| Patent application number | Description | Published |
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| 20090315522 | SELF-EXCITED CONTROLLED FREQUENCY GENERATOR SYSTEM WITH BI-DIRECTIONAL CONVERTER - A controlled frequency generating system (CFG) may be constructed with a main generator and an exciter driven by a common shaft. Excitation power may be provided from the common shaft; as distinct from prior-art systems which may require independent excitation power sources. While controlling the output voltage and frequency of the main generator, the bi-directional controller extracts power from a main generator output and may supply the extracted power to supplement excitation power when needed at certain rotational speeds. The controller may extract power from the exciter when, at other rotational speeds, the exciter produces excess power. The extracted excess power may be delivered to the output of the main generator to maintain a desired level of output power at a desired frequency, irrespective of speed of rotation of the CFG. | 12-24-2009 |
| 20090323377 | OPTIMAL UTILIZATION OF POWER CONVERTERS FOR ENGINE START SYSTEM - A method and system for utilization of power converters in an aircraft engine start system includes measurement of power converter operation data that is utilized with a mathematical model of the power converter thermal characteristics to calculate operation limits for subsequent start duty cycles. A warning indicator is utilized in the event the start duty cycle limits are exceeded. This invention can be extended for any More Electric Vehicle applications, which utilizes an electric engine start system. | 12-31-2009 |
| 20100013342 | OPTIMIZED MULTI-PHASE ARMATURE WINDING - An electrical motor or generator asymmetrical armature winding configuration generating a multi-phase balanced power output. Each winding group for each pole, and the conductors constituting each winding group, are chosen individually according to their magnetomotive force (MMF) vector relationship to provide a balanced power output even though the individual windings may not be balanced or symmetrical. | 01-21-2010 |
| 20100026089 | ELECTRICALLY CONTROLLED FREQUENCY-BASED POWER SYSTEM ARCHITECTURE FOR AIRCRAFT - An electrical power system and method utilizing a controlled frequency generator (CFG) that creates an electrical output with a constant frequency is disclosed. More specifically, an electrical power system and method utilizing controlled frequency to provide no break power to the various aircraft electrical power components as well as providing starting power to the main engine and the auxiliary power unit. An electrical power system in accordance with the present invention eliminates various unnecessary AC and DC conversions by generating a more user friendly electrical output at a constant frequency to be usable by various aircraft components such as the air compressor, electronics, hydraulic pressure, and air conditioning. Moreover, the current electrical power system architecture can also be used to provide main engine and auxiliary power unit starting power utilizing the constant frequency. | 02-04-2010 |
| 20100207590 | HIGH FREQUENCY GENERATOR WITHOUT ROTATING DIODE RECTIFIER - A high frequency starter-generator system uses an electric machine design that does not employ rotating rectifiers installed on the rotor. The output frequency of such a starter-generator is increased by about 200% as compared with a conventional starter-generator with the same number of poles operating in the same speed range. This design allows significant weight and volume reductions of the electric machine while its reliability is increased. The present invention may find application in any starter-generator application, including more electric architecture-type aircraft designs currently in development. | 08-19-2010 |
| 20100231181 | NOVEL STARTER-GENERATOR WITH IMPROVED EXCITATION - An electrical power system may comprise a main generator with a rotor having field windings and at least one embedded permanent magnet. A generator control unit (GCU) may be connected to receive excitation current produced by the main generator with flux from the at least one permanent magnet. An exciter generator may be connected to be provided with excitation from the GCU. The exciter generator may provide excitation current to the field windings of the main generator. The main generator may produce output current from flux from the field windings and the at least one permanent magnet. | 09-16-2010 |
