Improving performance using permanent magnets in synchronous reluctance motors

Electric motors have found a place in every aspect of life, from our smart devices to nuclear power plants. Although they are technologically advanced due to their high use, they contain different areas that need to be developed or that can be developed. 65% of the electricity produced in the world is consumed in electric motors. This rate rises to 70% in our country. In the electricity generation part, 93% is provided from electrical machines. Improvements to be made in an area with such high consumption and production globally will have a huge impact both economically and environmentally. As a result of both the increase in technology and need and the proliferation of electric vehicles, the amount of energy consumed in electric motors will reach serious dimensions. Today, efficiency and longevity have become one of the basic criteria we expect from every product. This also applies to electric motors. For this purpose, improvement studies on existing engines and trial studies of different combinations are ongoing. Magnet Assisted Synchronous Reluctance Motors (MDSynRM), which is one of these studies, has attracted attention recently. The basis of MDSynRM comes from Synchronous Reluctance Motors (SynRM) and Embedded Magnet Synchronous Motors. SynRM rotor has no windings, has a weight advantage thanks to flux barriers, is advantageous in terms of maintenance and cost, and is comparable to conventional motors with developing drive technologies, and it has a place for itself as a preferred motor type according to the application. Due to the low power factor and low power density, which are the disadvantages of the SynRM motor, it makes permanent magnet synchronous motors (PMSM) the leader in the relevant field in areas that require small volume and high performance (eg electric vehicles) or high efficiency. In order to eliminate these disadvantages of SynRM motors, MDSynRM type motors can be obtained by adding magnets to the flux barriers in the rotor. SynRM and MDSynRM type motors use the same stator structure as a standard polyphase electric motor. The main difference of these motors occurs in the rotor part. Its basic logic is based on following the path where the magnetic field formed in the stator will be mixed with the least resistance. Air gap is used in today's engines to provide this. These air gaps are created in a certain order and allow the magnetic field formed in the stator to create torque on the rotor. Since the solution of inductance matrices is long and complex, it is possible to define the rotor structure as d and q axes with certain conversion methods. The d axis defines the direction with the lowest magnetic resistance (Reluctance), while the q axis defines the path with the highest magnetic resistance. SynRM or MDSynRM type motors work according to the d and q axes inductance ratio (Dislocation). The d-axis inductance is high, while the q-axis inductance is small. The high rate of this ratio is important for the performance of the machine. To keep the ratio high, flux barriers are designed in different numbers, shapes and layouts. For MDSynRM, magnets are added to the q-axis of the rotor. In this way, the q-axis inductance reaches an even smaller value. As the flux passing over the q axis will decrease as a result of this decrease, the d axis will also be affected by this situation and its inductance will increase a little. As a result, there is a positive increase in performance thanks to the higher dislocation rate. In this thesis, an existing synchronous reluctance motor is taken as reference. MDSynRM is designed with the dimensions and power of the reference engine. First of all, the reference engine was modeled on package programs and the consistency of the catalog information and simulation results was observed. Then, studies were carried out for rotor design in these dimensions. Optimization studies were carried out on parameters such as the number of flux barriers, their widths, and margins. Although there are designs that give higher performance during these processes, manufacturability, cost and material supply issues are also taken into consideration. After the basic geometry of the rotor was prepared, simulations were carried out by placing magnets in all combinations and different lengths on the barriers. After the rotor design, studies were carried out on the stator. Here, too, optimization studies were carried out on different number of grooves, tooth width, winding type and arrangement. With these studies, a motor design that works with higher efficiency, higher power factor and lower current value and has the same power value as the reference motor has been created.