Technical Seminars 2012
Industrial Compressor Controls
Standard
Custom
CONTROLLING the power of ENERGY
TM
Compressor Application
Challenges
Hydrogen Separation Application
One component in a
complex process
Naphtha Cracker Application
1st
Stage
MPU MPU MPU
PT
PT
TT
TT
FT
FY
2nd
Stage
PT
PT
3rd
Stage
4th
Stage
PT
FT
TT
FT
PT
TT
FT
PT
TT
PT TT
TT
FY
TT
PT
PT
Stage to stage connections
Many failure points
Turbine part of process
4
FY
FY
Acetylene Vacuum Compressors
Parallel compressor connections
Starting/stopping challenges
5
Liquid Natural Gas Process
Stage to Stage Relationships
Multi-stage anti-surge controls
Stage to Stage decoupling
Each stage controller benefits from a decoupling
signal from the before or after stage controller.
Each stages flow has a direct effect on the attached
stage flow, control and protection.
Compressor Control
Overview
Compressor Control Functions
Surge Prevention
Compressor-Based
Anti-Surge Control (PID)
Rate Control (PID)
BOOST
Surge Recovery
Surge Detection
Surge Recovery Routines
Surge Min Position
Speed Bias Logic
Min Speed
Valve to Valve Decoupling
Process Limiting
Aux Functions
Sequence Positioning
Surge Control Line
Biasing
Manual Control modes
Auto Gain
Compensation
HSS Auxiliary Inputs
Surge Counter
Valve Freeze Logic
Compressor Operating Point Calculation
Standard Compressor
Performance Map
Volumetric Flow Referenced to Suction
Conditions
Surge
Region
Y-axis (Head) Represented by Polytropic
Head
Lin
e
Varying Molecular Weights, Pressures, and
Temperatures
Co
nt r
ol
Li n
Online Calculations Compensate for
N3
Su
rge
BO
OS
T
rge
Lin
e
Operating
Point
Su
Polytropic Hea
ad (HP)
X-axis (Flow) Represented by Actual
N2
N1
Volumetric Inlet Flow (QA)
10
Compressor Control Basics
Anti-Surge Control Modes
Automatic
Full Surge Prevention & Surge
Recovery Control
Manual with Backup
Operator Can Open Recycle
Beyond the Value Set by the
Automatic Demand
Cannot Close Beyond the Value
Set by the Automatic Demand
Full Manual
Total Manual Control of Recycle
Valve Position
Bypasses Automatic Controls
(Surge Recovery can be
Enabled)
Deactivates Decoupling
Routines
11
Starting, Shutdown &
Purging
Sequence Position Feature
Provides Fixed Position Control
Support Functions
On-Line Detection
Surge Detection
Captures Surge Signature via
Derivatives of Pressure & Flow
Surge Counter
Number of Surge Cycles Since
Last Reset
Freeze Mode
Stops Unnecessary Valve
Movement During Steady State
Operation
Compressor AntiAnti-Surge Control
The open- and closed-loop surge prevention and
recovery routines act together as a
comprehensive control strategy throughout the
compressor performance map.
Backup
Line
SCL PID
Controller
Rate PID
Controller
Surge
Backup
Line
SCL PID
Controller
Rate PID
Controller
12
Decoupling
Decoupling
Compressor Control Block Diagram
Anti-Surg
Accel
To Recycle
Valve
Suction
Discharge
13
Process / Performance Control
Typical performance or process control variables:
Compressor suction pressure
Compressor discharge pressure
Compressor flow
Another process dependent upon one of the above
FY
PT
ST
PT
TT
TT
FT
PT
PIC
SIC
UIC
FY
14
Other Controller Functions
Control capability
Parallel or Series Compressors
Load Sharing
Incipient Surge Detection
Performance Controller
Dynamic Compressor Surge Limit Line
Backup Strategies for Signal Failures
Auxiliary Controls
Bearing Temperature Monitoring
Turbine Lube Oil
Compressor Gas Seals
Load Limiting (power limit and/or compressor choked
flow)
15
Compressor Control Block Diagram
16
Compressor Operation Screen
17
Compressor Surge Capture
Recursion Rate 10 Milliseconds
The compressor is unloaded.
The control response returns the
compressor operating point to a safe
condition.
Operating Point
Anti-Surge Valve Demand
Closed-loop controls begin to open the
Anti-Surge Valve as the operating point
moves below setpoint.
18
Raw Flow Input Flow
Element dP
The primary closed-loop
controls cannot prevent
the operating point from
reaching the Surge Limit
LineA surge occurs.
Compressor Surge Capture
Recursion Rate 160 milliseconds
19
Woodward Solutions
20
Woodward Compressor Controls
21
Simple Compressor Control Options
505 CC-2 Controller
User configurable
Turbine Controller
Plant DCS
Single Valve Turbines
Single Extraction Turbines
Compressor Controller
1 or 2 Loop
Compressor Controller
Performance Control
included
Suction Pressure
Discharge Pressure
Operator
Control Station
(Optional)
Engineering Work Station
Simple Compressor Train
22
505CC--2 Turbine & Compressor Control
505CC
Two RS232 Serial Modbus Ports
AO
DO
AI
24 Vdc
6 Configurable Analog Outputs
Turbine/Comp Shutdown, Turbine/Comp Alarm, 10 Configurable Discrete Outputs
10 Configurable Analog Inputs
ESD, Reset, Raise/Lower Speed, Open/Close Recycle Valves, 16 Configurable Inputs
Turbine Speed
Actuator Demand Signal
Recycle Valve No. 1
Recycle Valve No. 2
Suction Flow No. 1
Suction Pressure No. 1
Side stream Flow
Side stream Pressure
T&T
Valve
Discharge Pressure No. 2
Compressor
Compressor
505CC-2 Application
PT
PT
FT
PT
FT
23
OCP Screen Turbine Performance Map
24
24
Vertex--Pro Compressor Controls
Vertex
Motor Drive Apps.
