HARMONIC ANALYSIS AND CALCULATION 

What is harmonics???  
Harmonics are currents or voltages with frequencies that are integer multiples of the fundamental power frequency. If the fundamental power frequency is 50 Hz, then the 2nd harmonic is 100 Hz, the 3rd is 150 Hz, etc. Harmonic frequencies from the 3rd to the 25th are the most common range of frequencies measured in electrical distribution systems. 

Sources of harmonics  
Harmonics are distorted normal electrical current waveform, generally transmitted by nonlinear loads. Singlephase nonlinear loads are prevalent in modern office buildings, while threephase, nonlinear loads are widespread in factories and industrial plants.  




An effective strategy for harmonic mitigation is to isolate the harmonic currents near the loads themselves through passive filters, phase shifting and zero sequence filtering. By reducing the current harmonics, the voltage distortion, neutralground voltage and overheating that these harmonic currents produce will be dramatically reduced.  
By drawing current in a nonsinusoidal manner, harmonic currents are circulated through the electrical distribution system which results in  




The harmonic analysis involves the use of predictive computer software to identify potential harmonic problems and resolve mitigation solutions. The Harmonic study shall consider operation during normal conditions, alternate operational configurations, emergency power conditions and any other operations which could result in harmonic distortion exceeding prescribed standards. It is important that these measurements be taken when your facility is operating at a minimum of 70% normal load. 