Remedies for Harmonics - How to Find the Solution [Demo]
Harmonics are mainly generated by rectifiers. powerqualityonline shows you different remedies for harmonics with their advantages and disadvantages.
This is how you get to the solution systematically.
| Advantages | Disadvantages |
|---|---|
| Immediate implementation possible | Generation of high-frequency currents due to operation (pulse inverter), which must be filtered sufficiently strongly |
| No interruption of operation (downtime) | Possible new grid resonances due to high frequency must be excluded (consider input and output side) |
| Elimination of classical harmonics | Not useful against high-frequency leakage currents from frequency converters and switching power supply units, ECGs etc. |
| Depending on the model, load balancing is also possible | No elimination of the primary cause of the problem: Loads that generate harmonic currents |
| No intervention in the plant/system structure | Metrological monitoring is recommended to ensure effectiveness and absence of retroaction on other loads |
Depending on the design, active filters can not only restore the waveform to a sinusoidal shape and thus cancel out the capacitive phase shift caused by the distortion, but they can also provide attenuation or complete suppression of the resonance phenomena. Positive side effects are energy saving effects, the suppression of harmonics and the strong reduction of vagrant currents.
| Advantages | Disadvantages |
|---|---|
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | |
| See more possibilities in the registered (full) version. | |
| See more possibilities in the registered (full) version. |
| Advantages | Disadvantages |
|---|---|
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
Another possible countermeasure to harmonics and resonances is the very strong increase of the short-circuit power.
This way is usually not justifiable for financial reasons (additional transformers, changeover to own medium-voltage transformer or even own 110 kV substation).
If problems with high frequency occur as a result of active filters or active rectifiers, the following should also be included:
| Advantages | Disadvantages |
|---|---|
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
Normally frequency converters, active harmonic filters etc. are already equipped with appropriate filters by the manufacturer. However, sometimes additional filtering is required, see Grid Resonances.
| Advantages | Disadvantages |
|---|---|
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | See more possibilities in the registered (full) version. |
| See more possibilities in the registered (full) version. | |
| See more possibilities in the registered (full) version. |