Severe Voltage Harmonics Distortion in Distribution System - The Expert's View

When we talk about power quality, in today’s digital world, quality of electrical power is very important and deviation from it can impact both output or final productivity in negative way. In providing good quality power, Distribution Company’s role becomes very important to provide a sinusoidal voltage waveform to its consumers without any deviations from prescribed limits. Deviation in voltage quality, including severe voltage harmonics can have catastrophic effect not only on the clients but also on distribution company itself.

In general, voltage supplied by the distribution company is a sinusoidal waveform and if any deviations from power quality norms, are generally within prescribed limit. The network, which supplies power also plays important role in determining power quality. Non linear loads in a distribution system will be generating current harmonics. Depending on type of load whether UPS, lighting, VFD,etc harmonic generated by the loads will differ in their amplitude and order. Whenever harmonics are discussed, in general only current harmonics and their impact is addressed. However, current harmonics and voltage harmonics have distinguish characteristic and impact on the system. Current harmonics will cause higher loading on the distribution system due to addition of other frequency currents being added up without doing any productive work. Current harmonics also increases distribution losses (Copper losses) in the system.

pManifold, National Support Network (NSN) partner of APQI recently interviewed Mr. A.D. Thirumoorthy, Technical Advisor, India Wind Power Association an industry expert, to understand his uptake on ‘Severe Voltage Harmonics Distortion in Distribution System’. (The views here are personal and not to be associated with any company in any forms.)