A supercharging system includes: a first supercharger including a first compressor for compressing air to be supplied to an engine and a motor for driving the first compressor; a leakage current measuring part for measuring a leakage current of the motor; and a first controller for controlling the first supercharger. The first controller includes a motor control part configured to, when a measurement result by the leakage current measuring part is not less than a first threshold, set an upper limit value of an output command value for the motor to be lower than when the measurement result is less than the first threshold, and to control an output of the motor within a range which does not exceed the upper limit value.

In a two-stage supercharging electric-assist turbocharger, a first compressor wheel, a rotor of an electric motor, a second compressor wheel, and a turbine wheel are coaxially coupled to a same, common shaft member, in that order. A compressor housing is structured to define therein a communicating passage to accommodate the electric motor in the communicating passage. A first water jacket is formed in at least one rib integrally formed with an outer periphery of a motor housing and also serving as a radiating fin, for forced-cooling air flowing through the communicating passage. A second water jacket is formed in a motor housing for forced-cooling a stator of the electric motor. A third water jacket is formed in an intermediate housing constructing a part of the compressor housing for forced-cooling a control unit configured to control the electric motor.

In a two-stage supercharging electric-assist turbocharger, a first compressor wheel, a rotor of an electric motor, a second compressor wheel, and a turbine wheel are coaxially coupled to a same, common shaft member, in that order. A compressor housing is structured to define therein a communicating passage to accommodate the electric motor in the communicating passage. A first water jacket is formed in at least one rib integrally formed with an outer periphery of a motor housing and also serving as a radiating fin, for forced-cooling air flowing through the communicating passage. A second water jacket is formed in a motor housing for forced-cooling a stator of the electric motor. A third water jacket is formed in an intermediate housing constructing a part of the compressor housing for forced-cooling a control unit configured to control the electric motor.

An example engine system is disclosed. The engine system may control a turbocharger of an internal combustion engine, and more particularly control a boost pressure provided by a turbocharger to an internal combustion engine. An example method for controlling a boost pressure provided by a turbocharger may include receiving a boost pressure demand and identifying a compressor speed demand to achieve the received boost pressure demand. The method may also include converting the compressor speed demand into a kinetic energy demand of the turbocharger rotating components and controlling the kinetic energy of the turbocharger rotating components to meet the kinetic energy demand by controlling power supplied by the turbine and the electric motor assist.

An example engine system is disclosed. The engine system may control a turbocharger of an internal combustion engine, and more particularly control a boost pressure provided by a turbocharger to an internal combustion engine. An example method for controlling a boost pressure provided by a turbocharger may include receiving a boost pressure demand and identifying a compressor speed demand to achieve the received boost pressure demand. The method may also include converting the compressor speed demand into a kinetic energy demand of the turbocharger rotating components and controlling the kinetic energy of the turbocharger rotating components to meet the kinetic energy demand by controlling power supplied by the turbine and the electric motor assist.

According to a device and a method for controlling an internal combustion engine, a control device (38) enables controllability of the internal combustion engine to be improved by preventing surging from occurring upon starting or stopping of the internal combustion engine, by opening a relief valve (28) as a turbine rotational speed reaches a surging rotational speed when the control device (38) causes a motor generator (32) to assist in rotation of the turbocharger (12) upon starting of a diesel engine body (11).

According to a device and a method for controlling an internal combustion engine, a control device (38) enables controllability of the internal combustion engine to be improved by preventing surging from occurring upon starting or stopping of the internal combustion engine, by opening a relief valve (28) as a turbine rotational speed reaches a surging rotational speed when the control device (38) causes a motor generator (32) to assist in rotation of the turbocharger (12) upon starting of a diesel engine body (11).

A supercharging system includes a charging device having a turbine and a compressor, the compressor having a high speed shaft; a planetary gear set coupled to the high speed shaft and an electric motor, or generator, via a low speed drive shaft; a clutch unit; a power transmission for connecting a crank shaft of the combustion engine to the drive shaft via the clutch unit; at least one sensor to measure at least one physical parameter of the exhaust gases inside, or after having passed, an exhaust gas catalyzer of the internal combustion engine, the at least one sensor being configured to provide an output signal representing a measured value of the at least one physical parameter; and a system control unit to receive the output signal and to control the speed or effect of the electric motor, or generator, based on the output signal. A method is also disclosed.

A supercharging system includes a charging device having a turbine and a compressor, the compressor having a high speed shaft; a planetary gear set coupled to the high speed shaft and an electric motor, or generator, via a low speed drive shaft; a clutch unit; a power transmission for connecting a crank shaft of the combustion engine to the drive shaft via the clutch unit; at least one sensor to measure at least one physical parameter of the exhaust gases inside, or after having passed, an exhaust gas catalyzer of the internal combustion engine, the at least one sensor being configured to provide an output signal representing a measured value of the at least one physical parameter; and a system control unit to receive the output signal and to control the speed or effect of the electric motor, or generator, based on the output signal. A method is also disclosed.

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.