Abstract: A power system includes an engine; an exhaust gas recirculation (EGR) system supplying a first portion of the engine exhaust gas from the exhaust manifold to the intake manifold; a turbine generator in communication with the exhaust manifold and configured to be driven by a second portion of the engine exhaust gas from the exhaust manifold to generate electrical power; a power network including at least one battery to store the electrical power generated by the turbine generator; and an electric compressor in fluid communication with the intake manifold and configured to be powered by the electrical power from the at least one battery of the power network and to compress at least a portion of the intake air for the engine.

Abstract: An exhaust-gas turbocharger having an electric drive unit for driving a compressor, a turbine, or a turbocharger shaft of the exhaust-gas turbocharger. The electric drive unit has a rotor and a stator. The rotor is equipped with a rotor body embodied around a rotation axis of the rotor. A receptacle for at least one permanent magnet is embodied on the rotor body. A permanent magnet is disposed in the receptacle of the rotor body. The rotor body is mountable using a threaded bushing on a turbocharger shaft of the exhaust-gas turbocharger. The rotor body has a further receptacle which extends in the direction of the rotation axis and in which the threaded bushing is disposed inside the rotor body. The further receptacle is disposed in the rotor body with an offset in the direction of the rotation axis relative to the receptacle.

Abstract: Methods and systems are provided for a turbocharger. In one example, the turbocharger comprises an injector configured to inject a medium therein, wherein the injector is configured to inject the medium toward a turbine of the turbocharger. The turbocharger further comprising a turbine driven by exhaust gases.

Abstract: The gas turbine engine can have a rotary shaft mounted to a casing via a bearing housed in a bearing housing, for rotation around a rotation axis, a gas path provided radially externally to the bearing housing, a feed pipe having a radial portion extending from an inlet end, radially inwardly across the gas path and then turning axially to an axial portion leading to an outlet configured to feed the bearing housing, the axial portion of the feed pipe broadening laterally toward the outlet.

Abstract: A bottoming cycle power system includes a turbine generator and an open cycle absorption system. The turbine-generator includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander is operable to rotate the turbo-crankshaft as a flow of exhaust gas from a combustion process passes through the turbo-expander. The turbo-compressor is operable to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. The open cycle absorption chiller system includes an absorber section that is operable to receive the flow of exhaust gas from the turbo-expander. The absorber section includes a first refrigerant solution that is operable to absorb water from the exhaust gas as the exhaust gas passes through the first refrigerant solution. The absorber section is also operable to route the flow of exhaust gas to the turbo-compressor after the flow of exhaust gas has passed through the first refrigerant solution.

Abstract: A control device for a hybrid vehicle includes: a drive control unit that calculates required drive power which is required for a hybrid vehicle based on an accelerator opening when an accelerator return operation is performed, calculates a target engine output which changes slowly with respect to a required engine output for realizing the required drive power through slow change processing, and controls an engine, a first rotary machine, and a second rotary machine such that an engine output reaches the target engine output; and a smoothing rate setting unit that changes a smoothing rate which is used for the slow change processing based on a supercharging pressure and sets the smoothing rate to a smaller value when the supercharging pressure is high than when the supercharging pressure is low.

Abstract: An exhaust system for a vehicle comprising an engine and a turbine generator comprises an engine exhaust system and a turbine exhaust system. The engine exhaust system comprises an engine exhaust pipe extending from the engine to a desired location relative to the vehicle. The turbine exhaust system comprises a turbine exhaust pipe operatively connected between the turbine generator and the engine exhaust pipe between the engine and the desired location.

Abstract: A power system is disclosed. The power system may include one or more memories and a controller. The controller may determine an exhaust temperature of an engine associated with a continuously variable transmission or a hybrid transmission. The controller may determine a target increase to the exhaust temperature based on the exhaust temperature failing to satisfy a threshold. The controller may determine, based on a lookup table, a target increase to a torque output of the engine based on the target increase to the exhaust temperature. The controller may cause a parasitic torque of the engine to be increased based on the target increase to the torque output.

