SOURCE OFHARMONICS Converters, Devices which includes semi-conductor elements, Generators, Motors, Computers, Electronic ballasts, Switching power supplies, Welding machines, Control circuits, HVDC transmission systems, Electrical Communication systems. Transformers
WHAT DO HARMONICDO ? HARMONIC ARE CARRIED THROUGH THE SYSTEM FROM THE SOURCE CAN BE NEARLY DOUBLE THE AMOUNT OF CURRENTON THE NEUTRAL CONDUCTOR IN 3 PHASE 4 WIRE DISTRIBUTION SYSTEM. OVERALL ELECTRICAL SYSTEM & POWER QUALITYIS AFFECTED BY THE HARMONICS.
EFECT OF HARMONIC ONSUPLY DISORTED VOLTAGE. OVERHEATED OF TRENSFORMER & MOTOR HEATING OF NEUTRAL CONDUCTOR.
EFFECT ONTRANSFORMER Transformer overheating and potential insulation failure result from several conditions caused by harmonics: Increased skin and proximity effects Harmonics circulating in the primary winding Increased hysteresis losses Increased eddy current losses
Solutions Power filters . Isolation transformer . Line reactors. Online UPS. HARMONIC CONVERTOR19-10-2005 10
HOW CAN ELIMINATE6-pulse converter note the level of distortion and steep current rise.12-pulse converter the waveform appears more sinusoidal, but still not very smooth.18-pulse converter virtually indistinguishable from the source current waveform.
CONCLUSION The harmonic distortion principally comes from Nonlinear-Type Loads. The application of power electronics is causing increased level of harmonics due to Switching!! Harmonic distortion can cause serious Failure/Damage problems