DC Line

Create Function

pandapower.create_dcline(net, from_bus, to_bus, p_kw, loss_percent, loss_kw, vm_from_pu, vm_to_pu, index=None, name=None, max_p_kw=nan, min_q_from_kvar=nan, min_q_to_kvar=nan, max_q_from_kvar=nan, max_q_to_kvar=nan, in_service=True)

Creates a dc line.

INPUT:

from_bus (int) - ID of the bus on one side which the line will be connected with

to_bus (int) - ID of the bus on the other side which the line will be connected with

p_kw - (float) Measurement value. Units are “kW” for P, “kVar” for Q, “p.u.” for V, “A” for I. Generation is a positive bus power injection, consumption negative.

loss_percent - (float) Standard deviation in the same unit as the measurement.

loss_kw - (int) Index of bus. Determines the position of the measurement for line/transformer measurements (bus == from_bus: measurement at from_bus; same for to_bus)

vm_from_pu - (int, None) Index of measured element, if element_type is “line” or “transformer”.

vm_to_pu - (int, None) Index of measured element, if element_type is “line” or “transformer”.

OPTIONAL:

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.

name (str, None) - A custom name for this dc line

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

max_p_kw - Maximum active power flow. Only respected for OPF

min_q_from_kvar - Minimum reactive power at from bus. Necessary for OPF

min_q_to_kvar - Minimum reactive power at to bus. Necessary for OPF

max_q_from_kvar - Maximum reactive power at from bus. Necessary for OPF

**max_q_to_kvar ** - Maximum reactive power at to bus. Necessary for OPF

OUTPUT:
index (int) - The unique ID of the created element
EXAMPLE:
create_dcline(net, from_bus=0, to_bus=1, p_kw=1e4, loss_percent=1.2, loss_kw=25, vm_from_pu=1.01, vm_to_pu=1.02)

Input Parameters

net.dcline

Parameter Datatype Value Range Explanation
name string   name of the generator
from_bus* integer   Index of bus where the dc line starts
to_bus* integer   Index of bus where the dc line ends
p_kw* float \(>\) 0 Active power transmitted from ‘from_bus’ to ‘to_bus’
loss_percent* float \(>\) 0 Relative transmission loss in percent of active power transmission
loss_kw* float \(>\) 0 Total transmission loss in kW
vm_from_pu* float \(>\) 0 Voltage setpoint at from bus
vm_to_pu* float \(>\) 0 Voltage setpoint at to bus
max_p_kw** float \(>\) 0 Maximum active power transmission
min_q_from_kvar** float   Minimum reactive power at from bus
max_q_from_kvar** float   Maximum reactive power at from bus
min_q_to_kvar** float   Minimum reactive power at to bus
max_q_to_kvar** float   Maximum reactive power at to bus
in_service* bool True/False specifies if DC line is in service

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

Note

DC line is only able to model one-directional loadflow for now, which is why p_kw / max_p_kw have to be > 0.

Electric Model

A DC line is modelled as two generators in the loadflow:

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The active power at the from side is defined by the parameters in the dcline table. The active power at the to side is equal to the active power on the from side minus the losses of the DC line.

\begin{align*} P_{from} &= p\_kw \\ P_{to} &= - (p\_kw - loss\_kw) \cdot (1 - \frac{loss\_percent}{100}) \end{align*}

The voltage control with reactive power works just as described for the generator model. Maximum and Minimum reactive power limits are considered in the OPF, and in the PF if it is run with enforce_q_lims=True.

Result Parameters

net.res_dcline

Parameter Datatype Explanation
p_from_kw float active power flow into the line at ‘from_bus’ [kW]
q_from_kvar float reactive power flow into the line at ‘from_bus’ [kVar]
p_to_kw float active power flow into the line at ‘to_bus’ [kW]
q_to_kvar float reactive power flow into the line at ‘to_bus’ [kVar]
pl_kw float active power losses of the line [kW]
vm_from_pu float voltage magnitude at ‘from_bus’ [p.u]
va_from_degree float voltage angle at ‘from_bus’ [degree]
vm_to_pu float voltage magnitude at ‘to_bus’ [p.u]
va_to_degree float voltage angle at ‘to_bus’ [degree]
\begin{align*} p\_from\_kw &= P_{from} \\ p\_to\_kw &= P_{to} \\ pl\_kw &= p\_from\_kw + p\_to\_kw \\ q\_from\_kvar &= Q_{from} \\ q\_to\_kvar &= Q_{to} \\ va\_from\_degree &= \angle \underline{v}_{from} \\ va\_to\_degree &= \angle \underline{v}_{to} \\ vm\_from\_degree &= |\underline{v}_{from}| \\ vm\_to\_degree &= |\underline{v}_{to}| \\ \end{align*}