Nowadays, two of the main research objectives are regarding the energy savings and proper management of the energy resources. In energy savings, the apparatus are designed and manufactured in order to reduce the energy consumption. For this purpose the efficiency was increased, i.e. the equipment that provides maximum performance while using minimum energy. In electrical machine the efficiency has been improved also, by changing the machine type, structure or improving the control of the machine. Electrical machines started to become simpler, reliable and less expensive in order to improve the selling capability. Synchronous machines are used now for application ranging from high power to low power. From this class of machines Permanent Magnet Synchronous Machines (PMSM) are very advantageous and challenging. This book, therefore, investigate the nonlinear phenomenon in buried permanent magnet synchronous machine. The inductance variation is investigated and Field Oriented Control is implemented and tested. IPMSM model based on laboratory data which include saturation is done. For validating the control, the laboratory and simulations results are compared.