Performs impedance-based stability assessment of network areas. More...

#include <Stability_estimate.h>

Public Member Functions
	StabilityEstimate ()=default
	Default constructor.

	~StabilityEstimate ()=default
	Default destructor.

void	add_areas (Network *net)
	Populates AC/DC area maps from the network hierarchy.

MatrixXcd	compute_equivalent_admittance_parameters_num (SubNetwork *subnet, double frequency)
	Computes numeric equivalent admittance parameters for a subnetwork.

MatrixXcd	compute_closing_impedance (SubNetwork *, string &, MatrixXcd &, MatrixXcd &)
	Computes the visible impedance when other subnetwork outputs are shorted.

MatrixXcd	compute_transfer_function (string converter_name, string location, double frequency)
	Evaluates a converter transfer function at a single frequency.

void	writeFileTF (string converter_name, string location, double start_frequency, double end_frequency, int number_of_points)
	Writes transfer function data to a file over a frequency sweep.

void	bodeplotTF (string converter_name, string location, double start_frequency, double end_frequency, int number_of_points)
	Plots the transfer function as a Bode diagram over a frequency sweep.

void	nyquistplotTF (string converter_name, string location, double start_frequency, double end_frequency, int number_of_points)
	Plots the transfer function as a Nyquist diagram over a frequency sweep.

void	print_summary () const
	Prints a summary of identified AC/DC areas and converters.

std::unordered_map< std::string, SubNetwork * > &	get_ac_grids ()
	Returns the map of AC grid subnetworks by name.

std::unordered_map< std::string, SubNetwork * > &	get_dc_grids ()
	Returns the map of DC grid subnetworks by name.

Detailed Description

Performs impedance-based stability assessment of network areas.

Partitions a Network into AC grids, DC grids, and converter subnetworks, then evaluates equivalent admittance parameters and transfer functions at specified frequencies for stability margin analysis.

Constructor & Destructor Documentation

◆ StabilityEstimate()

StabilityEstimate::StabilityEstimate ( )

default

Default constructor.

◆ ~StabilityEstimate()

StabilityEstimate::~StabilityEstimate ( )

default

Default destructor.

Member Function Documentation

◆ add_areas()

void StabilityEstimate::add_areas ( Network * net )

Populates AC/DC area maps from the network hierarchy.

Parameters

net	Network whose area decomposition is used.

References Network::add_areas(), Network::get_ac_grid_names(), Network::get_ac_grids(), Network::get_converters(), Network::get_dc_grid_names(), Network::get_dc_grids(), and Network::is_area_empty().

Referenced by example_stability_check().

◆ bodeplotTF()

void StabilityEstimate::bodeplotTF	(	string	converter_name,
		string	location,
		double	start_frequency,
		double	end_frequency,
		int	number_of_points
	)

Plots the transfer function as a Bode diagram over a frequency sweep.

Generates data and triggers a Bode plot for the Y-parameter matrix.

Parameters

converter_name	Name of the converter element.
location	Output port or bus identifier.
start_frequency	Sweep start frequency in Hz.
end_frequency	Sweep end frequency in Hz.
number_of_points	Number of frequency points.
start_frequency	The starting frequency for the plot.
end_frequency	The ending frequency for the plot.
number_of_points	The number of points to plot across the frequency range.

References bode_plot_implot(), compute_transfer_function(), and j.

Referenced by example_stability_check().

◆ compute_closing_impedance()

MatrixXcd StabilityEstimate::compute_closing_impedance	(	SubNetwork *	sub,
		string &	bus_name,
		MatrixXcd &	Y_parameters,
		MatrixXcd &	Y_closing
	)

Computes the visible impedance when other subnetwork outputs are shorted.

Computes the equivalent closing impedance for a subnetwork port.

Parameters

subnet	Subnetwork under test.
location	Output port identifier (modified in place if needed).
Y_param	Admittance matrix of the subnetwork.
Z_param	Impedance matrix of the subnetwork.

Returns: Closing impedance seen at location.

This function calculates the equivalent impedance seen from a specific output port (connection_name) of a subnetwork, considering the loading effects of other connected converters represented by Z_closing.

Parameters

sub	Pointer to the SubNetwork object.
connection_name	The name of the output port for which to compute the impedance.
Y_parameters	The multi-port admittance matrix of the subnetwork.
Z_closing	The closing impedance matrix representing loads at other ports.

Returns: An Eigen::MatrixXcd representing the equivalent closing impedance.

Exceptions

std::runtime_error if the connection_name is not found in the subnetwork's outputs.

References SubNetwork::getOutputs().

Referenced by compute_transfer_function().

