IN/0026 - MEASUREMENTS ON POWER SYSTEMS
Academic Year 2021/2022
Free text for the University
SARA SULIS (Tit.)
- Teaching style
- Lingua Insegnamento
|[70/89] ELECTRICAL, ELECTRONIC AND COMPUTER ENGINEERING||[89/10 - Ord. 2016] ELETTRICA||6||60|
|[70/89] ELECTRICAL, ELECTRONIC AND COMPUTER ENGINEERING||[89/46 - Ord. 2016] ELETTRICA ON LINE E IN PRESENZA (BLENDED)||6||60|
The course provides the theoretical knowledge and practical skills to carry out the main electrical measurements on power systems.
The lessons include the illustration of the general principles, of details and examples, essential for the translation of theoretical knowledge into concrete actions.
Moreover, practical training in the measurements laboratory is carried out for the assessment of the performance of some devices and equipment.
- knowledge and understanding
Knowledge and understanding of the theoretical fundamental and practical aspects of the measurements on power systems, with focus on digital instruments.
- applying knowledge and understanding
Capability to understand the performance of the basic methodologies and to choose measurement instruments according to technical and economic considerations.
Awareness of the safety aspects in the design of measurement systems.
- making judgements
Capability to interpret correctly the results provided by a measurement system, according to the characteristics of its components Capability to manage the results, by also assessing the possible decisional risks.
- communication skills
Capability to communicate appropriately technical information. Ability to discuss problems and solutions with specialists and non-specialists.
- Learning skills
Capability of continuous learning, through the proper interpretation of scientific and technical literature, manuals of manufacturers and technical standards.
Knowledge of the Courses of Circuit Theory and Electrical and Electronic Measurements are required in particular.
Measurements on three-phase systems (25 hours).
Connection schemes ("Y", star, or "Delta", triangle, with and without neutral conductor). Active and reactive powers. Power measurements in symmetrical systems. Aron's insertion. Reactive power evaluation from wattmetric measurements. Polyphase systems.
Lessons for LabVIEW beginners.
Devices operating in distorted regimes in power grids. New generation of measurement devices based on data acquisition systems. Algorithms and operating parameters.
Energy measurements. Electronic energy meters. Block diagrams and specifications. Remote measurements of electricity. Smart metering and smart meter.
Devices for measurements on power systems (25 hours).
Transformer: ideal and real operating conditions. Equivalent circuits. Instrument transformers. Technical specifications and standards. Errors in the TA and TV. Use of TA and TV. Power measurements with instrument transformers. TA saturation.
Protection Transformers. Specifications and standards. The current transformer under fault conditions, unidirectional and symmetrical components. Choice of protection transformers.
The principles of operation of Hall effect probes. Voltage and current measurements with Hall effect probes.
Programmable electronic relays. Architectures and RMS and DFT algorithms. Processing in DSP. Overcurrent relay.
Tests and measurements on electrical machines and equipment (10 hours).
Types of tests. Data on the nameplate. Standards. Efficiency evaluation: direct and conventional method. Assessment of losses.
Tests on power transformers. Open and short circuit tests. Winding resistance measurement. Return to reference temperature. Additional losses. Polarity check.
Dynamic hysteresis loops. Non-Linearity of the magnetic circuit.
Tests on asynchronous motors. Variable voltage tests. Mechanical measurements of torque speed. Locked rotor test.
- Three-phase network analyzer. Acquisition and measurement of voltages and currents. Virtual instruments.
- Tests on a transformer. Open and short circuit tests. Winding resistance measurement. Dynamic hysteresis loops.
- Tests on an induction motor. Measurement of the electrical and mechanical characteristics. Direct assessment of the performance.
Lectures: 40 hours approximately
Classroom exercises and Laboratory: 20 hours approximately
Verification of learning
The exam consists of three questions.
During the interview, topics also related to the LabVIEW project are discussed first and other course topics are discussed later.
The evaluation takes into account both phases and rewards in particular the ability to expose subjects with rigor and effectively, to link them and to highlight the practical aspects.
The exam score is awarded by a maximum score of 30/30, with a positive evaluation starting from the 18/30 vote, in the case of elementary knowledge / skills.
To achieve a score of 30/30 with honors, the student must demonstrate an excellent knowledge of the topics discussed.
1. Lecture Notes.
2. Standards: CEI 50160, 61869, MID.
3. ARERA consultation documents.
4. Standard Handbook for Electrical Engineers, Donald G. Fink, H. Wayne Beaty, McGraw-Hill, (2012).
Project in LabVIEW environment to support teaching.