Author 
Comment/Response 
fabian

04/20/07 02:32am
Dear Mathematica Users,
I am new to Mathematica and in the last couple of days got familiar with the standard principles and functions.
Now I am trying to implement a matrix transformation and elimination of the old variables. My basic problem is that I don't know how to implement it in the system. Defining the functions and matrices was not a problem:
eq1 = omega' == (Km ia Sin[N theta] + Km ib Cos[N theta]  B omega)/J
eq2 = ia' == (va  R ia + Km omega Sin[N theta])/L
eq3 = ib' == (vb  R ib  Km omega Cos[N theta])/L
eq4 = theta' == omega
T = {{Cos[N theta], Sin[N theta]}, {Sin[N theta], Cos[N theta]}}
vPark = {vd, vq}
v = {va, vb}
Solve[vPark == T .v, v]
iPark = {id, iq}
i = {ia, ib}
Solve[iPark == T.i, i]
Eliminate[{eq1, eq2, eq3}, {ia, ib, va, vb}]
This is what I have so far. But the last input (Eliminate[{eq1, eq2, eq3}, {ia, ib, va, vb}]) doesn't work. What do I have to do to get my first three equations (eq1, eq2, eq3) wihtout ia, ib, va and vb but with vd, vq, id and iq???
I appreciate any suggestions. Thanks a lot in advance.
Cheers
Fabian
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