Design of a dual winding permanent magnet electrical machine for hybrid electrical vehicles using conformal mapping

The main aim of the electrical machine designer should choose the most practical way in order to find out the best performance parameters of the electrical machine. Performance parameters are current density, airgap flux density distribution and electromagnetic moment etc. In order to calculate the fastest and the realistic values of these parameters, most of the electrical machine designers prefer packet programmes that use numerical solution. In these programmes, fabric characteristics of materials are used and rated working condition parameters of electrical machines are determined. Also in these programmes, it is simulated that, distribution of the air gap parameters or a flux density value anywhere in the rotor or magnetic vector potantial value anywhere in the machine are determined for rated working conditions on nominal phase currents. The more complicated of solution done, the more computer performance needed be used. Because, when we want to give the realistic solutions, calculation times of the simulations are strongly raised. Here are many programmes that standing by analytical solutions and that written by computer programmers who write mostly by themselves come up. The most important advantage of analytical solution method is being compact and giving fast result. One another important advantage of analytical method is that geometric and magnetic parameters changing in them can be stated as Fourier series. Because of these characteristics, comparing with finite element analyze, working speed of the programme raises due to supporting the closed form solutions for determining the parameters. On the other hand, using of the analytical method provides a great convenience in order to calculate the electromagnetic moment produced in the airgap of surface mounted synchronous machine basicly and reliably. Basic calculation of airgap electromagnetic torque consists of calculation of the magnet and winding flux densities seperately and determining the total flux density distribution uniformly. At the same time, by knowing the distribution of total flux density distribution described in airgap, it is possible to calculate the back EMFs produced in phase windings. Produced machine contains both motor and generator windings in the same stator core. It can be showed whether these windings effect magnetically each other or not by setting of the boundaries of the distribution of their flux densities in the airgap. For this procedure, analytical method was used as well. If it is thought the general working of this system, proposed dual winding machine being worked in motor mode, when the vehicle's internal combutsion engine is stopped, and will feed the accessories that fed by mechanical power. Electrical loads in the vehicle will be fed by generator windings in dual winding permanent magnet synchronous machine. Thanks to suggested method, with just one electrical machine, both motor and generator operations can be achieved and DC-DC converter requirement will be disappeared, therefore costs of productions will be decreased and it will be gained for volume which is so important for hybride electric vehicles. In this study, complex coordinate system conformal transformation based analytical designing of a dual winding permanent magnet synchronous machine is performed for hybride electric vehicle accessory system. Parameters obtained from analytical solution are comparisioned with the finite element based simulation programme results and manufacturing of the machine is performed. Windings in the magnetic circuit of the machine is designed with fractional slot winding technique. Analytical, numerical and experimental results are verified for advantages and disadvantages of the experimental setup.