For the first half cycle of supply voltage T1 will start conduction at a and will conduct upto pi+a as load is highy inductive current is continuous and the second thyristor T2 is triggered at pi+a which conducts upto 2pi+a so conduction period of each thyristor is pi. i hope it helps

Explanation:

Single Phase Full Wave Converter (M-2 Connection):
A single phase full wave converter with M-2 connection consists of two thyristors connected in parallel in each half cycle of the input voltage. This configuration is used to control the power delivered to a highly inductive load.

Firing Angle:
The firing angle is the delay between the instant at which the input voltage becomes positive or negative and the instant at which the thyristor is triggered or turned on. It determines the conduction angle of the thyristor and hence the power delivered to the load.

Firing Angle in Each Half Cycle:
In a single phase full wave converter with M-2 connection, the firing angle for each thyristor is different in the respective half cycle. Let's consider the positive half cycle first.

- Positive Half Cycle: In the positive half cycle, the input voltage becomes positive at t = 0. The first thyristor is triggered at a firing angle of α (0 < α="" />< π/2)="" and="" conducts="" for="" a="" conduction="" angle="" of="" π="" -="" α.="" the="" second="" thyristor="" is="" triggered="" at="" a="" firing="" angle="" of="" π="" -="" α="" and="" conducts="" for="" a="" conduction="" angle="" of="" />

- Negative Half Cycle: In the negative half cycle, the input voltage becomes negative at t = 0. The first thyristor is triggered at a firing angle of π + α (π/2 < π="" +="" α="" />< π)="" and="" conducts="" for="" a="" conduction="" angle="" of="" π="" -="" α.="" the="" second="" thyristor="" is="" triggered="" at="" a="" firing="" angle="" of="" 2π="" -="" α="" (π="" />< 2π="" -="" α="" />< 3π/2)="" and="" conducts="" for="" a="" conduction="" angle="" of="" />

Period of Conduction:
The period of conduction of each thyristor is the time for which the thyristor remains in conduction mode during each half cycle.

- Period of Conduction in Positive Half Cycle: The period of conduction for the first thyristor in the positive half cycle is π - α. The period of conduction for the second thyristor in the positive half cycle is α. Therefore, the total period of conduction in the positive half cycle is π - α + α = π.

- Period of Conduction in Negative Half Cycle: The period of conduction for the first thyristor in the negative half cycle is π - α. The period of conduction for the second thyristor in the negative half cycle is α. Therefore, the total period of conduction in the negative half cycle is π - α + α = π.

Therefore, the period of conduction of each thyristor in a single phase full wave converter with M-2 connection is π.