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










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


▪ 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


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


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


▪ 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


▪ During event, repair, and repressurization


13

Excessive pump operation


▪ Pump operated more than 30 times within 12 hour period

– Excessive pump operation alarm

14


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

15

Tanker of fluid injected


▪ 1 week after re-energization



16

178 psi


▪ 1 week after re-energization

▪ Tank level readings stabilized at STA A pump plant


17


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

plant

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


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


18

STA D PP approx.

elevation ~ 26 ft

STA C PP approx.

elevation ~118ft

Event location approx.

elevation ~148ft


▪ 1 week before event (summer)

– Line pressure readings at STA D pump plant


19


▪ 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



– Line pressure readings at STA D pump plant

21

Abnormal amount of pump operation


▪ Pump operated more than 25 times within 1 week

22



▪ Tank level readings at STA D pump plant

23


▪ 1 week after event

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


24


▪ 1 week after event

▪ Tank level readings stabilized at STA C pump plant


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


Data Analytics Cont.

27



28



29



30



▪ 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










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

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

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