Method and system for controlling a boost pressure of a turbocharged internal combustion engine

摘要

The boost level is controlled via control of the flow through a wastegate by calculating and comparing an actual turbine power and the desired turbine power. The method and system comprising the steps of calculating a desired compressor power and a desired turbine power from the desired compressor power; calculating an actual compressor power and an actual turbine power; calculating a desired turbine mass flow from the desired turbine power and an actual turbine mass flow from the actual turbine power; calculating a base waste gate flow from the desired turbine mass flow and an actual exhaust mass flow; calculating a corrected base waste gate flow by adding a difference between the actual turbine flow and the desired turbine flow to the base waste gate flow; calculating a waste gate opening area from the corrected base waste gate flow; calculating a control pressure ratio based on the waste gate opening area; and adjusting the waste gate according to the control pressure ratio.