OVERVIEW

During the course of their work, graduates will easily have to design, manage or simply use measurement systems. Regardless of the context and complexity of the measurement system, the metrology principles to be satisfied are substantially similar. In particular, aspects related to electrical energy, interaction with electrical networks (also from a smart grids perspective), evaluation of the characteristics and performance of electrical systems and components, etc. will be explored in detail.

The course therefore intends to provide the basis for approaching a metrological requirement and for processing the data obtained from measurements.

AIMS AND CONTENT

LEARNING OUTCOMES

Acquire knowledge of the basic elements for carrying out electrical measurements mainly in the industrial sector and on site.

AIMS AND LEARNING OUTCOMES

Students will be able to:

- plan a measurement and know the most suitable instrumentation to carry it out; examples of measurements: resistance or impedance measurements, electrical insulation measurements, power and power quality measurements;

- statistically treat the measurement results with a view to verifying and evaluating uncertainty; examples: management of outliers, evaluation of dispersion, sample representativeness, Type A and Type B approaches to uncertainty evaluation;

- process the results with simple signal processing techniques, such as Fourier analysis and signal power, filtering, correlation.

PREREQUISITES

Solving AC and DC electrical circuits, both with symbolic, phasor and time domain methods.

Concepts of impedance, admittance, power (active and reactive), harmonics.

Basic mathematical functions, Fourier analysis (Fourier series).

Risoluzione di circuiti elettrici in CA e CC, sia con metodi simbolici, fasoriali e nel dominio del tempo.

Concetti di impedenza, ammettenza, potenza (attiva e reattiva), armoniche.

Funzioni matematiche di base, analisi di Fourier (serie di Fourier).

TEACHING METHODS

Lectures with slides and blackboard (about 48 hours), interactive Matlab use and exercises (about 8 hours), laboratory (about 4 hours).

SYLLABUS/CONTENT

The course is divided into 5 parts:

1) Concepts of probability and statistics, applied to problems of analysis of measurement results: random variables (continuous and discrete), probability distributions and main properties (mean, dispersion, higher order moments); combinations of r.v. (joint and conditional probability), histograms, central limit theorem.

2) Principles of metrology: measurement system and model, errors or deviations, estimates, confidence interval, uncertainty with application of the concepts of part 1).

3) Sampling, data acquisition and signal processing: signal bandwidth and sampling; discrete Fourier transform; analog/digital conversion, noise and distortion, various forms of signal-to-noise ratio, frequency domain analysis, signal reconstruction; basic concepts of filters; other techniques, such as correlation; practical examples of acquisition and processing with oscilloscope and Matlab;

4) Instrumentation and measurement systems: voltage-amperometric, bridge, etc. measurement principles; examples of instruments and related operating principles (multimeter, oscilloscope, power meter); sensors and measurement chains: sensor parameters and performance, examples for temperature and electrical quantities;

5) Examples of measurements: low value and high value resistance measurement, insulation measurement, power measurement, impedance measurement.

RECOMMENDED READING/BIBLIOGRAPHY

Course notes in the form of slides partially in Italian and English.

Textbooks:

i) John Taylor, An Introduction to Error Analysis, 2nd ed., University Science Books, California, 1997. ISBN: 0-935702-42-3

ii)  Douglas C. Montgomery and George C. Runger, Applied Statistics and Probability for Engineers, 5th or 6th ed., Wiley, 2010-2013. ISBN: 978-1118539712

iii) JCGM 100, Evaluation of measurement data — Guide to the expression of uncertainty in measurement, 2008

Other texts like excerpts, manuals or papers will be provided in the classroom, made available through AulaWeb or a web-link.

TEACHERS AND EXAM BOARD

Exam Board

ANDREA MARISCOTTI (President)

MICAELA CASERZA MAGRO

FABIO D'AGOSTINO

LUIS RAMON VACCARO (President Substitute)

LESSONS

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Written exam with 3 free-response questions and related weights. Total score 30.

Short oral exam to discuss the answers provided and the calculations performed.

ASSESSMENT METHODS

The exam questions are "problems" or "exercises", divided into a more general part (which tests knowledge for the theory part) and one with numerical values assigned to the parameters and calculations to be carried out (this part verifies that the student be able to apply the theory, and in some cases may require formulating additional hypotheses to fill a deliberately ambiguous detail in the description of the problem).

Exam schedule