Abstract: An on board secondary propulsion system for an aircraft provides the capability of taxiing the aircraft on the ground without using the main aircraft engine(s). The power system includes a small taxi engine mounted on or in the aircraft at a location suitable to provide a thrust sufficient only to taxi the aircraft. Such a suitable system may be provided as original equipment to an aircraft or retrofitted to existing aircraft. The on board secondary propulsion system, in addition to the taxiing function, can provide electrical power, an environmental control unit, power for the aircraft hydraulic system and an emergency power unit as desired. The system can also be used to supplement the main aircraft engines as necessary during takeoff and climb to further reduce fuel consumption, noise, engine emissions, maintenance costs and extend the life of the main aircraft engines, reduce the required takeoff distance of an aircraft when used in conjunction with the main engines and provide emergency glide support.

Abstract: An on board secondary propulsion system for an aircraft provides the capability of taxiing the aircraft on the ground without using the main aircraft engine(s). The power system includes a small taxi engine mounted on or in the aircraft at a location suitable to provide a thrust sufficient only to taxi the aircraft. Such a suitable system may be provided as original equipment to an aircraft or retrofitted to existing aircraft. The on board secondary propulsion system, in addition to the taxiing function, can provide electrical power, an environmental control unit, power for the aircraft hydraulic system and an emergency power unit as desired. The system can also be used to supplement the main aircraft engines as necessary during takeoff and climb to further reduce fuel consumption, noise, engine emissions, maintenance costs and extend the life of the main aircraft engines, reduce the required takeoff distance of an aircraft when used in conjunction with the main engines and provide emergency glide support.

Abstract: Thrust systems for passenger aircraft provide at least one flight engine and a taxi engine wherein all flight engines together provide, in total, a takeoff thrust arranged in a takeoff thrust direction and the taxi engine provides a taxi thrust which does not exceed 15% of the takeoff thrust and is directed substantially the same as the takeoff thrust direction. The taxi thrust is thereby sufficient to taxi the aircraft along a taxi path. In a system embodiment, the taxi thrust does not exceed 7.5% of the flight thrust. In another system embodiment, the flight engines have, in total, a flight engine weight and the taxi engine has a taxi engine weight that does not exceed 10% of the flight engine weight. In a system embodiment, the taxi engine weight does not exceed 7.0% of the flight engine weight. In another system embodiment, the taxi engine has a rated thrust and is configured so that the taxi thrust is within 40% and 100% of the rated thrust.

Abstract: Thrust systems for passenger aircraft provide at least one flight engine and a taxi engine wherein all flight engines together provide, in total, a takeoff thrust arranged in a takeoff thrust direction and the taxi engine provides a taxi thrust which does not exceed 15% of the takeoff thrust and is directed substantially the same as the takeoff thrust direction. The taxi thrust is thereby sufficient to taxi the aircraft along a taxi path. In a system embodiment, the taxi thrust does not exceed 7.5% of the flight thrust. In another system embodiment, the flight engines have, in total, a flight engine weight and the taxi engine has a taxi engine weight that does not exceed 10% of the flight engine weight. In a system embodiment, the taxi engine weight does not exceed 7.0% of the flight engine weight. In another system embodiment, the taxi engine has a rated thrust and is configured so that the taxi thrust is within 40% and 100% of the rated thrust.

Abstract: An on board secondary propulsion system for an aircraft provides the capability of taxiing the aircraft on the ground without using the main aircraft engine(s). The power system includes a small driver mounted on the aircraft. In one embodiment of the invention, the driver may be mounted at any desirable location on the aircraft and is designed to provide sufficient thrust to taxi the aircraft. Such a suitable system may be provided as original equipment to an aircraft or retrofitted to existing aircraft. In a further embodiment of the invention, the on board secondary propulsion system, in addition to the taxiing function, may be incorporated with an alternator to provide electrical power, an environmental control unit, and an emergency power unit as desired. The system may also be used to supplement the main aircraft engines as necessary during takeoff and climb to further reduce fuel consumption, noise, engine emissions, maintenance costs and extend the life of the main aircraft engines.

