tailieunhanh - Fundamentals of electromechanical energy conversion

Electromechanical energy conversion is achievable in a number of ways. These possibilities rely on different fundamental laws of electrical engineering. As the only method that has importance on the large scale is electromechanical conversion achieved by means of electromagnetic converters, this section is fully devoted to the analysis of basic principles involved in electromagnetic electromechanical conversion. | ENGNG 2024 Electrical Engineering FUNDAMENTALS OF ELECTROMECHANICAL ENERGY CONVERSION CONSIDERATIONS Electromechanical energy conversion is achievable in a number of ways. These possibilities rely on different fundamental laws of electrical engineering. As the only method that has importance on the large scale is electromechanical conversion achieved by means of electromagnetic converters this section is fully devoted to the analysis of basic principles involved in electromagnetic electromechanical conversion. Electromechanical energy conversion is achieved by devices that are usually called electric machines. In principle laws of electromagnetics can be used to design converters with the linear and with the rotary motion. Converters with linear motion are called linear electric machines while those that rely on rotating motion are called rotating electric machines. Vast majority of existing machinery belong to the category of rotating electric machines. These include all the machines used to generate the electricity as well as the most of the machines used in industry to perform some useful work while converting electric into mechanical energy. Linear machines are used relatively rare for somewhat specialised applications. It is for this reason that only rotating electric machines will be dealt with here. Prefix rotating will be omitted and the converters will be called simply electric machines implying that devices under consideration are characterised with rotational movement. Operating principles of electric machines involve two basic laws of electromagnetism namely the law of the electromagnetic induction Faraday s law and the law of force creation in an electromagnetic field Bio-Savart s law . Consider the situation shown in Fig. 1. A conductor is connected to an electric source and it carries current I. It is placed in the magnetic field of certain flux density B which is of course a vector hence the arrow above the symbol in Fig. 1 . .