Power system requires appropriate analysis, studies, engineering and planning for its finest design and operation
In the United States, voltage and current waveform are designed in a sinusoidal wave whose frequency is an integer multiple of the fundamental frequency of 60 Hz.
By the action of non-linear loads like rectifiers, discharge lighting causes a change in frequencies.The presence of these higher frequencies is termed as power system harmonics. Causes a change in frequencies.The presence of these higher frequencies is termed as power system harmonics.
Due to the presence of high harmonics the equipment and machinery can malfunction or get damaged.
With technological advancements and the production of a whole new range of appliances, the range of equipment’s causing harmonics has also risen sharply. The statistics will continue to rise, so it becomes essential for designers to consider the harmonics and their side effects very carefully.
Care Labs is a competent provider of harmonic analysis in power system in the US. We have been offering this service to numerous fortune 500 companies.
What Causes Harmonics?
Harmonics are usually produced by electronic equipment with nonlinear loads which drawing the current in rapid short pulses. This type of short pulses cause distorted the current waveforms, which cause the harmonic currents to flow back into other parts of the power system
Harmonics commonly happens when there is much electrical equipment like personal computers, fax machines, laser printers, fluorescent lighting, Uninterruptible Power Supplies (UPS), and variable speed drives all on the same electrical system.
Meanwhile nonlinear loads are also a major proportion of the entire load in industrial and commercial electrical power distribution systems, harmonic studies become a vital part of overall system design and operation.
Harmonics worsen the level of power quality and its efficiency in a commercial building or industrial facility . In general, most buildings have the capability to withstand the nonlinear loads up to 15% of the total electrical system capacity without concern. However, if the nonlinear loads exceed the limit of 15% will results some negative consequences.
Common Problems Caused by Harmonics
- Nuisance Tripping of Circuit Breakers
- Due to harmonic resonance, it produces circulating currents and high voltages that cause malfunctioning of equipment.
- When the connected equipment increases the internal energy losses it affects component failure and shortened life span.
- Errors occur in metering
- Fires in wiring and distribution systems
- Generator failures
- Lower system power factor
- Overloading neutral conductors
What is done during harmonic study and analysis?
Harmonic analysis in power system is an arithmetical method of analyzing or predicting potential resonances and harmonic distortion levels depending on the existing power system data. Harmonics analysis is performed using software like ETAP (Electrical Transient Analyzer Program).
Harmonic study and analysis are achieved in accord to the IEEE Standard 3002.8 -Recommended Practice for Conducting Harmonic Analysis Studies of Industrial and Commercial Power Systems.
Harmonic analysis and studies in power system are usually performed when –
- While installing large nonlinear loads.
- To obtain solution to an existing harmonic problem
- To design a harmonic filter.
- During the installation of large capacitor banks on utility distribution /industrial systems it contains various nonlinear loads, then a harmonic analysis is necessary
Harmonic Analysis in Power System include two types
- Current and voltage distortion analysis
This method is done by the estimation of whole current and voltage harmonic distortions at several buses then the outcome is referred against the predetermined limits or values.
- Impedance versus frequency analysis
This method is done by analyzing the graph of system impedance at different buses which is plotted against the frequency. Harmonic analysis in power system is significant while calculating the system resonances prior to energizing the electrical system.
How are harmonic study and analysis performed?
Harmonics analyzer is very important for conducting study and analysis of power quality. It helps to calculate the wave shapes of current and voltage on corresponding frequency spectrums. A harmonics analyzer is used to provide a comprehensive analysis of the suspect source.
The harmonics study involves of the following steps:
- Analysis of harmonic producing equipment
- Determination of model representation of harmonic producing equipment.
- Calculations of models to represent other components in the system including external networks.
- Simulation of the system for various scenarios.
IEEE Standard 3002.8 standards provide methodologies to perform and conduct harmonic studies for industrial and commercial power systems. It provides all basic concepts for harmonic study, importance of this study, collecting the of data for analysis, study methodologies, prediction of potential problems, corrective measures, and benefits of harmonic analysis.
Care Labs provides a reliable and professional service for testing and inspection of all your electrical needs.
We offer our services in California, New York, Illinois, Ohio, Texas, New Jersey, Pennsylvania, Georgia, Washington, Florida, Massachusetts, Michigan, North Carolina, New Mexico, Virginia, and all the major states and cities in the United States of America.
Contact us to get your harmonic study and analysis today!
