ELECTRICAL CIRCUIT THEORY
The objective of the course is the definition of the circuit model, the description of its main properties, to give the electrical circuit analysis methods and to represent examples of application to energy and industry.
Learning results (according to Dublin descriptors)
Knowledge and understanding
In terms of knowledge and understanding an adequate knowledge of the circuit model, of its language, properties and analysis methods is expected, with special reference to linear circuits.
Applying knowledge and understanding
In terms of application the capability to analyze and solve linear circuits in all the typical operating modes of stationary, sinusoidal steady state and general dynamics is expected.
In terms of autonomous making judgements the ability to understand a circuit problem, formalize it and building an analysis path leading to the solution n rigorous and effective way is expected, also with the choice of most adequate methods.
In terms of communication skills a good familiarity with circuits language and symbols is expected, allowing the ability to clearly express technical concepts in both written and oral form.
In terms of specific learning skills the ability of usefully consulting technical stuff, integrating it from different fonts is expected, and more in general the ability to deepen autonomously topics of specific interest. Moreover it is expected the ability to elaborate schematize and summarize new acquired contents.
A fruitful exposition to the course topics requires the typical physical-mathematical knowledge of a first year in Engineering. In particular:
- elements of general physics (forces, work, energy, flux, conservation).
- elements of linear algebra (matrices, determinants, systems of linear equations);
- elements of complex numbers algebra;
- elements of mathematical analysis (differential and integral calculus, linear differential equations with constant coefficients);
- The circuit model (10 h lec. + 2 h ex.)
Fundamental electrical circuit quantities. Ideal one-port circuit elements, voltage and current. Kirchhoff’s laws. Energy aspects for electrical circuits: absorbed power, energy. Fundamental one-port elements and their classification.
- Analysis of simple circuits (6 h lec.)
Linear and nonlinear resistive circuit, graphical method of solution, Newton-Raphson algorithm; simple linear dynamical RC and RL circuits, transient and steady-state regime.
- Linear resistive circuits (6 h lec. + 6 h ex.)
Equivalence between two one-ports. Series and parallel equivalence, superposition principle, Thevénin-Norton’s theorem. Delta-Wye equivalence and transformations.
- General circuit properties (6 h lec.)
Graphs and circuit topology. Incidence matrix, loop matrix, Kirchhoff’s Laws in matrix form, linearly independent Kirchhoff’s equations. Fundamental circuit equation system, nodal and mesh current analysis. Electrical power conservation and Tellegen’s theorem. Non-amplification of voltages and currents.
- Linear dynamical circuits in DC/AC steady-state (10 h lec. + 6 h ex.)
Linear circuits in sinusoidal steady-state, phasors, symbolic method, impedance circuits and properties; complex power, average power, reactive power and conservation properties; general impedance two-ports and resonance; linear circuit in periodic and quasi-periodic steady-state. Hints on frequency response of a linear dynamical circuit. Basic aspects of electrical power transmission. Symmetric three-phase circuits.
- Multiterminal circuit elements (6 h lec. + 4 h ex.)
Circuit elements with N terminals, two-ports elements, linear controlled sources, gyrator, ideal transformer; resistive two-ports and their characterization, mutually coupled circuits, transformer.
- Linear Dynamical circuits (8 h lec. + 2 h ex.)
Dynamical circuits: state equations, associated resistive circuit, continuity of state variables, zero-input response, forced response, natural modes, natural frequencies, time constant, transient solution, permanent steady-state solution, dissipative circuits, time-variant circuits, solution of RLC series and parallel circuit, aperiodic and oscillating natural modes, general analysis of RC, RL, RLC second-order circuits. General methods of solution for linear time-invariant dynamical circuits.
- The circuit model
- Linear resistive circuits
- General circuit properties
- Linear dynamical circuits in steady-state
- Multiterminal circuit elements
- Dynamics of linear circuits
- Energy and industrial application examples
Frontal lectures; classroom exercises.
Textbook in Italian:
M. de Magistris, G. Miano, Circuiti: fondamenti di circuiti per l’Ingegneria, Springer, II ed. 2015
Textbook in English:
J. W. Nilsson, S. A. Riedel, Electric circuits 9th edition, Prentice Hall (2010).
The purpose of the examination is to check the achievement of the aforementioned skills, at the same time motivating the student to the best learning goals and giving him/her full consciousness of such achievements.
The evaluation procedure is composed of the evaluation of applicative abilities, that translates in the capability of solving in autonomous way standard problems in linear circuits analysis, and the verification of the acquisition of adequate theoretical mastery of the circuital model, its properties and the main analysis methodologies.
The learning verification, consequently, is typically divided in two different parts (possibly consecutive), where the first one, propaedeutical to the second, consists in the solution in written form of exercises, for which the evaluation is given in three intervals, A, B, C, with the following correspondence in marks (expressed in thirtieths) is as follows: A: 30-27, B: 26-23, C: 22-18.
After passing the exercises test the student will be asked to discuss some topics covered in the lectures, having to prove adequate mastery, connection capability and autonomy. The final mark, expressed in thirtieths, will take into account cumulatively all the acquired evaluation elements.
The different evaluation parts (exercises and theory) could be organized in different way depending on specific circumstances, in presence and remote way, possibly depending on the conditions and available tools. Anyway, for the exercises verification, the proposed exercises have to be all fully solved for passing, and the available time (normally two hours) will be anytime adequate with reference to the number and the difficulty of the proposed exercises.
During the exercises test it is allowed to consult textbooks and formularies. It is not allowed to consult handwritten and photocopy material of any kind. Cell phones and other web terminals should be turned off, with the exception of those possibly needed for communicating with the exam commission.
The discussion of theory topics, regardless of how is organized, will be anyway concluded in interlocutory form with the commission.
Exam booking is mandatory for any scheduled evaluation moment and should be carried out with the usual web tools.
Additional didactic material is available on the e-learning platform of the Engineering Department, at the URL http://edi.uniparthenope.it. Access to the platform occurs through authentication with student credentials.