Load

Note

Loads should always have a positive p_mw value, since all power values are given in the consumer system. If you want to model constant generation, use a Static Generator (sgen element) instead of a negative load.

See also

Unit Systems and Conventions

Create Function

pandapower.create.create_load(net, bus, p_mw, q_mvar=get_default_value('load', 'q_mvar'), const_z_p_percent=get_default_value('load', 'const_z_p_percent'), const_i_p_percent=get_default_value('load', 'const_i_p_percent'), const_z_q_percent=get_default_value('load', 'const_z_q_percent'), const_i_q_percent=get_default_value('load', 'const_i_q_percent'), sn_mva=nan, name=None, scaling=get_default_value('load', 'scaling'), index=None, in_service=get_default_value('load', 'in_service'), type='wye', max_p_mw=nan, min_p_mw=nan, max_q_mvar=nan, min_q_mvar=nan, controllable=get_default_value('load', 'controllable'), **kwargs)

Adds one load in table net[“load”].

All loads are modelled in the consumer system, meaning load is positive and generation is negative active power. Please pay attention to the correct signing of the reactive power as well.

Parameters:

  • net (pandapowerNet) – The net within this load should be created

  • bus (int | integer) – The bus id to which the load is connected

  • p_mw (float) –

    The active power of the load

    • positive value -> load

    • negative value -> generation

  • q_mvar (float) – The reactive power of the load

  • const_z_p_percent (float) – percentage of p_mw that will be associated to constant impedance load at rated voltage

  • const_i_p_percent (float) – percentage of p_mw that will be associated to constant current load at rated voltage

  • const_z_q_percent (float) – percentage of q_mvar that will be associated to constant impedance load at rated voltage

  • const_i_q_percent (float) – percentage of q_mvar that will be associated to constant current load at rated voltage

  • sn_mva (float) – Nominal power of the load

  • name (str | None) – The name for this load

  • scaling (float) – An OPTIONAL scaling factor. Multiplies with p_mw and q_mvar.

  • type (Literal['wye', 'delta']) – type variable to classify the load: wye/delta

  • index (int | integer | None) – Force a specified ID if it is available. If None, the index one higher than the highest already existing index is selected.

  • in_service (bool) – True for in_service or False for out of service

  • max_p_mw (float) – Maximum active power load - necessary for controllable loads in for OPF

  • min_p_mw (float) – Minimum active power load - necessary for controllable loads in for OPF

  • max_q_mvar (float) – Maximum reactive power load - necessary for controllable loads in for OPF

  • min_q_mvar (float) – Minimum reactive power load - necessary for controllable loads in OPF

  • controllable (bool) – States, whether a load is controllable or not. Only respected for OPF; defaults to False if “controllable” column exists in DataFrame

Returns:

The ID of the created load

Return type:

int | integer

Example

>>> create_load(net, bus=0, p_mw=10., q_mvar=2.)
pandapower.create.create_loads(net, buses, p_mw, q_mvar=_load_q_mvar, const_z_p_percent=_load_const_z_p_percent, const_i_p_percent=_load_const_i_p_percent, const_z_q_percent=_load_const_z_q_percent, const_i_q_percent=_load_const_i_q_percent, sn_mva=nan, name=None, scaling=_load_scaling, index=None, in_service=_load_in_service, type=_load_type, max_p_mw=nan, min_p_mw=nan, max_q_mvar=nan, min_q_mvar=nan, controllable=_load_controllable, **kwargs)

Adds a number of loads in table net[“load”].

All loads are modelled in the consumer system, meaning load is positive and generation is negative active power. Please pay attention to the correct signing of the reactive power as well.

Parameters:

  • net (pandapowerNet) – The net within this load should be created

  • buses (Sequence) – A list of bus ids to which the loads are connected

  • p_mw (float | Iterable[float]) –

    The active power of the loads

    • positive value -> load

    • negative value -> generation

  • q_mvar (float | Iterable[float]) – The reactive power of the loads

  • const_z_p_percent (float | Iterable[float]) – percentage of p_mw that will be associated to constant impedance loads at rated voltage

  • const_i_p_percent (float | Iterable[float]) – percentage of p_mw that will be associated to constant current load at rated voltage

  • const_z_q_percent (float | Iterable[float]) – percentage of q_mvar that will be associated to constant impedance loads at rated voltage

  • const_i_q_percent (float | Iterable[float]) – percentage of q_mvar that will be associated to constant current load at rated voltage

  • sn_mva (float | Iterable[float]) – Nominal power of the loads

  • name (Iterable[str] | None) – The name for this load

  • scaling (float | Iterable[float]) – An OPTIONAL custom scaling factor. Multiplies with p_mw and q_mvar.

  • type (Literal['wye', 'delta']) – type variable to classify the load

  • index (int | integer | Iterable[int | integer] | None) – Force a specified ID if it is available. If None, the index is set to a range between one higher than the highest already existing index and the length of loads that shall be created.

