Category
- Products
-
- FAQ
- Contact us
AC Drive Manufacturer
AC Drive Harmonics
What is harmonics?
The sine wave of a commercial power source provided from a power company is called a fundamental wave. The sine wave which has an integral multiple frequency of this fundamental wave is called harmonics. The power source waveform becomes a distorted waveform when the harmonics are added to the fundamental wave. (Refer to the following figure.)
When a rectifying circuit and a smoothing circuit with a capacitor are provided in the circuit of equipment, the input current waveform becomes distorted and the harmonics are generated.
Principle of harmonic generation
The AC input current supplied from the AC drive power supply side is rectified with a bridge rectifier, smoothed with a capacitor, converted to the DC and then supplied to the inverter part. To charge this smoothing capacitor, the AC input current becomes a distorted waveform with the harmonics.
Effects of harmonics
The harmonics generated by AC drives may give the following effects to the facilities or other equipments through cables.
Target models
Harmonic current suppression measures
As a harmonic current suppression measure for AC drives, connect a power factor improving reactor as shown in the figures below.
Even for consumers to whom the guideline is not applied, it is recommended to connect a power factor improving reactor in the same manner to avoid possible troubles due to the harmonic current.
The best way to mitigate harmonics generated by ac drives is with an active filter solution. No matter how low or high the load (AC drive) runs at an active mitigation solution is best. There are many non-active solutions on the market but they all fall flat under varying load conditions most are based on LC filters and need the C component switched out at low load conditions. Power factor is a vital consideration when looking at any harmonic mitigation.
The sine wave of a commercial power source provided from a power company is called a fundamental wave. The sine wave which has an integral multiple frequency of this fundamental wave is called harmonics. The power source waveform becomes a distorted waveform when the harmonics are added to the fundamental wave. (Refer to the following figure.)
When a rectifying circuit and a smoothing circuit with a capacitor are provided in the circuit of equipment, the input current waveform becomes distorted and the harmonics are generated.
Principle of harmonic generation
The AC input current supplied from the AC drive power supply side is rectified with a bridge rectifier, smoothed with a capacitor, converted to the DC and then supplied to the inverter part. To charge this smoothing capacitor, the AC input current becomes a distorted waveform with the harmonics.
Effects of harmonics
The harmonics generated by AC drives may give the following effects to the facilities or other equipments through cables.
- Unusual noise, vibration, burnout, etc. caused by the influx of the harmonic current to equipments.
- Malfunction, etc. caused by the harmonic voltage applied to equipments.
Target models
|
Input power |
Capacity of target motor |
Measures |
|
1-phase 100V |
Full capacity |
Make a judgment based on Harmonic suppression guideline for customers who receive high voltage or special high voltage and take measures if necessary. For calculation method of power supply harmonics, refer to materials below.
|
|
1-phase 200V |
||
|
3-phase 200V |
||
|
3-phase 400V |
Harmonic current suppression measures
As a harmonic current suppression measure for AC drives, connect a power factor improving reactor as shown in the figures below.
Even for consumers to whom the guideline is not applied, it is recommended to connect a power factor improving reactor in the same manner to avoid possible troubles due to the harmonic current.
The best way to mitigate harmonics generated by ac drives is with an active filter solution. No matter how low or high the load (AC drive) runs at an active mitigation solution is best. There are many non-active solutions on the market but they all fall flat under varying load conditions most are based on LC filters and need the C component switched out at low load conditions. Power factor is a vital consideration when looking at any harmonic mitigation.
Post a Comment:
You may also like:
