ENEE 474 Power Systems Material covered in this set Use Simulink to simulate a dynamic system Use Matlab to solve the same system Show how a canned program can make things very easy But we might loose the touch needed to solve new problems We may become like some high school students who need a calculator to make change for a dollar The problem simulated A motor driving a high inertia load has a simplified equation of the form s K 3 E s s K1s 2 K 2 s Assuming velocity feedback i e we want to control speed s s s Further simplification The transfer function from voltage to speed s K is then given by E s s K s K Assuming unity velocity feedback is introduced the transfer function becomes 2 1 s K 2 E s s K1s K 2 K If we let K 2 0 we have 2 Further simplification s K 2 E s s K1s K This can be directly simulated with Matlab as well as with Simulink Simulink is in sim2 1 Matlab is in doc2 1 Use of canned routines This can be dangerous Before using a canned program make sure you know the ingredients in the can Also be sure you know the recipe and that you are able to cook it from scratch As example let us run the trans program for transformers canned programs Note that some canned programs will not run inside the Notebook trans m will not run in the Notebook because it requires user input interactive input Now go to Matlab and run trans Parameters for trans 10 kVA 110 4400 V enter data on low voltage side lv OC data 110V 5A 250W SC data 10V 85A 230W Load 10 kVA pf 0 65 lagging 110V Very interesting results but how did the author do it Some last examples Find the root of sin x near x 3 This should be the number pi Find a root of sin x e x 5 0 Please check Go to http www enee umd edu class enee474 and follow the links about the class from there Files to look at You can copy these files to your directory print them etc Please check these files at least twice a week they will be updated often Simulink Motor Model