Abstract: An electro-hydraulic positioning system which has automatic calibration capabilities is disclosed. The system includes a microprocessor which accesses calibration parameters stored in a non-volatile memory unit. The microprocessor adjusts the position demand according to the stored calibration parameters. The system may be placed in an atuomatic calibration mode. In which case, update calibration parameters are automatically determined and stored. The system also includes a microcontroller which monitors system operating variables and reports deviations of the variables from expected values for same.

Abstract: A microprocessor-based controller for an extraction type steam turbine-generator unit capable of selecting from a variety of predetermined control strategies and implementing corresponding valve position control loops by generating appropriate valve position control signals in accordance with operator-chosen setpoint signals and turbine operating level signals. In a particular control strategy, automatic system frequency correction is achieved in a load control mode upon separation of the turbine-generator from the utility power grid, by detecting turbine speed deviation beyond predetermined limits and correcting turbine speed to synchronous speed without the need for operator intervention.

Abstract: A microprocessor-based controller for an extraction type steam turbine-generator unit capable of selecting from a variety of predetermined control strategies and implementing corresponding valve position control loops by generating appropriate valve position control signals in accordance with operator-chosen setpoint signals and turbine operating level signals. In a particular control strategy, automatic compensation of megawatt output is achieved during the extraction mode of turbine operation by summing a megawatt setpoint signal from a feedback loop with a feedforward extraction valve setpoint signal and a megawatt reference signal, which sum is then applied to the turbine control valves to enable tight megawatt control during the extraction operation.

Abstract: A microprocessor-based controller for an extraction type steam turbine-generator unit capable of selecting from a variety of predetermined control strategies and implementing corresponding valve position control loops by generating appropriate valve position control signals in accordance with operator-chosen setpoint signals and turbine operating level signals. The extraction mode of turbine operation is subdivided into a provided set of mutually exclusive extraction control loops, each of which can be placed in service in a bumpless fashion upon transition from any other extraction control loop in a predetermined sequence. Upon a return from the manual mode of turbine operation to the automatic mode, a particular extraction control loop is automatically placed in service without the need for operator intervention.