Control and Automation of Electrical Power Distribution Systems

by Northcote-Green; James

• ISBN13: 9780824726317
• ISBN10: 0824726316
• Edition: 1st
• Format: Hardcover
• Copyright: 2006-09-22
• Publisher: CRC Press

Summary

Implementing the automation of electric distribution networks, from simple remote control to the application of software-based decision tools, requires many considerations, such as assessing costs, selecting the control infrastructure type and automation level, deciding on the ambition level, and justifying the solution through a business case. Control and Automation of Electric Power Distribution Systems addresses all of these issues to aid you in resolving automation problems and improving the management of your distribution network.Bringing together automation concepts as they apply to utility distribution systems, this volume presents the theoretical and practical details of a control and automation solution for the entire distribution system of substations and feeders. The fundamentals of this solution include depth of control, boundaries of control responsibility, stages of automation, automation intensity levels, and automated device preparedness. To meet specific performance goals, the authors discuss distribution planning, performance calculations, and protection to facilitate the selection of the primary device, associated secondary control, and fault indicators. The book also provides two case studies that illustrate the business case for distribution automation (DA) and methods for calculating benefits, including the assessment of crew time savings.As utilities strive for better economies, DA, along with other tools described in this volume, help to achieve improved management of the distribution network. Using Control and Automation of Electric Power Distribution Systems, you can embark on the automation solution best suited for your needs.

Table of Contents

Chapter 1 Power Delivery System Control and Automation	1	(26)
1.1 Introduction	1	(1)
1.2 Why Distribution Automation?	1	(6)
1.2.1 Incremental Implementation	4	(1)
1.2.2 Acceptance of DA by the Utility Industry	5	(2)
1.3 Power Delivery Systems	7	(2)
1.4 Control Hierarchy	9	(2)
1.5 What Is Distribution Automation?	11	(2)
1.5.1 DA Concept	11	(2)
1.6 Distribution Automation System	13	(4)
1.7 Basic Architectures and Implementation Strategies for DA	17	(5)
1.7.1 Architecture	17	(2)
1.7.2 Creating the DA Solution	19	(2)
1.7.3 Distribution Network Structure	21	(1)
1.8 Definitions of Automated Device Preparedness	22	(1)
1.9 Summary	23	(2)
References	25	(2)
Chapter 2 Central Control and Management	27	(78)
2.1 Introduction	27	(1)
2.1.1 Why Power System Control?	27	(1)
2.2 Power System Operation	28	(1)
2.3 Operations Environment of Distribution Networks	29	(2)
2.4 Evolution of Distribution Management Systems	31	(4)
2.5 Basic Distribution Management System Functions	35	(4)
2.6 Basis of a Real-Time Control System (SCADA)	39	(11)
2.6.1 Data Acquisition	39	(2)
2.6.2 Monitoring and Event Processing	41	(3)
2.6.3 Control Functions	44	(1)
2.6.4 Data Storage, Archiving, and Analysis	44	(1)
2.6.5 Hardware System Configurations	45	(2)
2.6.6 SCADA System Principles	47	(1)
2.6.7 Polling Principles	48	(2)
2.7 Outage Management	50	(10)
2.7.1 Trouble Call-Based Outage Management	52	(5)
2.7.2 Advanced Application-Based Outage Management	57	(3)
2.7.3 GIS-Centric versus SCADA-Centric	60	(1)
2.8 Decision Support Applications	60	(9)
2.8.1 Operator Load Flow	61	(2)
2.8.2 Fault Calculation	63	(3)
2.8.3 Loss Minimization	66	(1)
2.8.4 VAR Control	66	(1)
2.8.5 Volt Control	67	(1)
2.8.6 Data Dependency	68	(1)
2.9 Subsystems	69	(8)
2.9.1 Substation Automation	69	(3)
2.9.2 Substation Local Automation	72	(5)
2.10 Extended Control Feeder Automation	77	(2)
2.11 Performance Measures and Response Times	79	(7)
