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In the last few years, the understanding of environmental problems has grown. Car producers – original equipment manufacturers – are aiming to reduce fuel consumption and pollution. In order to fulfil these aims, new technologies have been launched. Many hydraulics systems have been removed and replaced with electric ones, e.g. power steering, water and oil pump, etc. In this paper, an electromechanical subsystem used in an automotive application is analyzed. The subsystem is composed of interior permanent synchronous magnet motor and electronic control unit. The range of mechanical output power for studied system is up to 1 kW. The aim of this paper is to compare electromechanical systems working with different on‐board voltage levels in order to find the optimum balance between motors' and electronics' efficiency. This will help to decrease the total system's weight, the consequence of which will decrease fuel consumption and reduce CO₂ emissions.

During the analysis, the reduced order modelling (ROM) techniques has been applied. First, with utilization of finite‐elemente‐methode the basic motor's parameter like: synchronous inductance and flux per pole as a function of the direct‐axis current and also the quadrature‐axis current are calculated. In the second step, these parameters are used in the system simulation. During this simulation, the maximum torque per ampere control strategy together with ROM techniques was used.

As a result, the performance of the system for different voltage levels has been obtained. Additionally, the important factors for an electromechanical system, such as maximum power density, sizing and cost of the total electromechanical system, have been compared.

The performed comparison shows that the cost optimized system should work with the higher voltage, where the electric motor size is reduced ca. 25 per cent. This result is also valid for different electromechanical systems in an automotive area, e.g. automated manual transmission, engine cooling and electric compressor.

It is the first paper, where electric power steering system design for different on‐board voltage levels has been systematically analyzed and compared. Results from this paper can be also applied to different electromechanical systems mounted in hybrid or electric cars.

An electrical revolution in the automotive sector was decided on at the end of 2008, when the European Parliament passed legislation of lower CO₂ emissions of new cars. This causes and forces the development of alternative concepts of propulsion systems and alternative fuels. These new trends of propulsion technologies such as hybrid and pure electric drive will have an impact on the entire design of cars. The purpose of this paper is to present an evolution of selected fractional horsepower electrical drives used in cars. Analysis of electromechanical components can be divided into two groups: the first one contains the currently used subsystems, e.g. electric power steering system, engine cooling systems, etc.; and the second one presents the development of new components, e.g. electric air‐conditioning compressor and other by‐wire technologies. Additionally, the development and trends of new materials and technologies used in electrical drives for the automotive industry are presented.

Performed analysis based on a review of the literature and the author's own research and experience in the area of electromechanical systems for automotive applications. During motor design, computer numerical simulation method, CAD and experiment were used. The development perspectives in the area of electromechanical systems in automotive area are presented. Additionally, the evolution of fractional horse power electric motors, with the influence of new developments in the area of electric vehicles, are analysed and presented.

The presented analysis shows that a change of technology from brush type motors into brushless is inevitable. Additionally, further miniaturization will be conducted using a higher energy permanent magnet. Furthermore, an increase of efficiency will be achieved by increasing the voltage level from 12 V to 48 V or even higher, e.g. 120 V.

This is the first paper, where, in a comprehensive way, developments of fractional horse power electromechanical systems for electric and hybrid vehicles are presented. The results of this paper can be utilized during the creation of the products' road‐maps in this area.

In order to reduce CO₂ emissions of new cars many hydraulic and mechanical systems like e.g.: water pump, oil pump, power steering, clime compressor have been exchanged with pure electromechanical systems, which are driven only on request. This helps to reduce fuel consumption. This trend requires of utilization of modern brushless electric motors, which are controlled from power electronic control unit – ECU. In today's car can be found between 30 to 150 electric motors. Many of them are still simple brush type with ferrite magnets. Also in this area, drift in the direction of brushless motors can bee seen, because of higher efficiency, longer lifetime, lower noise, better EMC and more controllable torque vs speed characteristic. There are different technological solutions, which can been used in the area of brushless motors in order to reduce size and cost of single component. One major factor of BLDC/AC motor is rear earth permanent magnet material used during production. A magnet material cost could be in the range from 30 percent (basis price 2010) up to 90 percent (basis price 2011) of total material motor cost, depends on actual rear earth material price level. In order to reduce magnet cost, the aim of this paper is to find the most robust motor design, which can be resistant against maximum temperature and phase current amplitude for the same magnet material properties, coercive force – Hcj. This behaviour is called demagnetization property.

Analysis was performed based on review of literature, own theoretical and practical research and experience in the area of electromechanical systems for automotive application. During motor analysis computer numerical simulation method, CAD and experiment were used.

As a result, comparison of different motors' topologies with different properties of magnet materials is presented. The worked out methodology shows very good correlation between simulations and measurements. This work can be used in order to reduce test effort and reduce cost of design.

The presented methodology reduces for new designs test effort and development cost and gives an implication of robust motor topology for demagnetization effects.

It is the first paper where demagnetization effects have been studied theoretically and in laboratory in order to find the most robust design, reduce magnet cost by reduction of dysprosium content and develop simulation procedure for analysis of demagnetizations behaviours of interior and surface permanent magnet.