Читать книгу Artificial Intelligence for Renewable Energy Systems - Группа авторов - Страница 24

With the increase in magnetizing reactance xmq along q-axis, real part of stator eigenvalue of three- and six-phase generator was decreased by 34.4% and 68.8% (with no variation in stator eigenvalue I), as shown in Figures 1.20a and 1.21a, respectively. A major effect was noted from rotor side. Value of real part of rotor eigenvalue is increasing linearly for both three-phase and six-phase generator. It may be noted that the generator operation becomes unstable at higher value of xmq due to positive value of real part of rotor eigenvalue, as shown in Figure 1.21b. Hence, six-phase generator is more sensitive toward the variation of magnetizing reactance xmq. Also, a linear increase in the value of real eigenvalue II was noted for both three- and six-phase generator as shown in Figures 1.20c and 1.21d, respectively. But in three-phase generator, a higher decrease in real eigenvalue III was found in comparison with six-phase generator as shown in Figures 1.20d and 1.21e, respectively. No variation in real eigenvalue I was found for both three- and six-phase generator, as shown in Figures 1.20b and 1.21c, respectively.

Figure 1.19 Variation in eigenvalue II with damper leakage reactance change along q-axis in (a) three-phase and (b) six-phase generator.

Figure 1.20 Variation in eigenvalue of three-phase synchronous machine with magnetizing reactance change along q-axis (a) stator and rotor eigenvalue, (b) real eigenvalue I, (c) real eigenvalue II, (d) real eigenvalue III.

Figure 1.21 Variation in eigenvalue of six-phase synchronous machine with magnetizing reactance change along q-axis (a) stator eigenvalue I and II, (b) rotor eigenvalue, (c) real eigenvalue I, (d) real eigenvalue II, (e) real eigenvalue III.

Both three- and six-phase generator evaluated eigenvalues were found to unchanged with the variation in magnetizing reactance xmd along d-axis. Hence, it is not presented.