


Politecnico di Torino  
Academic Year 2017/18  
02LONQW Electrical machines 

Master of sciencelevel of the Bologna process in Mechatronic Engineering  Torino 





Subject fundamentals
The course is taught in English.
The aim of this course is to provide and explain the basic concept of the main electrical machine stationary and dynamic models. In addition, the use of these models will be deeply analyzed from the electrical drive point of view. In order to better link the theoretical part with the mechatronic practical ones information on electrical drives and static power converter will be include too. 
Expected learning outcomes
The student will be able to apply the knowledge for getting the following targets: Solve the analysis problems of electrical machines in drive applications. Understand the electrical machine technological specifications for a correct use in electrical drives with particular attention to the mechanical load. A correct use of the electrical machine dynamic model for the simulation og mechatronic apparatus. Electrical drive correct use with reference to the main set ups.

Prerequisites / Assumed knowledge
The course requires the basic notions of electrical circuit solution and electromagnetism. It is opportune but not necessary that the student has follow a basic course of electrical machines.

Contents
Main electrical and magnetic relationships involved in the electrical machines (flux density, electromotive force mechanical forces). Magnetic material classification, saturation phenomena magnetic, hysteresis, losses in electrical and magnetic materials. (7 hours of theory)
DC motor. Notes on the commutation and on the structural characteristics. Basic equations for motor with separate, series and parallel excitation. Mechanical characteristics and speed regulation. Notes on the universal motor. Electrical machines rated values and thermal problems. (8 hours of theory) Single phase transformer, ideal transformer and equivalent circuit of the actual transformer. No load and short circuit test. Equivalent circuit parameter determination. Transformer in parallel connection. Three phase transformer.(9 hours of theory) Three phase induction motor. Galileo Ferraris rotating field. Equivalent circuit in steady state condition. Mechanical characteristic, speed regulation by frequency regulation. Notes on single phase induction motor. Numeric exercises on three phase induction motor. (10 hours of theory) Basic notes on synchronous machine. Isotropic and anysotropic machine. Excitation and reactive power regulation. Torque and active power regulation. Phasor diagram of the synchronous generator. Synchronous reactance concept. Active and reactive power regulation. Parallel procedure on the main. (6 hours of theory + 2 ore in the laboratory) Introduction on the electromechanical conversion. Energy and coenergy concept. Analysis of the linear system in rotational and translation systems. Produced torque in the several electrical machine typologies. (6 hours of theory) Dynamic model of the DC Motor. Block scheme of a Dc drive. Bode diagram and phase margin. Mechanical pole compensation. Speed drive with a DC drive with current loop. Block schemes and related Bode diagram. Basic compensation network. Use of the DC motor dynamic model. (10 hours of theory + 2 hours in the laboratory). Three – two phase transformation. Rotational transformation. (4 hours of theory) Dynamic equation of the induction motor. Equation in stationary reference frame and rotating reference frame and torque equation. Inverter classification. Six Step and PWM inverter and their effects on the motor performances. Open loop drive for induction motor. Slip control drive. Notes on the field orientated control. (8 hours of theory + 2 ore in the laboratory) Dynamic model for the synchronous machine. Equations respect to rotor reference frame. Torque in the several synchronous motor typologies. Electromagnetic torque as interaction between Flux density and magnetomotive force. Notes on sinusoidal brushless and torque control. Trapezoidal brushless and related drive. Notes on the actual current commutation. (6 hours of theory + 2 ore in the laboratory) 
Delivery modes
The course includes simulation and laboratory activities both for stationary and dynamic behaviors of the electrical machines. The student will be able to check the simulation results with laboratory experiments. The simulations will be presented in the ambit of the theoretical lessons. For the laboratory activities the students are divided in groups.

Texts, readings, handouts and other learning resources
The teaching materials are lecture notes prepared by the professor and available at the "Printing center of the Politecnico".
Files will be available on the Portale della Didattica. (Books, to be considered for indepth studies only, will be indicated by the professor). 
Assessment and grading criteria
The exam test is a written test with the scope to verify the student theoretical knowledge. The written test includes two questions evaluated 15/30 each. The final grade is determined averaging the two student answers

