A turbomachine train with two shaft parts which each have a fixedly attached grooved wheel, with a first overrunning clutch, with two rotational speed sensors and with a control device. The clutch is designed to couple and decouple the first shaft part to and from the second shaft part. The first rotational speed sensor measures the rotational speed of the first grooved wheel. The second rotational speed sensor measures the rotational speed of the second grooved wheel. The control device determines the differential angle between the first shaft part and the second shaft part and accelerates the turbomachines, with an acceleration value determined on the basis of the measured rotational speeds and on the basis of the differential angle, such that the two shaft parts couple together at a predetermined target coupling angle.

A vehicle propulsion system includes an internal combustion engine with a cylinder, an intake valve, an exhaust valve, and a cylinder head defining a combustion chamber; an intake manifold in communication with the combustion chamber through the intake valve; an exhaust manifold in communication with the combustion chamber through the exhaust valve; a turbocharger with a compressor in communication with the intake manifold, a turbine in communication with the exhaust manifold, and an electric motor for selectively driving the turbine; and a controller in communication with the electric motor and configured to selectively operate electric motor to drive the turbine to reduce a pressure in the combustion chamber during an engine start process.

A vehicle propulsion system includes an internal combustion engine with a cylinder, an intake valve, an exhaust valve, and a cylinder head defining a combustion chamber; an intake manifold in communication with the combustion chamber through the intake valve; an exhaust manifold in communication with the combustion chamber through the exhaust valve; a turbocharger with a compressor in communication with the intake manifold, a turbine in communication with the exhaust manifold, and an electric motor for selectively driving the turbine; and a controller in communication with the electric motor and configured to selectively operate electric motor to drive the turbine to reduce a pressure in the combustion chamber during an engine start process.

Methods and systems are provided for expediting turbine spool up during an engine restart following an engine stop while a vehicle is in motion. In one example, a method includes, in response to engine restart conditions being met, operating an electrically driven compressor to supply compressed air to a turbocharger turbine for expedited turbine spool up during engine cranking.

Methods and systems are provided for expediting turbine spool up during an engine restart following an engine stop while a vehicle is in motion. In one example, a method includes, in response to engine restart conditions being met, operating an electrically driven compressor to supply compressed air to a turbocharger turbine for expedited turbine spool up during engine cranking.

A vehicle propulsion system includes an internal combustion engine with a cylinder, an intake valve, an exhaust valve, and a cylinder head defining a combustion chamber; an intake manifold in communication with the combustion chamber through the intake valve; an exhaust manifold in communication with the combustion chamber through the exhaust valve; a turbocharger with a compressor in communication with the intake manifold, a turbine in communication with the exhaust manifold, and an electric motor for selectively driving the turbine; and a controller in communication with the electric motor and configured to selectively operate electric motor to drive the turbine to reduce a pressure in the combustion chamber during an engine start process.

A vehicle propulsion system includes an internal combustion engine with a cylinder, an intake valve, an exhaust valve, and a cylinder head defining a combustion chamber; an intake manifold in communication with the combustion chamber through the intake valve; an exhaust manifold in communication with the combustion chamber through the exhaust valve; a turbocharger with a compressor in communication with the intake manifold, a turbine in communication with the exhaust manifold, and an electric motor for selectively driving the turbine; and a controller in communication with the electric motor and configured to selectively operate electric motor to drive the turbine to reduce a pressure in the combustion chamber during an engine start process.

Methods and systems are provided for turbine temperature control in an engine system having multiple staged charge boosting devices. In one example, compressed air is provided by a turbocharger compressor until an outlet temperature of the compressor reaches a limit. Thereafter, a compressor of a downstream supercharger is operated to share the load

Methods and systems are provided for turbine temperature control in an engine system having multiple staged charge boosting devices. In one example, compressed air is provided by a turbocharger compressor until an outlet temperature of the compressor reaches a limit. Thereafter, a compressor of a downstream supercharger is operated to share the load

A control device for an internal combustion engine includes circuitry. The circuitry is configured to determine whether a running state of the internal combustion engine is in an auxiliary driving state in which an electric motor drives a compressor. The circuitry is configured to increase an opening degree of a waste gate valve when the running state is determined to be in the auxiliary driving state. The circuitry is configured to control a valve actuation phase variable mechanism to increase an overlap period in which a valve opening period of an intake valve and a valve opening period of an exhaust valve are overlapped with each other when the running state is determined to be in the auxiliary driving state.