Abstract: Provided is a variable capacity turbocharger, including: a drive ring including a main body portion having an annular shape; a first projection portion and a second projection portion, which are formed on the main body portion, and are arranged apart from one another in a circumferential direction of the main body portion so as to sandwich a link plate to which a nozzle vane is mounted; and a cutout portion, which is formed in a portion of the main body portion between the first projection portion and the second projection portion.

Abstract: Methods and systems are provided for controlling a variable displacement engine (VDE) of a vehicle to adjust a power generated by the VDE based on a demand for power from an onboard AC power generator of the vehicle. In one example, a method for a vehicle includes, with an engine of the vehicle turned off, estimating a power draw of an external electrical device to be supplied power via an onboard generator of the vehicle, and starting the engine in a variable displacement engine (VDE) mode with a number of deactivated cylinders selected based on the estimated power draw.

Abstract: An integrated turbo-compressor includes a compressor with a compressor outlet, a turbine with a turbine inlet, the turbine operatively connected to the compressor by an interconnect shaft, and a compounding drive. The compounding drive is connected to the turbine and has a variable gear ratio and an output member, the variable gear ratio coupling the turbine to the output member to compound output of an internal combustion engine using energy recovered from an exhaust flow received from the internal combustion engine and in excess of energy required to compress combustion air provided to the internal combustion engine. Internal combustion engines, aircraft, and methods of compounding output of internal combustion engines are also described.

Abstract: A system and method is provided for controlling operating of an engine having a turbocharger with a compressor and an exhaust turbine, wherein the compressor is configured to provide a boost pressure and operate stably in a stable operating range between a surge line and a choke line of a compressor map. A controller is configured to control an actuator to cause an operating point of the compressor to move along a predetermined path within a corridor along a safety zone in the compressor map. The safety zone extends along the surge line. The safety zone is selected to provide a distance between the surge line and the corridor that minimizes a reduction of the boost pressure such that a sufficient boost pressure is available after the network fault.

Abstract: A power unit for use with an internal combustion engine including a compressor housing, a compressor wheel positioned within and rotatable with respect to the compressor housing, a shaft coupled to the compressor wheel and rotatable together therewith, a motor assembly in operable communication with the shaft, and a controller in operable communication with the motor assembly. Where the controller is adjustable between a first mode of operation, in which the motor assembly applies torque to the shaft in a first direction of rotation, and a second mode of operation, in which the motor assembly unit applies torque to the shaft in a second direction of rotation opposite the first direction of rotation.

Abstract: 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.

Abstract: A method and system for controlling temperature in an exhaust gas routing system of an internal combustion engine is provided. The exhaust gas routing system includes an exhaust gas manifold, an exhaust gas turbine which includes an electric machine arranged downstream of the exhaust gas manifold in the exhaust gas stream, an aftertreatment system arranged downstream of the exhaust gas turbine, and a control means configured to control the operation of the electric machine to adapt an operating mode of the exhaust gas turbine between motor operating, regeneration operating and neutral operating modes control means (50) such that the temperature of the aftertreatment system is controlled based on a target temperature.

Abstract: A fuel injection valve is for injecting fuel to cause combustion in an internal combustion engine. An injection rate adjuster is for adjusting an injection rate of the fuel injected by the fuel injection valve. A control device for the internal combustion engine includes a signal generator, and an outputter. The signal generator generates a command signal to cause the injection rate adjuster to adjust the injection rate based on a parameter, which is to estimate an internal EGR amount in which a part of exhaust gas remains in a cylinder. The outputter outputs the command signal to the injection rate adjuster.

Abstract: A control valve assembly for an engine system having a turbocharger system. The control valve is configured to control the position of a turbine actuator and a compressor actuator by directing hydraulic fluid into the proper passages. The control valve assembly includes a hydraulic powered bypass valve that, when energized, can reduce flow restriction of the hydraulic fluid, and can increase the speed of actuation of the turbine actuator.

Abstract: A compounding drive includes an input member, an epicyclical gear arrangement connected to the input member, an output member connected to the epicyclical gear arrangement, and a hydraulic pump/motor set. The hydraulic pump/motor set connects the epicyclical gear arrangement to the output member through an overrunning clutch for unidirectional communication of mechanical rotation between the input member and the output member. Engine arrangements, aircraft, and methods of compounding internal combustion engines are also described.

