Method for operating an internal combustion engine with a turbocharger arrangement and control unit for an engine with a turbocharger arrangement

Abstract

Methods are provided for controlling an engine. One method may include adjusting airflow to a turbocharger arrangement with a turbine bypass valve bypassing a first turbine from a high-pressure turbocharger and a wastegate bypassing a second turbine from a low-pressure turbocharger; responsive to valve degradation, setting the turbine bypass valve fully open and the wastegate fully closed; and limiting engine torque based on a flow through a compressor of the low pressure turbocharger. In the event of valve degradation, limiting torque may reduce overspeed and surge of the low pressure turbocharger.

Dependencies are inferred from the claim text.