Electrical drive for compressor on turbocharged engine

Abstract

Turbochargers are usually driven by turbine powered by exhausted gases. This conception is relatively simple but the compressor is not able to overcharge the compressed air or fuel-air mixture into the cylinder in the total revolution range and power regimes. Next disadvantage of turbine driven compressor is the low dynamic response of the turbine and compressor at quick fuel supply increase. There are two possible solutions. First - the “electrocharger”, that is the fully electric driven compressor can be used. Second - the hybrid driven charger is possible. Research of supercharging systems is one of activities of Josef Božek Research Centre of Engine and Automotive Technology on Faculties of Mechanical and Electrical Engineering at Czech Technical University in Prague. Part of this activity is research of electrical drive for the hybrid supercharging system especially from control point of view. Electric synchronous motor with permanent magnets was chosen as electric driving machine. Its robustness, high torque overload features, its small size and mass, high dynamical features and feasible high revolutions are promising for this implementation. Paper deals with torque control of high speed permanent magnet synchronous motor for driving compressor of supercharged combustion engines. Control structure which includes regimes with both full magnetic flux and flux weakening is described. Paper describes the research working place and presents test results achieved on 40 000 rev/min synchronous permanent magnet motor.