Abstract: A power system is disclosed. The power system may include one or more memories and a controller. The controller may determine an exhaust temperature of an engine associated with a continuously variable transmission or a hybrid transmission. The controller may determine a target increase to the exhaust temperature based on the exhaust temperature failing to satisfy a threshold. The controller may determine, based on a lookup table, a target increase to a torque output of the engine based on the target increase to the exhaust temperature. The controller may cause a parasitic torque of the engine to be increased based on the target increase to the torque output.

Abstract: A system and method for controlling a rotor of an aircraft is disclosed. A desired rotor speed for the rotor is received and a torque command that generates the received rotor speed is calculated. A fuel adjustment signal is calculated based on the torque command and a dynamic rotor measurement of the aircraft. The fuel adjustment signal is provided to the aircraft to track the rotor speed to the desired rotor speed.

Abstract: Methods and systems are provided for diagnosing a source of degradation in an exhaust system of a vehicle. In one example, a method may include actuating an electric turbocharger to rotate in a first direction to evaluate integrity of an exhaust pipe of the exhaust system and rotation the turbocharger in a second direction to assess an exhaust manifold of the exhaust system, after an engine of the vehicle is turned off. Pressures generated in the exhaust system are compared to thresholds based on barometric pressure and/or turbocharger speed.

Abstract: Methods and systems are provided for providing torque reserve via an electrically assisted turbocharger. A portion of requested torque reserve is provided by intentionally reducing turbine speed of an electric turbocharger by operating the associated electric motor as a generator. The resulting reduction in air mass allows for the torque reserve to be provided with reduced reliance on spark and throttle based torque reserve.

Abstract: A turbocharging system for an internal combustion engine includes a turbocharger having a shaft supported for rotation about an axis. The turbocharger also includes a turbine wheel mounted on the shaft and configured to be rotated about the axis by the exhaust gas, and a compressor assembly mounted on the shaft and configured to pressurize an airflow received from the ambient for delivery to the cylinder. The turbocharging system additionally includes an electric motor configured to generate electric motor torque. The turbocharging system further includes a one-way clutch configured to selectively connect the electric motor to the compressor assembly, such that the electric motor torque assists the turbocharger in generating boost pressure. An internal combustion engine employing such a turbocharging system is also disclosed.

Abstract: An electric supercharging system has an electric supercharger disposed on an intake air passage of an engine and a control unit in which a microcomputer is built. Then, control unit changes an actuation timing of the electric supercharger on the basis of change amounts of a rotational speed and an accelerator opening of the engine. At this time, the control unit changes the actuation timing of the electric supercharger by correcting the actuation timing of the electric supercharger according to the rotational speed of the engine with a coefficient according to the change amount of the accelerator opening.

Abstract: A turbocompound unit for converting energy of an exhaust gas from an internal combustion engine to torque increase of a crankshaft of the internal combustion engine includes a turbine arrangement and an arrangement configured to operatively connecting the turbine arrangement to the crankshaft is a hydrodynamic coupling and freewheeling arrangement. The turbocompound unit further includes a brake arrangement, wherein the brake arrangement and the freewheeling arrangement are located on an opposite side of the hydrodynamic coupling in relation to the turbine arrangement.

Abstract: The present disclosure describes a supercharging device for an internal combustion engine of a motor vehicle comprising: a planetary mechanism, a first electric machine, a second electric machine, a compressor impeller, and an internal combustion engine attachment for fastening to a drive output shaft of the internal combustion engine. The first electric machine, the second electric machine and the compressor impeller are connected to one another via the planetary mechanism. Along a longitudinal axis of the supercharging device, the compressor impeller is arranged on a first side of one of the electric machines, and the other of the electric machines is arranged on the second side situated opposite said first side.

