Switch

Create Function

pandapower.create.create_switch(net, bus, element, et, closed=True, type=None, name=None, index=None, z_ohm=0, in_ka=nan, **kwargs)

Adds a switch in the net[“switch”] table.

Switches can be either between two buses (bus-bus switch) or at the end of a line or transformer element (bus-element switch).

Two buses that are connected through a closed bus-bus switches are fused in the power flow if the switch is closed or separated if the switch is open.

An element that is connected to a bus through a bus-element switch is connected to the bus if the switch is closed or disconnected if the switch is open.

INPUT:

net (pandapowerNet) - The net within which this switch should be created

bus - The bus that the switch is connected to

element - index of the element: bus id if et == “b”, line id if et == “l”, trafo id if et == “t”

et - (string) element type: “l” = switch between bus and line, “t” = switch between

bus and transformer, “t3” = switch between bus and transformer3w, “b” = switch between two buses

OPTIONAL:

closed (boolean, True) - switch position: False = open, True = closed

type (int, None) - indicates the type of switch: “LS” = Load Switch, “CB” = Circuit Breaker, “LBS” = Load Break Switch or “DS” = Disconnecting Switch

z_ohm (float, 0) - indicates the resistance of the switch, which has effect only on

bus-bus switches, if sets to 0, the buses will be fused like before, if larger than 0 a branch will be created for the switch which has also effects on the bus mapping

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

in_ka (float, default None) - maximum current that the switch can carry

normal operating conditions without tripping

OUTPUT:

sid - The unique switch_id of the created switch

EXAMPLE:

create_switch(net, bus = 0, element = 1, et = ‘b’, type =”LS”, z_ohm = 0.1)

create_switch(net, bus = 0, element = 1, et = ‘l’)

Input Parameters

net.switch

Parameter	Datatype	Value Range	Explanation
bus*	integer		index of connected bus
name	string		name of the switch
element*	integer		index of the element the switch is connected to: - bus index if et = “b” - line index if et = “l” - trafo index if et = “t”
et*	string	“b” - bus-bus switch “l” - bus-line switch “t” - bus-trafo “t3” - bus-trafo3w switch	element type the switch connects to
type	string	naming conventions: “CB” - circuit breaker “LS” - load switch “LBS” - load break switch “DS” - disconnecting switch	type of switch
closed*	boolean	True / False	signals the switching state of the switch
in_ka*	float	>0	maximum current that the switch can carry under normal operating conditions without tripping

*necessary for executing a power flow calculation.

Electric Model

Bus-Bus-Switches:

Two buses that are connected with a closed bus-bus switches are fused internally for the power flow, open bus-bus switches are ignored:

This has the following advantages compared to modelling the switch as a small impedance:

• there is no voltage drop over the switch (ideal switch)

• no convergence problems due to small impedances / large admittances

• less buses in the admittance matrix

Bus-Element-Switches:

When the power flow is calculated internally for every open bus-element switch an auxilary bus is created in the pypower case file. The pypower branch that corresponds to the element is then connected to this bus. This has the following advantages compared to modelling the switch by setting the element out of service:

• loading current is considered

• information about switch position is preserved

• difference between open switch and out of service line (e.g. faulty line) can be modelled

Closed bus-element switches are ignored:

Result Parameters

net.res_switch

Parameter	Datatype	Explanation
p_from_mw	float	active power from bus [MW]
q_from_mvar	float	reactive power from bus [MVAr]
p_to_mw	float	active power to element [MW]
q_to_mvar	float	reactive power to element [MVAr]
i_ka	float	current on switch [kA]
loading_percent	float	loading of switch in percent of maximum current [%]