METHOD AND APPARATUS FOR IMPROVING ELECTRO-HYDRAULIC AND ELECTRO-MECHANICAL INTEGRATED CONTROL SYSTEMS OF A STEAM TURBINE

摘要

A means to effect a trip response regardless of the electro-mechanical actuator type used for improving electro-hydraulic and electro-mechanical integrated control systems for a steam turbine. To achieve this goal, electro-mechanical actuators can be equipped with multiple coils or multiple motors (usually a primary and a secondary). In a dual-coil configuration, the primary is energized according to an output of a PID controller, whereas the secondary coil is regulated by a separate control element. The entire system is powered by means of Uninterruptable Power Supply (UPS) with AC output which can provide sufficient time for trip response using primary coil or motor. At the same time, secondary coil or motor is powered by independent power from a UPS and/or separate battery backup. Whenever trip response is required, and there is a complete main power interruption secondary coil or motor is quickly energized to provide adequate trip response.