Online Junction Temperature Extraction With Gate Voltage for Thyristor Considering the Pressure Variation

The junction temperature
$(T_{\mathrm{j}})$
of the thyristor is closely related to its operating conditions, and
$T_{\mathrm{j}}$
significantly affects the performance and reliability of the thyristor. The
$T_{\mathrm{j}}$
is essential information for health assessment. This paper proposes an online junction temperature measurement method for high-voltage and large-power thyristors with the press-pack structure. Theoretical analysis shows that the gate voltage
$V$
GK
of thyristor during the trigger state can be utilized as a temperature-sensitive electrical parameter (TSEP) for online
$T_{\mathrm{j}}$
monitoring, and the influence of pressure variation on
$T_{\mathrm{j}}$
extraction is analyzed. Additionally, the proposed circuit can drive the thyristor and measure the V
GK.
V
GK
can be used for online monitoring
$T_{\mathrm{j}}$
fluctuations in the thyristor based on the long-term load test.