Surge Modeling and Control of Automotive Turbochargers
Mean Value Engine Modeling (MVEM) is used to make engine control development less expensive.
With more and more cars equipped with turbocharged engines good turbo MVEM models are needed.
A turbocharger consists of two major parts: turbine and compressor. Whereas the turbine is
relatively durable, there exist phenomenons on the compressor that can destroy the turbocharger.
One of these is surge.
Several compressor models are developed in this thesis. Methods to determine the compressor model
parameters are proposed and discussed both for the stable operating range as well as for
the surge region of a compressor map. For the stationary region methods to automatically
parameterize the compressor model are developed. For the unstable surge region methods to get
good agreement for desired surge properties are discussed. The parameter sensitivity of the
different surge properties is also discussed. A validation of the compressor model shows
that it gives good agreement to data, both for the stationary region as well as the surge region.
Different open loop and closed loop controllers as well as different performance variables
are developed and discussed. A benchmark is developed, based on a measured vehicle acceleration,
and the control approaches are compared using this benchmark. The best controller is found to be
a open loop controller based on throttle and surge valve mass flow.
Johan Bergström and Oskar Leufvén
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Last updated: 2019-12-02