The field of electric vehicles is one of the most popular research topics today. These vehicles require highly efficient and cost-competitive drive system solutions due to the increasing competition. The reluctance motor drive systems are excellent candidates for fulfilling these requirements However, the controlling of these drive systems is difficult as they represent a heavily nonlinear behavior due to the varying stator inductances. The stator inductances are changing both in the function of the stator currents- and that of the rotor position. This phenomenon makes it necessary to apply advanced modelling solutions that provide a more precise motor model for the torque control algorithm. This paper presents a novel motor modeling method for the reluctance motor drive systems. A new type of inductance matrix is derived, which is a critical part of the motor model. This inductance matrix is used to define new relationships for the electromagnetic torque and the phase voltages of the machine for a given stator current, leading to a novel motor model. This new motor model can serve as an input for the torque control algorithm research and development activities.

Electric vehicle applications are one of the most popular topics in the case of electric motor research & development activities. Novel types of electric motor solutions, offering new advantages are gaining significant attention today. Synchronous reluctance motors (SynRMs) have several advantages that are particularly useful in the case of electric vehicle applications. Their lower costs, their robust buildup and their excellent efficiency are all features that are greatly desired in the case of electric mobility applications. However, SynRMs are well known in the literature for producing more torque ripples with the conventional torque control methods. One way to reduce the torque ripples is to use advanced torque control algorithms. The other way is to use optimized motor topologies with the conventional torque control algorithms. The paper aims at the investigation of the motor design concepts that could be applied for reducing the torque ripples of a SynRM drive. It will be analyzed whether the typical relationships and concepts that are used for minimizing the torque ripples in the case of a PMSM can also be applied for a SynRM or not. Simulations will be carried out in JMAG environment to validate the new concepts. The reduced amount of the torque ripples leads to a less amount of audible noise, which can be an advantage in the case of certain electric vehicle applications and for certain customers.

Nowadays, the field of electric mobility is experiencing a rapid evolution. The need for more competitive electric vehicles is affecting the field of electric motor drive systems as well, placing the alternative types of electric motors into the center of research attention. The reluctance motors are one of these alternative motor types, but their highly nonlinear characteristics place a significant burden to their application. The stator inductances are varying in the function of the stator currents, and also in the function of the rotor position due to the magnetically asymmetric rotor structure. This means that the traditional calculation methods for the electromagnetic torque of the machine yield in inaccurate results. Therefore, this paper presents a novel, generalized coenergy-based torque calculation method, which eliminates a significant constraint of the traditional magnetic energy- and coenergy-based torque calculation methods, and considers the highly nonlinear behavior of the machine as well.