dcs controller tuning--it says all
TRANSCRIPT
DCS CONTROLLER“IT SAYS ALL”
NIDHIN MANOHAR
WHAT IS CONTROLLER ?
THE CONTROLLER IS ONE MAJOR ELEMENT IN THE CONTROL LOOP WHICH DETERMINES AND TAKES THE PROPER ACTIONS TO KEEP THE PROCESS WITHIN DESIRED STABLE CONDITION.
HOW DOES THE CONTROLLER REACT TO PROCESS DISTURBANCES?
HERE COMES THE TUNING IN THE PICTURE.
WHAT IS TUNING?TUNING IS HOW AND WHEN THE
CONTROLLER WILL RESPONSE TO PROCESS CHANGES IN ORDER TO
RESTORE STABLE CONDITION.AND THAT IS DONE BASED ON PROCESS
PARAMETERS ENTERED INTO THREE MATHEMATICAL FUNCTIONS.
PROPOTIONAL ( P )INTEGRAL ( I )
DERIVATIVE ( D )
WHY WE NEED TUNING?
.
GOOD TUNING IS NEEDED TO IMPROVE PROCESS STABLITY TO INCREASE:
1. PLANT PRODUCT QUALITY.
2. PLANT SAFETY.
3. PLANT AVAILABILITY.
HOW IS TUNING DONE?
THERE ARE DEFERENT METHODS AND RULES LIKE:
1.Ziegler & Nichols METHOD. 2. Shell METHOD.
STEP CHANGE Shell METHOD
1.TAKE CONTROLLER ON MANUAL. 2.MENTAIN MV & PV WITH IN
RANGE. 3. MAKE A STEP CHANGE IN MV. 4. WATCH PV UNTIL IT BECOMES STABLE. 5. SELECT THE BEST PLOT TIME & PRINT IT OUT. 6. USE THE PLOT TO CALCULATE
TUNING PARAMETERS.
RELATED TOPICSYOKOGAWA SPECIFICS.
DIGITAL FILTER-PV OVERSHOOT-CALIBRATION MODE..OUTPUT LIMITER-OUTPUT CLAMP-SCAN PERIOD AND
OTHERS .
TUNING & CONTROL SCHEMESCASCADE CONTROL-RATIO CONTROL-MULTIVARIABLE CONTROL-INTERACTING CONTROL –SPLIT RANGE AND
OTHERS.
TUNING START UP STRATEGIES.UNITED SPECIFICS ISSUES.
PERFORMANCE MONITORING .
