Harmonics 1Ph
The Harmonics module calculates the harmonics of current and voltage. In addition, the THD of the input values is calculated from the harmonics.
In the Beckhoff Information System you will find the documentation of the corresponding PLC function block FB_PMA_Harmonics_1Ph.
In the Beckhoff Information System you will find the documentation of the TF3650 TwinCAT 3 Power Monitoring function with descriptions of the corresponding PLC library.
Configuration parameters
- Num Harmonics: Number of harmonics to be calculated.
- Transform To Percent: Boolean value that specifies whether the result should be output as a percentage. The first harmonic corresponds to 100%.
- FFT Length: Length of the FFT. It must be greater than one and an integral power of two.
- Window Length: Length of the analysis window in samples. The length must be greater than one and an even number. It must not be greater than FFT Length.
- Sample Rate [Hz]: Sample rate (samples per second) of the input signal.
- Base Frequency: Frequency of the first harmonic in Hz.
- Num Bands: Specifies the number of bands for which the RMS is calculated.
- Bandwidth: Total bandwidth of a single RMS band.
- Window Type: Defines the window function used. The window type HannWindow is a good default value. The windowing can be switched off by the use of the window type RectangularWindow. See: E_PMA_WindowType
- Transform To Percent: Boolean value that specifies whether the result should be output as a percentage. The first harmonic corresponds to 100%.
Input values
- Input Voltage: Input values of the voltage.
- Input Current: Input values of the current.
- Reset Statistics (optional):
TRUEresets the min. and max. values of the outputs.
Output values
- THD U: THD of the voltage. The output is in percent.
- THD U Min: Minimum THD U value that has occurred. Can be reset via the Reset Statistics input.
- THD U Max: Maximum THD U value that has occurred. Can be reset via the Reset Statistics input.
- THD I: THD of the current. The output is in percent.
- THD I Min: Minimum THD I value that has occurred. Can be reset via the Reset Statistics input.
- THD I Max: Maximum THD I value that has occurred. Can be reset via the Reset Statistics input.
- Harmonics Voltage: Harmonics of the voltage.
- Harmonics Current: Harmonics of the current.