METHOD FOR CONTROLLING TWO STAGE SUPERIORING OF FIXED GEOMETRY TURBOCHARGERS WITH DYNAMIC ESTIMATOR AND LIMITING THE PRESSURE BEFORE TURBINE

摘要

This method for controlling the air supercharging of an internal combustion engine (1) of a motor vehicle equipped with a stepped turbocharger (6, 7) comprises two turbines (10, 12) driven in rotation by the exhaust gases of the engine (1), two superchargers (11, 13) driven by each of the turbines (10, 12), and two valve actuators (17, 18) high pressure and low pressure. This method comprises regulating the compression ratio of the compressor (PRc) around a compression ratio setpoint value (PRc, cons), and regulating the expansion ratio (PRt) of the turbine (12) to limit the value of the pressure (Pavt, t) upstream of the turbine (12), said regulation being implemented as soon as the pressure (Pavt, t) upstream of the high-pressure turbine (12) exceeds a threshold value (CONSPavt) .