Harmonic filters are commonly used to reduce distortion in voltage and current waveforms of network or utilized equipment. The main source of this distortion are power systems containing non-linear loads or semiconductor devices such as thyristors, IGBT, TRIAC, etc.
Main disadvantages due to presence of harmonics on power systems
- Increase voltage and current peaks, exceeding their nominal values
- Increase the RMS value of consumed current
- Increase the working temperature of the equipment
- Insulation breakdown and excessive arcs
- Incorrect performance of protection relays in detecting “Zero Crossing” resulting in excessive arcs in breakers
- Reduce the life-time of equipment such as motors, transformers, circuit breakers and switches
Harmonic filters are ideal option to solve the issue of harmonic distortion, which are mainly used as ohmic-inductive, inductive-capacitive and ohmic-inductive-capacitive circuits. These filters are used for voltage regulation, power quality, and reactive power control in steel mills, large aluminum smelters, induction furnaces, electric arc welding, speed control inverters, HVDC substations, wind and solar fields, transmission and distribution lines.