A single$-$phase voltage source inverter $($VSI$)$ is connected to a $240$V$/50$Hz utility system, as

shown in Figure $2.$

A$.$ Build the circuit of the DC$/$AC converter for the inverter to output $10$A current $($RMS$)$ in phase with the grid voltage; Assume bipolar PWM scheme applied to the inverter and the Total harmonic distortion $($THD$)$ needs to be less than $5\%.$ answer the following question:

$1.$ Specify a suitable PWM switching frequency, a line inductance L and a DC link

voltage for the inverter. Comment on the specifications. What is the minimum dc$-$link

voltage required for the inverter to grid connection requirment?

$2.$ Explain how the PWM signals are generated.

$3.$ Present the output current and voltage waveforms. Comments on the effects of the

switching frequency and the inductor on the ripple $($THD$)$ of the output current.

$4.$ How to achieve $6$ A $($RMS$)$ output current with a leading output power factor of $0\mathrm{.}866$

for the inverter? Present the output current and voltage waveforms.

$5.$ Assume $10\%$ variation for the grid voltage, what is the minimum DC link voltage

required for the grid connection?