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Energy storage devices have become an important part of many mobile applications, such as conventional, electric or hybrid electric vehicles. For an optimal and efficient system design, simulation models have become an inevitable tool. Accuracy over a wide range of operating conditions is very important. However, electrochemical storage devices are strongly nonlinear and often show inhomogeneous current distribution leading to performance and lifetime limitations. Keywords -Battery model, electric vehicle, electric drive train, impedance-based model, lithium-ion battery. I. INTRODUCTIONVarious simulation models for batteries and other electrochemical storage systems exist for a wide range of applications. Typical applications are the design and dimensioning of battery driven or supported systems, battery development or battery and energy management systems. In the first case, the simulation model is an important tool e.g. to evaluate suitable battery technologies, to find suitable dimensions in volume, weight and electrical properties, to test if system and battery are compatible in all operating conditions, to test charge procedures or resulting current profiles from drive cycles and to predict the lifetime of a battery in a certain application. For battery and energy managements, a battery model is necessary to predict the condition of the battery, e.g. state of charge (SOC) or state of health (SOH), and if the battery will be able to deliver the power for a certain operation, state of function (SOF). Depending on aims and requirements of use, different kinds of models are needed. The realisation of a model is always a compromise between precision and computation time.In this paper, a lithium-ion battery model is used to evaluate the suitable size of a pack for an electric-vehicle drive train.

This paper describes a method to operate a switched reluctance machine (SRM) sensorless with a precise position estimation but without the necessity of a prior known machine characteristic. When a machine is connected to the inverter for the first time, an initialization sequence is started to determine the inductance profile of the machine automatically. Within this sequence the machine is started and the inductance of all phases is recorded over time while the machine is rotating. From the data the rotor position is extracted and linked to the recorded inductance values. The data is finally merged to one inductance profile, which is used for controlling the machine. Only information about the machine configuration, the maximum allowable machine speed and phase currents must be provided. The proposed method was implemented on a test bench and verified with a 2 kW four-phase SRM using direct average torque control (DATC).

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This paper presents a topology of an onboard charger with direct grid connection for battery electrical vehicle in which the system components are adapted and optimized by integrating the electrical machine and the voltage source inverter of the traction drive into the charging strategy. The particular safety issues concerning the impact of the common mode voltage in the charging operation are pointed out and its solution of integrating a filter capacitor between the protection earth conductor and the neutral conductor is described. A system simulation model including the electrical components and the control strategy is discussed. An integrated loss calculation of the power electronic components in the simulation model enables the analysis of the efficiency of the introduced on-board charger. Based on the simulation results a design of the electrical machine and the filter capacity can be performed to discuss the packaging issues of the concept introduced.