In the figure shows on period of the output voltage of an inverter. $$\alpha $$ should be chosen such that $${60^0} < \alpha < {90^0}.$$ If $$rms$$ value of the fundamental component is $$50$$ $$V$$, then $$\alpha $$ in degree is _________.

The Voltage Source Inverter $$(VSI)$$ shown in the figure below is switched to provide a $$50$$ $$Hz,$$ square-wave $$ac$$ output voltage ($${V_0}$$) across an $$R$$-$$L$$ load. Reference polarity of $${V_0}$$ and reference direction of the output current $${I_0}$$ are indicated in the figure. It is given that $$R = 3\,\,\Omega ,\,\,L = 9.55\,\,mH.$$

Appropriate transition $$i.e,,$$ $$Zero$$ voltage switching $$(ZVS)/Zero$$ current switching $$(ZCS)$$ of the $$IGBTs$$ during turn - on/turn off is

The Voltage Source Inverter $$(VSI)$$ shown in the figure below is switched to provide a $$50$$ $$Hz,$$ square-wave $$ac$$ output voltage ($${V_0}$$) across an $$R$$-$$L$$ load. Reference polarity of $${V_0}$$ and reference direction of the output current $${I_0}$$ are indicated in the figure. It is given that $$R = 3\,\,\Omega ,\,\,L = 9.55\,\,mH.$$

In the interval when $${V_0} < 0$$ and $${i_0} > 0$$ the pair of devices which conducts the load current is

In the $$3$$-phase inverter circuit shown, the load is balanced and the gating scheme is $${180^ \circ }$$ -conduction mode. All the switching devices are ideal.

If the $$dc$$ bus voltage $${V_d} = 300\,\,V,$$ the power consumed by $$3$$-phase load is