High-Voltage Thyristor Leakage Current Measurement Using Gate Voltage Vgk Under Non-trigger Current

Thyristor is widely used in the industrial field, especially in high-voltage direct current (HVDC) transmission. It is the core component of the converter valves. The device characteristics of thyristors seriously affect the safe operation of converter valves and even the entire HVDC transmission system. In this paper, a voltage and temperature accelerated aging test platform is built, and the degradation law of thyristor characteristic parameters is analyzed. The results show that the degradation of thyristor leakage current is the most obvious, which is the precursor of its aging. This paper proposes a method to measure the leakage current of thyristors by gate voltage V
gk
under non-trigger current. The feasibility of the method is verified by experiments. The V
gk
can measure both junction temperature (T
j
) and leakage current. The monitoring of T
j
and leakage current is very important to ensure the safe and reliable operation of thyristors.