The reliability and cost of any electrical system depend greatly on the quality of the power supplied to and consumed by the system. Poor power quality may result in an improper function, overheating, accelerated wear and tear, falsely tripped circuit breakers and, in some cases, hazardous conditions. With the introduction of new electronic technologies over the last several decades, the world has placed new and more complex demands for clean and reliable power.
Measuring Power Quality typically involves calculating indicators of power demand, power consumption and power cleanliness. By measuring demand and consumption, consumers can identify cost centers in their electrical infrastructures as well as engineer the electrical infrastructure required to meet those demands. By measuring cleanliness, consumers are able to avoid improper function, overheating and a plethora of other consequences of unclean power.
What is power demand and how do we measure it?
Power demand is that the quantity of average power that's consumed over some amount of your time by a tool, machine building, etc.Power Quality Analyzers, electronic instruments wont to measure indicators of power quality, can average the electrical energy and display it in units of "kilowatts". It is necessary that electrical systems square measure provided with enough power to satisfy peak periods of demand.
How does power consumption differ from power demand?
Power consumption, like demand, is that the "sum" of electrical usage over time. Power demand reflects an on the spot read of electrical usage, whereas, power consumption sums the electrical usage over an equivalent amount of your time. Power Quality Analyzers measure consumption in units of watt-hours (Wh) or kilowatt-hours (kWh). Most calculations of the price of power square measure supported consumption and measured by $ per kWh.
Once we all know power consumption, we can calculate a useful metric called "Power Factor". Power issue could be a quantitative relation of the particular power utilized by Associate in Nursing electrical system to the apparent power delivered by the utility. In most cases, the actual power used will be less than the apparent power delivered because of heat dissipation, frictional loss, work performed and another release of energy by the electrical system.
We can North American country Power issue to assist us to place a tag on the number of labor the electrical system is activated, as well as help us install capacitors and other devices that store real energy to avoid being charged for excess apparent power. With an influence Quality analyzer, you can calculate the "Reactive Compensation", the amount of capacitive value required to correct a low Power Factor.
Power cleanliness and the need to understand harmonics
Power cleanliness refers to identifying and freeing power of "harmonics". The idea of harmonics could be a bit harder to grasp than demand and consumption. Harmonics square measure results of non-linear masses that cause irregular spikes Associate in Nursing dips in voltage and current on an electrical system.
The power provided by utility corporations is delivered within the sort of a relentless voltage AC (Alternating Current) and takes the form of an undulation. Ohms law says the number of current utilized by Associate in Nursing device depends on the load (inductance) of that device. If the load varies over time, thus can this. Harmonics appear when varying loads (non-linear) create short pulses of current that deform the supplied, sinusoidal current waveform, creating an arbitrary waveform.
You can consider Associate in Nursing discretional wave as being created from many basic waveforms. The easiest illustration of an arbitrary wave is to picture two people on opposite sides of a pool who create a wave towards each other with a pool float. When the waves run across within the middle, the result is a wave that is twice as tall. The ensuing wave is created from 2 basic waves.
This illustration will be accustomed to making a case for that happens once harmonics occur because of non-linear masses. The current wave becomes distorted from an ideal undulation and peaks and valleys produce un-clean power. Harmonics can cause devices to overheat, electrical wire ratings to be reduced, motors to prematurely wear and circuit breakers to falsely trip.
Power Quality Analyzers have the power to spot Associate in Nursing analyze the basic harmonics that structure a discretional current wave. Measurements such as THD (Total Harmonic Distortion) can tell you the contribution of harmonic currents to the fundamental current required. Measured as a proportion, 10% would be a reason for concern. Another measuring is known as "Crest Factor" can indicate the extent of peaking caused by harmonics. The Crest issue could be a quantitative relation of the height price / RMS price, that in an exceedingly excellent undulation would be one.414.
Choosing a Power Quality Analyzer
There area unit variety of various Power Quality analyzer makers like Fluke, AEMC, Hioki, and Extech. Some analyzers area unit designed to live single section systems whereas others area unit for three-phase systems. Many PQAs integrate with PCs, have increased knowledge work capabilities and might turn out skilled reports usually requested for power quality applications. Power Quality Analyzers range in price from $1500 to $6500 with the more expensive products offering greater analysis functionality.
Whatever your application or budget it's necessary that power quality could think about the look and maintenance of your electrical system. In order to reduce costs, avoid downtime, and increase the service life of your system, power quality is a force to be reckoned with.