Page 250 - Modern Control Systems
P. 250

2 2 4           Chapter  3  State Variable  Models

                            X, I  7                                  1
                                                           1   X =  Xenon  135
                                 \                         I
                                                           1   I =  Iodine  135
                           ? ;


                           I
                                      v  X
                            §  A         1 6
                                      \io

                           I   2
                                             \
                                        1            \
                                       10 15


           FIGURE  P3.20                   1
           Nuclear  reactor                10   15   20   25   30   35    40
           response.                            Time (t) in hours


                                                                                           -o  +
                      K                                                                       Oulput
           V(s)  •       fc      —  4   -K  %   s   Y(s)                         ;Cj   < R 3  ^o  voltage
                               J
                          \
                           V  «1

                                                        FIGURE  P3.22  RLC circuit.
                              «0
           FIGURE  P3.21  Model of second-order system.       Motor and
                                                                valve   1  Valve
                                                         /(.0
              ultimately  varying  the  output  flow  rate. The  system  Input
              has the transfer  function                signal                |  Q,(s)

                                        1                                        ^ ¾
                                                                                  3
                        =  G(.v)                                                    I & M    <2 0 (.v)
                                S 3  +  10J  2  +  31s  +  30
                                                                                            Output
                                                                                             flow
              for the block diagram shown in Figure P3.23(b). Obtain
              a block diagram model  and  a state variable  model.
                                                                            (a)
           P3.24  It  is  desirable  to  use  well-designed  controllers  to
              maintain  building  temperature  with  solar  collector
                                                         /CO                                 Q„U)
              space-heating  systems. One  solar  heating  system  can  Input                Output
                                                         i n p Ut
              be described  by  [10]                     signal   1   am     i   Qii-i)   1   flow
                                                                s  +  5    s + 2       s  + 3
                             =  3.V)  +  Hi  + U%
                          (it
                                                                            lb)
              and
                                                        FIGURE  P3.23  A two-tank system with the motor
                          dx 2                          current controlling the output flow rate, (a) Physical diagram.
                               2*2  +  «2  +  d,
                           dt                           (b) Block diagram.
   245   246   247   248   249   250   251   252   253   254   255