7.1 Structural diagram of a turbogenerator

10.1

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The structural diagram of a turbogenerator in load mode is shown in Fig. 4. A linearized system of equations [L1] is taken as the basis.

ΔE′q✱ = K3 1+p·K3·T′do · ΔEfd✱ - K3·K4 1+p·K3·T′do · Δδ

ΔMЭ✱ = K1 · Δδ + K2 · E′q✱

ΔUа✱ = K5 · Δδ + K6 · ΔE′q✱

Tj · dω✱ dt = Mизб✱

Torque is expressed in per-unit (p.u.) based on the three-phase power rating, and the d/dt operator is replaced by p. Symbol definitions are provided in Fig. 4.

Main assumptions: neglecting magnetic circuit saturation, stator active resistance, and the influence of damper windings; assuming operation into an infinite bus system.

7.1.1 Transfer function of Gв(p) element

We derive it from the relation: Ef = if · Rв + Lв ·p ·if Rв and Lв - resistance and inductance of the excitation circuit.

if·Rв Ef

=

1 1+p·Lв/Rв

=

1 p·Tв

In per-unit system (relative units):

if✱ ·ifб ·Rf✱ ·Rfб Ef✱ · Ufб

=

1 1+p·Rв/Lв·Rfб/Lfб