A 3 phase full converter has an average output voltage of 200 volt for...
Answer:Given
- Average output voltage at zero-degree firing angle = 200V
- Resistive load
To find
Output voltage at 90-degree firing angle
Solution
A 3 phase full converter is a circuit that converts AC voltage to DC voltage. The output voltage of the full converter depends on the firing angle of the thyristors. The firing angle is the delay between the zero crossing of the input voltage and the triggering of the thyristors.
The output voltage of the full converter can be calculated using the following formula:
V_avg = (3V_m/π) * (1 - cosα)
Where,
V_avg = average output voltage
V_m = maximum output voltage
α = firing angle
At zero-degree firing angle, cosα = 1, hence
V_avg = (3V_m/π) * (1 - 1) = (3V_m/π) * 0 = 0
Therefore, V_m = 200V
At 90-degree firing angle, cosα = 0, hence
V_avg = (3V_m/π) * (1 - 0) = (3V_m/π) * 1 = 3V_m/π
V_avg = 200V
3V_m/π = 200V
V_m = (π/3) * 200V
V_m = 209.44V
Therefore, the output voltage at 90-degree firing angle is 209.44V.
Conclusion
The output voltage of a 3 phase full converter depends on the firing angle of the thyristors. At zero-degree firing angle, the output voltage is zero, and at 90-degree firing angle, the output voltage is (π/3) times the average output voltage at zero-degree firing angle.