HYBRID PHOTOVOLTAIC AND WIND SYSTEMS The portion "Hybrid photovoltaic and wind systems" (2 ECTS), together with the "Solar Photovoltaic Systems" course (6 ECTS) and with "Wind Energy Systems" (2 ECTS), represents the course entitled "Photovoltaic and wind system operation and design" (10 ECTS) that provides knowledge, skills and abilities regarding photovoltaic and wind power systems in grid connection. In particular, this portion of course is devoted to present the procedure to integrate and harmonize the photovoltaic and wind power systems, with appropriate storage systems, in such a way as to meet the global consumption of users for the distribution/transmission lines at regional/national level. The required functions of active power/frequency regulation and reactive power/RMS voltage regulation will be studied for this intermittent power generation. RENEWABLE ENERGY SYSTEMS The portion "Wind energy systems" dedicated to wind power (2 ECTS), together with the "Solar Photovoltaic Systems" course (6 ECTS), represents the course entitled "Renewable energy systems" (8 ECTS) that provides knowledge, skills and abilities regarding photovoltaic and wind power systems. In particular, this portion of course is devoted to present the wind power systems starting from the knowledge of their structure and the understanding of operating principle, in which general aspects of power electronics are included. The knowledge of the wind resource, the skills and the abilities to correctly design the system by the main components, to evaluate the energy production, with the economic analysis of investment, are the main objectives of the course.

HYBRID PHOTOVOLTAIC AND WIND SYSTEMS After passing the exam, the students will acquire the following knowledge and understanding: - the main technologies to convert photovoltaic and wind energy into electricity by power electronic converters, transformers and distribution/transmission lines for the proper grid connection; Then, the students will acquire the following skills and abilities: - the calculation of the power losses, efficiencies and voltage regulation of transformers and distribution lines by using simplified assumptions, valid for a grid with only radial lines; - the calculation of the RMS voltages and voltage angles of transformers and distribution lines by using the power flow (or load flow) analysis, valid for a grid characterized by redundancy (meshed lines) in the connections among its buses. RENEWABLE ENERGY SYSTEMS After passing the exam, the students will acquire the following knowledge: - the main technologies to convert wind energy into electricity by AC rotating generators, power electronic converters, transformers and distribution lines for the grid connection; Then, the students will acquire the following skills and abilities: - the calculation of the wind-speed frequency and the energy productivity, according to the manufacturer power curve and the variations of wind speed (magnitude and direction); - the calculation of the power losses, efficiencies and voltage regulation of AC rotating generators with their power electronic converters; - the calculation of the optimal power ratings of photovoltaic and wind power systems to maximize self-sufficiency and self-consumption of active users, subjected to environmental, electrical and economic constraints in the regions of the installations.

HYBRID PHOTOVOLTAIC AND WIND SYSTEMS Basic knowledge about electric circuit theory (electrical circuit analysis). RENEWABLE ENERGY SYSTEMS Basic knowledge about electric circuit theory (electrical circuit analysis) and applied mechanics.

HYBRID PHOTOVOLTAIC AND WIND SYSTEMS Lectures (about 12 h) Structure of power transformers with on-load tap changers and distribution lines for connection to High Voltage (HV) network with the appropriate protection devices. Operation of the above mentioned components by the corresponding equivalent circuits. The active power/frequency regulation and the reactive power/RMS voltage regulation for an appropriate grid connection of photovoltaic/wind power generation: role of the central controller of the system, according to the standard entitled "Reference technical rules for the connection of active and passive consumers to the HV and MV electrical networks of distribution Company" (CEI 0-16 in Italian language). Calculations of voltage regulation and power losses, between two buses of a line, by simplified assumptions valid for radial lines, in case of photovoltaic/wind generation. Calculations of RMS voltages and voltage angles in the buses by using the power flow (or load flow) study, valid for a grid characterized by redundancy (meshed lines) in the connections among its buses, in case of photovoltaic/wind generation. RENEWABLE ENERGY SYSTEMS Lectures (about 12 h) Energy conversion from wind kinetic energy to mechanical energy of blades (horizontal axis and vertical axis). Aerodynamics of blades: lift and drag forces, thrust and torque components. Coefficient of power vs. tip-speed ratio in a horizontal axis wind turbine: variable-speed operation for maximum power tracking. AC rotating generators and power electronic converters in the variable-speed wind turbines: equivalent circuits of DFIG generators with induction machines and PMSG with synchronous generators. Power transformers for connection to Medium Voltage (MV) grids with proper protection devices: equivalent circuits, voltage regulation and power losses. Factors affecting the energy production of a wind park: wake losses, reliability and availability of wind power systems, deviations from the power curve of the turbine manufacturer, curtailment of wind power. Optimal choice of power ratings of photovoltaic and wind power systems to maximize self-sufficiency and self-consumption of active users, subjected to environmental (slope of the terrain, altitude of the sites, distances from buildings, extreme climatic conditions, ...), electrical (power profiles of consumption, location of point of common coupling, ...) and economic (levelized cost of electricity, net present value of investment, internal rate of return, ...) constraints in the regions of installation.

