Question

1- Classify the power switches according to the ability to control

2- What are the conditions of turning on the thyristor. State the methods of turning it off. What is the main difference between thyristors and GTO

3- Describe the behavior of TRIAC

4- Derive the expressions of the average load voltage and current in single-phase half-wave controlled rectifiers and resistive load. Draw the waveforms of supply voltage, output voltage, output current, thyristor voltage and thyristor current

5- In a single-phase half-wave controlled rectifier and resistive load, it is desired to get an average load voltage of 80 V. Determine the firing angle if the ac supply voltage is 220 V. If the load resistance is 30 Ω, calculate the average load current and design the thyristor. The volt-drop across the device Von during conduction is 2V. Determine the average conduction losses.

6- In a single-phase half-wave controlled rectifier and R-L load it was found that conduction angle of the thyristor is 160o when the firing angle is 50o. Calculate the average load voltage if the circuit is supplied from a 140 V ac source. Draw the waveforms of supply voltage, output voltage, output current and thyristor voltage.

7- In a single-phase half-wave rectifiers with R-L load and a freewheeling diode FWD, calculate the average load voltage if the firing angle is 30o and the supply voltage is 150 V. Draw the waveforms of supply voltage, output voltage, load current, thyristor current, FWD current and thyristor current.

8- Derive the expressions of the average load voltage and current in single-phase full-wave controlled rectifier with center tapped transformer and resistive load. Draw the waveforms of supply voltage, output voltage, output current, and thyristor current.

9- In a single-phase full-wave controlled rectifier with center tapped transformer and resistive load, it is desired to get an average load voltage of 140 V. Determine the firing angle if the ac supply voltage is 200 V. If the average load power is 700 W, calculate the average load current and design the thyristor. The volt-drop across each thyristor Von during conduction is 1.8V. Determine the average conduction losses of the thyristors.

10- Derive the expressions of the average load voltage and current in single-phase full-wave controlled rectifier (bridge rectifier) and resistive load. Draw the waveforms of supply voltage, output voltage, output current and thyristor current.

11- In a single-phase full-wave controlled rectifier (bridge rectifier) and resistive load, it is desired to get an average load voltage of 50 V. Determine the firing angle if the ac supply voltage is 150 V. If the average load power is 300W, calculate the average load current and. Design the thyristor.

12- Derive the expressions of the average load voltage in single-phase full-wave controlled rectifier (bridge rectifier) and highly inductive load. Draw the waveforms of supply voltage, output voltage, output current and thyristor current.

13- In a single-phase full-wave controlled rectifier (bridge rectifier) and resistive load, it is desired to get an average load voltage of 90 V. Determine the firing angle if the ac supply voltage is 230 V. If the average load power is 270 W, calculate the load current and. Design the thyristor.

14- The single-phase half wave rectifier has a purely resistive load of R and the delay angle is α=π/2, determine: ??? , ??? , ????, ????.
Plot : Is , Vs , VL , VT , Ig

Answer 1