Shunt elements

Impedances that can be connected beetwen phases, phases and neutral and phases and neutral and ground.

"shunts":[
          {"bus": "Bus_1" , "R": 0.001, "X": 0.0, "bus_nodes": [4,0]},
          {"bus": "Bus_2" , "R":  40.0, "X": 0.0, "bus_nodes": [4,0]}
         ]

where:

• "bus": name of the bus
• "bus_node": list of nodes where the shunt element is connected
• "R": shunt element resistance (Ω)
• "X": shunt element reactance (Ω)