Ain shams University
Faculty of Engineering
Electrical Power and Machines Department
Instructors: Prof. Dr. Mostafa I. Marei
Power Electronics (2) - EPM 352s
Spring 2024
Assignment (1)
DC/ DC Converters
1) A step-down DC chopper is feeding an RLE load where: R=0.25 Ω, L=20 mH,
Vs = 600 V and E=150 V and chopping frequency (f)=250 HZ. For k=0.1 and
k=0.9. Without performing any calculations and only using one of simulation
packages (MATLAB/Simulink - PSCAD):
a. Skitch waveforms of inductor current, switch current, supply current and
load output voltage.
b. Determine:
i. Minimum and maximum load current.
ii. Peak to peak load ripple current.
iii. Average load voltage.
iv. Average load current.
v. Comment on your results.
2) A boost regulator has an input voltage of Vs= 50V. the regulator’s parameters are
L= 0.1 mH, C=50μF, R = 100 ohm and the duty cycle k = 0.6. the switching
frequency has three values (2KHz, 6KHz and 10KHz), For each switch
frequency, without performing any calculations, by using one of simulation
packages (MATLAB/Simulink – PSCAD):
a. Skitch the waveforms of inductor current and load output voltage.
b. Which current mode does this regulator operate in?
c. Determine:
i. The load average output voltage.
ii. The ripple current of inductor ΔI.
iii. The peak current of inductor I2.
iv. The ripple voltage of filter capacitor Δ Vc.
v. comment on the results.