with mi = 10 Simulate the circuit and verify the manual calculation results as obtained in part (a) using PSpice. Display the current waveform in the load and the harmonic spectrums of the current.

Solution

a)i) Irms = m*V/R

= 21* 150/12

= 350

ii) Irms = 41*150/12

   = 210 A