Exam text content

Tampere University Modeling and Analysis in Power Electronics DEE-34107 6.2.2020
Electrical Engineering Unit
Henrik Alenius, Teuvo Suntio Programmable calculator is allowed

Note: The answers can be given either in English or Finnish.

Ouestion 1. The transfer function of a certain system is given below. Each guestion below will give 2 ptsif
the answer and its justification are correct.

a) Whatis the order of the system? (Justify your answer)
b) Is the system stable? (Justify your answer).
€) Is the system critically damped? (Justify your answer)

s? +5-9.66-10* +6.72-107

G(5)=
() s? -30.3+5-21431+1.74-107

Ouestion 2. The set of transfer functions of a second-order switched-mode converter, which operates
in CCM, can be given in a general form as shown in Fig. 1. Bach guestion will give 2

pts.

a) Compute the output impedance of the converter.
b) Compute the input-to-output transfer function of the converter.
c) Compute the control-to-output-voltage transfer function of the converter.

 

 

Fig. 1

 

Ouestion 3. Fig. 2 shows two-port network model of a switched-mode converter in general. Construct the
corresponding input-to-output variable representation of the dynamics of the converter with
correct input and output-variable vectors connected by the corresponding transfer functions. The
correct input and output variable vectors will give 2 two points and the correot transfer function
matrix 4 points.

 

Fig. 2

102)
Tampere University Modeling and Analysis in Power Electronics DEE-34107 6.2.2020
Electrical Engineering Unit
Henrik Alenius, Teuvo Suntio Programmable calculator is allowed

Ouestion 4. Fig. 3 shows the single-section LC filter with the component definitions, where the resonant
freguency and the maximum value of the magnitude are given below in terms of the standard
second-order system.

a) Compute the transfer function of the output impedance of the circuit (2 pts)

b) Compute the characteristic impedance of the circuit (1 pt)

c) Compute the resonant freguency of the circuit in Hz (1 pt)

d) Compute the maximum value of the output impedance of the circuit in Ohms (2 pts)

o 1
[€ n 0 - =222 |G ==.
(5) Nes a 1-20? | Ax % 1-7

Ta +520, + &

 

Fig. 3

22)