PowerSystem

Module for creating power system objects.

This module provides classes and methods to define power systems, including phases, zero-crossing detection, and calculation of electrical quantities like voltage, current, and power.

Classes:

Name	Description
PowerSystem	Represents the overall power system, allowing configuration, data processing, and analysis.
PowerPhase	Represents a single phase of the power system.

Imports

• numpy: For numerical calculations.
• List: For type hinting lists.
• logging: For logging messages.
• AcqBuffer, DataChannelBuffer: From daqopen.channelbuffer for data handling.
• ZeroCrossDetector: From pqopen.zcd for detecting zero crossings in signals.

PowerPhase

Bases: object

Represents a single phase in the power system.

Attributes:

Name	Type	Description
_u_channel	AcqBuffer	Voltage channel buffer for the phase.
_i_channel	AcqBuffer	Current channel buffer for the phase.
_number	int	Identifier number for the phase.
name	str	Name of the phase.
_calc_channels	dict	Dictionary for storing calculated data channels.

__init__(u_channel, i_channel=None, number=1, name='')

Initializes a PowerPhase object.

Parameters:

Name	Type	Description	Default
u_channel	AcqBuffer	Voltage channel buffer.	required
i_channel	AcqBuffer	Current channel buffer. Defaults to None.	None
number	int	Phase number. Defaults to 1.	1
name	str	Name of the phase. Defaults to an empty string.	''

update_calc_channels(features)

Update the calculation channels depending of active features

Parameters:

Name	Type	Description	Default
features	dict	Dict of features	required

PowerSystem

Bases: object

Represents the overall power system, including zero-crossing detection, phase management, and power system calculations.

Attributes:

Name	Type	Description
_zcd_channel	AcqBuffer	Channel buffer for zero-crossing detection data.
_samplerate	float	Sampling rate of the input signal.
_time_channel	AcqBuffer	Optional time channel buffer.
_zcd_cutoff_freq	float	Cutoff frequency for the zero-crossing detector.
_zcd_threshold	float	Threshold for zero-crossing detection.
_zcd_minimum_frequency	float	Minimum frequency for valid zero-crossing detection.
nominal_frequency	float	Nominal frequency of the power system.
nper	Optional[int]	Number of periods for analysis (if applicable).
_phases	List[PowerPhase]	List of phases in the power system.
_features	dict	Configuration for harmonic and fluctuation calculations.
output_channels	dict	Dictionary of output data channels.

__init__(zcd_channel, input_samplerate, zcd_cutoff_freq=50.0, zcd_threshold=1.0, zcd_minimum_freq=10, nominal_frequency=50.0, nper=10)

Initializes a PowerSystem object.

Parameters:

Name	Type	Description	Default
zcd_channel	AcqBuffer	Channel buffer for zero-crossing detection.	required
input_samplerate	float	Sampling rate of the input signal.	required
zcd_cutoff_freq	float	Cutoff frequency for zero-crossing detection. Defaults to 50.0.	50.0
zcd_threshold	float	Threshold for zero-crossing detection. Defaults to 1.0.	1.0
zcd_minimum_freq	float	Minimum frequency for valid zero crossings. Defaults to 10.	10
nominal_frequency	float	Nominal system frequency. Defaults to 50.0.	50.0
nper	int	Number of periods for calculations. Defaults to 10.	10

add_phase(u_channel, i_channel=None, name='')

Adds a phase to the power system.

Parameters:

Name	Type	Description	Default
u_channel	AcqBuffer	Voltage channel buffer.	required
i_channel	AcqBuffer	Current channel buffer. Defaults to None.	None
name	str	Name of the phase. Defaults to an empty string.	''

enable_debug_channels()

Enables channel for debugging purposes and exposes them to a separate output_channel group named 'debug_channels'

enable_energy_channels(persist_file, ignore_value=False)

Enables the calculation of energy channels (overall, not by phase) Two separate channels are created, one for positive and one for negative energy (like energy consumption and delivery of typical metering devices)

Parameters:

Name	Type	Description	Default
persist_file	Path	file path of the file, where the persisted data is stored and loaded from	required
ignore_value	bool	Ignore persist value for initializing the energy counter	False

enable_harmonic_calculation(num_harmonics=50)

Enables harmonic analysis for the power system.

Parameters:

Name	Type	Description	Default
num_harmonics	int	Number of harmonics to calculate. Defaults to 50.	50

enable_mains_signaling_calculation(frequency)

Enables calculation of mains signaling voltage Complies to IEC 61000-4-30

Parameters:

Name	Type	Description	Default
frequency	float	Expected frequency of signaling voltage	required

enable_mains_signaling_tracer(frequency, trigger_level)

Enables high res tracing of mains signaling voltage for potential data decoding.

Parameters:

Name	Type	Description	Default
frequency	float	Expected frequency of signaling voltage	required
trigger_level	float	Binary conversion level in volt	required

enable_nper_abs_time_sync(time_channel, interval_sec=600)

Enables synchronisation of multi-period calculation to absolute rounded timestamp. Complies to IEC 61000-4-30 overlapping

Parameters:

Name	Type	Description	Default
time_channel	AcqBuffer	Channel buffer for time information	required
interval_sec	int	Resync interval in seconds	600

enable_under_over_deviation_calculation(u_din)

Enables calculation of under and overdeviation Complies to IEC 61000-4-30

Parameters:

Name	Type	Description	Default
u_din	float	Dimensioned voltage (typ. nominal voltage)	required

get_aggregated_data(start_acq_sidx, stop_acq_sidx)

Retrieves aggregated data for the specified sample range.

Parameters:

Name	Type	Description	Default
start_acq_sidx	int	Start sample index.	required
stop_acq_sidx	int	Stop sample index.	required

Returns:

Name	Type	Description
dict	dict	Aggregated data values.

process()

Processes new data samples, performing zero-crossing detection and calculations for each period.