Abstract: Embodiments for operating an engine having parallel turbochargers and two fluidically coupleable, separated intake manifolds is provided. In one example, a method includes responsive to a first condition, operating a first cylinder group of an engine, deactivating a second cylinder group of the engine, and blocking fluidic communication between a first intake manifold coupled to the first cylinder group and a second intake manifold coupled to the second cylinder group, and responsive to a second condition, activating the second cylinder group and establishing fluidic communication between the first and second intake manifolds.

Abstract: A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. A second electric machine is coupled to the engine to provide torque to start the engine from an inactive state. A high-voltage power source is configured to power both of the first electric machine and the second electric machine over a high-voltage bus. A propulsion controller is programmed to start the engine using cranking torque output from the second electric machine powered by the high-voltage power source. The controller is also programmed to operate both of the first electric machine and the combustion engine to propel the vehicle in response to an acceleration demand greater than a threshold. The controller is further programmed to decouple the engine and propel the vehicle using the first electric machine in response to vehicle speed less than a speed threshold.

Abstract: A method of operating an automotive system having an internal combustion engine equipped with an electric compressor and a turbocharger having a turbocharger compressor is disclosed. A surge threshold line and a pre-surge threshold line in a turbocharger compressor map are defined as a function of a turbocharger compressor pressure ratio and mass flow rate. The pre-surge threshold line is defined in terms of greater mass flow values for each corresponding pressure ratio value of the surge threshold line. The position of a turbocharger compressor working point in the turbocharger compressor map is monitored as a function of the turbocharger compressor pressure ratio and mass flow rate. When an increased torque request is detected, the electric compressor is activated to assist the turbocharger compressor in delivering the requested torque when the turbocharger compressor working point crosses the pre-surge threshold line in a direction towards the surge threshold line.

Abstract: A method of controlling an engine system equipped with a supercharger may include determining a target value of boost pressure, depending on an rpm of an engine and then determining whether the supercharger is in an operable region, deducing a target rpm of the supercharger, based on a reference value previously input into the controller and a current state value of a vehicle input into the controller, when it has been determined in the operating-region determination that the supercharger is in the operable region, setting a maximum value, in the target rpm deduced in the target-rpm deduction, to a drive rpm of the supercharger, and verifying whether the set drive rpm is greater than or equal to a predetermined reference value previously input into the controller, and driving the supercharger at the set drive rpm, by closing the bypass valve to open the supercharger path.

Abstract: A method for operating a drive system including an internal combustion engine, the drive system including an electromotively-assisted exhaust-driven supercharging device or a strictly electrically operated supercharging device, the method including checking on whether a gear change has been initiated and a drive train has been disengaged accordingly; upon detecting an initiated gear change, adjusting the compressor power of the supercharging device by additionally facilitating electric power to the electromotively-assisted exhaust-driven supercharging device or to the strictly electrically operated supercharging device, in such a way that, at least toward the end of the gear change, a charging pressure is made available in a charging pressure section of the drive system which is higher than a charging pressure resulting at a compressor power, which corresponds to the exhaust gas enthalpy of the internal combustion engine provided during the gear change.

Abstract: An exemplary method of providing torque-assist to a crankshaft of an internal combustion engine includes, among other things, assisting a rotation of the crankshaft using an electric machine during the transition between stages of a multi-stage forced induction system.

Abstract: An internal combustion engine includes: plural cylinders, a first exhaust gas turbocharger having a high-pressure turbine and a high-pressure compressor, a second exhaust gas turbocharger having a low-pressure turbine and a low-pressure compressor, and an SCR catalytic converter positioned between the high-pressure turbine and the low-pressure turbine, via which exhaust gas leaving the high-pressure turbine is conducted upstream of the low-pressure turbine. The low-pressure compressor is assigned a power take-in, via which the low-pressure compressor can be driven when as a consequence of a relatively large exhaust gas temperature drop at the SCR catalytic converter via the low-pressure turbine an adequate amount of energy required to supply the cylinders of the internal combustion engine with a desired quantity of charge air can no longer be provided.

