11th & 13th Harmonics
Interactive simulation of harmonic distortion, equipment effects and mitigation
1. Harmonic Controls
2. Mitigation
Reduces the 11th harmonic component.
Reduces the 13th harmonic component.
Actively compensates harmonic currents.
Reduces harmonic current produced by nonlinear loads.
3. Distorted Voltage/Current Waveform
The blue waveform represents the fundamental sine wave. The red waveform represents the actual waveform containing the 11th and 13th harmonics.
4. Harmonic Spectrum
5. Electrical Condition
6. Effects of 11th and 13th Harmonics
11th Harmonic
The 11th harmonic has a frequency of 550 Hz in a 50 Hz system. It is a high-order harmonic that can increase motor and transformer losses.
- Additional copper loss
- Additional iron/core loss
- Motor heating
- Torque pulsation
- Possible vibration and acoustic noise
13th Harmonic
The 13th harmonic has a frequency of 650 Hz in a 50 Hz system. It can contribute to additional heating, losses and waveform distortion.
- Motor heating
- Transformer heating
- Extra winding losses
- Torque pulsation
- Noise and vibration
Motor
Higher-order harmonics can create additional rotating magnetic-field components. These can produce extra losses and torque disturbances.
Transformer
Harmonic currents increase RMS current and can increase winding and core losses, resulting in additional temperature rise.
7. How to Mitigate 11th & 13th Harmonics
- Passive harmonic filters: tuned filters can target specific harmonic orders.
- Active harmonic filters: inject compensating current to reduce harmonic current.
- Line reactors: help reduce harmonic current from power-electronic loads.
- DC-link chokes: commonly used with variable-frequency drives.
- 12-pulse / 18-pulse rectifiers: can substantially reduce characteristic harmonics.
- Good system design: reduce harmonic-producing nonlinear loads and avoid resonance.
- Harmonic monitoring: use a power-quality analyzer to measure actual THD and individual harmonics.