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Looking for insight on electrical testing?
Join Megger’s expert Applications Engineers and Product Managers in our upcoming webinars:
Offline Partial Discharge Diagnostic of Medium Voltage Cables
Testing Tactics Webinar
Offline Partial Discharge Diagnostic of Medium Voltage Cables
When:
10 a.m. CT Friday, May 19
Attendees of this webinar are eligible to receive
1 PDH or 0.1 CEU
Most outages in electrical power distribution systems are related to Medium Voltage (MV) cables. Aging and workmanship are two main reasons for underground cable faults. Tan Delta (TD) is the most popular diagnostic test to assess the aging and overall condition of MV cables with extruded insulation. Cables and accessories can pass Tan Delta and VLF withstanding tests and yet may show significant Partial Discharge (PD) pulses. The PD test is a complementary tool to cover some blindness of other testing methods.
PD pulses reduce the lifetime of assets by deteriorating insulation at the weak spot. The PD test is a more predictive diagnostic test in comparison with TD. The test report adds valuable information to asset management systems in order to perform condition-based maintenance. Offline PD tests can find the trigger voltage level for PD pulses, localize PD in a shielded cable, and measure apparent discharges in Picocoulomb.
Calibration is a necessary step to measure apparent discharges in Picocoulomb based on the IEC60270 standard. Understanding the concept of calibration helps us to simply comprehend the basics of PD measurement. This presentation will illustrate attenuation and dispersion effects on PD pulses and explain background noise. As PD pulses can easily be buried by environmental noise and corona discharges, we will also discuss some of the best practices to filter or minimize background noise as much as possible.
This webinar will discuss the testing setup, calibration, noise, appropriate excitation voltage, and PD report. We will talk about excitation voltage and review the advantages and disadvantages of VLF, Damped AC (DAC), and Cosign Rectangular (CR) for different field scenarios.
This is a free webinar
All webinar attendees are eligible to receive 1 NETA CTD and 1 PDH or 0.1 CEU.
PRESENTED BY
Shahryar Farhang
Applications Engineer
Sha Farhang is a P. Eng, an experienced electrical field engineer and master electrician in USA and Canada. He is an applications engineer at Megger with a focus on Partial Discharge testing and online monitoring. With research and lab testing, Sha is focused on developing a deep understanding of PD diagnosis and interpreting results.
Shahryar provides technical and engineering support for online and offline PD testing including medium voltage cables, transformers, and gas-insulated substations. He has previously worked with Magna IV Engineering on several commissioning and maintenance medium and high voltage projects in the USA, Canada, and Chile.
Application of Symmetrical Components in Distance Protection
Testing Tactics Webinar Application of Symmetrical Components in Distance Protection
When:
10 a.m. CT Friday, June 23
Attendees of this webinar are eligible to receive
1 PDH or 0.1 CEU
Microprocessor relays use symmetrical components by converting 3-phase unbalanced systems into two sets of balanced phasors and one set of single-phase phasors, called positive, negative, and zero-sequence components. This method simplifies the fault analysis process and is applied in common protection schemes.
Assuming normal operating conditions, a balanced three-phase power system can be modeled based on the electrical characteristics of the current-flowing components which comprise the system. This also holds true during balanced three-phase faults, which are symmetrical in nature, but least common. Typical faults, such as line-to-ground, line-to-line, and double-line to ground, are unbalanced and asymmetrical. The method of symmetrical components was introduced to simplify the calculation and analysis of the fault characteristics by creating a balanced system made up of sequence components. These components are combined of positive-sequence phasors which share the original system sequence, negative-sequence phasors (opposite of original system sequence), and the three zero-sequence components which share a common phase angle. This concept is applied in protection schemes to increase sensitivity for specific fault types and provide supervision to improve security.
This presentation will introduce symmetrical components, and discuss the application of sequence elements to enhance protection for transmission, transformer, and generator/motor applications. Fault-type identification and location will be discussed, as well as implementing sequence elements for directional and differential protection, and distance element polarization. Creating test parameters for sequence element pickup and timing will also be discussed.
This is a free webinar
All webinar attendees are eligible to receive 1 NETA CTD and 1 PDH or 0.1 CEU.
PRESENTED BY
Michael Wilson
Applications Engineer
Michael (Mike) spent his childhood in rural West Virginia and southeastern North Carolina. In 2004, he earned his Bachelor of Science in Electrical Engineering from University of Missouri – Rolla (now Missouri University of Science & Technology). While working at United States Steel Corporation as a manager in the Electrical Operations & Services division between 2004 - 2008, he earned his Master of Science in Management from Indiana Wesleyan University. From 2009 to 2013, Mike worked as an engineering consultant and NERC compliance manager for Jo-Carroll Energy Cooperative near Chicago, Illinois. Mike went on to work for TRC Companies and Burns & McDonnell as Lead Testing & Commissioning Engineer before accepting the position of Senior Relay Applications Engineer at Megger Group in May, 2022.