Designing For a Critical Load using a Spot Network

Transcription

1 This is a photographic template your photograph should fit precisely within this rectangle. Designing For a Critical Load using a Spot Network Tony Oruga, P.E. Product and Sales Manager Network Protectors 2007 Eaton Corporation. All rights reserved Eaton Corporation. All rights reserved.

2 Network Systems Who? When? What? How? Why? Where? 2 2

3 Network Systems Who knows what distribution network systems are? When? What? How? Why? Where? 3 3

4 Network Systems Who? When were they first used? What? How? 1882 DC networks Why? 1907 Memphis; AC network Where? 1921 Seattle 1922 NY; first system 4 4

5 When were they first used? 1922 Westinghouse Electric developed first Network System Union Electric in New York, now called Consolidated Edison. Con Ed - 25,000 Network Protectors on their system. 85% of Con Ed load supplied by Networks. Today Commercial areas of most major cities over 200,000 have network systems. Secondary Network voltages are 216, 480, and 600VAC 5 5

6 When were they first used? 6 6

7 Network Systems Who? When? What is a Network System? How? Why? Where? 7 7

8 What is a Network System? Alternative to traditional power distribution topologies Radial Primary Selective Secondary Selective Network System Spot Grid That s the way we have always done it 8 8

9 What is a Network System? Utility Substation Spot Network System Utility Substation Feeder Breaker Network Transformers Network Protector Network Breaker Fuse Cable Limiter Load Collector Bus *2 or more parallel feeders to a load supply allow uninterrupted power during contingency 9 9

10 What is a Network System? Grid Network System 10 10

11 What is a Network System? Grid Network System 3 Feeder Distributed

12 What is a Network System? Highest level of reliability for power distribution systems Most desirable for critical loads Two main topologies: Spot One dedicated customer Grid Several customers; i.e. City block 12 12

13 What is a Network System? Substation and Primary Feeders Nominal Voltages 4.16 kv to 34.5 kv Dedicated primary feeders- supply only network transformers 13 13

14 Network Systems Who? When? What? How does it work? Why? Where? 14 14

15 How does it work? Spot Network Fault on Primary side which causes breaker to open Spot Network - Fault on Primary Feeder Network Transformer Network protector Network breaker fuse Cable Limiters Collector Bus 15 15

16 How does it work? Spot Network Station Breaker opens which causes NP to open Spot Network - Station Breaker 1 is Opened Network Relay Trips Upon the Flow of Reverse Magnetizing Current of its Associated Network Transformer. Collector Bus 16 16

17 How does it work? Spot Network Station Breaker opens which causes NP to open Spot Network Continues operation at N-1 contingency Customer never experiences interruption of service Collector Bus 17 17

18 MPCV Relay Family Robust design for extreme temperatures (-40C to 125C).25 Thick Solid Brass Case Submersible Communication activated Advanced Safety Algorithms Only sequence based relay Replaces any Electro-Mechanical Network relay, solid state, or digital relays regardless of vintage or protector type. Specification preferred for foreign and domestic utilities 18 18

19 LV Secondary Network System Philosophy Underground Systems Reference Book, EEI T&D Committee (1957) Page 5-2: Operation is based on 3 principles: Westinghouse Electric Reference Book: Vol 3 Distribution Systems (1965) 1. The self-clearing of faults on the secondary grid either by burning-off faults or clearing by use of limiters. 2. Automatic opening of network protectors when a feeder breaker is opened or in event of a fault on a primary feeder cable or in a network transformer. 3. Automatic closing of network protectors to connect the network transformers to the secondary grid when the primary feeder is energized. 19 (Page 167) 19

20 Sample SLD 2-Unit Spot Network 20 20

21 Sample Network Floor Plan (Switchgear) 21 21

22 Sample SLD 3-Unit Spot Network 22 22

23 Sample Network Floor Plan (Switchgear) 23 23

24 Sample Profile Network view (submersible) Collector Bus Sudden Pressure Relay Visual Disconnect Visual Status Indicator Network Protector Network Transformer Source Bus Bulkhead *Throat or Wall mount Primary Disconnect Switch 24 24

25 Vault Vision Vault protection Family of sensors that seamlessly integrate into communication platform Multi-platform communication Heat detection systems 25 25

