There is a very close relationship between the parameters of the thyristor and the environment. When working in high altitude and low temperature environments, users need to pay attention to reasonable application to ensure the device reliable working.

When used in application at high altitudes and low temperatures, the following points need to be noted:

1.Under the condition of -40℃, the value of thyristor gate trigger current will be doubled compared with 25℃, and the gate trigger voltage will be increased by about 30%, therefore, to ensure the equipment can be started reliably, it is necessary to require sufficient strength of the thyristor gate trigger current. That is, we recommend the user to use the strong trigger measures. At the same time, it improves the device’s di/dt performance, reduces the turn-on time and turn-on loss, and facilitates the series and parallel operation of the device. The recommended gate trigger conditions are: gate trigger current amplitude IG=10IGT (2-5A, <10A); gate current on-off time tr≤1µs.
2.In high altitude conditions, the cooling capacity of the air-cooled heatsink will be reduced, but the lower environmental stability is conducive to the device heat dissipation, so the use of the site must be based on the highest possible ambient temperature to consider the selection of the device and heatsink, to leave a certain current margin.

3.If the equipment is started and stopped very frequently, and the device is frequently subjected to temperature cycling between -35℃ and 125℃, the life and reliability of the device will be reduced compared to normal operation.