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.

Create Function

pandapower.create_load(net, bus, p_mw, q_mvar=0, const_z_p_percent=0, const_i_p_percent=0, const_z_q_percent=0, const_i_q_percent=0, sn_mva=nan, name=None, scaling=1.0, index=None, in_service=True, type='wye', max_p_mw=nan, min_p_mw=nan, max_q_mvar=nan, min_q_mvar=nan, controllable=nan, **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:

created (**net** - The net within this load should be)
**bus** (int)
**p_mw** (float)
load (- positive value ->)
generation (- negative value ->)
**q_mvar** (float, default 0)
**const_z_p_percent** (float, default 0)
**const_i_p_percent** (float, default 0)
**const_z_q_percent** (float, default 0)
**const_i_q_percent** (float, default 0)
**sn_mva** (float, default NaN)
**name** (string, default None)
**scaling** (float, default 1.)
q_mvar. (Multiplies with p_mw and)
**type** (string, 'wye') – wye/delta
**index** (int, None)
**in_service** (boolean)
**max_p_mw** (float, default NaN)
**min_p_mw** (float, default NaN)
**max_q_mvar** (float, default NaN)
**min_q_mvar** (float, default NaN)
**controllable** (boolean, default NaN)
net (pandapowerNet)
bus (int | integer)
p_mw (float)
q_mvar (float)
const_z_p_percent (float)
const_i_p_percent (float)
const_z_q_percent (float)
const_i_q_percent (float)
sn_mva (float)
name (str | None)
scaling (float)
index (int | integer | None)
in_service (bool)
type (Literal['wye', 'delta'])
max_p_mw (float)
min_p_mw (float)
max_q_mvar (float)
min_q_mvar (float)
controllable (bool | float)

Returns:

index (int) - The unique ID of the created element

Return type:

int | integer

Example

create_load(net, bus=0, p_mw=10., q_mvar=2.)

pandapower.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:

created (**net** - The net within this static generator should be)
**bus** (int)
**sn_mva** (float)
**cos_phi** (float)
**mode** (str) - "underexcited" (Q absorption, decreases voltage) – (Q injection, increases voltage)
create_load (same as in)
function (keyword arguments are passed to the create_load)
net (pandapowerNet)
bus (int | integer)
sn_mva (float)
cos_phi (float)
mode (Literal['underexcited', 'overexcited'])

Returns:

index (int) - The unique 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).

Input Parameters

net.load

Parameter	Datatype	Value Range	Explanation
name	string		name of the load
bus *	integer		index of connected bus
p_mw*	float	\(\geq 0\)	active power of the load [MW]
q_mvar*	float		reactive power of the load [MVar]
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	\(\geq 0\)	scaling factor for active and reactive power
in_service*	boolean	True / False	specifies if the load is in service.
type*	String	wye/delta	Connection Type of 3 Phase Load(Valid for three phase load flow only)
controllable**	bool		States if load is controllable or not, load will not be used as a flexibilty if it is not controllable
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):

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{align*} z_{const_p} =& const\_z\_p\_percent / 100 \\ z_{const_q} =& const\_z\_q\_percent / 100 \\ i_{const_p} =& const\_i\_p\_percent / 100 \\ i_{const_q} =& const\_i\_q\_percent / 100 \\ p_{const_p} =& (100 - const\_z\_p\_percent - const\_i\_p\_percent) / 100 \\ p_{const_q} =& (100 - const\_z\_q\_percent - const\_i\_q\_percent) / 100 \end{align*}

The load power values are then defines as:

\begin{align*} 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{align*}

Result Parameters

net.res_load

Parameter	Datatype	Explanation
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 \(Q_{load}\).