Switch

Create Function

pandapower.create_switch(net, bus, element, et, closed=True, type=None, name=None, index=None)

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

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

Two buses that are connected through a closed bus-bus switches are fused in the power flow if the switch es 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 this transformer 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 3-winding transformer, “b” = switch between two buses

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

OPTIONAL:
name (string, default None) - The name for this switch
OUTPUT:
sid - The unique switch_id of the created switch
EXAMPLE:

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

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 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

*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:

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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:

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