high pressure fluid filled (hpff) hydraulic system data ......line elevation profile from sta a pump...

Safety First and Always

High Pressure Fluid Filled (HPFF)

Hydraulic System Data Analytics

&

Transition Joint Application

Eversource Energy

Demetrios Sakellaris, Lead Engineer, Transmission Lines Engineering

ICC Conference

Scottsdale, Arizona

October 23rd, 2019

Subcommittee: Educational

Presentation Agenda

▪ Background

▪ Topic 1: HPFF hydraulic monitoring and data analytics

– Basics of the hydraulic system

– Examples of hydraulic events

– Potential opportunities for advanced data analytics

▪ Topic 2: Cable conversion – pilot project

– Project background and location

– Unique challenges

– Current status and next steps

▪ Closing / Questions

2

Background

▪ Over 3 million electric

customers across three states

▪ Approximately 300 circuit miles

of pressurized transmission

cable

– Heavily concentrated in the

Greater Boston area

▪ Ranging in voltage from 115kV

to 345kV

3

Background Cont.

▪ Growing amount of scrutiny surrounding HPFF systems

– Particularly from local authorities and environmental agencies

▪ Growing emphasis on reducing the impact of hydraulic events

– Proactive versus reactive

▪ Opportunities to collaborate with agencies to selectively migrate

towards a non-fluid based solution

– Display our environmental stewardship

4

Presentation Agenda

▪ Background

▪ Topic 1: HPFF hydraulic monitoring and data analytics

– Basics of the hydraulic system

– Examples of hydraulic events

– Potential opportunities for advanced data analytics

▪ Topic 2: Cable conversion – pilot project

– Project background and location

– Unique challenges

– Current status and next steps

▪ Closing / Questions

5

Basics of the Hydraulic System

» All three cable phases within the same steel pipe (filled

with dielectric fluid)

▪ Hydraulic system in EMA has pressure vessels at both remote end line

terminals

– Primary and secondary pressure sources

▪ Multiple lines can be hydraulically fed from the same manifold

– Dual headers: system and maintenance

▪ Pressure vessels have numerous data points that are recorded and

communicated back to the Supervisory Control And Data Acquisition

(SCADA) center

– Data is remotely accessible by users via process book

6

Basics of the Hydraulic System Cont.

7

PP A PP B

PP A

Basics of the Hydraulic System Cont.

▪ As with any pressurized system, outside elements can influence

system readings (ex temperature fluctuation – day versus night)

▪ Particularly when there is a very slow hydraulic event, it can be

very difficult to immediately identify and categorize the nature of

the anomaly

– Typical practice to conduct field investigation

▪ How can a loss of fluid event more easily be identified?

– Can we analyze historic patterns to better identify potential

loss of fluid events?

▪ Legacy systems can be prone to hydraulic events

8

Basics of the Hydraulic System Cont.

Typical Pump Operation

▪ Normal pump operation – triggered at low pressure setting

▪ Temperature influenced (i.e conductor)

9

200 psi @ 1:39AM 200 psi @ 6:55AM 200 psi @ 3:26PM

165 psi @ 1:29AM 165 psi @ 6:41AM 165 psi @ 3:20PM

Examples of Hydraulic Events

▪ Line elevation profile from STA A pump plant to STA B

▪ At Station A pump plant with higher elevation point, typical pump

operation line pressure of 180 psi once pressure drops to 130 psi

▪ At Station B pump plant with lower elevation point, typical pump

operation line pressure of 230 psi once pressure drops to 180 psi

10

STA B approx.

elevation ~ 26 ft

STA A PP approx.

elevation ~131ft

Event location approx.

elevation ~ 37ft

Examples of Hydraulic Events Cont.

▪ 1 week before event (summer)

– Line pressure readings at STA A pump plant

– Min 130 psi, Max 180 psi

11

Examples of Hydraulic Events Cont.

▪ 1 week before event

▪ Tank level readings at STA A pump plant

– Min tank level 2,133 gal, Max tank level 2,145 gal, Avg tank level 2,138 gal

*Note* tank capacity is 3,000 gal

12

Examples of Hydraulic Events Cont.

▪ During event, repair, and repressurization

– Line pressure readings at STA A pump plant

13

Excessive pump operation

Examples of Hydraulic Events Cont.

▪ Pump operated more than 30 times within 12 hour period

– Excessive pump operation alarm

14

Examples of Hydraulic Events Cont.

▪ During event, repair (line de-energized), and repressurization

15

Tanker of fluid injected

Examples of Hydraulic Events Cont.

