Harmonic Distortion: Definitions And Countermeasures
Mar 1, 1998, Cory J. Lemerande
While harmonics are important, they need to fit into the larger context of power quality. While you must consider harmonics, they are not the demon some...
A Balanced Way To Look At Power
Feb 1, 1998, Mark Lamendola
Balance is so important. We have balanced meals, balanced checkbooks, and balanced tires. We pride ourselves on laying out distribution panels such that...
Engine Gen-Sets: Investing In Power Reliability
Feb 1, 1998, Staff
New Jersey-New York City bridge uses packaged twin 400kW engine-generators to keep toll booths and roadway lighting operating.How do you keep the revenue...
Meeting IEEE 519 THD Limitations: A Case Study
Dec 1, 1997, Marina Dishel, P.E. and John R. Nasto, P.E.
Don't place a variable frequency drive (VFD) on a circuit until you determine the nature and magnitude of harmonics the drive may pump back into the feeding...
The how, what, and where of power conditioning. (part 7)
Dec 1, 1996, Waggoner, Ray
New MV products can transfer in milliseconds while others sense sags and boost voltages quickly.Although we usually don't associate the term "power quality"...
Power conditioning and protection
Nov 1, 1996,
Manufacturers provide a wide array of answers to power quality questions. Some of these answers are whole new technologies, while others are reincarnations...
The how, what, and where of power conditioning. (part 6)
Nov 1, 1996, Waggoner, Ray
Solid-state subcycle switching devices can eliminate the need for a UPS, if two sources of power are available.For more than 70 years, we've had the motor-generator...
The how, what, and where of power conditioning
Oct 1, 1996, Waggoner, Ray
Depending on the sensitivity of the load and its critically, differing configurations of solid-state UPS systems can do the job.In last month's session,...
The how, what, and where of power conditioning. (part 4)
Sep 1, 1996, Waggoner, Ray
New motor/alternator technologies revolutionize the concept of the uninterruptible power supply.In our last episode of "Power Conditioning," we looked...
Why poor power quality causes electronics failures.
Sep 1, 1996,
Why does a two-cycle power outage create havoc with electronic equipment when, sometimes, a three-cycle outage causes no problems?We seem to know so little...
Steel mill tackles power quality and power factor problems
Sep 1, 1996, Bishop, Martin T.; Witte, John F.; Morgan, Robert B.
North Star Steel confronted low power factor (PF) and harmonics problems prior to installing a new ladle furnace by conducting a computerized analytical...
The how, what, and where of power conditioning. (part 3)
Aug 1, 1996, Waggoner, Ray
Older motor-generator technology has been updated so that the MG set is still a reliable and viable source of conditioned power.Don't discount old power...
The how, what, and where of power conditioning - Part 2.
Jul 1, 1996, Waggoner, Ray
A quick jump to a power conditioning device may not solve the problem and actually may create more of a problem.Let's begin the examination of power conditioning...
The how, what and where of power conditioning, part 1.
Jun 1, 1996, Waggoner, Ray
Depending on the situation and problem, power conditioning may not be the solution. And, in the majority of instances, it isn't.At past EC&M Harmonics...
Watch out for induced electrical noise, part 3
May 1, 1996, Waggoner, Ron
Electrical noise can be reduced or eliminated by using chokes, shielded isolation transformers, dedicated circuits, and shielding.In protecting our sensitive...
Watch out for induced electrical noise. (part 2)
Apr 1, 1996, Waggoner, Ray
Other types of transients can be transmitted through the air and/or coupled onto nearby conductors.In Part 1, we examined the effects of induced electrical...
Watch out for induced electrical noise. (part 1)
Mar 1, 1996, Waggoner, Ray
Common mode electrical noise can cause system shutdowns relating to signal transmission problems.Over the years, we've spent considerable time in covering...
Applying VSDs with power quality and line considerations in mind
Feb 1, 1996, Shipp, David D.; Vilcheck, W.S.
Each type of drive impacts power quality, power factor, and harmonic content as a function of the line (source) inductances.AC variable speed drives (VSDs)...
Power conditioning & protection
Nov 30, 1995,
Included in this category are static and rotary UPSs, isolation transformers, transient suppressors, and voltage regulators, along with CAD/CAM systems...
Conducting a power quality site analysis
Nov 1, 1995, Waggoner, Ray
There are three locations where you can determine the extent of harmonic interaction: the nonlinear load, the next upstream transformer, and the point...