  • in_service (bool | Iterable[bool]) – True for in_service or False for out of service

  • max_p_mw (float | Iterable[float]) – Maximum active power load - necessary for controllable loads in for OPF

  • min_p_mw (float | Iterable[float]) – Minimum active power load - necessary for controllable loads in for OPF

  • max_q_mvar (float | Iterable[float]) – Maximum reactive power load - necessary for controllable loads in for OPF

  • min_q_mvar (float | Iterable[float]) – Minimum reactive power load - necessary for controllable loads in OPF

  • controllable (bool | Iterable[bool]) – States, whether a load is controllable or not. Only respected for OPF Defaults to False if “controllable” column exists in DataFrame

Returns:

The IDs of the created loads

Return type:

ndarray[tuple[Any, …], dtype[int | integer]]

Example

>>> create_loads(net, buses=[0, 2], p_mw=[10., 5.], q_mvar=[2., 0.])
pandapower.create.create_load_from_cosphi(net, bus, sn_mva, cos_phi, mode, **kwargs)

Creates a load element from rated power and power factor cos(phi).

Parameters:

  • net (pandapowerNet) – The net within this static generator should be created

  • bus (int | integer) – The bus id to which the load is connected

  • sn_mva (float) – rated power of the load

  • cos_phi (float) – power factor cos_phi

  • mode (Literal['underexcited', 'overexcited']) –

    • “underexcited” (Q absorption, decreases voltage)

    • ”overexcited” (Q injection, increases voltage)

  • **kwargs – any parameter from create_load, as these get passed to the create_load function

Returns:

The ID of the created load

Return type:

int | integer

Load elements are modeled from a consumer point of view. Active power will therefore always be positive, reactive power will be positive for underexcited behavior (Q absorption, decreases voltage) and negative for overexcited behavior (Q injection, increases voltage).

Table Structure

net.load

Parameter

Datatype

Value Range

Explanation

nullable

required

3ph

name

name of the load

✓

bus

int

>=0

index of connected bus

✓

p_mw

float

active power of the load [MW], a positiv value means power consumption

✓

q_mvar

float

reactive power of the load [MVar], positive for inductive consumers, negative for capacitive consumers

✓

const_z_p_percent

float

[0, 100]

percentage of p_mw that is associated to constant impedance load at rated voltage [%]

✓

const_i_p_percent

float

[0, 100]

percentage of p_mw that is associated to constant current load at rated voltage [%]

✓

const_z_q_percent

float

[0, 100]

percentage of q_mvar that is associated to constant impedance load at rated voltage [%]

✓

const_i_q_percent

float

[0, 100]

percentage of q_mvar that is associated to constant current load at rated voltage [%]

✓

sn_mva

float

>0

rated power of the load [kVA]

✓

scaling

float

>=0

scaling factor for active and reactive power

✓

in_service

bool

specifies if the load is in service.

✓

type

Connection Type of 3 Phase Load(Valid for three phase load flow only) Naming convention: wye, delta

✓

✓

controllable

bool

States if load is controllable or not, load will not be used as a flexibility if it is not controllable

zone

can be used to group loads, for example network groups / regions

✓

max_p_mw

float

Maximum active power

✓

min_p_mw

float

Minimum active power

✓

max_q_mvar

float

Maximum reactive power

✓

min_q_mvar

float

Minimum reactive power

✓

*necessary for executing a power flow calculation.

Note

The apparent power value sn_mva is provided as additional information for usage in controller or other applications based on pandapower. It is not considered in the power flow!

Electric Model

Loads are modelled as PQ-buses in the power flow calculation, with an option to use the so-called ZIP load model, where a load is represented as a composition of constant power (P), constant current (I) and constant impedance (Z):

alternate Text

What part of the load is considered constant with constant power, constant current or constant impedance is defined as follows. This is considered separately for active and reactive power:

\[\begin{split}z_{const_p} &= \frac{const\_z\_p\_percent}{100} \\ z_{const_q} &= \frac{const\_z\_q\_percent}{100} \\ i_{const_p} &= \frac{const\_i\_p\_percent}{100} \\ i_{const_q} &= \frac{const\_i\_q\_percent}{100} \\ p_{const_p} &= \frac{100 - const\_z\_p\_percent - const\_i\_p\_percent}{100} \\ p_{const_q} &= \frac{100 - const\_z\_q\_percent - const\_i\_q\_percent}{100}\end{split}\]

The load power values are then defines as:

\[\begin{split}P_{load} &= p\_mw \cdot scaling \cdot (p_{const_p} + z_{const_p} \cdot V^2 + i_{const_p} \cdot V ) \\ Q_{load} &= q\_mvar \cdot scaling \cdot (p_{const_q} + z_{const_q} \cdot V^2 + i_{const_q} \cdot V)\end{split}\]

Result Tables

net.res_load

Parameter

Datatype

Explanation

nullable

required

p_mw

float

resulting active power demand after scaling and after considering voltage dependence [MW]

✓

✓

q_mvar

float

resulting reactive power demand after scaling and after considering voltage dependence [MVar]

✓

✓

The power values in the net.res_load table are equivalent to \(P_{load}\) and \(Q_{load}\).