Power Electronics Questions

• A cycloconverter uses
• In a half bridge inverter circuit fed by a battery of voltage V, the rms value of fundamental component of output voltage is
• A step down cycloconverter has an input frequency f. If it uses natural commutation, the output frequency
• Assertion (A): SUS is a PUT and avalanche diode connected between gate and cathode Reason (R): SBS has two SUS inbuilt together and connected in anti-parallel
• Which statement is correct?
• A class E chopper
• Which of the following commutation methods is the overall circuit under damped?
• In a full bridge single phase inverter feeding RLC load
• In a parallel inverter the turn off time tq of thyristor and values of commutating elements L and C are related as
• A single phase full wave regulator feeds a resistive load. The firing angle of thyristors is 90°. The input power factor is
• A rectifier is fed by a transformer. The rms voltage and current at secondary of transformer are Vs and Is. Output dc power is Vdc Idc and output ac power is (Vrms ) (Irms), Transformer utilisation factor TUF is
• In the below figure, the load is highly inductive. The firing angle is a for each of the thyristors. The periods of conduction of Th1 and Th2 respectively are
• A single phase semiconverter is feeding a highly inductive load and has a freewheeling diode across the load. The waveshape of input current is
• A crowbar circuit is generally needed for protection under fault conditions.
• A single phase fully controlled bridge converter is fed by a voltage Vm sin ωt. The average and rms values of output voltage are
• In a bridge inverter
• In a modified series inverter with two inductors and two capacitors, the load current
• The number of leads in a DIAC are
• An ideal rectifier should have
• To turn off an SCR, it is necessary to reduce its current to less than :