Woodward 505 Digital Control for Steam Turbi

Applications

The 505 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 header pressure,

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.

The 505 controller also includes the following turbine protection functions to ensure that the

turbine or its driven load (compressor, pump, generator) is not operated outside of its

designed limits:

 3 Critical speed avoidance bands

 Overspeed anticipation and shutdown protection

 Configurable under- or over-pressure shutdown logic

 Minimum and maximum speed and load settings

Ethernet and serial communications allow users to easily connect the 505 into the plant or

process control system. All controller inputs, outputs, and statuses can be monitored, and all

start/stop or enable/disable commands can be given through industry standard Modbus® *

TCP or OPC protocols. The 505 uses SNTP (synchronized network time protocol) over

Ethernet to allow users to synchronize the 505’s real-time clock to the plant distributed control

system.

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

controller’s 8.4-inch (21 cm) graphical 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. Un-pluggable terminal blocks allow for easy system installation, troubleshooting, and

replacement.

Designed for steam turbine control, the 505 control includes four PID controllers (Speed, Cascade, Aux-1, Aux-2), multiple start-up

routines (manual, semi-auto, automatic, remote control), and multiple protection functions (overspeed, critical speed range, max

power, etc.) which can be configured by a user depending on the specific turbine application’s requirements. Users can configure

the 505’s different PID controllers, start routines, and protection levels themselves without the need for a special control engineer.

Once configured, the 505 performs a configuration check routine to ensure that the programmer did not make any basic

configuration mistakes.

Optionally, users can utilize Woodward’s RemoteView software program with the 505 to function as a remote operator control

panel and/or engineering station. Once loaded onto a remote computer or touch panel, this software program allows the computer

or touch panel to perform all of the 505 front panel display functions (monitor, operate, tune, and configure). Password-based login

level security allows users to manage which functions they want the remote panel user to have. Refer to product specification

03424 for more information on RemoteView’s capabilities.

The 505 includes a suite of service tools to allow users to perform the following functions:

 Download configuration settings files to the 505

 Upload configuration settings files from the 505 to save on another device

 View real-time or saved trend files

Cost‐Effective Design

The 505 control is designed to function as the turbine control, system sequencer, operator control panel, and first-out indicator.

This encompassing design minimizes external system devices as well as system installation, wiring, and troubleshooting.

This field-configurable controller allows major functional changes to be made on-site, often by knowledgeable plant personnel, and

minor functional changes to be on-line as process changes require. The 505 control’s first-out-indicator logic indicates internal as

well as external system related alarm and shutdown conditions, greatly simplifying and reducing system troubleshooting.

Communications

The 505 controls can communicate directly with plant Distributed Control Systems and/or CRT-based operator control panels,

through four Ethernet ports using Modbus TCP or OPC communication protocols, or via one serial Modbus port. The single serial

port supports RS-232 or RS-485 communications using ASCII or RTU Modbus protocols.

Communications between the 505 and a plant DCS can also be performed through hard-wired connections.

Control

The following PIDs are available to perform as process controllers or limiters:

 Speed/Load PID (with multiple dynamics & Adaptive PID)

 Extraction/Admission Pressure/flow PID

 Cascade PID (Header Pressure or Tie-Line Control)

 Auxiliary PID 1 (limiter or control)

 Inlet Header PID

 Exhaust Header PID

 Rotor Acceleration PID (on startup)

System Protection

 Integral Overspeed Protection Logic & Test Capability

 First-out Indication (15 individual shutdown inputs)

 External Alarm Indication (15 individual alarm inputs)

 Stuck in critical speed band logic

 Bumpless transfer between control

 Local/Remote control priority and selection

 Internal CPU watchdog circuit in case of failure

 Password security for operation and configuration modes

INPUTS

 Power:

LV models = 18–36 Vdc

HV models = 88–264 Vac & 90–150 Vdc

 Speed:

2 Passive MPUs or 2 Active Proximity probes

(0.5—35 000 Hz)

 Discrete Inputs: 20 Configurable Contact Inputs

(optionally 16 additional inputs via LinkNet-HT modules)

 Analog Inputs: 8 Configurable 4–20 mA Inputs

(optionally 16 additional 4-20mA inputs via LinkNet-HT modules)

(optionally 8 additional RTD inputs via LinkNet-HT modules)

OUTPUTS

 Valve/Actuator Drivers: 2 Actuator Outputs, 4–20 mA or 20–200 mA

 Discrete Outputs

8 configurable Relay Outputs; contacts rated

24 Vdc @ 5 A.

 Analog Outputs: 6 Programmable 4– 20 mA Current Outputs

COMMUNICATIONS

 Ethernet: 4 ports (Modbus TCP or OPC protocols)

 Serial: 1 Modbus port (ASCII or RTU) Comm Ports

(RS-232 or RS-485 compatible)

 CAN: 4 ports (Woodward CANopen protocol)