(4 marks) Question 4. Consider the circuit shown below, where
i(0)=i_(0)
and
v_(c)(0)=v_(0)
. a) (4 marks ) Write the KVL equation for the system. Hint: recall that
v_(c)=(1)/(C)\int_0^t id\tau +v_(c)(0)
. b) (4 marks ) Define the initial conditions problem. c) (4 marks) Write the problem in Laplace domain. Hint: if you take the Laplace transform of a constant,
K
, the result is the same as the Laplace transform of
Kh(t).L{K}=(K)/(s)
. d) (4 marks) Solve for
I(s)
. Carefully simplify your solution to the form
I(s)=U(s)(N_(1)(s))/(P_(1)(s))+
(N_(2)(i_(0),v_(0),s))/(P_(2)(s))
, where
N_(1),N_(2),P_(1),P_(2)
are polynomial functions of
s,N_(2)
may also depend on
i_(0)
and
v_(0)
, and
U(s)
is the Laplace Transformation of
u(t)
. e) (2 marks) What is the relationship between
P_(1)
and
P_(2)
? f) (20 marks) Use Simulink or any other simulation software you are familiar with to construct a simulation model of the system above. Consider the following cases: \table[[Parameter,Case 1,Case 2,Case 3,Case 4],[L,1,1,1,1],[C,1,1,1,1],[R,4,4,1,1],[i_(0),0,5,0,5],[v_(0),0,0,0,0],[u,h(t),0,h(t),0]] For each case answer the following: i. What are the roots of the polynomial
P_(1)(s)
for
sinC
, where
C
is the set of complex numbers? ii. Find an expression for
i(t)
that is valid for
t>0
. iii. Plot your solution and the output of the simulations. Hint: They should be exactly the same. Consider using dashed lines to make your result visible. g) (2 marks) What happens when the roots of
P_(1)(s)
have non-zero imaginary part?