26 Today s Product Suite for Underground 26 26

27 How does it work? Spot Network Submersible model CM-52 shown Switchgear Line-Up 27 27

28 Network Systems Who? When? What? How? Why use a Network System? Where? 28 28

29 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage 29 29

30 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required 30 30

31 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand 31 31

32 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand Transformer losses are typically less 32 32

33 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand Transformer losses are typically less Protectors assure positive power into load 33 33

34 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand Transformer losses are typically less Protectors assure positive power into load System provides improved voltage regulation 34 34

35 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand Transformer losses are typically less Protectors assure positive power into load System provides improved voltage regulation Less voltage sag on Motor starting (up to 70% less than a radial system) 35 35

36 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand Transformer losses are typically less Protectors assure positive power into load System provides improved voltage regulation Less voltage sag on Motor starting (up to 70% less than a radial system) Automatic open and close operation 36 36

37 Advantages of Network System Design Outage on primary feeder does NOT cause customer outage Less transformer capacity is required Lower peak loads on transformers - diversity of demand Transformer losses are typically less Protectors assure positive power into load System provides improved voltage regulation Less voltage sag on Motor starting (up to 70% less than a radial system) Automatic open and close operation LV Network Customer outage rate Approaching zero Radial systems once every year. BEST SOLUTION FOR CRITICAL LOAD APPLICATIONS! 37 37

38 Number of Outages Reliability Design Considerations Spot Network Primary Selective Primary Loop Double-Ended Radial Investment Cost Radial Primary Selective Primary Loop Double-Ended Spot Network Costs associate with outages 38 38

39 Network Systems Who? When? What? How? Why? Where are they used today? 39 39

40 Where are they used today? 40 40

41 Where are they used today? *Selected example utilities 41 41

42 Where are they used today? Network Systems are also widely used in other parts of the world such as: Canada Asia and Asia Pacific Philippines Thailand South Korea Australia Latin America Central and South America Mexico Columbia Brazil Venezuela 42 42

43 Example Installations Electrical Room Installation Subsurface Vault Installation 43 43

44 Example Installations Platform installation Roof installation 44 44

45 Example Installations Detroit Edison Design 45 45

46 Example Installations Subsurface Vault Installation 46 46

47 Example Installations 3 Unit 480Y/277 V Spot Network- Seattle, WA- Building Vault 47 47

48 480V Spot Network Example (1-4 Feeders at kv) Load Estimation Study Maximum Short Term Peak Load: 1250 kva Continuous Average Load: 800 kva Minimum Baseline Load: 275 kva All above loading conditions at 0.87 Lagging PF 3 Standardized 480V Transformer Options 1000 kva (1200A) 1500 kva (1800A) 2500 kva (3000A) Network Unit Options 2-Unit through 6-Unit Spot Networks 48 48

49 Optimal Transformer / #-Unit Combination (N-1 Contingency)? 49 49

50 Transformer Calculations 50 50

51 Network Protector Selection 51 51

52 Network Protector Selection Rationale Choose 1000kVA 5% Impedance Transformers (125% Maximum Short Term = 1504A) 1600A NWP Rating Provides 133% Transformer Nameplate Overload Margin, a good fit. 1875A NWP 156% Rating also utilizes 1600:5 CTs but unnecessary higher amperage fuses. Select 1600A CM52 NWP for a 2-Unit 1000kVA Spot Network. Notice that a 2-Unit 1500kVA Spot would yield: Higher Transformer $, Higher NWP $ (4-Pole CM52), for undesired excess load capacity

53 IEEE Standards & References IEEE C Secondary Network Transformers Subway and Vault Type (Liquid Immersed) Requirements IEEE C Standard Requirement for Secondary Network Protectors EPRI Bronze Book Underground Distribution Systems Reference Book 53 53

54 Additional Network System Training Electrical Networks Systems Conference (ENSC) Annual Conference Guest Speakers and Vendor Trade Show 16 th Annual ENSC Tempe, AZ March 30 th to April 2 nd 2015 Troubleshooting Training (3-day)- covers all brands of NWPs Factory or Onsite Classes are available Greenwood Seminar to be held 2x per year, 4.0 CEU credits awarded NWP Engineer Application Training (2 days) Greenwood and On-Site 54 54

55 Questions? 55 55