Test: Power Electronics- 5 - Electrical Engineering (EE) MCQ

The overlap angle of a phase controlled converter will increase if

1. The firing angle increases
2. The frequency of supply increases
3. The supply voltage increases

Among the above statements 

A separately excited DC motor fed from 3-phase semi converter develop a full load torque at 1500 rpm when firing angle is 60°. The armature taking 50 A at 400 V DC and having the resistance of 0.4 Ω, then supply voltage per phase will be ________

A 3 ϕ 180°-mode bridge inverter has star-connected load of R = 8 Ω and L-30 mH. The inverter is fed from 220 V dc and its output frequency is 50 Hz. Find the R.M.S value of 1^st harmonic current (in A)

A 3-ϕ, 3 pulse converter, fed from delta star transformer, is connected to a load requiring ripple free current. A freewheeling diode is connected across the load. Find the R.M.S value of thyristor current (in A) for firing angle 60°. (Take V_mp = 200 V)

A 240 V battery is being charged through a three phase diode bridge rectifier. The rectifier is fed by a three – phase 230 V. 50 Hz source current limiting resistance in series with battery is 8Ω and load current is assumed to be ripple free. The value of average battery charge current is –

A solar cell of 400 V is feeding power to an ac supply of 440 V, 50 Hz through a 3 – phase fully controlled bridge converter. A large inductance is connected in the dc circuit to maintain the dc current at 12 A. If the solar cell resistance is 1 Ω, then each thyristor will be reverse biased for a period of – (in degrees)

A three phase fully controlled bridge converter is feeding a load drawing a constant and ripple free load current of 20 A at a firing angle of 60°. The approximate total harmonic distortion (% THD) and the rms value of fundamental component of input current will respectively