Out of the following options, the most relevant information needed to specify the real power (P) at the PV buses in a load flow analysis is
solution of economic load dispatch
rated power output of the generator
rated voltage of the generator
base power of the generator
ANSWER
The real power at the PV buses is specified from the solution of economic load dispatch, so the answer is (A).
Official answer: ASource: Official answer key, GATE 2020 EE (IIT Delhi)
At a PV (generator) bus in a load flow study, the specified quantities are the real power and the voltage magnitude . The unknowns are the reactive power and the voltage angle .
The real power at a PV bus is the generator's scheduled active output. This schedule is not fixed by the machine's nameplate. It is the operating point assigned to each unit by the economic load dispatch (ELD) solution, which shares the total demand among the units at least cost.
Check the other options. The rated power output is only a capacity limit, an upper bound on , not the operating value. The rated voltage relates to the specified , not to . The base power only sets the per-unit scale and does not fix .
So the most relevant information needed to specify at the PV buses is the solution of economic load dispatch, which is option (A).
KEY IDEA
At a PV bus, and are specified. is the scheduled generation, which comes from the economic load dispatch. is the voltage set-point.
WATCH OUT FOR
Choosing the rated power output (B). The rating is only an upper limit on generation, while the scheduled is the dispatched value. Likewise, the rated voltage (C) relates to , not to .
From the GATE 2020 EE paper. Every question of this paper · Download the full paper · All 10 Per unit & load flow questions, with notes
