Power electronics circuits of hybrid electric vehicle modelling with generalized state-space averaging method

Hybrid Electrical Vehicles (HEVs) are defined as a vehicle, where its energy is provided by two or more energy sources and one of these sources has to be an electrical energy in hybrid electrical vehicle. Firstly a brief history of electrical and hybrid electrical vehicles and their historical developments are mentioned in this thesis. After that, subsystems of hybrid electrical vehicles using and HEVs structure are explained in detail. Power electronics circuits are used for control and realization of transfer operations in subsystems of HEVs. These are periodic time-variant systems because of their switching operation. Therefore, converters have non-linear characteristic as dynamic behavior. Analysis and design of such systems is rather difficult. In this case, modeling and simulation is becoming one of the most important elements of power electronic circuit?s analysis and design process. In this thesis, DC/DC converter topologies have been mathematically analyzed with generalized state space averaging (GSSA) method. The non-linear equations of the system have been converted to a linear state space model by GSSA method. Also, harmonic state variables of the counted signal has been defined and calculated for the next step in this method. In addition, an exact and fast approximation to the system parameters has been achieved. Therefore the non-linearity of the system has been removed thanks to the method. Thus, the relationship between the system state variables is described by using these linear equations. In the last section of the thesis converters have been analyzed using MATLAB SIMULINK program as a sample. Then the same topology has been experimented with generalized state space averaging (GSSA) method. The results of the simulation of the GSSA models have been compared using real-time MATLAB simulations applications. Consequently, the validity of suggested method has been proved in this study.