Page 207 - Hybrid-Renewable Energy Systems in Microgrids

Sensitivity and transient stability analysis of fixed speed wind generator 187

speed, and turbine speed are stable after the fault for higher value of shaft stiffness.
Because the more the value of the shaft stiffness, the more rigid the system is. On the
other hand, for lower value of shaft stiffness the response of electrical torque, stator
voltage, generator speed, and turbine speed become unstable after the fault. So, it can
be stated that the more rigid system offers better stability margin, whereas lower rigid
system offers lower stability margin.
With the introduction of SDBR the system transient performance improves even
in lower rigid system. Although the shaft stiffness is lower, the SDBR is capable of
increasing the terminal voltage of IG and hereby dissipating the energy and system
remains stable.

Figure 9.28 Stator voltage response.

Figure 9.29 Generator speed response.