Modern development of new technologies, equipment and materials in the field of electric power engineering has allowed a fresh look at the problem of increasing economic efficiency, environmental performance and reliability of electric propulsion for different types of the vehicle drive trains. Considering the higher requirements regarding reliability and fault tolerance, efficiency, ecological parameters and limitations on the installation space and weight of the all traction equipment, the correct choice of type and design features of the electric propulsion drive is extremely important carry out on the basis of a system approach. This paper describes the experience of using stochastic models to assess the operational efficiency of the vehicle electric propulsion systems, consisting of a few generating elements, and one or more traction motors. This type of propulsion system is typical for the icebreakers, arctic cargo ships, diesel-electric locomotives, hybrid cars and aircraft. The deterministic approach does not allow evaluate probabilistic character of operational processes, such as energy output of thermal engines, operational fuel consumption, load modes of traction electric motors, as well as a large number of random factors affecting the accuracy of the simulation results.

Within this paper, an application based comparison of electrical machines will be presented. The constant need of electrical drive trains asks for the appropriate selection of electrical machines regarding application requirements. Applications, such as aircraft, cars, ships, and trains are considered within the comparison and each electric vehicle needs differently weighted parameters. The results show that the selection of the appropriate electrical machine depends on the application case. Furthermore, in most cases there is not only one appropriate machine type, since the focus - which has to be defined in advance for each application respectively - is decisive for comparison.

The problem of improving the reliability and creation of fault tolerant systems is one of the most important in modern technology and engineering. Actually, the complexity of technical systems is increasing, thus the requirements to reliability indices is constantly increasing. Especially the correct assessment as in the design stage as well as in operating conditions is important in order to improve reliability. Modern trends in the electrification of various types of vehicles set up similar tasks for developers and engineers of electric propulsion systems. Considering that the electric propulsion systems are safety critical, very strict requirements are imposed on reliability and fault tolerance to each of their component units, such as traction motor, power electronics, electric power source, and control unit. This paper presents a systematic method of estimation the fault tolerance of a multi-phase permanent magnet synchronous motors based on a multi-level Markov model of the lifecycles for the multi-state system. The impact on the fault tolerance degree regarding the number of phases of permanent magnet synchronous motors is investigated. The practical application of the proposed technique for the multi-phase traction motor and results are presented. Finally, the results of the study allowing fault tolerance assessment and the choice of the most appropriate traction electric motor design considering reliability and fault tolerance are discussed.

Automotive companies are developing hybrid electric vehicles in different ways. There are several system topologies and component configurations used for prototype and mass production. To save time and money during the design process empirical values are necessary. In this paper, the hybridization factor is advanced to a design parameter using well-known characteristics of existing vehicles. In addition, a full vehicle simulation system is used to verify the practical results. A scalable model that is able to vary the hybridization factor is defined and applied. The requirements of machine design and control strategy are also presented. Closing, the similarities and differences of practice and simulation results are discussed.

The paper presents a feasibility study for full-electric aircraft in terms of a conversion design. The advancement of energy storage technologies has given the potential to fully electrify future transport systems. The means of electrifying aircraft are to reduce carbon emission and increase efficiency in air transport. This paper studies the feasibility of developing an all-electric short to midrange aircraft. The study investigates the possibility of replacing the aircraft’s conventional system with an all-electric drive train. Using the current conventional aircraft model, different types of electrical systems are compared to examine their advantages and limitations. The parameters of De Havilland Canada Dash 8 (DH8D) and the average flight are used to analyze the feasibility of completing a desired range. The results show that the electrification of aircraft with the studied propulsion system is not feasible for the conventional range, but producing an all-electric aircraft is possible when the technology allows for it. Additionally, a reliability analysis is conducted for both the conventional and the electrified version of aircraft, including different electric topologies, whereas a multiple electric motor topology is nearly as available as the conventional one.

This paper presents the results of a system analysis of different options for electric inverters for the traction drive of an electrical helicopter. The article explains the optimal choice, in terms of the design requirements and future operation conditions, and the type and topology of electric inverter, to supply the traction permanent magnet synchronous motor from the batteries. The main focus has been given to the study of reliability and fault tolerance of the electric energy inverter. In order to estimate these parameters, the Markov models of the multi-state system reliability evaluation were used.