2.11.1 Scenario Definitions	79	(2)
2.11.2 Calculation of DA Response Times	81	(4)
2.11.3 Response Times	85	(1)
2.12 Database Structures and Interfaces	86	(14)
2.12.1 Network Data Model Representations	86	(1)
2.12.2 SCADA Data Models	87	(2)
2.12.3 DMS Data Needs, Sources, and Interfaces	89	(4)
2.12.4 Data Model Standards (CIM)	93	(7)
2.12.5 Data Interface Standards	100	(1)
2.13 Summary	100	(3)
Appendix 2A — Sample Comprehensive CIM Structure	103	(1)
References	104	(1)
Chapter 3 Design, Construction, and Operation of Distribution Systems, MV Networks	105	(44)
3.1 Introduction	105	(2)
3.2 Design of Networks	107	(35)
3.2.1 Selection of Voltage	109	(1)
3.2.2 Overhead or Underground	110	(1)
3.2.3 Sizing of Distribution Substations	110	(4)
3.2.4 Connecting the MV (The Upstream Structure)	114	(2)
3.2.5 The Required Performance of the Network	116	(1)
3.2.6 The Network Complexity Factor	117	(4)
3.2.7 Voltage Control	121	(7)
3.2.8 Current Loading	128	(1)
3.2.9 Load Growth	129	(2)
3.2.10 Earthing (Grounding)	131	(1)
3.2.11 Lost Energy	132	(5)
3.2.12 Comparison of U.K. and U.S. Networks	137	(3)
3.2.13 The Cost of Installation of the Selected Design	140	(1)
3.2.14 The Cost of Owning the Network after Construction	141	(1)
3.3 LV Distribution Networks	142	(3)
3.3.1 Underground LV Distribution Networks	142	(1)
3.3.2 Overhead LV Distribution Networks	143	(2)
3.4 Switchgear for Distribution Substations and LV Networks	145	(1)
3.5 Extended Control of Distribution Substations and LV Networks	146	(2)
3.6 Summary	148	(1)
References	148	(1)
Chapter 4 Hardware for Distribution Systems	149	(38)
4.1 Introduction to Switchgear	149	(5)
4.1.1 Arc Interruption Methods	150	(4)
4.2 Primary Switchgear	154	(4)
4.2.1 Substation Circuit Breakers	154	(4)
4.2.2 Substation Disconnectors	158	(1)
4.3 Ground-Mounted Network Substations	158	(6)
4.3.1 Ring Main Unit	160	(3)
4.3.2 Pad-Mount Switchgear	163	(1)
4.4 Larger Distribution/Compact Substations	164	(3)
4.5 Pole-Mounted Enclosed Switches	167	(1)
4.6 Pole-Mounted Reclosers	168	(2)
4.6.1 Single-Tank Design	169	(1)
4.6.2 Individual Pole Design	169	(1)
4.7 Pole-Mounted Switch Disconnectors and Disconnectors	170	(1)
4.8 Operating Mechanisms and Actuators	171	(4)
4.8.1 Motorized Actuators	172	(1)
4.8.2 Magnetic Actuators	173	(2)
4.9 Current and Voltage Measuring Devices	175	(6)
4.9.1 Electromagnetic Current Transformers	177	(3)
4.9.2 Voltage Transformers	180	(1)
4.10 Instrument Transformers in Extended Control	181	(1)
4.11 Current and Voltage Sensors	182	(3)
4.11.1 Current Sensor	182	(1)
4.11.2 Voltage Sensor	183	(1)
4.11.3 Combi Sensor and Sensor Packaging	184	(1)
Reference	185	(2)
Chapter 5 Protection and Control	187	(64)
5.1 Introduction	187	(1)
5.2 Protection Using Relays	187	(3)
5.2.1 Discrimination by Time	188	(1)
5.2.2 Discrimination by Current	189	(1)
5.2.3 Discrimination by Both Time and Current	189	(1)
5.3 Sensitive Earth Fault and Instantaneous Protection Schemes	190	(2)
5.4 Protection Using Fuses	192	(5)
5.5 Earth Fault and Overcurrent Protection for Solid/Resistance Earthed Networks	197	(1)
5.6 Earth Faults on Compensated Networks	198	(5)
5.7 Earth Faults on Unearthed Networks	203	(1)
5.8 An Earth Fault Relay for Compensated and Unearthed Networks	204	(3)
5.9 Fault Passage Indication	207	(7)
5.9.1 The Need for FPI on Distribution Networks with Manual Control	207	(2)
5.9.2 What Is the Fault Passage Indicator, Then?	209	(2)
5.9.3 The Need for FPI on Distribution Networks with Extended Control or Automation	211	(1)
5.9.4 Fault Passage Indicators for Use on Closed Loop Networks	212	(1)
5.9.5 Other Applications of Directional Indicators	213	(1)
5.10 Connection of the FPI to the Distribution System Conductor	214	(4)
5.10.1 Connection Using Current Transformers	214	(1)
5.10.2 Connections Using CTs on Underground Systems	215	(1)
