Equipment Track

Title: The Importance of Condenser Type Bushing

9:30AM - 10:15AM
Presenter: Keith Hill, Doble Engineering Company

A short history of the bushing from the first used bulk type bushing to the dry and oil filled condenser type bushing. This paper will point out how the condenser type bushing allowed for higher voltages to be used. Without the condenser type bushing higher voltages were limited to the physical size of the bulk type bushings. A review of the standard recommended off-line test procedures such as C1 and C2 as well as diagnostic tests such as inverted C1, C1 + C2 and tip-up will be reviewed. Abnormal power factors and capacitances will be covered and some common causes for these abnormal test results. Importance of the BIL rating and various voltage classes will also be covered.

Equipment Track

Title: Review of Medium-Voltage Asset Failure Investigations

10:30AM - 11:15AM
Presenter: William Higinbotham, EA Technology LLC

A forensic investigation, or "post mortem", of failed equipment is an excellent tool to gain insight into the methods by failures occur. Knowing the root cause failure mechanism allows you to determine the best practice for condition assessment. It can also provide input into workmanship or equipment issues that might make future failures preventable. EA Technology maintains a forensic failure investigation lab that specializes in failures of medium voltage switchgear, cables, and cable accessories. In the past several years, this lab has done dozens of failure investigations for power system operators around the world.
This paper reviews the existing failure investigation reports and uses that experience to look at the most common failures and their root causes. It summarizes the best methods for avoiding the failures and for detecting impending failures on in-service equipment. The failure studies include equipment from 11KV to 33KV. Cables, splices, terminations, and metal clad switchgear failures are all examined in this paper.

Equipment Track

Title: A Customer’s Perspective: Electrical Testing Agencies

11:30AM - 12:15PM
Presenter: Randall Sagan, MBUSI

As a facility electrical engineer at a large automotive assembly plant for over twenty-three years, I have had the opportunity to work with several different electrical testing agencies on many different projects. This paper discusses some of my experiences related to acceptance testing, commissioning, startup, and annual power system maintenance. I will cover the most successful projects along with the not-so-successful projects, and describe the factors that contributed to each.

When properly planned and executed, the best projects were done safely, in a timely manner, and provided reliable and useful information related to the condition of the power system. My experiences as a "customer" provide a unique perspective that can be beneficial to anyone who may be involved with these types of electrical projects.

Equipment Track

Title: Don’t Let a Bad Leak Spoil Your Day, The Latest Solutions for Online Leak Repair of Transformers, Circuit Breakers, & GIS

2:15PM - 3:00PM
Presenter: Jim Hackett, The Colt Group

Oil and SF6 leaks develop at various locations on both new and aged HV apparatus. If oil or gas are getting out, air and moisture are getting in and impacting equipment condition. In the past repair options were limited to draining/de-pressurizing and re-gasketing, welding, applying epoxy or just wrapping with an absorbent material. Today these leaks can be repaired using a time-proven method that is completed while the leak is active and in many cases with the equipment in-service. No epoxies or welding - a sealant specifically developed for electric apparatus is used - flexible and easily removed. Over 15,000 leak repairs have been documented with this proven process. This presentation will explain the methodology with numerous "before and after" photographs and examples.
Attendees to this presentation will learn some of the latest Leak Detection and Repair (LDAR) programs from utilities and power plants in North America, as well as current R & D projects on leak repair solutions.

Equipment Track

Title: Application of OLPD Sensor Technologies

3:15PM - 4:00PM
Presenter: Michael Nie, Power Monitoring and Diagnostic Technology LTD.

Applications of OLPD Technology, UHF, HFCT, TEV, Ultrasonic and Acoustic Emission methods. Review the application to different HV equipment. A field testing approach to OLPD challenges and practical solutions. As more and more testing companies are applying OLPD to their services, understanding the challenges for testing different types of MV and HV equipment in a field environment is critical to the success of an OLPD program. Understanding the sensor capabilities and the different signal attenuation properties is a must for valid and actionable results. This technical presentation will provide a detailed and pragmatic look at the sensor types and signal propagation and attenuation for different types of MV and HV Assets with a focus on the challenges in the field and solutions to overcome those challenges.

UHF - Ultra High Frequency Sensor Technology - Transmitted RF Signals
HFCT - High Frequency Sensor Technology - Induced PD Currents
TEV - Transient Earth Voltage - Induced PD voltage on the ground plane
Ultrasonic - 40 kHz Centered frequency - Airborne Sound Frequency
AE - Acoustic Emission Audible and non audible sound vibration frequency through liquids and solid materials
Phase-Resolved Measurements: PRPD and PRPS

When using UHF, HFCT or ultrasonic sensors, we use a concept called "phase-resolved" analysis. Consider the sensor that you are using. It has a bandwidth that spans portions of the radio frequency spectrum or the ultrasonic spectrum. There are all kinds of other signals and other energy in that bandwidth that has got nothing to do with PD. It's what we call "noise". Telecommunication signals for example are noise.

Phase-Resolved Partial Discharge (PRPD) and Phase Resolved Pulse Sequence (PRPS) are two modes of comparing the incoming signals to the AC power frequency. The PRPD and PRPS "charts" are shown in real-time. The horizontal x-axis is the phase angle of the power system under test. The x-axis is labeled from 0 to 360 degrees. This is the same thing as 0 to 16.667ms. This is the time it takes for one cycle of the AC power frequency. The vertical y-axis represents the amplitude of the signal. This amplitude depends on the strength of the signal and also on the distance from the sensor to the PD event. In the PRPS mode there is a third dimension. The z-axis represents 5 seconds back in time. So the front of the z-axis shows the timing of the signal arriving right now, and the back of the z-axis shows the signals from 5 seconds ago. This allows you to see the continuity of the pattern of signal timing.

Equipment Track

Title: Proper Grounding to Avoid Disasters

4:15PM - 5:00PM
Presenter: David Brender, Copper Development Association, Inc.

Data centers and other sensitive facilities have both unique and universal powering, grounding and bonding requirements, often overlooked, and not understood by most designers and contactors.

The primary focus of this presentation is to recommend wiring and grounding techniques and practices that should be part of the design of new or renovated structures, and to examine in particular several case studies of actual data centers that were designed above Code minimums. These practices will help prevent power quality problems from occurring in the first place, or diminish their effect to the point where they are not significant.

We will discuss:

  • The cause of power quality problems
  • The limitations of the National Electrical Code
  • Proper wiring of the ground conductors
  • Isaolated grounds
  • Grounding impedance
  • Backfill materials
  • General rules and other topics