An AC voltage of maximum value equal to 100V is applied to a sing

SOLUTION

Concept:

Single-phase fully controlled bridge circuit:

• The bridge rectifier circuit is made of four SCRs T₁, T₂, T₃, T_4, and a load resistor R_L.
• The four SCRs are connected in a closed-loop configuration to effectively convert the alternating current (AC) into Direct current (DC).
• The input signed is applied across terminals A and B and output DC signal is obtained across the load resistor R_L connected across the terminals C and D.
• The four SCRs are arranged in such a way that only two SCRs conduct electricity during each half cycle.
• SCRs T1 and T3 are pairs that conduct electric current during the positive half cycle.
• Similarly, SCRs T2 and T4 conduct electric current during a negative half cycle.
• During the positive half cycle, SCRs T1 and T3 become forward biased while SCRs T2 and T4 become reverse biased.
• During the negative half-cycle, SCRs T2 and T4 become forward biased while SCRs T1 and T3 become reverse biased.
• The current flow across load resistor R_L is the same during positing half-cycles and the negative half cycles.
• The output DC signal polarity may be either completely positive or negative.
• The bridge rectifier allows electric current during both positive and negative half cycles of the input AC signal.
• Peak inverse voltage is the maximum voltage that an SCR can withstand in a reverse bias condition.
• During the positive half cycle, SCRs T1 and T3 are conducting.
• Similarly, during the negative half cycle, SCR T2 and T3 are in the conducting stage while SCRs T1 and T3 are in a non-conducting state.

Calculation:

Given that

V_m = 100 V (AC signal)

PIV of bridge Rectifier =  PIV of SCR T1 and T3 = V_m = 100 V

Similarly, PIV of SCR T2 and T2 is V_m = 100 V.

i.e. PIV of each SCR T1, T2, T3, T4 is V_m = 100 V