Electric Utility Infrastructure Norman P. Baron, PE and James J. Havrilla, PE, Esq.

Pennsylvania Municipal Electric AssociationOctober 15, 2015

Utility Engineers, PC

Generation Transmission Distribution

Utility Components

Generation - electric energy generation takes primary energy (fuel resources) to create a secondary form of energy (electricity).

Transmission – process of transferring electric energy from one location to another in an electric power system.

Distribution - final stage in the delivery of electricity to end users. Carries electricity from the transmission system and delivers it to consumers.

Utility Components

Safety Customer Service

ReliableCost-effectiveSufficient

Short TermLong Term

Planned Loads Unplanned Loads

System Goals

Safety- No electrical hazards

◦ Customers◦ Utility personnel

Safety

Multiple utility power sources◦ Supplying multiple connection paths to the loads

served. Selecting quality electrical equipment and

conductors Using the best installation methods. System alarms

◦ monitoring ◦ diagnostics

Reliable

Budget - key factor in assessing competing designs. ◦ Initial cost of installation

Material Labor

In House Outside Contractors

◦ Life cycle cost

Cost Effective

System design to accommodate changes. Future expansion

◦ Additional load Justification with trending and historical data.

Transformers◦ increase capacity◦ fan cooling◦ pump cooling

Circuits◦ Capacity◦ Quantity

Sufficient

System redundancy – Ability to take electrical equipment out of service without dropping loads.◦ Dual Transformers◦ Transfer Bus◦ Circuit Ties◦ Redundant Equipment

Service Continuity

Transformer Evaluation Transformer Choices

Remanufactured Rebuilt New

Evaluate operating losses Higher first cost compared to life cycle cost Utility energy charge applied for the losses in the

transformer considering initial cost and cost of money (life cycle cost)

Efficiency

Substation Structure◦ Aluminum 50+ Years◦ Steel 40 Years

Power Transformers 40 Years Distribution Transformers 25 Years Distribution Switch 25 Years Circuit Breakers 40 Years Instrument Transformers 45 Years Relay and Control 15 Years Communications 10 Years SCADA 15 Years

Typical Asset Life

Fencing 20 Years Distribution Lines 40 Years Street Lighting 20 Years Meters, Mechanical 20 Years Meters, Solid State 12 Years Poles

◦Steel 55 Years◦Concrete 55 Years◦Wood 45 Years

Towers 50 Years Underground Conduit 50 Years Underground Conductors 25 Years Fiber Optic 20 Years

Typical Asset Life

Design Standards Construction Standards Loading Maintenance

◦ Policy◦ Procedure◦ Practice

Operating Practice

Impacts on Asset Life

Environment◦ Switching◦ Lightning and Surges◦ Location

Impacts on Asset Life

◦ System Location◦ Temperature◦ Moisture◦ Protection◦ Load factor◦ Power factor

Operating Environments

Scheduled Maintenance Diagnostic Maintenance Predictive Maintenance

Maintenance

Per Manufacturer Recommendations Manage Risk with

Predictive Maintenance◦ Testing◦ Diagnostics◦ Monitoring

Maintenance

System Equipment

Substation Structure◦ Aluminum 50+ Years◦ Steel 40 Years

System Equipment

Power Transformers 40 Years

System Equipment

Unit Substation Transformers 40 Years

System Equipment

Distribution Transformers 25 Years

System Equipment

Distribution Transformers 25 Years

System Equipment

Distribution Switch 25 Years

System Equipment

Group Operated Air Break Switch 25 Years

System Equipment

Circuit Breakers 40 Years

System Equipment

Instrument Transformers 45 Years

System Equipment

Relay and Control 15 Years

System Equipment

Communications 10 Years

System Equipment

SCADA 15 Years (Supervisory Control and Data Acquisition)

System Equipment

Substations

Typical Substation Equipment

Power transformers are the most significant portion of municipal system assets representing 35 percent of typical substation costs.

Major concern to every electric utility. All transformers are not the same.

◦ Materials◦ Construction◦ Cooling

Transformers

After Failure - ◦ When equipment fails it is repaired or replaced.

Outage Maintenance - ◦ Equipment is de-energized and maintenance is

performed. Predictive Maintenance –

◦ Based on early indications, equipment is maintained.

Maintenance Alternatives

Acceptance Test – Verifies that equipment supplied is functional and within specifications.

Diagnostic Test – Detection of specific issues or problems.

Predictive – Identifies early indications of potential issues.

Testing

Distribution

Typical Distribution Equipment

Open Construction

Typical Distribution Line

Armless Construction◦ 3 covered conductors on fiberglass supports.

Typical Distribution Line

Hendrix Cable Construction◦ Hendrix Cable - 3 covered conductors supported

by a messenger and separated and by spacers.

Typical Distribution Line

Underground

Typical Distribution Line

15 KV Cutout◦ Solid Blade◦ Fusible

First Line of Protection for Faults

Distribution Equipment

Surge Arrester Load Break Cutout Termination

Distribution Equipment

Surge Arrester

Distribution Equipment

Group Operated Air Break Switch

Distribution Equipment

Recloser

Distribution Equipment

Sectionalizer

Distribution Equipment

Lighting Security Meter Replacement

Trends

Electric Utility Infrastructure

Norman P. Baron, PE and James J. Havrilla, PE, Esq.

Questions?

Utility Engineers, PC