The parameters of power electronic devices such as thyristors and diodes have a very close relationship with the environmental conditions of the chip. When working at high altitude and low temperature, users need to pay attention to reasonable use to ensure the reliable operation of the device.

In the factory parameter values of thyristor, the blocking voltage, leakage current, di/dt, dv/dt and other parameters refer to the test values under rated junction temperature conditions, and these parameters can still ensure their performance at low temperature; Gate trigger current and gate trigger voltage are the test values at 25 ° C, and they generally decrease with increasing temperature.

When used at high altitudes and low temperatures, attention should be paid to:

one At -40℃, the gate trigger current value of the thyristor will double compared with that at 25℃, and the gate trigger voltage will increase by about 30%. Therefore, in order to ensure the reliable start-up of the device, it is necessary to require sufficient strength of the gate trigger current of the thyristor. That's the strong trigger we ask our users to use. It also plays an important role in improving the di/dt performance of the device, reducing the turn-on time and turn-on loss, and facilitating the serial and parallel operation of the device. Recommended gate trigger conditions are: gate trigger current amplitude IG=10IGT (2-5A, <10A); Gate current upturning time tr≤1µs.

2. Under high altitude conditions, the heat dissipation capacity of the air-cooled radiator will be reduced, but the lower environmental stability is conducive to the heat dissipation of the device, so the choice of the device and the radiator must be considered according to the highest ambient temperature that may appear on the site in use, and a certain current margin should be left.
3. If the device starts and stops very frequently, and the device frequently cycles between -35 ° C and 125 ° C, the life and reliability of the device will be reduced compared with normal operation, and attention should be paid to it in use.