◆ compute_equivalent_admittance_parameters_num()

MatrixXcd StabilityEstimate::compute_equivalent_admittance_parameters_num	(	SubNetwork *	subnet,
		double	frequency
	)

Computes numeric equivalent admittance parameters for a subnetwork.

Computes the numerical equivalent multi-port admittance parameters for a subnetwork.

Parameters

subnet	Subnetwork whose Y-parameters are evaluated.
frequency	Evaluation frequency in Hz.

Returns: Complex admittance matrix at frequency.

Parameters

subnet	Pointer to the SubNetwork object.
frequency	The frequency in Hz for the calculation.

Returns: An Eigen::MatrixXcd containing the computed Y-parameter matrix for the subnetwork's output ports.

Exceptions

std::invalid_argument if the subnet pointer is null or the subnetwork name is invalid.

References Network::getBuses(), SubNetwork::getName(), SubNetwork::getOutputs(), SubNetwork::getTransformation(), Bus::isGround(), and j.

Referenced by compute_transfer_function().

◆ compute_transfer_function()

MatrixXcd StabilityEstimate::compute_transfer_function	(	string	converter_name,
		string	location,
		double	frequency
	)

Evaluates a converter transfer function at a single frequency.

Computes the transfer function for stability analysis of a specific converter.

Parameters

converter_name	Name of the converter element.
location	Output port or bus identifier.
frequency	Evaluation frequency in Hz.

Returns: Complex transfer function value.

Parameters

converter_name	The name of the converter under analysis.
location	The side of the converter from which the analysis is performed (e.g., "AC1" or "DC1").
frequency	The frequency in Hz for the calculation.

Returns: An Eigen::MatrixXcd representing the resulting transfer function matrix.

References compute_closing_impedance(), compute_equivalent_admittance_parameters_num(), Element::compute_y_parameters(), Converter::getACarea(), Bus::getBusLocation(), Bus::getBusName(), Element::getConnections(), Converter::getDCarea(), and vectorToMatrix().

Referenced by bodeplotTF(), example_stability_check(), nyquistplotTF(), and writeFileTF().

◆ get_ac_grids()

std::unordered_map< std::string, SubNetwork * > & StabilityEstimate::get_ac_grids ( )

inline

Returns the map of AC grid subnetworks by name.

Returns: Reference to the AC grids map.

◆ get_dc_grids()

std::unordered_map< std::string, SubNetwork * > & StabilityEstimate::get_dc_grids ( )

inline

Returns the map of DC grid subnetworks by name.

Returns: Reference to the DC grids map.

◆ nyquistplotTF()

void StabilityEstimate::nyquistplotTF	(	string	converter_name,
		string	location,
		double	start_frequency,
		double	end_frequency,
		int	number_of_points
	)

Plots the transfer function as a Nyquist diagram over a frequency sweep.

Generates data and triggers a Nyquist plot for the Y-parameter matrix.

Parameters

converter_name	Name of the converter element.
location	Output port or bus identifier.
start_frequency	Sweep start frequency in Hz.
end_frequency	Sweep end frequency in Hz.
number_of_points	Number of frequency points.
start_frequency	The starting frequency for the plot.
end_frequency	The ending frequency for the plot.
number_of_points	The number of points to plot across the frequency range.

References compute_transfer_function(), j, and nyquist_plot_implot().

Referenced by example_stability_check().

◆ print_summary()

void StabilityEstimate::print_summary ( ) const

Prints a summary of identified AC/DC areas and converters.

◆ writeFileTF()

void StabilityEstimate::writeFileTF	(	string	converter_name,
		string	location,
		double	start_frequency,
		double	end_frequency,
		int	number_of_points
	)

Writes transfer function data to a file over a frequency sweep.

Writes the Y-parameter matrix to a CSV file over a specified frequency range.

Parameters

converter_name	Name of the converter element.
location	Output port or bus identifier.
start_frequency	Sweep start frequency in Hz.
end_frequency	Sweep end frequency in Hz.
number_of_points	Number of logarithmically spaced frequency points.
start_frequency	The starting frequency for the sweep.
end_frequency	The ending frequency for the sweep.
number_of_points	The number of frequency points to compute and write.

References compute_transfer_function(), and j.

The documentation for this class was generated from the following files:

harmony/src/Solver/Stability_Estimate/Stability_estimate.h
harmony/src/Solver/Stability_Estimate/Stability_estimate.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ StabilityEstimate()

◆ ~StabilityEstimate()

Member Function Documentation

◆ add_areas()

◆ bodeplotTF()

◆ compute_closing_impedance()

◆ compute_equivalent_admittance_parameters_num()

◆ compute_transfer_function()

◆ get_ac_grids()

◆ get_dc_grids()

◆ nyquistplotTF()

◆ print_summary()

◆ writeFileTF()