| 20110062710 | MULTI-STAGE CONTROLLED FREQUENCY GENERATOR FOR DIRECT-DRIVE WIND POWER - A multi-sage controlled frequency generator is described that has a low size, weight and cost. The new generator requires an electronic controller that requires only 25% of the total generated power (100%) when the generator shaft speed varies by +/−25% around its synchronous speed. The shaft driving the generator in the direct-drive controlled frequency generator may be moved at a variable speed. The output frequency of the generator may be controlled by electrically controlling the frequency of the first stator stage and by selecting the control frequency, the number of poles, and the number of stages, such that the output of the last stage will be maintained constant at the desired grid frequency. | 03-17-2011 |
| Patent application number | Description | Published |
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| 20080303280 | ENGINE START SYSTEM WITH QUADRATURE AC EXCITATION - A starter-generator system may be used to supply sufficient starting torque to start an aircraft main engine. The main starter-generator stator winding may be connected to a constant frequency (CF) power source to create a rotating field in the main starter-generator air gap. This rotating field, in turn, may induce current on the main rotor winding, which may be a closed circuit formed by main rotor field winding and exciter armature winding. The interaction between the main rotor current and the air gap flux may give rise to the starting torque to start the main engine. Adjusting the voltage supplied to the exciter stator field winding can modify the induced voltage and current on the rotor circuit to control the rotor current and starting torque. The starter-generator system may also be used to start an aircraft main engine by directly connecting the main stator winding to a power source without powering the exciter stator. | 12-11-2008 |
| 20080303490 | GENERATOR WITH QUADRATURE AC EXCITATION - A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required. | 12-11-2008 |
| 20090012742 | ENERGY BASED POSITION AND SPEED SELF-SENSING METHOD AND APPARATUS FOR SYNCHRONOUS MACHINE - An envelope of a voltage may be extracted using an operator to calculate a position and speed of a rotor. A position and speed sensing method may include supplying voltage to a rotor, extracting an envelope of the voltage using an operator, and calculating a rotor angle of the rotor based on the extracted envelope. A position and speed sensing apparatus may include a rotor, and a controller to extract an envelope of a voltage supplied to the rotor using an operator and to calculate a rotor angle of the rotor based on the extracted envelope. | 01-08-2009 |
| 20090045784 | A NOVEL AIRCRAFT ENGINE STARTER/GENERATOR - A rotor resistor and switch combination may cause a starter/generator device to function as an asynchronous device when in a start mode. Thus, starting torque may result. A starter/generator device may include an exciter rotor winding, a main rotor winding, and a resistor and switch combination positioned between the exciter rotor winding and the main rotor winding to control a flow of current in the main rotor winding during a start mode of the starter/generator device. A method of optimizing starting torque of a starter/generator device without a start controller unit during a start mode may include providing a main rotor winding of the starter/generator device, and providing a control to control a flow of current in the main rotor winding during the start mode. | 02-19-2009 |
| 20090256419 | AC/AC POWER CONVERTER FOR AIRCRAFT - A matrix converter circuit having two AC/AC matrix converters coupled in parallel in a first mode to power a starter and decoupled in a second mode to each power separate functions used in aircraft power applications. Three common functional modes include 1) start mode with two matrix converters operating in parallel powering the starter, 2) a motor mode where one matrix converter powers a motor, and 3) a constant frequency power mode where the other matrix converter provides constant frequency AC power. | 10-15-2009 |
| 20100308581 | POSITION-CONTROLLED START FROM THE AC LINE USING A SYNCHRONOUS MACHINE - A synchronous electric machine operates as a starter-generator for an aircraft. When operating in a starting mode, a main stator of the machine is supplied with electrical power at a constant frequency. An exciter stator is supplied with variable frequency power. As rotational speed increases, the exciter variable frequency changes correspondingly to maintain synchronous operation of the machine and maximum torque. In a generator mode, variable frequency is applied to the exciter stator with the exciter frequency varying as a function of rotational speed of an engine driving the machine. This provides for a constant frequency output from the machine. | 12-09-2010 |
| 20110068753 | GENERATOR WITH QUADRATURE AC EXCITATION - A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required. | 03-24-2011 |
