PowerQuality

VoltageFluctuation

Bases: object

process(start_sidx, hp_data, raw_data)

calc_harmonics(fft_data, num_periods=10, num_harmonics=100)

Calculate harmonic rms and phase for a given FFT dataset. Grouping according to IEC 61000-4-7

Parameters:

Name	Type	Description	Default
fft_data	ndarray	The FFT data array.	required
num_periods	int	The number of fundamental periods in the origin time domain data	10
num_harmonics	int	The number of harmonics to calculate.	100

Returns:

Type	Description
Tuple[ndarray, ndarray]	Tuple[np.ndarray, np.ndarray]: harm_rms (np.ndarray): The RMS values of the harmonics. harm_phi (np.ndarray): The phase angles of the harmonics in degrees.

calc_interharmonics(fft_data, num_periods=10, num_iharmonics=100)

Calculate interharmonic rms for a given FFT dataset. Grouping according to IEC 61000-4-7

Parameters:

Name	Type	Description	Default
fft_data	ndarray	The FFT data array.	required
num_periods	int	The number of fundamental periods in the origin time domain data	10
num_iharmonics	int	The number of interharmonics to calculate.	100

Returns:

Name	Type	Description
iharm_rms	ndarray	The RMS values of the interharmonics.

calc_mains_signaling_voltage(u_fft_rms, msv_freq, num_periods, f_fund)

Calculate mains signaling voltage according to IEC 61000-4-30 with method of fft-neighbourhood.

Parameters:

Name	Type	Description	Default
u_fft_rms	ndarray	magnitude (rms) fft result	required
msv_freq	float	frequency of expected msv	required
num_periods	int	number of periods used for calculation of fft	required
f_fund	float	fundamental frequency	required

Returns:

Name	Type	Description
msv_rms	float	magitude of msv

calc_over_deviation(u_rms, u_din)

Calculate Overdeviation according to IEC 61000-4-30

Parameters:

Name	Type	Description	Default
u_din	float	Dimensioned voltage (typ. nominal voltage)	required
u_rms	ndarray	Array of n-period voltage rms values	required

calc_thd(harm_rms, max_harmonic=40, min_harmonic=2, fund_rms=None)

Calculate the Total Harmonic Distortion (THD).

Parameters:

Name	Type	Description	Default
harm_rms	ndarray	The RMS values of the harmonics.	required
max_harmonic	int	The maximum harmonic order to include in the THD calculation.	40
min_harmonic	int	The minimum harmonic order to include in the THD calculation.	2
fund_rms	float	The RMS value of the fundamental frequency. If None, the first harmonic is used.	None

Returns:

Name	Type	Description
float	float	The calculated THD percentage.

calc_unbalance(u_cplx)

Calculate voltage unbalance of a 3-phase power system according to IEC 61000-4-30 with method of symmetrical components.

Parameters:

Name	Type	Description	Default
u_cplx	list	List of complex voltage vectors of each phase	required

Returns:

Type	Description
tuple	Tuple[float, float]: u0: relative zero sequence in % u2: relative negative sequence in %

calc_under_deviation(u_rms, u_din)

Calculate Underdeviation according to IEC 61000-4-30

Parameters:

Name	Type	Description	Default
u_din	float	Dimensioned voltage (typ. nominal voltage)	required
u_rms	ndarray	Array of n-period voltage rms values	required

normalize_phi(phi)

Normalize phase angle to +-180°

Parameters:

Name	Type	Description	Default
phi	float	Phase angle to normalize	required

Returns:

Type	Description
float	normalized phase angle

resample_and_fft(data, resample_size=None)

Resample the input data to a specified size and compute its FFT.

Parameters:

Name	Type	Description	Default
data	ndarray	The input data array.	required
resample_size	int	The size to which the data should be resampled. If None, the size is determined as the next power of 2.	None

Returns:

Type	Description
ndarray	np.ndarray: The FFT of the resampled data, scaled by sqrt(2) and normalized by the resample size.