Ward

See also

Unit Systems and Conventions

Create Function

pandapower.create.create_ward(net, bus, ps_mw, qs_mvar, pz_mw, qz_mvar, name=None, in_service=True, index=None, **kwargs)

Creates a ward equivalent.

A ward equivalent is a combination of an impedance load and a PQ load.

Parameters:

  • net (pandapowerNet) – The pandapower net within the element should be created

  • bus (int | integer) – bus of the ward equivalent

  • ps_mw (float) – active power of the PQ load

  • qs_mvar (float) – reactive power of the PQ load

  • pz_mw (float) – active power of the impedance load in MW at 1.pu voltage

  • qz_mvar (float) – reactive power of the impedance load in MVar at 1.pu voltage

  • name (str | None)

  • in_service (bool)

  • index (int | integer | None)

Returns:

the id of the created ward

Return type:

int | integer

pandapower.create.create_wards(net, buses, ps_mw, qs_mvar, pz_mw, qz_mvar, name=None, in_service=True, index=None, **kwargs)

Creates ward equivalents.

A ward equivalent is a combination of an impedance load and a PQ load.

Parameters:

  • net (pandapowerNet) – The pandapower net within the element should be created

  • buses (Sequence) – bus of the ward equivalent

  • ps_mw (float | Iterable[float]) – active power of the PQ load

  • qs_mvar (float | Iterable[float]) – reactive power of the PQ load

  • pz_mw (float | Iterable[float]) – active power of the impedance load in MW at 1.pu voltage

  • qz_mvar (float | Iterable[float]) – reactive power of the impedance load in MVar at 1.pu voltage

  • name (Iterable[str] | None)

  • in_service (bool | Iterable[bool])

  • index (int | None)

Returns:

the ids of the created ward

Return type:

ndarray[tuple[Any, …], dtype[array]]

Input Parameters

net.ward

Parameter

Datatype

Value Range

Explanation

name

string

name of the ward equivalent

bus*

integer

index of connected bus

ps_mw*

float

constant active power demand [MW]

qs_mvar*

float

constant reactive power demand [MVar]

pz_mw*

float

constant impedance active power demand at 1.0 pu [MW]

qz_mvar*

float

constant impedance reactive power demand at 1.0 pu [MVar]

in_service*

boolean

True / False

specifies if the ward equivalent is in service.

*necessary for executing a power flow calculation.

Electric Model

../_images/ward.png

The ward equivalent is a combination of a constant apparent power consumption and a constant impedance load. The constant apparent power is given by:

\begin{align*} P_{const} &= ps\_mw\\ Q_{const} &= qs\_mvar\\ \end{align*}

The shunt admittance part of the ward equivalent is calculated as described here:

\begin{align*} \underline{y}_{shunt} &= \frac{pz\_mw + j \cdot qz\_mvar}{S_{N}} \end{align*}

Result Parameters

net.res_ward

Parameter

Datatype

Explanation

p_mw

float

active power demand of the ward equivalent [MW]

q_mvar

float

reactive power demand of the ward equivalent [kVar]

vm_pu

float

voltage at the ward bus [p.u]
\begin{align*} vm\_pu &= v_{bus} \\ p\_mw &= P_{const} + Re(\frac{\underline{V}_{bus}^2}{\underline{Y}_{shunt}}) \\ q\_mvar &= Q_{const} + Im(\frac{\underline{V}_{bus}^2}{\underline{Y}_{shunt}}) \end{align*}