Power Electronics Questions

• In integral cycle control the period of on-off control should be more than mechanical time constant of load.
• Two semiconverters are connected in series to form a single phase series converter. The input v = Vm sin ωt and a1 = a2 are the firing angles of the two converters. If a1 = a2 = 0, the dc output voltage is
• In a 3 phase full wave regulator feeding a star connected resistance load the input voltage is 400 V line to line. The firing angle is 160°. The line to line output voltage would be
• A single phase semiconverter has a freewheeling diode. If the firing angle is a and the load is purely resistive, the periods of conduction and freewheeling respectively are
• A cycloconverter is
• During forward blocking state of SCR, the voltage and current respectively are
• A 3 phase bridge inverter is fed by 400 V battery. The load is star connected and has a resistance of 10 Ω per phase. The peak value of load current is
• A single phase half wave controlled rectifier circuit is feeding on RL load. The circuit has a freewheeling diode. The input voltage is v = Vm sin ωt. If I0 is the load current during the conduction of freewheeling diode, the KVL equation during the conduction of free wheeling diode is
• A 750 A circuit uses thyristor of current rating 175 A. If derating is 25%, the number of thyristors in parallel is
• Which of these triggering methods for series connected SCRs use LASCR in the gate circuit?
• In a series inverter supplying a load resistance R, the commutating elements L and C should be such that
• An RC snubber circuit is used to protect a thyristor against :
• In a single phase full wave ac regulator the rms value of load current is 20 A load is purely resistive. Then
• A 3 phase ac regulator uses
• HVDC transmission systems generally use
• A dc separately excited motor has a constant field current. The armature is fed from a single phase supply through a semi-converter. When a = 0, speed is 600 rpm. If a = 90°, the speed is likely to be
• Assertion (A): An inverter does not require forced commutation Reason (R): A series inverter is a forced commutation inverter.
• A single phase series converter is used for
• The average load current supplied by a thyristor depends on
• An SBS can conduct is one direction only.