This thesis proposes improved techniques for controlling of induction machine based integrated starter alternator in order to achieve the challenging requirements of future automotive on-board power system. The proposed techniques are focused on improving DC voltage regulation, maximum power extraction and efficiency improvements. A new sophisticated DC voltage controller that provides tight voltage regulation is proposed. The proposed controller is based on a linearized model for the combined inverter and induction machine. The proposed DC controller is included with speed and flux decoupling and an antiwindup technique. Extensive simulation and experimental results demonstrate the excellent DC voltage control performance of the proposed DC controller over a wide speed range and under various operating conditions. This thesis proposes an improved field weakening implementation which is based on stator voltage control for maximum power extraction in generation mode. The controllers in proposed implementation included use a non-linear dynamic compensator (NDC), stator frequency decoupling and an anti-windup technique. This thesis investigates and eliminates the oscillation in high speed field weakening region caused when large loads are applied. The proposed implementation also provides better regulation for the stator voltage and stable operation over a wide speed range in the generation mode of the ISA. The proposed implementation allows extracting significant amount of additional power compared to conventional field weakening technique. The simulation and experimental results clearly demonstrate the performance of the proposed implementation for ISA. A new loss minimised control method for the integrated starter alternator based on a loss model of the system was developed. The loss model operates in dq − axes and takes into account the inverter and the machine losses. The experimental results demonstrates that proposed loss minimised control provides significant efficiency improvements under light load condition of the ISA. This thesis also presents complete modeling of ISA, an extensive study on induction machine parameter variations and overall control design of the ISA system. The extensive simulation and experimental studies presented in this thesis clearly demonstrates the development of a new ISA which is low-cost, optimised for high efficiency and maximised power over a wide speed range and excellent DC bus voltage regulation under all conditions of generation.
展开▼
