E. Handschin • A. Petroianu

Energy ManagementSystemsOperation and Control of Electric EnergyTransmission Systems

With 43 Figures

Springer-VerlagBerlin Heidelberg NewYorkLondon Paris TokyoHong Kong Barcelona Budapest

Contentsi

1.1

1.2

1.3

1.4

1.4.1

1.4.2

1.4.3

2

2.1

2.22.2.1

2.2.2

2.2.3

2.3

2.3.1

2.3.2

2.3.3

2.3.4

2.4

2.4.1

2.4.2

2.5

2.6

2.6.1

2.6.2

2.7

2.7.1

2.7.2

2.7.3

2.8

2.9

2.9.1

2.9.2

2.10

Introduction

Electric energy systems

Power system engineering

Evolution of power system control technology

Control centre justification

Associated effortFactors justifying a new control centre

Conclusions

System engineering aspects of power system operation

Classification

Time decomposition1 Pre-dispatch

DispatchPost-dispatch

Network level decomposition

Transmission

Sub-transmission

Distribution

General remarksMode decomposition

Operation

Operational planning

Operation state decomposition

Activity decomposition

Power management

Network management

Control decompositionCentralised control

Decentralised control

Centralised versus decentralised policy

User oriented decomposition

Analysis decomposition

Primary analysis functions

Secondary analysis functions

Control flow decomposition

1

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4

7

9

911

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3 Typical energy control centre functions 31

3.1 System monitoring and security 31

3.2 System economy 33

3.2.1 Minimum cost of operation -34

3.2.2 Minimum active power transmission losses 34

3.2.3 Minimum deviation from a specific operating point 34

3.2.4 Minimum number of controls scheduled 35

3.3 System control 35

3.4 Restorative control 36

4 Power system control centre: hardware structure 37

4.1 Overview 37

4.2 Remote terminal unit 37

4.3 Communication 39

4.4 The real-time computer system 39

4.4.1 Central processing unit 39

4.4.2 Computer memory system 42

4.4.3 Man-machine interface 43

4.5 Review of hardware structure for network control centres 45

4.5.1 The dual computer configuration 46

4.5.2 The front-end computer configuration 47

4.5.3 Triple configuration 48

4.5.4 The quad computer configuration 48

4.5.5 Distributed system configurations 49

4.6 Hardware design considerations 51

4.7 Hardware obsolescence 53

4.8 Performance of SCADA/EMS 53

5 Power system control centre: software structure 58

5.1 Overview 58

5.2 Data acquisition subsystem 59

5.2.1 Collection of data 60

5.2.2 Error checking and plausibility tests 60

5.2.3 Conversion to engineering units 60

5.2.4 Limit checking 60

5.2.5 Handling of alarms 61

5.3 Supervisory control subsystem 61

5.4 Real-time software environment 62

5.4.1 Operating system 62

5.4.2 Real-time traffic manager subsystem 62

XI

5.5 Data base management system 62

5.5.1 Overview 62

5.5.2 Requirements 63

5.5.3 Software aspects 64

5.5.4 Structure of the data base 64

5.5.5 Storage and effort requirements 66

5.5.6 Access methods 67

5.5.7 Performance requirements 67

5.6 Man-machine interface 68

5.6.1 Importance 68

5.6.2 Human factors 68

5.6.3 Display formats 69

5.6.4 Features, design, requirements 70

5.7 Inter-utility communication subsystem 72

6 Power system control centre: dispatcher's activities 74

6.1 Introduction 74

6.2 Salient features of the operator activity 74

6.3 A conceptual model of the dispatcher's activity 75

6.4 Requirements 78

6.5 Trends in power dispatch operator's activity 79

7 Power system and dispatch training simulator 83

7.1 Introduction 83

7.2 Power system technological requirements 84

7.3 Functions of a training simulator 88

7.3.1 General functions 88

7.3.2 Specific functions 91

7.4 Modelling aspects 93

7.5 Different types of training simulators 98

7.5.1 Stand-alone version 98

7.5.2 Integrated version 99

7.5.3 Implementation 101

7.5.4 Economic considerations 102

7.6 Training scenarios and training sessions 102

7.7 Concluding remarks 105

8 Existing energy management systems 107

8.1 General remarks 107

8.2 Energy management systems in a US utility 107

XII

8.2.1 System characteristics 107

8.2.2 The concept of hierarchical control 108

8.2.3 Enhanced control and security assessment 109

8.2.4 Implementation 109

8.3 Energy management systems in Germany 111

8.3.1 Introduction 111

8.3.2 Load-frequency control 113

8.3.3 Energy management systems 116

8.3.4 Concluding remarks 117

8.4 Energy management systems in developing countries 118

8.4.1 Introduction 118

8.4.2 Electrical characteristics of longitudinal power systems 119

8.4.3 Security assessment in longitudinal power systems 123

8.4.4 Concluding remarks 125

9 Project management of energy management systems 126

9.1 Overview 126

9.2 Stages in the implementation of a new control centre 129

9.2.1 Feasibility study 130

9.2.2 System justification 130

9.2.3 Functional requirements and preliminary specifications 130

9.2.4 Releasing the specification 131

9.2.5 Evaluating proposals 131

9.2.6 Negotiating a contract 132

9.2.7 Design specifications 133

9.2.8 Implementation and organisation 133

9.2.9 Training 133

9.2.10 System operation 133

9.3 A step-by-step plan for implementing a new control centre 134

9.3.1 Preliminary system design (pre-contract) 134

9.3.2 Work statement 134

9.3.3 System design (post-contract) 135

9.3.4 Detailed design specifications 135

9.3.5 Development 135

9.3.6 System integration and tests 136

9.3.7 System acceptance 136

9.4 Design, development, and maintenance of software 137

9.4.1 Software development phases 137

9.4.2 Concluding remarks 139

XIII

10 Expert systems for' power system operation 142

10.1 Overview 142

10.2 Security monitoring and control 143

10.3 Definitions 145

10.4 Structure of the expert system 147

10.5 Possibilities and limits of expert systems 151

10.6 Applications 152

10.7 Conclusions 155

Glossary 157

References 179