Part 2- 2
                  Seamless discussion of dynamic 
                  control and encoder-less operation
                                      T
                                        Load
                                            0                                                   t
                                        
                                          m
                                            0                                                   t
   ©Copyright Ned Mohan 2005, by         ©Copyright Ned Mohan 2005, by 
      permission from MNPERE                permission from MNPERE
                                                                                                 Part 2- 3
                What is an Electric-Motor Drive?
                                                 Electric 
                                                  Drive
                                          Power 
                                       Processing            Motor                        Load        
                          fixed        Unit (PPU)
                          form
          Electric Source                         adjustable       speed /
                                                     form          position
              (utility)
                                                            Sensors
                                      Controller                 measured                Power
                                                               speed/ position           Signal
                                                 input command 
                                                 (speed / position)
                                  - Harnessing of Wind Energy
   ©Copyright Ned Mohan 2005, by  -     ©Copyright Ned Mohan 2005, by 
                                          permission from MNPERE
     permission from MNPERE        Hybrid Electric Vehicles
                                                                                                                                                                                Part 2- 4
                                                Power Processing Unit
                                           aa                                                                              aa
                                                                                                                                              bb
                VV                                     bb                                                                                                          cc
                  dd
                                                                 cc                                                                                                                                               
                                                                                                VV                                                                                 
                                                                                                     dd
                                                                                                                                                                               aaccmmoottoorr
                                                                                                     
  vv            ((tt))
   ccoonnttrrooll,,aa                 qq ((tt))    qq ((tt))   qq ((tt))
                                        aa           bb          cc
                                                                                                                      dd ((tt))           dd ((tt))           dd ((tt))
  vv            ((tt))                                                                                                  aa                  bb                  cc
   ccoonnttrrooll,,bb
 vv            ((tt))
   ccoonnttrrooll,,cc
             vv   ((tt))
              ttrrii
               Reference Book: First Course on Power Electronics by Ned Mohan, published 
               by MNPERE (See www.MNPERE.com for details).
    ©Copyright Ned Mohan 2005, by                                       ©Copyright Ned Mohan 2005, by 
          permission from MNPERE                                             permission from MNPERE
                                                                                                                                 Part 2- 5
                           Equivalent Windings in A Squirrel-Cage Rotor
                                 b axis
                         B axis                                                         Stator
                                                               m
                                     ib                                                 i (t) i (t)i (t) 0
                                                                  A axis                a        b         c
                                                              m                                3
                                        iB                         a axis              L  L
                                                i                                         m          m,1 phase
                                                A      i                                        2
                                             i          a
                                             C                                           L L L
                                                                                          s       s      m
                                        ic
                               c axis
                                      C axis                                             Rotor
                                         (a)            i
                         ib                             B                                i   (t) i (t)i (t) 0
                                                                                          A         B         C
                                                                i
                             vb                      vB 0 R      A                              3
                                    R i                        r                         L  L
                                    s  a                                                m          m,1 phase
                                                      vA 0                                 2
                         v        va
                           c                     vC 0                                   L L L
                                                                                          r      r      m
                                                            i
                         i                                    C
                          c
                         Stator circuit                   Rotor circuit
                                          (b) (b)                                       Mutual
                   Figure 2-5 Rotor circuit represented by three-phase windings.       L     L                 cos
   ©Copyright Ned Mohan 2005, by                                                         aA       m,1 phase            m
       permission from MNPERE
                                              Part 2- 6
        Dynamic Analysis of Induction 
       Machines in Terms of dq-Windings
  ©Copyright Ned Mohan 2005, by 
   permission from MNPERE