An engine including an exhaust bypass valve and an intake bypass valve. The exhaust bypass valve is disposed in an exhaust bypass channel connecting an outlet of an exhaust manifold and an exhaust outlet of a turbocharger to each other. The intake bypass valve is disposed in an intake bypass channel connecting an inlet of an intake manifold and an inlet of the turbocharger. An intake pressure sensor detects a pressure of the intake manifold. If an instruction value indicating an upper limit or a lower limit of the valve opening degree of the intake bypass valve is continuously output for a predetermined time or more, an engine control device determines that an abnormality occurs in at least one of the exhaust bypass valve and the intake bypass valve.

A method for operating a supercharged internal combustion engine. Before a cold start of the engine, an electric drive device of an electrically assisted exhaust-gas turbocharger of the engine is activated such that fresh air is compressed by a compressor of the turbocharger and, in the process, is heated and is conveyed via an open overrun air recirculation valve arranged downstream of the compressor, through a short circuit back to a suction side of the compressor of the turbocharger. A proportion of the air that is heated by way of the short-circuit operation of the compressor is, downstream of the compressor and upstream of a closed throttle flap of the engine, conducted via a secondary air system into an exhaust manifold and from there via a wastegate of the turbocharger into the catalytic converters of an exhaust-gas aftertreatment device of the engine.

The present disclosure relates to improvements in turbocharger efficiency and more particularly to a method and system for estimating the efficiency loss of a turbocharger. The method comprises the steps of monitoring a plurality of operating parameters and determining a compressor exit temperature according to a first calibration map based on these operating parameters. An estimate of instantaneous turbocharger efficiency loss according to a second calibration map is then determined, based on the compressor exit temperature. The instantaneous turbocharger efficiency loss is used to determine an estimate of cumulative turbocharger efficiency loss during engine service. The estimate of cumulative turbocharger efficiency loss is compared with a first predetermined efficiency loss threshold and a first signal is generated if the first predetermined efficiency loss threshold is exceeded.

The present disclosure relates to improvements in turbocharger efficiency and more particularly to a method and system for estimating the efficiency loss of a turbocharger. The method comprises the steps of monitoring a plurality of operating parameters and determining a compressor exit temperature according to a first calibration map based on these operating parameters. An estimate of instantaneous turbocharger efficiency loss according to a second calibration map is then determined, based on the compressor exit temperature. The instantaneous turbocharger efficiency loss is used to determine an estimate of cumulative turbocharger efficiency loss during engine service. The estimate of cumulative turbocharger efficiency loss is compared with a first predetermined efficiency loss threshold and a first signal is generated if the first predetermined efficiency loss threshold is exceeded.

A method for controlling a speed of a turbocharger that is in operative connection with a compressor, the steps including: provision of a setpoint for the speed of the turbocharger on the basis of a model-based precontrol for a calculation of a desired boost pressure ahead of the turbocharger; determination of an actual value for the speed of the turbocharger; control of an actuator of the turbocharger in order to compensate for the difference between the desired value and the actual value for the speed of the turbocharger. A main signal and a subsidiary signal are provided during the determination of the actual value for the speed of the turbocharger, wherein the main signal and the subsidiary signal are combined in order to validate the actual value for the speed of the turbocharger.

A method for controlling a speed of a turbocharger that is in operative connection with a compressor, the steps including: provision of a setpoint for the speed of the turbocharger on the basis of a model-based precontrol for a calculation of a desired boost pressure ahead of the turbocharger; determination of an actual value for the speed of the turbocharger; control of an actuator of the turbocharger in order to compensate for the difference between the desired value and the actual value for the speed of the turbocharger. A main signal and a subsidiary signal are provided during the determination of the actual value for the speed of the turbocharger, wherein the main signal and the subsidiary signal are combined in order to validate the actual value for the speed of the turbocharger.

Various methods and systems are provided for controlling air flow through an engine by adjusting an electric turbocharger of a vehicle. In one embodiment, a system for a vehicle comprises an electric turbocharger comprising a compressor, an exhaust turbine coupled to the compressor via a shaft, and an electric machine mechanically coupled to the shaft; and a controller including a processor and instructions stored on a non-transient memory of the controller that, when executed, cause the controller to: adjust an amount of power provided to or extracted from the shaft by the electric machine based on at least one of a speed of the electric turbocharger, a cylinder pressure, and an exhaust gas temperature. By adjusting the amount of power provided to or extracted from the electric machine, the exhaust gas temperature and the speed of the electric turbocharger may be efficiently maintained within a desired operating range.

Various methods and systems are provided for controlling air flow through an engine by adjusting an electric turbocharger of a vehicle. In one embodiment, a system for a vehicle comprises an electric turbocharger comprising a compressor, an exhaust turbine coupled to the compressor via a shaft, and an electric machine mechanically coupled to the shaft; and a controller including a processor and instructions stored on a non-transient memory of the controller that, when executed, cause the controller to: adjust an amount of power provided to or extracted from the shaft by the electric machine based on at least one of a speed of the electric turbocharger, a cylinder pressure, and an exhaust gas temperature. By adjusting the amount of power provided to or extracted from the electric machine, the exhaust gas temperature and the speed of the electric turbocharger may be efficiently maintained within a desired operating range.

An electric assist turbocharger unit for use in an internal combustion engine, comprising a shaft configured for torque-transmittingly connecting a compressor to a turbine of the turbocharger unit and an electric motor configured for rotatably actuating the shaft in a first rotational direction and in an opposed second rotational direction. The engine includes an aftertreatment system, and the rotation of the shaft is designed to retard the flow of intake air through an intake passage and of exhaust gases through the aftertreatment system, thereby controlling the temperature in the aftertreatment system.

A watercraft propulsion system includes a propulsion unit to be driven by an engine. The engine includes a cylinder block, an air intake channel, an exhaust channel, a supercharging device, and a fuel injector. The watercraft propulsion system includes the engine, the propulsion unit to be driven by the engine, a rotation speed sensor to detect a rotation speed of the engine, an air intake pressure sensor to detect an air intake pressure of the engine, and a controller. The controller is configured or programmed to compute a command fuel injection amount so that the engine performs a combustion operation at an air/fuel ratio in a lean-burn range (lean-combustion range) according to the rotation speed detected by the rotation speed sensor and the air intake pressure detected by the air intake pressure sensor, and to drive the fuel injector based on the computed command fuel injection amount.