April 27, 2012 Presented by: Andy Justice SWEDE Southwest Electric Distribution Exchange “The Evolution of Distribution Switchgear”

B1 Switchgear 1 NC S2 NC NO S3S4B2 Breaker WHY USE SWITCHES ? Loop system with sectionalizing switches 3-way Unit Switching & Manual Sectionalizing Reliability Basics

3-way Unit B1 Switchgear 1 NC S2 NC NO S3S4B2 Breaker Locks Out Switching & Manual Sectionalizing WHY USE SWITCHES ? Reliability Basics

WHY USE IT? 3-way Unit B1 Switchgear 1 OPENNC S2 NC CLOSE S3S4B2 Manual Sectionalizing Allows Faster Restoration of Power to Unfaulted Portions of the Underground Loop Switching & Manual Sectionalizing Breaker Locks Out Reliability Basics

Common Interrupting Mediums: –Oil –Air –SF6 –Vacuum Insulation Mediums: –Air Insulated (AIS) –Oil –Combination Air and Gas – Gas (SF6) –Solid Dielectric Switchgear Design Overview

Air Switchgear Concerns Outages due to Corrosion, Animals, Dirt, Flashovers, Lack of Maintenance and Moisture Longer outage times to replace and upgrade Larger Equipment Footprint Solid Dielectric Design Principles

Oil Switchgear Concerns Oil is vaporized and gas extinguishes arc Old technology – Outages due to lack of maintenance and loss of insulation Environmental issue of Oil Spill Safety Concern/Risk associated with Fires Solid Dielectric Design Principles

SF6 Switchgear Concerns Outages due to loss of insulation, low gas pressure levels, low temperature and lack of maintenance. Environmental concerns – green house gases Difficult to fit into confined spaces Gas Disposal Issues Solid Dielectric Design Principles

Air, SF6 and Oil Switchgear Summary Larger Footprints Sensitive to Environment and Contaminates Frequent maintenance/monitoring Required Higher Risk of Failure Higher Risk of Fire Higher Costs for Maintenance Staff & Switching Longer Outages to Repair/Replace Solid Dielectric Design Principles

Desire for alternate mediums after WWII due to unavailability of Porcelain and Glass Insulators Epoxy Resin Current & Voltage Transformers were introduced in Europe in the 1947 In 1952 Polymer insulation casting was introduced in USA GE began a material study in 1954 & from there insulator trials began Ethylene-Propylene introduced in 1962 In 1965, Cycloaliphatic Epoxy was applied in outdoor applications In 1966, first few air-blast breaker insulators were made out of fiberglass reinforced Epoxy Since the 1960’s, EPDM rubber experienced rapid growth In 1996 Elastimold introduced the first Solid Dielectric Switchgear Design Solid Dielectric Insulation Background Solid Dielectric Design Principles

Dielectric strength Mechanical strength Impact strength Light weight Thermal shock resistance Tracking resistance Inertness to contamination & weathering Consistent and easy manufacturing processing Economic Reliability Solid Dielectric Desirable Properties Solid Dielectric Design Principles

Vacuum = ~1/2” Dielectric in Inches HIGH DIELECTRIC STRENGTH Example: 38kV 150 kV BIL Solid Dielectric Design Principles

1.SAFETY 2.RELIABILITY 3.OPERATIONAL FLEXIBILITY 4.ENVIRONMENTAL FRIENDLY Overall Design Principles Solid Dielectric Design Principles

1. Increased Safety –Dead-Front Construction – Insulated and shielded product with not high-voltage exposed components –Not dependent on oil, gases or air for proper isolation from high voltage 2. Reliability –Utilizes Maintenance-Free Vacuum and EPDM Molded Insulation Technology which has over 50 years of field proven performance –Fewer Outages and significantly Lower Outage Durations –All Switchgear Components are Sealed and Fully Submersible Solid Dielectric Design Principles

3. Operational Flexibility –Compact and Lightweight Design allows installation in tight spaces –Modular Design allows combining with other devices Interchangeable, Upgradeable, Customer Configurable Less Inventory (Stock Common Components) –Non-Position Sensitive so it can be installed anywhere & in any orientation –Overall Lower Cost of Ownership 4. Environmentally Friendly –No oils or gases to monitor, maintain or dispose of –EPDM Rubber is a GREEN solution; Contains no greenhouse gases, such as SF6 Solid Dielectric Design Principles

Switchgear Applications & Configurations

Typical Configurations PadmountSubsurface Riser Pole Vault Switchgear Applications & Configurations

New Modular Design Switchgear

New Modular Design Switchgear will provide solutions to: –Installations with confined vault spaces –Modular Design Retrofits –Ease of installation –Unlimited number of ways –Configuration flexibility –Upgradable –Provide Overall installation cost savings New Modular Switchgear

Up to 35 kV rating for both Load-Break Switches and Fault Interrupting Devices New Modular Switchgear Interrupters Load Switches Standard Buses Bar Connection

New Modular Switchgear Unlimited number of ways and configurations

Modular Design Retrofits New Modular Switchgear

Motor Operator Control

Motor Control System – Motor Installation Motor Operator Control

Motor Control System Overview Motor Operator Control

Control and Automation Advances

Stand Alone Controls Automation Controls Auto-Transfer Controls Control and Automation Advances Protection & Automation Controls

Switchgear Accessories

Voltage Sensors Components 200A Source Input Elbows Bushing Extenders for other phases w/o PT Cable Connection Voltage Sensor Note: No angle correction (offset) with Elastimold resistive style Voltage Sensors making them compatible with SEL Control Voltage Inputs. Automation Controls

Start Up Connections: 1.Insert the Voltage Sensors into the 600A Elbow and tighten using a 600ATM Assembly Tool (See IS-1127). 2.Connect all the Voltage Sensors to the corresponding marked cables from the Switch Motor Box. Note: Connections are based on Motor Operator being supplied as a system. If Motor Operators are not packaged as a system, the Voltage Sensors will plug directly into the Control. Voltage Sensors Voltage Sensor Cables Cables From Control Cables From Motor Box Automation Controls

Voltage Sensors View Automation Controls

Solid Dielectric Deadfront Control Power Transformer / V (60:1 Ratio) Automation Controls

Select State-of-the-art technology and suppliers with strong commitment to customer support. Utilize Solid Dielectric insulation and vacuum switching/ interruption which translate into small footprint and maintenance free Equipment. Specify that the Switchgear be fully submersible and feature deadfront construction for increased safety of operation. Supplier needs to provide a wide range of configurations that fits multiple application needs and contributes to improve the reliability and operating performance of underground distribution systems. Look for Modular Platforms and Designs in order to Maximum Flexibility and allow Future Expansion. Summary of Switchgear Selection Considerations

Questions? Advances in Underground System Automation SWEDE Southwest Electric Distribution Exchange