MicroNet platform
Simplex or Redundant
User Configurable
Compressor Controller
Software
1 or 2 Loop Compressors
Performance Control
included
Compressor Load Sharing
Optional - HMI Touch Panel
Plant DCS
Touchscreen
(153 mm)
Vertex-Pro
Compressor Controller
Configuration Tool
VFD
Simple Compressor Train
25
EWS Screen Compressor Config
26
26
OCP Screen - Overview
Configured for
both turbine and
compressor
27
27
OCP Screen Turbine Performance Map
28
28
OCP Screen Compressor Performance Map
29
OCP Screen - Compressor Control
30
OCP Screen - Compressor Control
31
Custom Compressor
Controllers
32
Custom Compressor Controls
Fault Tolerant
Controller
Plant Control
Compressor Controls
Motor Drive
Turbine drive
Parallel & Series compressors
Surge Anticipation Technology
33
Compressor Island
VFD
Custom MicroNet System Overview
Ethernet, RS232, RS422, RS485 Ports
AO
Programmable Analog Outputs
DO
Programmable Discrete Outputs
AI
Programmable Analog Inputs
Programmable Discrete Inputs
Exhaust Pressure Signal
Turbine Speed
Inlet Pressure Signal
Actuator Demand Signal
Recycle Valve No. 1
Single, Dual or
Triplicated I/O As
Required To Meet
Availability Goals
Recycle Valve No. 2
Suction Flow No. 1
Suction Pressure No. 1
Side stream Flow
Side stream Pressure
T&T
Valve
Discharge Pressure No. 2
PT
Compressor
Compressor
PT
PT
PT
FT
PT
FT
34
Compressor Train Control Functionality
Compressor Control Functionality
Anti-Surge protection for all loops
Start/Stop sequencing (valve positioning)
Suction/Discharge pressure control
Loop-to-Loop performance control
Loop-to-Loop decoupling action
Compressor load sharing
Compressor
Compressor
Train Controller
Compressor
Compressor
Compressor
PT
PT
35
PT
PT
PT
FT
FT
PT
PT
FT
FT
CORE Software Modules
Single Stage Industrial Compressor
Dual Stage Industrial Compressor
Dual Stage Industrial Compressor with Side Stream
Three Stage Industrial Compressor
Three Stage Industrial Compressor with Side Streams
Four Stage Industrial Compressor
Four Stage Industrial Compressor with Side Streams
Five Stage Industrial Compressor
Five Stage Industrial Compressor with Side Streams
Parallel compressors (3 max)
Series compressors (2 max)
API-611 Steam Turbine
API-612 Single Valve Steam Turbine
API-612 Single Extraction Steam Turbine
API-612 Double Extraction Steam Turbine
OEM Qualified / Field Proven Software Logic
36
NetSim Simulation Software
Complete Package
Simulation
Control
Software
Emulation
Control
Hardware
Emulation
Control Logic
Start Sequencing
Communications
CPU Scan Rate
I/O delays
I/O Resolution
SIMULATION PACKAGE
( MatrixX, Matlab, Simulink, ACSL )
Debug Software in the Office
Import & Use OEM Models
Reduce Commissioning Time
Reduce Commissioning Risk
Motor
Actual Compressor Control
37
Compressor
Package
Emulation
Compressor
Recycle Valve
Package Aux
Why Operators Choose Woodward?
Woodward?
Reliable Hardware
Long MTBF periods
Field proven hardware and software
Global Support
Advanced control algorithms developed
specifically for industrial compressors
Smart-PID algorithms for bumpless mode
transfers and load response anticipation
Adaptive Speed and analog anti-aliasing filters
Advanced load rejection and decoupling routines
to increased stability
Simulation Tools (used for training & validation)
38
Why Woodward?
Faster scan rates:
5 10 milliseconds
Faster compressor control point acceleration
sensing
WGC = 100 microseconds
Hardware reliability
DR or TMR offerings
True System Determinism
Synchronized Software & I/O
Better Service
MHI, Ebara, Conoco Phillips, Dresser Rand, BP,
Chevron
39
Why Woodward?
Easier Software Changes
Changes can easily be made and tested at site
(KBR report)
Woodward NetSim Simulation package
Better Control stability
Automatic PID dynamics selections makes starts easier
(BP report)
Faster Flow signal filtering
Woodward uses 4 point filter 20 milliseconds
Better Service Tools
Woodward = 5 millisecond
Safety Certified Products
MicroNetTMR, MicroNet-Plus, ProTech203
40
Dushanzi Chooses Woodward
Dushanzi Chooses Woodward
Woodward was selected as the control of choice
for all three of Dushanzis new
critical compressor trains (cracked gas, ethylene,
and propylene) due to
Woodwards highly reliable control platforms,
advanced compressor protection algorithms, and
ability to control very difficult ITCC applications.
The Woodward MicroNet TMR control platform
met all of Dushanzis, Lindes, and Siemens
stringent system control, protection, and plant
interface requirements.
41
Industrial Turbomachinery Systems
Improve Reliability Enhance Performance
TM
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