Title |
The Analysis of Electrical Conduction and Corrosion Phenomena in HVDC Cooling System and the Optimized Design of the Heat Sink of the Semiconductor Devices |
Authors |
Chan-Ki Kim ; Chang-Hwan Park ; Jang-Mok Kim |
DOI |
https://doi.org/10.6113/TKPE/2017.22.6.484 |
Keywords |
HVDC ; Cooling water ; Corrosion ; Heat sink ; Spiral channel water cooling |
Abstract |
In HVDC thyristor valves, more than 95% of heat loss occurs in snubber resistors and valve reactors. In order to dissipate the heat from the valves and to suppress the electrolytic current, water with a high heat capacity and a low conductivity of less than 0.2 uS/cm must be used as a refrigerant of the heat sink. The cooling parts must also be arranged to reduce the electrolytic current, whereas the pipe that supplies water to the thyristor heat sink must have the same electric potential as the valve. Corrosion is mainly caused by electrochemical reactions and the influence of water quality and leakage current. This paper identifies the refrigerants involved in the ionization, electrical conductivity, and corrosion in HVDC thyristor valves. A method for preventing corrosion is then introduced. The design of the heat sink with an excellent heat radiation is also analyzed in detail. |