Title |
Evaluation on Design of Thyristor Snubber Circuit considering Switching Characteristics in LCC HVDC System |
Authors |
이철희(Chur Hee Lee) ; 김승완(Seung Wan Kim) |
DOI |
https://doi.org/10.5370/KIEE.2019.68.11.1292 |
Keywords |
HVDC; Snubber Circuit; Damping; Thyristor Valve |
Abstract |
This paper deals with the evaluation on the design of thyristor snubber circuit for LCC(Line Commutated Converter) HVDC system. Snubber circuit consists of capacitance and resistance to protect thyristor in HVDC system. Based on turn off model, mathematical expressions are derived by considering the maximum device stress, maximum reverse dv/dt, and reverse energy loss of a power device. The total turn-off loss in the device with the associated snubber circuit is considered as stray inductance. In the case of determining ratio between resistance and capacitance, it is important to reflect their relation and the purpose of protecting thyristor. Considering these analytical solutions to 500kV HVDC system in Korea, we can calculate the range of maximum and minimum rate of the thyristor snubber circuit. This study can be applied to review the design of thyristor snubber circuit of HVDC projects. |