Various strategies are proposed to date in order to convert CO₂to large diversity of useful chemicals. The following review discusses two important approaches that produce methanol from CO₂. These two includes CO₂hydrogenation and electrocatalytic routes. These processes could recycle CO₂, permitting a carbon neutral, closed loop of fuel combustion and CO₂reduction to prevent a rising concentration of this greenhouse gas in the atmosphere. Besides, intermittent electricity generation can be stored in an energy-dense, portable form in chemical bonds. The present review reports more recent findings and drawbacks of these two processes. The present review study revealed that the hydrogenation process could become readily operational in comparison to electrocatalytic process. The electrocatalytic approach still has serious technical issues in terms of kinetically sluggish multi-electron transfer process during CO₂reduction reaction that requires excessive over-potential, relatively poor selectivity, poor durability in the long term, and the absence of the optimized standard experimental and commercial systems.

The comparison of permanent magnet motors with integer and fractional number of slots per pole and phase was made. The torque developed by the motor and the torque ripples level were chosen as the major criterions. The comparison was made according to the results of equations of numerical calculation of magnetic field in active motors volumes using the finite element analysis. The recommendations on the choice of the most suitable option are given.

This article shows the advantages in application of the brushless machines with combine excitation (excitation from permanent magnets and excitation coil) for small and medium power windmills. This type of electric machine is compared with a typical brushless motor and an induction motor. The main advantage is the decreasing of the outline sizes of electric machine and the reduction of price for an electronic control system. The design and the principle of operation of the electric machine are provided. This machine was modeled using Solisworks program to create the design and Maxwell program to analyze the magnetic field. The results of testing are shown too.

This article shows an application of a double source generator for windmills. It is shown the design and the principle of operation of the electric machine. This machine was modeled with using Solisworks program for creating design and Maxwell program for analyzing of magnet field. The result of modeling is shown too.

A new class of brushless electric machines with axial magnetic flux (BMAF) is actively developing for small and medium-power drives. Firstly, they had special and military applications, but now they are widely used in industry. This type of electrical machines becomes competitive with traditional electric machines. Practice makes us develop systems for the optimal design of this class of electrical machines. The Department of Theoretical Fundamentals of Electrotechnology, SUSU, developed a software package for the design of various types of the BMAF, which implements multi-level optimization, analysis of magnetic and thermal fields, solid 3D models, analysis of circuit solutions. The developed complex is a professional design tool, which have to be included in a larger system of end-to-end design system for machines of this class. It allows solving complex tasks for different project situations. Structurally, it consists of two parts. It is a synthesis system and an analysis system. The synthesis system implements the creation of optimal geometry. The analysis system is based on the technology of digital twins. The digital copy of the electric machine is created using the finite element method. This model is used to assess the magnetic and thermal state and correctness of circuit solutions. This article presents the analysis system.

A new class of brushless electric machines with axial magnetic flux (BMAF) is being actively developed for small and medium-power drives. Firstly, they had special and military applications, but now they are widely used in industry. This type of electrical machines is competing with traditional electric machines. Practice makes us develop systems for the optimal design of this class of electrical machines. The article describes a method for the estimation of axial flux permanent magnet synchronous generators with segment magnets and trapezoid coils, based on the charts, calculated with a special program, developed by the Department of Theoretical Fundamentals of Electrotechnology, SUSU. The variables, describing the motor dimensions, are the outer and inner diameters, height of coils and magnets, number of pole pairs. Other parameters depend on these ones or supplied by technology. The developed method of estimation provides a quick-time calculation of the axial motor design in engineering practice. This article presents the main results of this work.