Water Cooling System for High Voltage Thyristor Valves

The paper refers on the design and tests of a direct water cooling system for high voltage thyristor valves for synchronous generator starting equipments and static var compensation systems. Accelerated ageing tests (dielectric and thermome- chanical), carried out for more than one year on a prototype thyristor valve, have permitted to acquire experience on reliability of fine water circuits, on metallic parts (heat sinks, fittings) and electrolytic corrosion and on long term behaviour of insulating pipes. The good results obtained up to now, indicate that properly engineered water cooling systems can be very reliable and therefore very attractive for high voltage power conversion equipments.