▪ 1 week after re-energization

– Line pressure readings at STA A pump plant

– Min 130 psi, Max 180 psi

16

178 psi

Examples of Hydraulic Events Cont.

▪ 1 week after re-energization

▪ Tank level readings stabilized at STA A pump plant

– Min tank level 1,329 gal, Max tank level 1,335 gal, Avg tank level 1,334 gal

17

Examples of Hydraulic Events Cont.

▪ Line elevation profile from STA C pump plant to STA D pump

plant

▪ At Station C pump plant with higher elevation point, typical pump

operation line pressure of 190 psi once pressure drops to 130 psi

▪ At Station D pump plant with lower elevation point, typical pump

operation line pressure of 230 psi once pressure drops to 170 psi

18

STA D PP approx.

elevation ~ 26 ft

STA C PP approx.

elevation ~118ft

Event location approx.

elevation ~148ft

Examples of Hydraulic Events Cont.

▪ 1 week before event (summer)

– Line pressure readings at STA D pump plant

– Min 170 psi, Max 230 psi

19

Examples of Hydraulic Events Cont.

▪ 1 week before event

▪ Tank level readings at STA D pump plant

– Min Tank level 2,571 gal, Max Tank level 3,308 gal, Avg Tank level 2,769 gal

*Note* Tank Capacity is 10,000 gal

20

Examples of Hydraulic Events Cont.

▪ During event, repair, and repressurization

– Line pressure readings at STA D pump plant

21

Abnormal amount of pump operation

Examples of Hydraulic Events Cont.

▪ Pump operated more than 25 times within 1 week

22

Examples of Hydraulic Events Cont.

▪ During event, repair, and repressurization

▪ Tank level readings at STA D pump plant

23

Examples of Hydraulic Events Cont.

▪ 1 week after event

▪ Pump operation and line pressure stabilized at STA D pump plant

– Min 170 psi, Max 230 psi

24

Examples of Hydraulic Events Cont.

▪ 1 week after event

▪ Tank level readings stabilized at STA C pump plant

– Min tank level 3,717 gal, Max tank level 3,851 gal, Avg tank level 3,777 gal

25

Potential Opportunities for Advanced

Data Analytics ▪ Can we asses historic information to identify trends associated

with past occurrences to flag when these trends occur again?

▪ What data is critical to achieving a successful predictive model?

▪ Algorithm that can identify non-typical patterns and raise such

occurrences as anomalies to the system operator

26

Potential Opportunities for Advanced

Data Analytics Cont.

27

Potential Opportunities for Advanced

Data Analytics Cont.

28

Potential Opportunities for Advanced

Data Analytics Cont.

29

Potential Opportunities for Advanced

Data Analytics Cont.

30

Potential Opportunities for Advanced

Data Analytics Cont.

▪ Currently we are working to advance the hydraulic study

▪ Also pursuing a tracer injection of the hydraulic system

– Reduce time to locate

▪ Identification of critical input parameters

▪ Benefits of such a software

– Larger HPFF systems can be challenging to monitor,

opportunities to reduce cycle time are critical

– System will continue to age, need advanced solutions to help

better manage aging assets

31

Presentation Agenda

▪ Background

▪ Topic 1: HPFF hydraulic monitoring and data analytics

– Basics of the hydraulic system

– Examples of hydraulic events

– Potential opportunities for advanced data analytics

▪ Topic 2: Cable conversion – pilot project

– Project background and location

– Unique challenges

– Current status and next steps

▪ Closing / Questions

32

Project Background and Location

▪ Attachment to bridge crossing

▪ Investigated other crossing options during project review

33

Project Background and Location

34

Unique Challenges

• Design requirement entailed

need to stay within close

proximity of the existing HPFF

circuits

• Due to limited available space,

need to remove one HPFF

circuit during conduit installation

became apparent

• Restrictions on location of

ductbank as well as extent of

visual exposure

35

Unique Challenges

36

Unique Challenges

37

Unique Challenges

▪ Hydraulic loop has high speed circulation between stations

▪ Study completed to determine if high speed circulation loop can

be broken into two smaller loops and achieve the published

ratings

▪ Need for turnaround piping on either side of the bridge

▪ Avoid need for a hydraulic pipe across bridge

38

Unique Challenges

39

Current Status and Next Steps

▪ Completing design work for circuit alignment on easterly and

westerly bridge approaches

▪ Progress with street test pitting work, utility conflict identification,

obtain approvals from authorities having jurisdiction

▪ Vault placement – determine optimal locations for transition joint

vaults (i.e minimize extent of line pipe rerouting to be needed)

▪ Determine optimal outage schedule to support construction

schedule

40

Questions

41