505 Enhanced Digital Control for Steam Turbines (with Redundancy)

Applicatons

The 505 Enhanced controller is designed to operate industrial steam turbines of all sizes and applications. This steam turbine controller includes specifically designed algorithms and logic to start, stop, control, and protect industrial steam turbines or turbo-expanders, driving generators, compressors, pumps, or industrial fans. The 505 control’s unique PID structure makes it ideal for applications where it is required to control steam plant parameters like turbine speed, turbine load, turbine inlet or exhaust header pressure, or tie-line power.

The control’s special PID-to-PID logic allows stable control during normal turbine operation and bumpless control mode transfers during plant upsets, minimizing process over- or undershoot conditions. The 505 controller senses turbine speed via passive or active speed probes and controls the steam turbine through one or two (split-range) actuators connected to the turbine inlet steam valves.

For critical applications requiring increased reliability and redundancy, optionally two 505 controls can be connected in a redundant configuration to increase overall system availability. With this type of configuration, the two controls operate in a master/slave manner, where the master unit controls all aspects of the turbine system, and the slave unit tracks the master unit’s PIDs and control modes. This configuration allows for automatic and/or manual transfers between the two 505 controllers in cases of control, transducer, or actuator failure, or when on-line program changes are desired.

Description

The 505 control is packaged in an industrial hardened enclosure designed to be mounted within a system control panel located in a plant control room or next to the turbine. The control’s front panel serves as both a programming station and operator control panel (OCP). This user-friendly front panel allows engineers to access and program the unit to the specific plant’s requirements, and plant operators to easily start/stop the turbine and enable/disable any control mode. Password security is used to protect all unit program mode settings. The unit’s two-line display allows operators to view actual and setpoint values from the same screen, simplifying turbine operation.

Turbine interface input and output wiring access is located on the controller’s lower back panel. Unpluggable terminal blocks allow for easy system installation, troubleshooting, and replacement.