Abstract: Control techniques for a turbocharger of an engine utilize a wastegate valve configured to divert exhaust gas from a turbine of the turbocharger that is rotatably coupled to a compressor of the turbocharger. A controller is utilized to obtain a torque request for the engine, determine a target compressor power based on the engine torque request, determine a normalized target turbine power based on the target compressor power, determine a target position for the wastegate valve based on the normalized target turbine power and a normalized exhaust flow, and actuate the wastegate valve to the target position. Such control techniques involve the actual calculation of much less intermediate parameters, such as target turbine pressure ratio, which results in more efficient calibration and implementation.

Abstract: 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.

Abstract: In a controller of an internal combustion engine equipped with an electric supercharger driven by a motor, an object is to attempt to improve fuel consumption of a vehicle. The controller includes an electric supercharger driven by a motor; a generator that performs power generation using the output of the internal combustion engine as power; a charging device which is charged by the generator and can store electricity; and an accelerator opening degree detector that detects an accelerator opening degree. In the controller, a configuration is made such that, the controller controls supply electricity to the electric supercharger and generated electricity by the generator by the output of the accelerator opening degree detector, output needed for the electric supercharger calculated depending on the accelerator opening degree, and an state of charge in the charging device.

Abstract: Embodiments of an internal combustion engine are provided. In one example, an engine includes at least one cylinder, an intake system for supplying charge air to the at least one cylinder, an exhaust-gas discharge system for discharging exhaust gas from the at least one cylinder, a first exhaust-gas turbocharger including a first turbine arranged in the exhaust-gas discharge system and a first compressor arranged in the intake system; and an exhaust-gas recirculation (EGR) system. The EGR system includes a line which branches off from the exhaust-gas discharge system and opens into the intake system, a second exhaust-gas turbocharger comprising an EGR turbine arranged in the line on a shaft and an EGR compressor arranged in the line on the shaft upstream of said EGR turbine, and an EGR cooler positioned between the EGR turbine and the EGR compressor.

Abstract: A control apparatus for an internal combustion engine executes shaft heating control that controls the energization of an electric motor so that a driving torque and a braking torque are alternately imparted from the electric motor to a rotary shaft when the temperature of a lubricating oil (lubricant) is less than or equal to a predetermined value. According to the shaft heating control, in a case where a target intake air pressure Pt is higher than an actual intake air pressure P, a proportion that a driving torque impartation period ?D occupies in a cycle T is increased relative to a case where Pt and P are equal or substantially equal, and in a case where Pt is lower than P, the proportion ?D that the driving torque impartation period occupies in the cycle T is decreased relative to a case where Pt and P are equal or substantially equal.

Abstract: Methods and systems for operating an engine that includes a compressor and charge air cooler are disclosed. In one example, air flow through the charge air cooler is increased in response to condensation accumulating in the charge air cooler without increasing engine torque. Air flow through the charge air cooler is increased to gradually reduce condensation within the charge air cooler.

Abstract: Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.

Abstract: Starting an internal combustion engine may be difficult as a consequence of the operating conditions of the engine. Even after the engine has started, it may take a long period of time for the engine to reach operating temperatures. In the present disclosure, when engine start difficulty is expected, before starting the engine a forced induction compressor arranged with the engine may be turned on to increase the engine intake air pressure before the engine is started.

Abstract: Systems and methods for operating a compressor and a compressor recirculation valve of a turbocharged engine to avoid the possibility of compressor surge are presented. The systems and methods position the compressor recirculation valve responsive to a compressor surge line that is based on two other compressor surge lines that may be a function of compressor pressure ratio and compressor flow.

Abstract: The invention relates to a method for determining the pressure Pavcm upstream of a mechanical compressor (3) equipped with a double supercharging circuit of a combustion engine. The pressure Pavcm is determined by a dynamic model based on a law of conservation of flow rate in the volume upstream of the mechanical compressor. The model links the pressure Pavcm upstream of the mechanical compressor (3) to a temperature Tavcm upstream of the mechanical compressor (3), to a boost pressure Psural and boost temperature Tsural on the intake side of the engine, and to an openness Bypass of the bypass valve (4).

