Single-phase Controlled Rectifiers (Part 6)

Choose power switches used in controlled rectifier circuits.

• BJTs

• Diodes

• IGBTs

• Thyristors

During the positive half-cycle of the supply voltage, the power switches of controlled rectifiers are automatically turn-on.

• True

• False

Choose the requirements to turn-on the thyristors in a controlled full-wave rectifiers.

• The anode terminal of the thyristors is positive.

• The cathode terminal of the thyristor is positive.

• The half-cycle of the AC supply voltage is positive.

• Applying a control signal to the gate terminal of the thyristors.

The function of controlled rectifiers is to vary the DC power supplied to the load.

• True

• False

Under typical operation, the current conduction range of controlled rectifiers is larger than uncontrolled rectifiers.

• True

• False

Calculate the RMS output current if the firing angle is 28⁰

• 3.57 A

• 3.61 A

• 5.05 A

• 5.11 A

Determine the average value of v_o(t) if the firing angle, α is 35⁰. Note: V_m = 100 V.

• 28.95 V

• 31.83 V

• 40.95 V

• 57.91 V

Find the R value if the average output voltage of the rectifier is 57 W, and the firing angle is 20⁰.

• 16.72 Ω

• 33.44 Ω

• 66.88 Ω

• 133.76 Ω

The figure shows the output voltage v_o(t) waveform of a controlled full-wave rectifier with a resistive load. The input voltage equation is 150 sin (ωt), and the firing angle is 140⁰. Determine the rectification ratio, η.

• 8%

• 17%

• 41%

• 81%

A single-phase controlled bridge rectifier is converting 230 V, 50 Hz AC voltage. The rectifier is supplying 780 W average power to a 50 Ω resistive load. Identify the conduction angle of each thyristor.

• 155.1⁰

• 180⁰

• 335.1⁰

• 360⁰