A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.

The magnetless rotary electric machine includes an annular rotor, an outer stator and an inner stator. The annular rotor includes an annular rotor yoke portion, outer salient poles, outer rotor coils, inner salient poles, inner rotor coils, first rectifying devices and second rectifying devices. The first salient pole is configured to be magnetized by an induction current induced by the first coil. Each of the first rectifying devices is configured to rectify current such that a direction of a magnetic pole of the first salient pole is a first direction. The second salient pole is configured to be magnetized by an induction current induced by the second coil. Each of the second rectifying devices is configured to rectify current such that an direction of a magnetic pole of the second salient pole is a second direction. The second direction is a reverse direction to the first direction.

The magnetless rotary electric machine includes an annular rotor, an outer stator and an inner stator. The annular rotor includes an annular rotor yoke portion, outer salient poles, outer rotor coils, inner salient poles, inner rotor coils, first rectifying devices and second rectifying devices. The first salient pole is configured to be magnetized by an induction current induced by the first coil. Each of the first rectifying devices is configured to rectify current such that a direction of a magnetic pole of the first salient pole is a first direction. The second salient pole is configured to be magnetized by an induction current induced by the second coil. Each of the second rectifying devices is configured to rectify current such that an direction of a magnetic pole of the second salient pole is a second direction. The second direction is a reverse direction to the first direction.

Exhaust gases (28) from an engine (16, 16), input to turbo-compounder (20), drive a bladed turbine rotor (48) therein, which drives a generator (56, 56.1, 56.1, 126, 126, 126), the output of which is used to electrically drive an induction motor (104, 104), the rotor (106) of which is mechanically coupled to the engine (16, 16) so as to provide for recovering power to the engine (16, 16). The turbo-compounder (20) also incorporates a wastegate valve (36, 36) to provide for the exhaust gases (28) to bypass the bladed turbine rotor (48). Upon startup the wastegate valve (36, 36) is opened, and the generator may be decoupled from the engine (16, 16). The generator (56, 56.1, 56.1, 126, 126, 126) may be coupled to the engine (16, 16) either by closure of a contactor (110, 110), engagement of an electrically-controlled clutch (124), or by control of either a solid-state switching (125) or control system or an AC excitation signal (130), when the frequency (f.sub.GENERATOR) of the generator (56, 56.1, 56.1, 126, 126, 126) meets or exceeds that (f.sub.MOTOR) of the induction motor (104, 104). Wastegate valve (36, 36) closure provides for the generator (56, 56.1, 56.1, 126, 126, 126) to recover power from the exhaust gases (28).

Exhaust gases (28) from an engine (16, 16), input to turbo-compounder (20), drive a bladed turbine rotor (48) therein, which drives a generator (56, 56.1, 56.1, 126, 126, 126), the output of which is used to electrically drive an induction motor (104, 104), the rotor (106) of which is mechanically coupled to the engine (16, 16) so as to provide for recovering power to the engine (16, 16). The turbo-compounder (20) also incorporates a wastegate valve (36, 36) to provide for the exhaust gases (28) to bypass the bladed turbine rotor (48). Upon startup the wastegate valve (36, 36) is opened, and the generator may be decoupled from the engine (16, 16). The generator (56, 56.1, 56.1, 126, 126, 126) may be coupled to the engine (16, 16) either by closure of a contactor (110, 110), engagement of an electrically-controlled clutch (124), or by control of either a solid-state switching (125) or control system or an AC excitation signal (130), when the frequency (f.sub.GENERATOR) of the generator (56, 56.1, 56.1, 126, 126, 126) meets or exceeds that (f.sub.MOTOR) of the induction motor (104, 104). Wastegate valve (36, 36) closure provides for the generator (56, 56.1, 56.1, 126, 126, 126) to recover power from the exhaust gases (28).

A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.

A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine and configured to start the engine from an inactive state. A controller is programmed to execute a first control algorithm while output speed of the second electric machine is less than a first speed threshold. The controller is also programmed to execute a second control algorithm while output speed of the second electric machine is greater than the first speed threshold and less than a second speed threshold.

A transverse flux induction motor (TFIM) is described in accordance with the present invention. The TFIM may be a linear induction motor or a rotary induction motor. The TFIM includes a primary motor element and secondary motor element. The primary motor element includes a plurality of coils and at least one magnetic element. The plurality of coils are arranged to generate a control flux along a first direction when power is applied to at least one coil of the plurality of coils and the at least one magnetic element is arranged to generate a bias flux in a second direction that is substantially transverse to the first direction. The secondary motor element is moveable in the first direction, relative to the primary motor element, in response to the control flux.

A transverse flux induction motor (TFIM) is described in accordance with the present invention. The TFIM may be a linear induction motor or a rotary induction motor. The TFIM includes a primary motor element and secondary motor element. The primary motor element includes a plurality of coils and at least one magnetic element. The plurality of coils are arranged to generate a control flux along a first direction when power is applied to at least one coil of the plurality of coils and the at least one magnetic element is arranged to generate a bias flux in a second direction that is substantially transverse to the first direction. The secondary motor element is moveable in the first direction, relative to the primary motor element, in response to the control flux.

A linear-motor stator assembly comprising a stator and an integral line reactor in one housing. The reactor has inductor coils which are connected in series with the stator windings to compensate for unequal inductances in the stator phases and balance the polyphase currents into the stator.