/
xward.rst
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/
xward.rst
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=============
Extended Ward
=============
.. seealso::
:ref:`Unit Systems and Conventions <conventions>`
Create Function
=====================
.. autofunction:: pandapower.create_xward
Input Parameters
=========================
*net.xward*
.. tabularcolumns:: |p{0.10\linewidth}|p{0.1\linewidth}|p{0.15\linewidth}|p{0.55\linewidth}|
.. csv-table::
:file: xward_par.csv
:delim: ;
:widths: 10, 10, 15, 55
\*necessary for executing a power flow calculation.
Electric Model
=================
The extended ward equivalent is a :ref:`ward equivalent<ward>`: with additional PV-node with an internal resistance.
.. image:: xward.png
:width: 25em
:align: center
The constant apparent power is given by:
.. math::
:nowrap:
\begin{align*}
P_{const} &= ps\_mw\\
Q_{const} &= qs\_mvar\\
\end{align*}
The shunt admittance part of the extended ward equivalent is calculated as described :ref:`here<shunt>`:
.. math::
:nowrap:
\begin{align*}
\underline{y}_{shunt} &= \frac{pz\_mw + j \cdot qz\_mvar}{S_{N}}
\end{align*}
The internal resistance is defined as:
.. math::
:nowrap:
\begin{align*}
\underline{z}_{int} &= r\_pu + j \cdot x\_pu
\end{align*}
The internal voltage source is modelled as a PV-node (:ref:`generator<gen>`) with:
.. math::
:nowrap:
\begin{align*}
p\_mw &= 0 \\
vm\_pu &= vm\_pu
\end{align*}
Result Parameters
==========================
*net.res_xward*
.. tabularcolumns:: |p{0.10\linewidth}|p{0.1\linewidth}|p{0.50\linewidth}|
.. csv-table::
:file: xward_res.csv
:delim: ;
:widths: 10, 10, 50
.. math::
:nowrap:
\begin{align*}
vm\_pu &= v_{bus} \\
p\_mw &= P_{const} + Re(\frac{\underline{V}_{bus}^2}{\underline{Y}_{shunt}}) + Re(\underline{I}_{int} \cdot \underline{V}_{bus}) \\
q_mvar &= Q_{const} + Im(\frac{\underline{V}_{bus}^2}{\underline{Y}_{shunt}} + Im(\underline{I}_{int} \cdot \underline{V}_{bus}) )
\end{align*}