Harmonics Disadvantages in Power System

Sources of Harmonics:

Several sources of harmonic currents that may be found on electrical power distribution networks are listed below:

• Variable speed motor drives
• Rectifiers
• Arc furnaces
• Wielding equipment
• Uninterrupted power supplies
• Switching mode power supplies
• Compact fluorescent lamps
• Electronic ballasts

Disadvantages of Harmonics:

Harmonics degrades the performance of power system. Some of the disadvantages of harmonics in the power distributed network are listed below:

• The harmonics flowing in the distribution network downgrade the quality of the electrical power supply. There can have several negative effects on the operation of the power system
• Increased losses on the distribution system due to increase in the effective rms current
• Over-load in neutral conductors due to cumulative increase in the third harmonics created by the single phase loads
• Overloads, vibration and premature ageing of the generators, transformers and motors as well as increase in the noise level
• Overloads and premature ageing of the power factor correction capacitors
• Distortion of the supply voltage that can disturb the operation of the sensitive loads
• Disturbances in the communication networks and telephone lines
• Resonance between the supply inductance and capacitance of the power factor correction capacitors