Control Of Integrated Starter Alternator System For Vehicle

The rapid development of hybrid vehicles with low emissions, low energy consumption, energy optimization, was promoting by Oil crisis and environmental pollution. Simplify the control system and the utilization of renewable energy technology research is the development trend of ISA,who has become the key components of most hybrid vehicles. The control strategy of ISA system was studied in this paper.Firstly, in this paper, only a converter and a interior permanent magnet synchronous motor with lower rated speed were used in the ISA system Compared with other ISA system,Who uses multiple motors and multiple converters, system cost and reduces the volume of space were saved. However, the algorithms must be optimized to get the system to the success of control. Some methods of measuring motor parameters were introduced to in this paper. The motor parameters of ISA system were measured by a special method of those and Laboratory equipments. The motor parameters are the key to successful operation of the control system.Secondly, mathematical model of IPMSM was analyzed on the basis of ISA system. This is the basic theory of control systems. And then, the rotor position observer method was proposed based on the flux observer. The rotor position was estimated by this method and the angle error was smaller. The installation and maintenance of the encoder were saved by the observer. It ensures safe operation of the system. Then control strategy based on the current was proposed. In this method, the minimum current was used to produce the maximum output torque of the motor when the motor speed Lower than the rated speed. Weakening control is applied in the opposite. When the speed was increased to certain value, the IPMSM was controlled to maintain maximum power output. The current, the battery voltage and the maximum capacity of converters were fully utilized. When the motor was converted to power state at a high speed, weakening control method was used. Armature voltage and current were limited to ultimate value. The engine energy was back to the battery and car electronics.Finally, current decoupling control model was analyzed and the current Track function was expressed by per unit value. Current control model is greatly simplified. AC-DC matrix converter was analyzed and the Possibility that it can be used in ISA system was confirmed. Safe commutation strategy was also analyzed. Engine was simulated of high-speed motor. Validity, feasibility and accuracy of all this theory in this paper were verified by the experimental installation.