Question

A single-phase bridge inverter, fed from a 230 V dc is connected to the load R = 10 Ω and L = 0.03 H. Determine the fundamental component of rms output current. Fundamental output frequency of the square wave output = 50 Hz.

(a) 30 A

(b) 15 A

(c) 2.3 A

(d) 20.7 A

The question was asked in an online quiz.

This key question is from PWM Inverters-5 in division Inverters of Power Electronics

Answer 1

Correct choice is (b) 15 A

Easiest explanation: Vo1 (rms fundamental voltage) = 4Vs/π√2 = 207.10 V.

Now, the load impedance at the fundamental frequency i.e. at 50 Hz will be

Z1 = [10^2 + (2π x 50 x 0.03)^2]^1/2 = 13.7414 Ω

Hence, I = V1/Z1 = (207.10)/(13.7414) = 15.07 A.