EEC 426 Modelling and Simulation in Power Systems Exam 2022

About this paper

EEC 426: Second Semester Examination for EEC426, Modelling and Simulation in Power Systems, College of Technology, University of Buea, June 2022. The paper opens with a theoretical part: Exercise 1 asks for the name of the Simulink-based software used in the course, the two procedures used to run it, and five of its libraries. Exercise 2 presents ten Simscape Electrical block icons (scope, switch/breaker contacts, pulse source, Vabc/Iabc measurement block, a three-phase coupled-coil transformer block with Yg-Yg winding, a parallel RLC-to-ground block, a three-phase voltage source in series with RL branch, a series RC block, and a power (P,Q) measurement block) and asks the student to name each block. Problem 1 is a short-transmission-line modelling question: given a 220 kV, 60 Hz, 40 km three-phase line with resistance 0.15 ohm/km and inductance 1.3263 mH/km (negligible shunt capacitance), the student must propose a Simulink short-line model to find sending-end voltage and power, voltage regulation, and efficiency when supplying 381 MVA at 0.8 lagging power factor, 220 kV at the receiving end. Problem 2 is a classic three-bus power-flow case study: given a one-line diagram with generation at bus 1 (V1=1.05 pu), scheduled loads at buses 2 and 3, and line admittances y12=10-j20, y13=10-j30, y23=16-j32 pu on a 100 MVA/25 kV base at 50 Hz, the student must compute actual R and X (or admittance-derived capacitance) between each bus pair, draw the Simulink circuit diagram, and fill in parameter dialogs for the Three-Phase Source, Three-Phase V-I Measurement, and Three-Phase Parallel RLC Load blocks shown in an accompanying figure.