During The winter holiday season, houses are often decorated inside and out with little blinking lights. But, when the regular house or commercial lights blink or flicker, that’s a different story, and it is about to change.
If one searches for power quality tools on the internet,- the most common results will be for equipment, such as digital multimeters, harmonic analyzers and, most often, power quality analyzers or monitors.
When most people think of the source and effects of power quality problems, they think of voltage interruptions, harmonics, transients, sags, swells and even flicker, all of which are phenomena that occur on the alternating current (AC) voltage system.
Last month, I covered common power quality phenomena with regards to the National Electrical Code (NEC). Two articles address specific topics related to power quality: Article 647, Sensitive Electronic Equipment, and Article 708, Critical Operations Power Systems (COPS).
Even after 30 years-plus of power-quality monitoring, no national design code standard exists for minimizing the impact of power quality phenomena; there isn’t an equivalent of the National Electrical Code (NEC) anywhere.
Some of the concepts in electrical engineering are more easily visualized by using physical phenomena. Power quality phenomena is not different, since it is just a specialized application of the same principles, particularly Ohm’s and Kirchoff’s Laws.
About a year ago, we covered some of the initiatives of the smart grid that came out of the Energy Independence and Securities Act of 2007 (EISA), which was funded last year with more than $3.4 billion of stimulus money from the America Reinvestment and Recovery Act of 2009 (ARRA).
During my career, I have encountered many electricians and engineers who considered installing power quality monitors to be a nonhazardous job that requires nothing more than hooking up the voltage clip leads and putting on the current probes to the proper conductors.
Though there are many green buildings being designed and built from the start with significant considerations for the environmental effect or footprint, many renovation projects include alternative or renewable-energy sources, such as solar power.
In the September issue, I discussed some of the claims that various organizations working on the smart grid have made in the two years since the Energy Independence and Security Act of 2007 passed. The act contained Title XIII, which has 10 characterizations of a smart grid.
Recently, I needed to dig up a paper I wrote more than a decade ago for a conference in the United Kingdom. Part of the paper was devoted to expert systems that were beginning to gain momentum as a possible way to solve power quality problems, rather than just provide more data or information.
My past two columns covered monitoring from the service entrance and down into the facility to record what happened and to determine what caused it. At last, we get down to probably the most important aspect: monitoring at a load to determine why it is not operating properly.