Power System Operation and Control

6.3 STEADY STATE ANALYSIS

6.3.1 Uncontrolled Case

Consider Fig 6.4 with

 

ΔP_c1(S) = ΔP_c2(S) = 0                    (6.10)

In the case when ∆P_c1 = ∆P_c2 = 0, the speed changer setting is fixed irrespective of whether the load changer is in area 1 and area 2.

Let a sudden change occur at both the areas 1 and 2. In incremental steps ∆P_D1 and ∆P_D2.

Due to load change the frequencies drops by ∆ƒ₁ and ∆ƒ₂. If load increment in the two areas is equal and if the frequency drop is also equal i.e., if ∆ƒ₁ = ∆ƒ₂ = ∆ƒ (ss).

From the block diagram in Fig. 6.4 the incremental increase of generation is written as

We have,

Since ∆ƒ_ss(S) is a steady state ...