Abstract: An auxiliary on board power system for an aircraft provides the capability of taxiing the aircraft on the ground without using the main aircraft engine(s). The power system includes a small driver mounted on the aircraft. In one embodiment of the invention, the driver may be mounted at any desirable location on the aircraft and is designed to provide sufficient thrust to taxi the aircraft. Such a suitable system may be provided as original equipment to an aircraft or retrofitted to existing aircraft. In another embodiment of the invention, the driver includes a speed reducer with an output shaft to drive the wheels of one of the landing gear assemblies to provide power to taxi the aircraft. In a further embodiment of the invention, the auxiliary on board power system, in addition to the taxiing function, may be incorporated with an alternator to provide electrical power, an environmental control unit, and an emergency power units as desired.

Abstract: An electric machine comprises a rotor assembly and a stator assembly adjacent the rotor assembly. The stator assembly includes windings disposed around a plurality of teeth, with each phase of the winding including at least one pair of coils wrapped in opposite directions around adjacent teeth to induce mutual inductance between the coils when electrical current flows through the phase of the winding. The coils of different phases are arranged to cancel magnetic coupling between the different phases. The winding arrangement provides a way to accomplish multiple, redundant, magnetically and electrically isolated windings with current limiting means in a single stator of an electric machine. The winding arrangements inherently provide an increase in mutual inductance and, therefore, an increase in impedance over that possible with prior art winding arrangements to limit the maximum short circuit current in the windings.

Abstract: A method for driving a neutral point clamped three-level inverter is provided. In one exemplary embodiment, DC current is received at a neutral point-clamped three-level inverter. The inverter has a plurality of nodes including first, second and third output nodes. The inverter also has a plurality of switches. Faults are checked for in the inverter and predetermined switches are automatically activated responsive to a detected fault such that three-phase electrical power is provided at the output nodes.

Abstract: A method for driving a neutral point-clamped multi-level voltage source inverter supplying a synchronous motor is provided. A DC current is received at a neutral point-clamped multi-level voltage source inverter. The inverter has first, second, and third output nodes. The inverter also has a plurality of switches. A desired speed of a synchronous motor connected to the inverter by the first second and third nodes is received by the inverter. The synchronous motor has a rotor and the speed of the motor is defined by the rotational rate of the rotor. A position of the rotor is sensed, current flowing to the motor out of at least two of the first, second, and third output nodes is sensed, and predetermined switches are automatically activated by the inverter responsive to the sensed rotor position, the sensed current, and the desired speed.

Abstract: A method for driving a neutral point clamped three-level inverter is provided. In one exemplary embodiment, DC current is received at a neutral point-clamped three-level inverter. The inverter has a plurality of nodes including first, second and third output nodes. The inverter also has a plurality of switches. Faults are checked for in the inverter and predetermined switches are automatically activated responsive to a detected fault such that three-phase electrical power is provided at the output nodes.

Abstract: A method for driving a neutral point-clamped multi-level voltage source inverter supplying a synchronous motor is provided. A DC current is received at a neutral point-clamped multi-level voltage source inverter. The inverter has first, second, and third output nodes. The inverter also has a plurality of switches. A desired speed of a synchronous motor connected to the inverter by the first second and third nodes is received by the inverter. The synchronous motor has a rotor and the speed of the motor is defined by the rotational rate of the rotor. A position of the rotor is sensed, current flowing to the motor out of at least two of the first, second, and third output nodes is sensed, and predetermined switches are automatically activated by the inverter responsive to the sensed rotor position, the sensed current, and the desired speed.

Abstract: An electrical system for a turbine/alternator comprising a gas driven turbine and permanent magnet alternator rotor rotating on a common shaft and comprising an inverter circuit connected either to an AC output circuit or the stator windings of the alternator. A control circuit during start-up mode connects the inverter circuit to the stator windings of the alternator and during the power generation mode it switches and connects the inverter circuit to the AC output circuit. Thus, during the start-up mode, the alternator functions as a motor to raise the speed of the turbine to a safe ignition speed and in the power generation mode the system provides power through the AC output circuit, electrical power having a frequency and voltage unrelated to the rotational speed of the turbine/alternator.