Cabling Design Helpers

Cabling Design Helpers#

For details of the code implementation, please see the Cabling Helpers API documentation.

Overview#

This overview provides the Cable class, Plant class, and CableSystem parent class.

Cable#

The cable class calculates a provided cable's power rating for determining the maximum number of turbines that can be supported by a string of cable.

Character Impedance ($\Omega$)#

\[ Z_0 = \sqrt{\frac{R + 2 \pi f L}{G + j 2 \pi f C}} \]

$R=$ ac_resistance
$j=$ the imaginary unit
$f=$ line_frequency
$L=$ inductance
$G=$ \frac{1}{R} =${py:attr}`conductance` \ $C=$ capacitance

Power Factor#

\[\begin{split} |P| &= \cos(\theta) \\ &= \cos(\arctan(\frac{j Z_0}{Z_0})) \end{split}\]

$\theta=$ the phase angle
$jZ_0=$ the imaginary portion of character_impedance
$Z_0=$ the real portion of character_impedance

Cable Power ($MW$)#

$P = \sqrt{3} * V * I * |P|$
$V=$ rated_voltage
$I=$ current_capacity
$|P|=$ power_factor

Plant#

Calculates the wind farm specifications to be used for array cable design phase. The "data class" accepts either set distances between turbines and rows or calculates them based off of the number of rotor diameters specified, for example:

# First see if there is a distance defined
self.turbine_distance = config["plant"].get("turbine_distance", None)

# If not, then multiply the rotor diameter by the turbine spacing,
# an integer representation of the number of rotor diameters and covert
# to kilometers
if self.turbine_distance is None:
    self.turbine_distance = (
        rotor_diameter * config["plant"]["turbine_spacing"] / 1000.0
        )

# Repeat the same process for row distance.
self.row_distance = config["plant"].get("row_distance", None)
    if self.row_distance is None:
        self.row_distance = (
            rotor_diameter * config["plant"]["row_spacing"] / 1000.0
        )

where config is the configuration dictionary passed to the array cable design phase

The cable section length for the first turbine in each string is calculated as the distance to the substation, substation_distance.

CableSystem#

CableSystem acts as the parent class for both ArrayDesignSystem and ExportDesignSystem. As such, it is not intended to be invoked on its own, however it provides the shared frameworks for both cabling system.

In particular, the CableSystem offers the cabling initialization and most of the output properties such as cable_lengths_by_type, total_cable_lengths_by_type, cost_by_type, total_phase_cost, total_phase_time, detailed_output, and most importantly design_result to avoid redefinition of multiple core calculations.