HYBRID PHOTOVOLTAIC AND WIND SYSTEMS The course is organized with 12 h of lectures (above described) and 8 h of project work in team groups. The team groups consist of 2 to 4 students who are responsible for the writing of design documents regarding: - schematics of photovoltaic generators and wind turbines with power electronic converters for grid connection by transformers and distribution lines (including the central controller of the system); - voltage regulation and power losses within the transformers and the distribution lines at MV and HV levels; - usage of available software for solving the power flow problem in MV or HV networks with low degree of redundancy. RENEWABLE ENERGY SYSTEMS The course is organized with 12 h of lectures (above described) and 8 h of project work in team groups. The team groups consist of 2 to 4 students who are responsible for the writing of design documents regarding: - schematics of photovoltaic generators and wind turbines with power electronic converters for grid connection; - power losses in the energy conversion from mechanical power to electric power for AC generators in variable speed turbines; - power and energy productivity according to the power ratings of generators and the sun/wind resources; - maximization of self-sufficiency and self-consumption for active users with grid/environment constraints, knowing their hourly power profiles of consumption.

HYBRID PHOTOVOLTAIC AND WIND SYSTEMS Teaching documents (handouts on wind power systems and slides on the lectures) on the POLITO portal of the teacher. For deepening, it is suggested to read the book "M. Patel, Wind and Solar Power Systems, 2006, CRC Press, USA”. RENEWABLE ENERGY SYSTEMS Teaching documents (handouts on wind power systems and slides on the lectures) on the POLITO portal of the teacher. For deepening, it is suggested to read the book "M. Patel, Wind and Solar Power Systems, 2006, CRC Press, USA”.

Slides; Dispense; Esercitazioni di laboratorio; Strumenti di collaborazione tra studenti;

Modalità di esame: Prova scritta (in aula); Elaborato progettuale in gruppo;

Exam: Written test; Group project;

... HYBRID PHOTOVOLTAIC AND WIND SYSTEMS The written test lasts 1,25 h and consists of two theoretical questions regarding the knowledge of multiple topics (each one with 10 points) and one exercise regarding the skills and abilities of the "Expected Learning Outcomes" (7 points), like the sample written tests on the portal. The theoretical questions for a total of 20 points require short discussions, drawings and formulas, while the numerical exercise regards the skills and abilities acquired during the classroom exercises for a total of 7 points. Up to additional 4 points may be given by the exam commission as a result of the project-work assessment. The exam is passed if the students reach 18 points as a summation of the scores in the two theoretical questions and in the exercise, without any constraint regarding a minimum score in each of the three parts (theoretical questions and exercise), including the project-work assessment. The "30/30 cum laude" grade can be obtained only if the exam commission gives the maximum grade (4 points), regarding the project-work, and the written test is perfect. It is possible to use a pocket electronic calculator, but it is not permitted to use handouts or notes regarding the program of the course. NO oral test is possible to improve the grade. The space at disposal for the answers, on the single sheet of the written exam (front and back sides), is limited to test the ability of the student to summarize the concepts. RENEWABLE ENERGY SYSTEMS The written test lasts 1.25 h and consists of two theoretical questions regarding the knowledge of multiple topics (each one with 10 points) and one exercise regarding the skills and abilities of the "Expected Learning Outcomes" (7 points), like the sample written tests on the portal. The theoretical questions for a total of 20 points require short discussions, drawings and formulas, while the numerical exercise regards the skills and abilities acquired during the classroom exercises for a total of 7 points. Up to additional 4 points may be given by the exam commission as a result of the project-work assessment. The exam is passed if the students reach 18 points as a summation of the scores in the two theoretical questions and in the exercise, without any constraint regarding a minimum score in each of the three parts (theoretical questions and exercise), including the project-work assessment. The "30/30 cum laude" grade can be obtained only if the exam commission gives the maximum grade (4 points), regarding the project-work, and the written text is perfect. It is possible to use a pocket electronic calculator, but it is not permitted to use handouts or notes regarding the program of the course. NO oral test is possible to improve the grade, The space at disposal for the answers, on the single sheet of the written exam (front and back sides), is limited to test the ability of the student to summarize the concepts.

Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.