Partial discharge (PD) measurement has been used for several decades to assess the condition of high-voltage (HV) and medium-voltage (MV) electrical apparatus. In the past, PD measurements were largely limited to the production stages of various assets (e.g., during R&D, factory-type tests, and factory acceptance tests). However, the advantages of such testing have resulted in it being used more often …
What do robotics, artificial intelligence (AI), automation, synaptic performance indicators (SPI), and machine learning (ML) have in common? In addition to being buzzwords for the reliability professional to throw around, the reliability world uses these terms to get practitioners to spend a lot of money on the shiny new thing. Sadly, too much of that money will be wasted by …
Most of us started our electrical careers with fairly good knowledge about the practical aspects of our jobs. We understood voltage, current, power, resistance, etc. We mastered the more esoteric areas such as electrical fields and stress control and only revisited these topics if our day-to-day job required it. Partial discharge (PD) is one of those areas where we might …
ANSI/NETA ATS–2017 Revision Underway ANSI/NETA ATS–2017, Standard for Acceptance Testing Specifications for Electrical Power Equipment & Systems continues an American National Standard revision process that is scheduled to be completed by the end of 2020. The new edition will be released in March 2021. A project intent notification published in ANSI’s Standards Action on January 3, 2020, announced the opening …
Large power transformers are widely used in the electrical grid, and interconnecting solar farms to the utility is one of their many applications. To control voltage variations throughout the day, an on-load tap changer (OLTC) is used to adjust the number of effective windings to match the utility’s voltage. Proper functionality of the OLTC requires a specific sequence of operations, …
As time progresses and a cable system ages, the system’s bulk dielectric strength degrades. During this aging process, artifacts such as water trees, delamination, voids, and shield corrosion raise the local stress placed on the cable during normal operation. The exact way in which the strength of a device degrades depends upon many factors including voltage, thermal stresses, maintenance practices, …
The semi-annual ASTM-F18 Committee Meeting on May 28, 2020, was hosted on the WebEx app. This takes the place of the April meeting that was scheduled in Boston and cancelled due to the COVID-19 crisis. There were 74 participants. F1506 Antitrust laws were read first. The first and only subject was F1506 arc-rated face masks, which are similar to a …
Safety in high-voltage substations is the highest priority for all personnel involved, and regulations and laws require all objects to be grounded on both sides before any maintenance work is performed. Failure to ground the circuit breaker (CB) on both sides creates risk of induced high voltages and currents at the ungrounded terminal. Eliminating this risk improves the safety of …
Methods to check medium voltage cable integrity have evolved drastically in the last 30 to 40 years. The DC hipot test has largely been replaced by the 0.1 Hz very-low-frequency (VLF) test, and North American (IEEE) and European (IEC, CE, CIGRE) standards specify the VLF test method for solid dielectric medium-voltage cables. Throughout these years, the 0.1 Hz VLF test …
The NFPA 70B committee has continued to meet every two weeks via conference and video calls. We are working on revamping chapters to make it into a standard, and while progress is sometimes slow, we appear to be on track for a First Draft for public comment sooner rather than later. With the continued issue of COVID-19, our tentative in-person …