Abstract: A vehicle is equipped with an internal combustion engine having a forced-induction apparatus with variable boost pressure, a first motor generator for generating electricity while applying negative torque to the engine, and a battery for storing the electricity generated by the first motor generator. During the operation of the engine, a target boost pressure is set lower as the rotational speed of the first motor generator is increased. The engine is controlled such that, with the boost pressure adjusted to the target boost pressure, the output torque of the engine has a required value determined by the accelerator operation amount. Further, while the output torque of the engine is adjusted to the required value, the magnitude of the negative torque by the first motor generator acting on the engine is adjusted such that the engine rotational speed has a target value.

Abstract: A system and method are provided for controlling an air handling system for an internal combustion engine including a turbocharger having a variable geometry turbine fluidly coupled to an exhaust manifold of the engine and a compressor fluidly coupled to an intake manifold of the engine, and an electric motor coupled to a rotatable shaft connected between the compressor and the variable geometry turbine. A target torque required to drive the compressor to achieve target compressor operating parameters is determined, a maximum available torque that can be supplied by the variable geometry turbine in response to a target exhaust gas flow through the variable geometry turbine is determined, and the electric motor is enabled to supply supplemental torque to the rotatable shaft if the target torque is greater than the maximum available torque.

Abstract: A turbocharger system for achieving both improvement of fuel efficiency by engine downsizing and excellent shock loading resistance. The system includes: a power-assisted turbocharger mounted on a vehicle having an accessory and including a turbine disposed on an exhaust passage of an engine and driven by exhaust, a compressor disposed on an intake passage and driven by a rotational torque of the turbine, and an electric motor that assists a drive force of the compressor; and an electric motor control unit that drives the electric motor when the accessory is being driven.

Abstract: A method and apparatus for controlling a speed change of a hybrid vehicle are provided. The apparatus includes an engine for combustion of fuel to generate power and a motor that is configured to supplement the power from the engine and operate as a generator during braking to generate electrical energy and store the generated electrical energy generated a battery. A transmission is configured to convert the power from the engine to a required torque based on a speed and transmit the power to wheels and is directly connected to the motor. In addition, a controller is configured to operate the transmission to shift in a constant power section of the motor when the motor is performing regenerative braking. The apparatus minimizes the sense of difference felt by a driver by shifting in the constant power section of the motor during the regenerative braking of a hybrid vehicle.

Abstract: The invention relates to an internal combustion machine (10), comprising a combustion engine (1) having an exhaust gas side (AGS) and a charging fluid side (LLS), and having a supercharger system (14) comprising an exhaust gas turbo charger (40) for charging the combustion engine (1), having a condenser array (41) on the charging fluid side (LLS) and a turbine arrangement (42) on the exhaust gas side (AGS), a compressor (3), the primary side (I) of which is connected to the charging fluid side (LLS), and the secondary side (II) of which is connected to the exhaust gas side (AGS). An electric machine (4) configured as a motor/generator is coupled to the combustion engine (1), wherein the electric machine (4) as a generator can be powered by the combustion engine (1), or can power the combustion engine (1) as a motor, wherein the compressor (3) can be powered directly by the electric machine (4) via a mechanical drive coupling (13).

Abstract: A pressure-assisted precision purge valve system is provided in an evaporative emission control system that provides flow of fuel vapor-air mixture from a fuel tank to an intake manifold. The pressure-assisted precision purge valve system comprises an absorbent canister through which the fuel vapor-air mixture flows, a purge valve configured to regulate flow of the fuel vapor-air mixture to the intake manifold and a fuel vapor pump configured to provide a forced flow to the purge valve dependent on a system differential pressure. The output of the purge valve can be connected to an upstream injection point and/or a downstream injection point of a forced induction device.

Abstract: A turbocharger system for ensuring a sufficient exhaust gas recirculation (“EGR”) amount in all operating conditions, and reducing NOx emission from an engine. The system includes an EGR controller that re-circulates a part of exhaust gas discharged from the engine to an intake side. The turbocharger is a power-assisted turbocharger including an electric motor that assists a drive force of a compressor. The EGR controller controls an amount of exhaust gas recirculated to the intake side so as to inhibit the generation of NOx regardless of an amount of oxygen necessary for combustion of the engine. An electric motor control unit drives the electric motor, by the control of the EGR controller, when the amount of oxygen necessary for the combustion of the engine is deficient.