Gesamtsystemoptimierung eines Antriebs für batteriegespeiste Elektrofahrzeuge

Research output: ThesisDoctoral Thesis

Abstract

For the dimensioning of the power train a modelling of the vehicle was done before. Thereby all requirements for electrical vehicles in terms of forces, speeds, voltages, currents, powers and energies could determined. For the battery a modelling was done too. The result was a fully automatic computer-controlled battery tester. With the above requirements the power inverter could be designed, the main part of the dissertation in the hardware is the development of a new power inverter. In particular, a new power inverter topology for electric vehicles was introduces. Thus we obtain the additional degree of freedom of variable DC link voltage. This allows the system efficiency can be improved especially at lower output voltages. In addition, the battery can be divided: If in one part a cell fails, we can drive on with the other parts of the battery. For the power inverter a new cooling plate was developed. This allows a special two-sided construction together with optimized low inductive configuration (laminations). This results in low switching surges (good utilization of the valves) and low power losses. The power inverter is also the battery charger, an additional separated high power battery charger is unnecessary. Matching the power inverter a new 3-phase motor was being considered. The rotor was optimized so that it results in an approximately sinusoidal flux in the machine. The motor is also suitable for grid applications, very high rotating speeds and sensorless control. Much value was placed on the concept of modular hardware. The purpose is, that hardware components (machine, PC/DSP/microcontroller and sensors) are easily exchangeable at several positions (interfaces). In chapter „Modular software“ a new variant for the access to the periphery was introduced. This saves additional – only poorly portable to other platforms – code in the compiler and linker (linkerscript) for mapping records to physical registers. New functions were demonstrated that significantly improve and simplify the work with records (eg 2 values for complex values, 3 values for 3D, 3 values for 3-phase machines, 2 values for d-q-control of 3-phase machines and so on). The main part of the dissertation in the software is a new fix point data type. For most applications for embedded devices this data type will be enough, no other floating or fix point data type is necessary. The requirements for a computer architecture have been accurately described. Also new trigonometric functions for a new optimized possibility for angel specification have been implemented. How to use them is shown for angular measurement. In conclusion the control of the PMSM was considered and how to get out more torque.

Details

Translated title of the contributionSystem optimization of a power train for battery driven electrical vehicles
Original languageGerman
QualificationDr.mont.
Supervisors/Advisors
  • Weiß, Helmut, Assessor A (internal)
  • Schrödl, Manfred, Assessor A (external), External person
Publication statusPublished - 2012