Due to rapid advancement in the field of power electronics, numerous new applications are operational in industrial & domestic sectors. The LV equipments like VSDs & VFDs for motors, Rectifiers, UPS, Arc & Plasma welding machines, Soft Starters distort the current waveform in the Electrical Distribution System. It also impacts the voltage waveform and gives rise to harmonics.
Harmonic current generates excess heat in transformers, motors and inductive loads. It also impacts cables, fuses, busbars and circuit breakers. Harmonic frequencies are integral multiples of the base frequency. Those are termed as 'order' such as III, V, VII, etc.
These signals over-riding the pure sinusoidal signal are selectively filtered out using appropriate L & C combinations.
Every consumer of Electricity Board up to 36 kV should possess, who experience harmonic related issues such as:
Malfunction in control circuitry
NuisanceTripping &mis-coordination of relays
Over heating of system components