Given 3 buses with line impedance, generators and loads provided, where must the protection circuit be allocated?

Thread Starter

Lambo Av

Joined Apr 24, 2019
The 3 buses are
Bus 1: Slack bus with a voltage source of E=1.0 and phase of 0°
Bus 2: a generator and a load.
Bus 3: a load.

The line impedance are given below:
z12 = 0.05 + j0.1
z13 = 0.02 + j0.05
z23 = j0.05
z11 = -j100
z22 = infinity
z33 = -j40

The generators and loads are given below:
Pg1=0, Qg1=0, Pl1=0, Ql1=0 --> (no power source on the slack bus)
Pg2=2, Qg2=0, Pl2=1, Ql2=1 --> (bus 2. Generator and load)
Pg3=0, Qg3=0, Pl3=3, Ql3=0.5 --> (bus 3. A load)

Where must the protection circuit be allocated to protect the three-bus network above? My guess would be all of the buses need a protection circuit, but that is just a guess. If I am wrong, do you mind pointing out where it should be? Thank you