5.10.3 Connections Using CTs on Overhead Systems	216	(1)
5.10.4 Connection without CTs on Overhead Systems (Proximity)	216	(2)
5.11 Distribution System Earthing and Fault Passage Indication	218	(4)
5.11.1 Detection of Steady-State Fault Conditions	220	(1)
5.11.2 Detection of Transient Fault Conditions	221	(1)
5.11.3 Indication of Sensitive Earth Faults	222	(1)
5.12 AutoReclosing and Fault Passage Indicators	222	(1)
5.13 The Choice of Indication between Phase Fault and Earth Fault	223	(1)
5.14 Resetting the Fault Passage Indicator	224	(1)
5.15 Grading of Fault Passage Indicators	224	(1)
5.16 Selecting a Fault Passage Indicator	225	(1)
5.17 Intelligent Electronic Devices	225	(4)
5.17.1 Remote Terminal Unit	226	(3)
5.17.2 Protection-Based IED	229	(1)
5.18 Power Supplies for Extended Control	229	(5)
5.19 Automation Ready Switchgear — FA Building Blocks	234	(5)
5.19.1 Switch Options	237	(1)
5.19.2 Drive (Actuator) Options	237	(1)
5.19.3 RTU Options	237	(1)
5.19.4 CT/VT Options	237	(1)
5.19.5 Communications Options	238	(1)
5.19.6 FPI Options	238	(1)
5.19.7 Battery Options	238	(1)
5.19.8 Interfaces within Building Blocks	238	(1)
5.20 Examples of Building Blocks	239	(2)
5.21 Typical Inputs and Outputs for Building Blocks	241	(3)
5.21.1 Sectionalizing Switch (No Measurements)	241	(1)
5.21.2 Sectionalizing Switch (with Measurements)	242	(1)
5.21.3 Protection-Based Recloser for Overhead Systems	243	(1)
5.22 Control Building Blocks and Retrofit	244	(1)
5.23 Control Logic	244	(7)
5.23.1 Option 1, Circuit A with 1.5 Switch Automation, FPI and Remote Control of Switches	245	(1)
5.23.2 Option 2, Circuit B with 2.5 Switch Automation, FPI and Remote Control of Switches	246	(1)
5.23.3 Options 3 and 4, No Fault Passage Indicators	247	(1)
5.23.4 Options 5 and 7, Local Control Only	248	(1)
5.23.5 Options 6 and 8, Local Control Only	249	(1)
5.23.6 Special Case of Multishot Reclosing and Automatic Sectionalizing	249	(2)
Chapter 6 Performance of Distribution Systems	251	(38)
6.1 Faults on Distribution Networks	251	(8)
6.1.1 Types of Faults	251	(3)
6.1.2 The Effects of Faults	254	(1)
6.1.3 Transient Faults, Reclosers, and Compensated Networks	254	(5)
6.2 Performance and Basic Reliability Calculations	259	(13)
6.2.1 System Indices	259	(1)
6.2.2 Calculating the Reliability Performance of Networks	260	(1)
6.2.3 Calculation of Sustained Interruptions (SAIDI)	261	(2)
6.2.4 Calculation of Sustained Interruption Frequency (SAIFI)	263	(1)
6.2.5 Calculation of Momentary Interruption Frequency (MAIFI)	264	(1)
6.2.6 Summary of Calculated Results	264	(2)
6.2.7 Calculating the Effects of Extended Control	266	(1)
6.2.8 Performance as a Function of Network Complexity Factor	267	(1)
6.2.9 Improving Performance without Automation	268	(4)
6.3 Improving the Reliability of Underground Networks	272	(6)
6.3.1 Design Method 1 — Addition of Manually Operated Sectionalizing Switches	272	(1)
6.3.2 Design Method 2 — Addition of Manually Switched Alternative Supply	273	(1)
6.3.3 Design Method 3 — Add Automatic in Line Protection	274	(1)
6.3.4 Design Method 4 — Add Continuous Alternative Supply	275	(3)
6.4 Improving the Reliability of Overhead Networks (Design Methods 5, 6, and 7)	278	(3)
6.5 Improving Performance with Automation	281	(1)
6.6 Improvements by Combining Design Methods 1, 2, 3, 4, and 8 on Underground Circuits	282	(5)
References	287	(2)
Chapter 7 Communication Systems for Control and Automation	289	(68)
7.1 Introduction	289	(1)
7.2 Communications and Distribution Automation	289	(3)
7.3 DA Communication Physical Link Options	292	(1)
7.4 Wireless Communication	293	(11)
7.4.1 Unlicensed Spread Spectrum Radio	293	(1)
7.4.2 VHF, UHF Narrow Bandwidth Packaged Data Radio (Licensed/Unlicensed)	293	(1)
7.4.3 Radio Network Theory	293	(9)
7.4.5 Trunked Systems (Public Packet-Switched Radio)	302	(1)
