HYDRAULIC TURBINE OVERSPEED PROTECTION SYSTEM Russian patent published in 2001 - IPC

FIELD: mechanical engineering; hydraulic turbines. SUBSTANCE: proposed hydraulic turbine control system has main spool position microswitch, emergency spool with control solenoid connected to circuit with normally open contact, and speed sensor with connected relay unit. The first one is set for operation at controlled speed rise, and the second one is set for operation at maximum tolerable speed under emergency conditions. Systems has also intermediate relay with coil placed in series with circuit with main spool position microswitch contact and normally open contact or first speed relay and with normally open contact placed in parallel with main spool position microswitch contact and normally closed contact connected in series with normally open contact of second speed relay. To set emergency spool into action, system is provided additionally with actuating relay whose coil is connected in series with circuit with normally open contact of second speed relay and normally closed contact of intermediate relay/ This system precludes false operation of emergency spool and provides its reliable cutting-in in case of abnormal operation of speed governor and overspeeding of turbine. EFFECT: prevention of uncontrollable overspeed of hydraulic turbine. 1 dwg