Advanced Regulatory Control: Applications and Techniques

by David W. Spitzer

Overview

Without modern instrumentation control, industry would be at a standstill. Whether the control hardware consists of local mechanical, pneumatic, or electronic controls, electronic or pneumatic analog controllers, microprocessor-based controllers, programmable logic controllers, personal computer-based controls, or a distributed control system, a keen awareness of advanced regulatory control is required by engineers, technicians, educators, managers, salespersons, and marketing personnel in order that appropriate control technology be applied to industrial processes.

This book is intended to describe advanced regulatory control and its application to continuous processes in a nonmathematical format and in as practical a manner as possible in order to be of benefit to all skill levels. Manual and regulatory control are described in the text as a prelude to advanced regulatory control so that their differences might be explored. It focuses on control but integrates the operations of measurement devices and final control elements into discussions, because their importance is often the limiting factor in control system performance.

Readers will Find…

An explanation of the operation and limitations of feedback control

Illustrations of the integration of cascade and feedforward control into feedback control loops

A clear approach to design and implement advanced regulatory control

An instructor at the ISA Training Center in Research Triangle Park, N.C., throughout the United States, and internationally in the ISA Short Course Program, Mr. Spitzer is the author of Industrial Flow Measurement (ISA Press), Variable Speed Drives: Principles and Applications for Energy Cost Savings (ISA Press), Consumer Guides to Coriolis Mass, Differential Pressure, Magnetic, Ultrasonic, and Vortex Shedding Flowmeters, and Contact and Non-Contact Level Gauges (Copperhill and Pointer), as well as the Volume Editor of Flow Measurement (ISA Press). Mr. Spitzer has also written some 15 articles in various technical magazines.

Product Details

ISBN-13:	9781606501245
Publisher:	Momentum Press
Publication date:	10/28/2009
Pages:	145
Product dimensions:	7.30(w) x 10.20(h) x 0.60(d)

Table of Contents

Preface ix

1 Introduction 1

2 Manual Control 3

3 Field Measurement Devices 7

Flow Measurement 8

Level Measurement 14

Pressure Measurement 16

Temperature Measurement 18

Transmitter Technology 21

Summary 25

For Further Information 26

4 Controllers 27

Controlling Instruments 29

Local Control 30

Centralized Control 33

Distributed Control 35

Summary 35

5 Final Control Elements 37

Control Valves 37

Variable Speed Drives 41

Summary 43

References 43

6 Field Equipment Tuning 45

Control Loop Tuning Procedure 46

Equipment Adjustments 46

Sensor Adjustments 46

Transmitter Adjustments 48

Controller Input Adjustments 50

Final Control Element Adjustments 52

Summary 54

7 Regulatory Controller Features 55

Anti-Reset Windup 55

Bumpless Transfer (Set Point Tracking) 57

Control Dead Band 58

Controller Range 60

Direct Forward/Reverse Control Action 61

Failure Modes 62

Event-Related Controller Features 64

Output Limits 67

Remote Set Point 68

Set Point Limits 68

Slew Rates 69

Totalizer 70

Summary 70

8 PID Control 71

Proportional Control 71

Integral Control 73

Derivative Control 75

PID Control 77

Summary 78

9 Controller Tuning 79

Controller Tuning Strategies 79

Quarter Amplitude Oscillation Method 82

Trial and Error Method 84

Self-Tuning Method 84

Typical Controller Settings 84

Summary 85

For Further Information 85

10 Regulatory Control Loop Pairing 87

Regulatory Control Strategy 87

Summary 92

11 The Limitations of Regulatory Control 95

Control Loop Response 95

Process Upsets 99

Control Loop Interaction 100

Summary 101

12 Advanced Regulatory Control Tools 103

Mathematical Functions 103

Advanced Regulatory Control Process Variables 105

Feedback Control 109

Cascade Control 100

Feedforward Control 113

Feedforward Action 119

Constraint and Override Control 121

Summary 122

13 Advanced Regulatory Control Design and Implementation 123

Design 123

Implementation 127

Summary 128

14 Applying Advanced Regulatory Control 129

Define the Product and Its Quality 130

Define the Raw Materials 130

Define the Boundaries of the Process 130

Define Quality Measurements for Evaluation 130

Define Quality Measurements for On-Line Operation 131

Develop the Control Strategy 131

Define Instrumentation Hardware 138

Critique the Process 138

Summary 138