INNER COLD WATER ENTRANCE VALVE TEMPERATURE HIGH PROTECTION METHOD FOR VALVE COOLING SYSTEM OF CONVERTER VALVE

摘要

An inner cold water entrance valve temperature high protection method for a valve cooling system of a converter valve. The method comprises: a valve cooling control protection system reading a direct current real-time value from a pole control apparatus, and reading inner cold water entrance valve real-time temperature values from three inner cold water entrance valve temperature sensors at the same time; if all the three temperature sensors break down, the valve cooling control protection system sending a tripping command to lock a direct-current power transmission system, or else, selecting a maximum temperature value as the inner cold water entrance valve real-time temperature value; calculating a real-time junction temperature of a converter valve thyristor according to the inner cold water entrance valve temperature and a direct current value; and comparing a junction temperature value of the thyristor with a junction temperature limit value, sending an alarm signal when the junction temperature of the thyristor reaches an alarm value, and sending the tripping command to lock the direct-current power transmission system when the junction temperature of the thyristor reaches the junction temperature limit value. The method has good coordination control performance and can be adapted to various voltage levels and direct-current power transmission system converter valves in various direct-current load conditions.