function that applies the parabolic interpolation method

The torque transmitted to the induction motor is a function of the slip between the rotation of the stator field and the speed of the rotor s, with the slip defined as , where n is the number of revolutions per n seconds from the stator (stator speed) and nR is the rotor speed. By applying Kirchhoff's law, the relationship between torque and slip can be represented by the following equation:

A. Create a function that applies the parabolic interpolation method (e.g. parabolicmin.m), to look for extreme values.

B. Create a program to determine the slip value of s to obtain the maximum T torque, with 0 ≤ s ≤ 10, which calls the above function a) (parabolicmin.m) and also include another method in the program, namely the built-in Matlab function: fminbnd as a comparison.

[Steven Lord]

This sounds like a homework assignment. If it is, show us the code you've written to try to solve the problem and ask a specific question about where you're having difficulty and we may be able to provide some guidance.

If you aren't sure where to start because you're not familiar with how to write MATLAB code, I suggest you start with the free MATLAB Onramp tutorial to quickly learn the essentials of MATLAB.

If you aren't sure where to start because you're not familiar with the mathematics you'll need to solve the problem, I recommend asking your professor and/or teaching assistant for help.

Answer 1

[Sam Chak]

Hi @Miftahul Jannah,

Can you provide the parabolicmin.m file?

help parabolicmin

parabolicmin not found.

Use the Help browser search field to search the documentation, or
type "help help" for help command options, such as help for methods.

By the way, you should be able to visually determine the extrema from the basic plot.

s = linspace(0, 10, 1001);
T = (15*s.*(1 - s))./((1 - s).*(4*s.^2 -3*s + 4));
plot(s, T, 'linewidth', 1.5), grid on, xlabel('s'), ylabel('T')