27.02.2013 Views

an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

It c<strong>an</strong> be concluded that when the rotor speed is greater th<strong>an</strong> zero, a positive k i value<br />

will enh<strong>an</strong>ce the stability <strong>of</strong> the speed estimator. However, when the rotor speed is<br />

negative, a negative value <strong>of</strong> k i enh<strong>an</strong>ces the system stability.<br />

Since the instability <strong>of</strong> the system is always found at low speed under the generating<br />

condition, the same method is applied to that condition to check the effect <strong>of</strong> k i .<br />

Simulation results for the middle speed <strong>an</strong>d the low speed r<strong>an</strong>ge are given in Figure 10.21<br />

<strong>an</strong>d Figure 10.22 respectively.<br />

Figure 10.21 Pole-zero maps with different k i values ki = −1<br />

or − 3 when ω r1<br />

= −377<br />

rad/s<br />

<strong>an</strong>d ω r1<br />

= −110<br />

rad/s while the slip = - 0.05<br />

404

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!