Electrical Circuits

This unit focuses mainly on Alternating-Current (AC) circuit analysis. A revision on DC circuit analysis will be given in the beginning of the semester. Definitions of instantaneous power, the load convention, active electrical circuit elements (sources) and passive electrical circuit elements (sinks) will then be introduced. Time domain voltage-current relationships of ideal capacitors and ideal inductors are explored. These will lead to the calculation of energy storage in a capacitor and an inductor. Analysis of simple RC and RL circuits in time domain will then be covered. Steady-state sinusoidal analysis of series RL, RC, and RLC circuits will be performed with phasors and complex numbers. The concepts of impedances, admittance, average power, RMS values, and crest and form factors will also be covered. The Nodal Voltage Method, the Principle of Superposition, Thevenin’s Theorem, Norton's theorem, and equivalent circuits will be emphasised. For applications in the power engineering area, students will learn to calculate real power, reactive power, complex power, and power factor along with power factor correction for single phase and balanced three-phase circuits.