Storage¶

Create Function¶

pandapower.create_storage(net, bus, p_kw, max_e_kwh, q_kvar=0, sn_kva=nan, soc_percent=nan, min_e_kwh=0.0, name=None, index=None, scaling=1., type=None, in_service=True, max_p_kw=nan, min_p_kw=nan, max_q_kvar=nan, min_q_kvar=nan, controllable = nan)¶

Adds a storage to the network.

In order to simulate a storage system it is possible to use sgens or loads to model the discharging or charging state. The power of a storage can be positive or negative, so the use of either a sgen or a load is (per definition of the elements) not correct. To overcome this issue, a storage element can be created.

As pandapower is not a time dependend simulation tool and there is no time domain parameter in default power flow calculations, the state of charge (SOC) is not updated during any power flow calculation. The implementation of energy content related parameters in the storage element allows to create customized, time dependend simulations by running several power flow calculations and updating variables manually.

INPUT:

net - The net within this storage should be created

bus (int) - The bus id to which the storage is connected

p_kw (float) - The momentary real power of the storage (positive for charging, negative for discharging)

max_e_kwh (float) - The maximum energy content of the storage (maximum charge level)

OPTIONAL:

q_kvar (float, default 0) - The reactive power of the storage

sn_kva (float, default None) - Nominal power of the storage

soc_percent (float, NaN) - The state of charge of the storage

min_e_kwh (float, 0) - The minimum energy content of the storage (minimum charge level)

name (string, default None) - The name for this storage

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

scaling (float, 1.) - An OPTIONAL scaling factor to be set customly

type (string, None) - type variable to classify the storage

in_service (boolean) - True for in_service or False for out of service

max_p_kw (float, NaN) - Maximum active power injection - necessary for a controllable storage in OPF

min_p_kw (float, NaN) - Minimum active power injection - necessary for a controllable storage in OPF

max_q_kvar (float, NaN) - Maximum reactive power injection - necessary for a controllable storage in OPF

min_q_kvar (float, NaN) - Minimum reactive power injection - necessary for a controllable storage in OPF

controllable (bool, NaN) - Whether this storage is controllable by the optimal powerflow

OUTPUT:

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

EXAMPLE:

create_storage(net, 1, p_kw = -30, max_e_kwh = 60, soc_percent = 1.0, min_e_kwh = 5)

Input Parameters¶

net.storage

Parameter	Datatype	Value Range	Explanation
name	string		name of the storage unit
bus*	integer		index of connected bus
p_kw*	float	\(\leq\) 0	Momentary real power of the storage (positive for charging, negative for discharging)
q_kvar*	float		Reactive power of the storage [kVar]
sn_kva	float	\(>\) 0	Nominal power ot the storage [kVA]
scaling*	float	\(\geq\) 0	scaling factor for the active and reactive power
soc_percent	float	0 \(\leq\) soc_percent \(\leq\) 100	The state of charge of the storage
max_e_kwh	float		The maximum energy content of the storage (maximum charge level)
min_e_kwh	float		The minimum energy content of the storage (minimum charge level)
max_p_kw**	float		Maximum active power
min_p_kw**	float		Minimum active power
max_q_kvar**	float		Maximum reactive power
min_q_kvar**	float		Minimum reactive power
controllable**	bool		States if sgen is controllable or not, sgen will not be used as a flexibilty if it is not controllable
in_service*	boolean	True / False	specifies if the generator is in service.

*necessary for executing a power flow calculation
**optimal power flow parameter

Electric Model¶

Storages are modelled as PQ-buses in the power flow calculation:

The PQ-Values are calculated from the parameter table values as:

\begin{align*} P_{storage} &= p\_kw \cdot scaling \\ Q_{storage} &= q\_kvar \cdot scaling \\ \end{align*}

Note

Since all power values are given in the consumer system, negative power models charging and positive activee power models discharging.

Note

The apparent power value sn_kva, state of charge soc and storage capacity max_e_kwh are provided as additional information for usage in controller or other applications based on panadapower. It is not considered in the power flow!

Result Parameters¶

net.res_storage

Parameter	Datatype	Explanation
p_kw	float	resulting active power after scaling [kW]
q_kvar	float	resulting reactive power after scaling [kVar]

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