[...]... number of turns in series number of coil turns in series in a single pole Nusselt number number of bars of a coil side in the slot number of turns of compensating winding number of turns of one pole pair number of conductors in each side Nondrive end set of integers set of even integers set of odd integers normal unit vector of the surface rotation speed (rotation frequency) [1/s], ordinal of the harmonic... principle, this vector equation is the basic equation in the computation of the torque for various electrical machines The latter part of the expression in particular, formulated with a current-carrying element of a conductor of the length dl, is fundamental in the torque production of electrical machines Design of Rotating Electrical Machines Juha Pyrh¨ onen, Tapani Jokinen and Val´ria Hrabovcov´ e a ©... of Technology and Helsinki University of Technology have found it necessary to maintain and expand the instruction given in electric machines The objective of this book is to provide students in electrical engineering with an adequate basic knowledge of rotating electric machines, for an understanding of the operating principles of these machines as well as developing elementary skills in machine design. .. [ ], number of bars, number of positive and negative phasors of the phase characteristic impedance of the motor [ ] surface impedance [ ] characteristic impedance [ ] coordinate, length, integer, total number of conductors in the armature winding number of adjacent conductors number of brushes number of coils number of parallel-connected conductors number of conductors in a slot number of conductors... depiction of a phase magnetic voltage [A] peak value of the impulse voltage [V] coil voltage [V] terminal of the head of the U phase of a machine terminal of the end of the U phase of a machine voltage, instantaneous value u(t) [V], number of coil sides in a layer blocking voltage of the oxide layer [V] commutation voltage [V] mean fluid velocity in tube [m/s] volume [m3 ], electric potential depiction of. .. to Come xvii current of the lower bar, slot current, slot current amount [A] classes of electrical machines International Electrotechnical Commission imaginary part current [A], instantaneous value i(t) moment of inertia [kg m2 ], current density [A/m2 ], magnetic polarization Jacobian matrix moment of inertia of load [kg m2 ] moment of inertia of the motor, [kgm2 ] saturation of polarization [V s/m2... magnetizing winding The effects of load currents are analysed later The design of a magnetic circuit of an electrical machine is based on Amp` re’s law (1.4) e and (1.8) The line integral calculated around the magnetic circuit of an electrical machine, that is the sum of magnetic potential differences Um,i , is equal to the surface integral of the current densities over the surface S of the magnetic circuit... terminal of the head of the W phase of a machine terminal of the end of the W phase of a machine magnetic energy [J] length [m], energy per volume unit reactance [ ] coordinate, length, ordinal number, coil span decrease [m] relative value of reactance admittance [S] temperature class 90 ◦ C coordinate, length, step of winding winding step in an AC commutator winding coil span in slot pitches coil span of. .. [m] conductor height [m] tooth height [m] height of a subconductor [m] height of pole body [m] stator slot height [m] height of rotor yoke [m] height of stator yoke [m] electric current [A], RMS, brush current, second moment of an area, moment of inertia of an area [m4 ] induction motor counter -rotating current (negative-sequence component) [A] current of the upper bar [A] conductor current OTE/SPH OTE/SPH... loss [W] number of pole pairs, ordinal, losses per core length aluminium content number of pole pairs of a base winding partial discharge electric charge [C], number of slots, reactive power [VA], average number of slots of a coil group number of free slots number of radii in a voltage phasor graph number of slots of a base winding OTE/SPH OTE/SPH FM JWBK312-Pyrh¨ nen o November 23, 2008 13:4 Printer . 23, 2008 13:4 Printer Name: Yet to Come DESIGN OF ROTATING ELECTRICAL MACHINES i Design of Rotating Electrical Machines Juha Pyrh¨onen, Tapani Jokinen. Hrabovcov ´ a is a Professor of Electrical Machines in the Department of Power Electrical Systems, Faculty of Electrical Engineering, at the University of ˇ Zilina,