The block diagram of a cascade system used to control water level in a steam generator of a nuclear power plant (Wang, 2009) was presented in FigureP6.14. In that system, the level controller, G_LC(s), is the master controller and the feed-water flow controller, G_FC(s), is the slave controller. Consider that the inner feedback loop is replaced by its equivalent transfer function, G_WX(s). Using numerical values in (Wang, 2009) and (Bhambhani, 2008) the transfer functions with a 1 second pure delay are:

Use MATLAB or any other program to:

a. Obtain Bode magnitude and phase plots for this system using a fifth-order Padé approximation (available in MATLAB). Note on these plots, if applicable, the gain and phase margins.

b. Plot the response of the system, c(t), to a unit step input, r(t) = u(t). Note on the c(t) curve the rise time, T_r, the settling time, T_s, the final value of the output, and, if applicable, the percent overshoot, %OS, and mid peak time, T_p.

c. Repeat the above two steps for a pure delay of 1.5 seconds.

Transcribed Image Text:

2.ers 2.es Gfw(s) = S(T,s+ 1) s(25s+ 1) (4s + 1) 3(3.333s + 1) Gwx(s) = GLC(S) = K c + KDs = 1.5(10s+ 1)