Parameter name (unit)

Notation

Steam turbine

Hydraulic turbine

Synchronous reactances (p.u.)

X_d

1.0 - 2.3

0.6 - 1.5

X_q

1.0 - 2.3

0.4 - 1.0

Transient reactances (p.u.)

${X^{\prime }}_{\text{d}}$

0.15 - 0.4

0.2 - 0.5

${X^{\prime }}_{\text{q}}$

0.2 - 1.0

0.2 - 1.0

Subtransient reactances (p.u.)

${X^{″}}_{\text{d}}$

0.1 - 0.25

0.15 - 0.35

${X^{″}}_{\text{q}}$

0.1 - 0.25

0.2 - 0.45

Open circuit transient time constants (s)

${T^{\prime }}_{\text{d0}}$

3.0 - 10.0

1.5 - 9.0

${T^{\prime }}_{\text{q0}}$

0.5 - 2.0

0 - 2.0

Open circuit subtransient time constants (s)

${T^{″}}_{\text{d0}}$

0.02 - 0.05

0.01 - 0.05

${T^{″}}_{\text{q0}}$

0.02 - 0.07

0.01 - 0.09

Stator leakage reactance (p.u.)

X_sa

0.05 - 0.2

0.05 - 0.2

Stator resistor (p.u.)

R_a

0.0015 - 0.005

0.0015 - 0.005

Inertia time constant (s)

T_J

4.0 - 8.0

8.0 - 16.0