An engine includes a dynamo-electric machine which generates electricity by the rotation of the engine; a secondary battery which stores electricity generated by the dynamo-electric machine; an electric supercharger including an electric compressor for supercharging intake air into combustion chambers; and a mechanical supercharger including an exhaust turbine configured to be driven by exhaust gas in the exhaust passage, and a mechanical compressor configured to supercharge intake air into the combustion chamber. An ECU (50) includes a remaining charge detector for detecting the remaining amount of charge of the secondary battery; and a supercharge control means for adjusting the ratio between a supercharging pressure by the electric supercharger and a supercharging pressure by the mechanical supercharger according to the remaining amount of charge of the secondary battery.

A variable flow valve assembly is disclosed, and includes a main body, a piston, a position sensor, a controller, a solenoid, and a cover. The main body defines a chamber, an inlet port, an outlet port, and a wall located between the inlet port and the outlet port. The wall defines a metering orifice for selectively allowing a medium to flow from the inlet port to the outlet port. The chamber of the main body includes a pressurized chamber. The piston is moveable within the chamber of the main body in a plurality of partially open positions to vary the amount of medium flowing through the modulation orifice. The piston separates the pressurized chamber from the inlet port. The position sensor determines the position of the piston within the chamber of the main body, and the controller is in signal communication with the position sensor.

Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include coordinating the operation of the electric supercharger and an electric supercharger bypass valve and to open the electric supercharger bypass valve to reduce the extent and duration of electric supercharger overboost.

An object is to enable low fuel-consumption operation of an engine by controlling a back pressure and a power generation amount taking account of a trade-off relationship between deterioration of fuel efficiency due to an increase in pumping loss due to a back-pressure rise of the engine and improvement of fuel efficiency due to recovery of exhaust energy by a turbo compound.

Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger based on altitude. During vehicle operation at higher altitudes, where vacuum availability for wastegate actuation is limited, boost pressure may be provided by operating the electric supercharger more aggressively. The wastegate may be used for boost control once the vacuum reserve is replenished.

Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include coordinating the operation of the electric supercharger and an electric supercharger bypass valve and to open the electric supercharger bypass valve to reduce the extent and duration of electric supercharger overboost.

A turbocharger device includes: a turbocharger (3); and a turbo controller (35) configured to control a waste-gate valve (31) or a variable-displacement mechanism of an exhaust-gas amount supplied to the turbine to control a boost pressure of the turbocharger, the turbo controller (35) including a control calculation part (44) and a sensor signal input part (45) provided separately and independently from an engine controller (33) and being mounted to a compressor housing at a side of the compressor (23b) of the turbocharger (3).

Methods and systems are provided for controlling boost pressure in a staged engine system comprising a turbocharger and an upstream electric supercharger. In one example, a method may include accelerating an electric supercharger to choke the flow of air to the engine in the event of turbocharger overboost.

A method is provided for modeling the compressor speed of a turbocharger, and includes determining the temperature difference across the compressor, determining the mass flow through the compressor, and calculating a compressor speed value as a function of the temperature difference across the compressor and the mass flow.

The present invention relates to a control device (26) for a turbocharger (17) for supplying compressed intake air to an internal combustion engine (1). The control device includes: a storage part (27) configured to pre-store a map (33); a detection part (28) configured to a characteristic parameter; a calculation part (29) configured to obtain an efficiency of the turbocharger on the basis of the detected characteristic parameter; a determination part (30) configured to determine presence of deterioration of the turbocharger by comparing the detected characteristic parameter and the obtained efficiency with the map (33); and an informing part (31) configured to inform a user of a maintenance request.