A three-phase thyristor rectifier bridge is required to control a DC motor. The suitable device is important to ensure the stable operation of the soft starter to control the motor and it must selected to coincide with the property of motor and requirement of system. The selection principle provided as below:

1.Condition: input voltage V_line=380V (3N 50Hz), output DC current I_d=3600A, cooling mode of thyristor is air cooling, environment temperature T_A=40℃, the desired surge current I_TSM=20KA.

2.Selection of voltage: peak value of rated line voltage

V_D(max)=*V_I=*380=537V, the anti-impact coefficient is considered as 2.5, the formula to calculate the voltage grade is: V_DSM≥537V*2.5= 1343V, so

V_DSM = V_RSM = 1400V.

3.Selection of current: due to the outline of thyristor is different in addition to different current, so we should calculate the suitable current value from the thyristor with Vrrm=1400V. I_d=3600A, the average current pass through on each thyristor I_T =1200A, the rated current of thyristor I_T(AV) =1200A*2.5=3000A.

4.Such the air cooling heatsink will be selected according to the outline of thyristor.

5.The thyristor and heatsink should be selected against the application and detailed requirement of motor control system. The phase control thyristor and heatsink manufactured by Jiangsu Yangjie Runau Semiconductor Co are highly integrated with the state of the art technology of manufacturing high power semiconductor device. It’s widely used in motor transmission control application. Please contact our professional technicians to select the suitable thyristor and heatsink for the best performance of your application.