While renovating a basement, I came across a poster for “The Endless Summer,” a film released 50 years ago in which two surfers travel the world’s oceans, chasing warm weather and surfing adventures. It reminded me of a meeting with a group of executives in a multibillion-dollar company 25 years ago. They were all convinced there would be no need for power quality (PQ) monitors in 10 years because manufacturers would make equipment immune to PQ-related problems.
Flash forward to PQ interest group meetings at the IEEE Power & Energy Society summer meeting. Every year, attendees relate stories that demonstrate how wrong those executives were. Typical PQ problems persist. Data centers still shut down; remember the Delta Airlines computer center outage in August? There are countless vegetation- and animal-contact-initiated events (from squirrels, monkeys, snakes and even humans), and harmonics continue to increase with failures of capacitor banks, transformers and electric motors.
At the PQ interest meetings, case studies of unique and intriguing PQ-related problems are brought up to tap the group’s collective knowledge and see if anyone can figure out the cause.
The group has seen everything.
The interconnection of a large solar farm on one feeder results in misoperation of protective circuits on a different circuit. Hundreds of light-emitting diode (LED) lamps on a dimmer circuit in a chicken farm building cause an exterior spotlight on a separate circuit to “go all disco,” flashing like a strobe light whenever the interior lights are dimmed. Harmonics above the highest limited frequencies (typically 3-kilohertz reference point of the 50th harmonic) are rising with the increase in inverters used in energy-saving devices (such as compact fluorescent and LED lamps) and renewable-energy sources (such as photovoltaic panels). This is causing misoperation of power-line-carrier communication and system-protective devices miles away.
Promises of smart-grid initiatives to minimize or eliminate PQ problems haven’t really fared better than those executives’ comments 25 years ago. The proliferation of smart meters is perhaps the most visible result from the 2007 Energy Independence and Securities Act and the American Recovery and Reinvestment Act of 2009 (only 1 percent of the $787 billion spent went toward energy-reliability projects).
As studies from the Electric Power Research Institute and others have shown, many of these meters don’t do much for PQ reporting besides outage reports; although, they have little energy storage to keep them operating during an interruption so they could produce a report. The PQ functionality also is often minimal or turned off because utility communication systems cannot deal with the massive increase in data as compared to hourly revenue data.
PQ monitoring and troubleshooting remains a viable revenue source for electrical contractors and is anticipated to be like the quest for the perfect wave in that old surfing movie; an endless pursuit that will continue well into the foreseeable future. The basic problems and solutions will still exist in addition to a new set of complications resulting from changes in electricity production and consumption that will need fixing if the beer is to stay cold and the pizza hot.