p12.1 - Transfer function of link G5 and G6

Transfer functions of links

12.1

7.1.2. Transfer function of link G₅

Defined from [L1]

E_fd*_/E_f* (see page 21.2)

E_fd — equivalent stator EMF corresponding to rotor current i_f with open stator winding in steady-state mode.

From page 8.2: E_fd*₌E_fd_/Uб=3.2 pu

	E_fd*
	E_f*

E_fdн

E_fн*

3.2·166·10³

600

= 885

7.1.3. Transfer function of link G₆
According to [L4]

Δi_р(p)

Δi_f(p)

= K_{_ср}·

T_{_кд}p + 1

T_{_ср}p + 1

i_р — reactive current
i_f — excitation current
T_{_кд} and T_{_с}′ — time constants of the damper windings (absent)

K_{_ср} =

J_{_рн}

i_{_вн0} − i_{_в0}

J_{_рн} — reactive current equal to the rated value
i_{_в0} — excitation current at no-load (х. ходу)
i_{_вн0} — excitation current at cosφ=0, J_a=0, J_p=J_{_н}
i_{_вн0} is defined from the diagram in Fig. 5, page 12.2
i_{_вн0} = 4440 A.

In per-unit (relative) units:

G₆ =

ΔJ_p*

Δi_f*

J_{_рн}·i_{_вб}

J_{_б}·(i_{_вн0} − i_{_в0})

1780

4440 − 1400

= 0.59

o.e.