analysis of electric machinery and drive systems third edition pdf

Those familiar with previous editions of this book will fi nd that this edition has been
expanded and modifi ed to help meet the needs of the electric machinery, electric drives,
and electric power industries. Like previous editions, reference-frame theory is at the core of this book. However, new material has been introduced that sets the stage for machine design.

In particular,in Chapter 2 , the winding function approach is used to establish the rotating air-gap
magnetomotive force and machine inductances, including end-turn winding effects. In addition, an introduction to machine design is set forth in Chapter 15 . These two new chapters, combined with reference-frame theory-based machine analysis, add a signifi – cant dimension not found in other texts.

Another major change is set forth in Chapter 8 , wherein the standard linear and
reduced-order machine equations are derived and a section has been added on the
method of analysis referred to as voltage behind reactance . This new formulation of
the machine equations is especially useful in the analysis and modeling of electric
machines that are coupled to power electronic circuits.

Consequently, this technique has become a useful tool in the electric power and electric drives industries. There are other, less major, changes and additions in this edition that warrant
mentioning. In Chapter 1 , the electromagnetic force (torque) equations are derived without the need of numerous, involved summations that have plagued the previous approach.

This straightforward approach is made possible by the identifi cation of a
second energy balance relationship. Also, the chapter on reference-frame theory has
been augmented with transformations that apply when the three-phase currents, currents, and fl ux linkages sum to zero. Although this is not the case if a third harmonic
is present, it is quite common, and the transformations are helpful in cases where the
neutral is not accessible, and only the line-to-line voltages are available.

Calculation of operational impedances is given in Chapter 7 . Added to this material
is a generalized approach of determining machine parameters from machine measurements. An interesting combination of Park ’ s approach to the derivation of the torque relationship and reference-frame theory is set forth in Chapter 6 . In the previous editions the synchronous machine was analyzed assuming positive current out of the machine, convenient for the power system engineer.

Unfortunately, this approach is somewhat frustrating to the electric drives engineer. The
chapter on synchronous machines has been modifi ed in an attempt to accommodate
both drive and power system engineers. In particular, the analysis is fi rst carried out
with positive currents into the machine and then with the current direction reversed.