7.4.6 Cellular	303	(1)
7.4.7 Paging Technology	303	(1)
7.4.8 Satellite Communications — Low Earth Orbit	303	(1)
7.5 Wire Communications	304	(29)
7.5.1 Telephone Line	304	(1)
7.5.2 Fiber Optics	304	(1)
7.5.3 Distribution Line Carrier	304	(27)
7.5.4 Summary of Communications Options	331	(2)
7.6 Distribution Automation Communications Protocols	333	(13)
7.6.1 MODBUS	333	(3)
7.6.2 DNP 3.0	336	(6)
7.6.3 IEC 60870-5-101	342	(3)
7.6.4 UCA 2.0, IEC 61850	345	(1)
7.7 Distribution Automation Communications Architecture	346	(4)
7.7.1 Central DMS Communication	346	(2)
7.7.2 Polling and Report by Exception	348	(1)
7.7.3 Intelligent Node Controllers/Gateways	349	(1)
7.7.4 Interconnection of Heterogeneous Protocols	349	(1)
7.8 DA Communications User Interface	350	(1)
7.9 Some Considerations for DA Communications Selection	350	(1)
7.10 Requirements for Dimensioning the Communication Channel	351	(6)
7.10.1 Confirmed and Nonconfirmed Communication	351	(1)
7.10.2 Characterization of Communication Systems	351	(2)
7.10.3 Communication Model	353	(1)
7.10.4 Calculation of the Reaction or the Response Time	353	(4)
Chapter 8 Creating the Business Case	357	(74)
8.1 Introduction	357	(1)
8.2 Potential Benefits Perceived by the Industry for Substation Automation	358	(5)
8.2.1 Integration and Functional Benefits of Substation Control and Automation	358	(2)
8.2.2 SCADA vs. SA	360	(1)
8.2.3 Economic Benefits Claimed by the Industry	360	(3)
8.3 Potential Benefits Perceived by the Industry for Feeder Automation	363	(1)
8.4 Generic Benefits	364	(3)
8.5 Benefit Opportunity Matrix	367	(1)
8.6 Benefit Flowchart	367	(1)
8.7 Dependencies, and Shared and Unshared Benefits	367	(12)
8.7.1 Dependencies	367	(4)
8.7.2 Shared Benefits	371	(1)
8.7.3 Unshared Benefits from Major DA Functions	372	(6)
8.7.4 Benefit Summary	378	(1)
8.8 Capital Deferral, Release, or Displacement	379	(9)
8.8.1 Deferral of Primary Substation Capital Investment	379	(4)
8.8.2 Release of Distribution Network Capacity	383	(4)
8.8.3 Release of Upstream Network and System Capacity	387	(1)
8.8.4 Displacement of Conventional Equipment with Automation	388	(1)
8.9 Savings in Personnel	388	(15)
8.9.1 Reduction in Substation/Control Center Operating Levels	389	(1)
8.9.2 Reduction in Inspection Visits	389	(1)
8.9.3 Reduction in Crew Time	390	(12)
8.9.4 Calculation of Crew Times Savings Associated with Investment- and Operation-Related Savings	402	(1)
8.9.5 Reduced Crew Time and Effort for Changing Relay Settings for CLPU	402	(1)
8.10 Savings Related to Energy	403	(4)
8.10.1 Reduction in Energy Not Supplied Savings Due to Faster Restoration	403	(1)
8.10.2 Reduced Energy Revenue Due to Controlled Load Reduction	404	(1)
8.10.3 Energy Savings Due to Technical Loss Reduction	405	(2)
8.10.3.1 Loss Reduction from Feeder Volt/VAR Control	405	(2)
8.11 Other Operating Benefits	407	(4)
8.11.1 Repair and Maintenance Benefits	408	(1)
8.11.2 Benefits from Better Information (DMOL)	408	(2)
8.11.3 Improved Customer Relationship Management	410	(1)
8.12 Summary of DA Functions and Benefits	411	(1)
8.13 Economic Value — Cost	412	(14)
8.13.1 Utility Cost	413	(8)
8.13.2 Customer Cost	421	(1)
8.13.3 Economic Value	422	(4)
8.14 Presentation of Results and Conclusions	426	(2)
References	428	(3)
Chapter 9 Case Studies	431	(20)
9.1 Introduction	431	(1)
9.2 Case Study 1, Long Rural Feeder	431	(6)
9.2.1 Evaluation of Performance	431	(2)
9.2.2 Crew Time Savings	433	(1)
9.2.3 Network Performance and Penalties	434	(3)
9.3 Case Study 2, Large Urban Network	437	(14)
9.3.1 Preparation Analysis — Crew Time Savings	437	(2)
9.3.2 Preparation Analysis — Network Performance	439	(7)
9.3.5 Summary of Cost Savings	446	(1)
9.3.6 Cost of SCADA/DMS System	447	(1)
9.3.7 Cost Benefits and Payback Period	448	(1)
9.3.8 Conclusions	448	(3)
Glossary	451	(8)
Index	459