摘要:
A high voltage direct current (DC) tether for an airborne wind turbine includes one conductor in the center of the feeder and the shielding of the feeder as a second conductor. A mechanical strength element is disposed in between the center conductor and the shielding. In this configuration, the mechanical strength element acts also as an insulator. The center conductor and the shielding can be made of aluminum or copper. The strength element can be a high strength fiber composite, woven such as VECTRAN® or SPECTRA®. The shielding is typically used as the return conductor.
摘要:
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.
摘要:
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.
摘要:
A circuit producing power with controlled frequency from a variable frequency power source (14) includes an AC bus (20) connected to the variable frequency power source (14) and a plurality of load circuits, each load circuit including an AC input (24) and an AC output (26), an AC contactor (30) between the input (24) and output (26), a rectifier (32) between the AC contactor (30) and the output (26) and an inverter (34) between the rectifier (32) and the output (26). A method of producing power with controlled frequency is also disclosed.
摘要:
A power conversion system eliminates output transformers and replaces them with a zig-zag transformer and a filter that provides a 3-phase 5-wire system with significantly reduced weight and size as compared with conventional systems. The zig-zag transformer may have a low zero sequence impedance. The power conversion system also ensures operational safety by detecting various types of ground faults.
摘要:
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.
摘要:
A power system for a vehicle may comprise an electric machine attached to an engine of the vehicle. The electric machine may comprise only one stator core; a stator main winding wound on the one stator core; a stator exciter winding wound on the one stator core. The stator main winding and the stator exciter winding may be magnetically independent from one another even though magnetic-field-isolation material is not interposed between the stator main winding and the stator exciter winding.
摘要:
A method of supplying mechanical power to an operating gas turbine engine includes supplying mechanical power from the operating gas turbine engine to a starter-generator, to thereby generate electrical power using the starter-generator. One or more operational parameters of the operating gas turbine engine are sensed and, based on the one or more sensed operational parameters, electrical power is selectively supplied to the starter-generator to thereby generate and supply mechanical output power to the operating gas turbine engine.
摘要:
A position sensing apparatus (300) derives rotor position of a synchronous machine (200) from signals output from the machine (200). In one embodiment, the position sensing apparatus (300) comprises: a bandpass filter (322) that filters phase voltage signals output from main stator windings (216) of the synchronous machine (200) during AC excitation, thereby extracting a rotor position-indicating component from the phase voltage signals; a converter (324) that converts the filtered phase voltages into balanced two-phase quadrature signals, the balanced two-phase quadrature signals indicating positioning of the rotor (212); and an excitation controller (204) for controlling AC excitation frequency as a function of rotor speed.
摘要:
A starting system may include a wound-field electric machine with a main generator and an exciter generator. The main generator and the exciter generator may each have stator windings and rotor windings. A shorting switch may be provided for interconnecting the stator windings of the exciter generator together when power is applied to stator windings of the main generator. This may result in starting torque being produced by the exciter generator, which starting torque may be additive to starting torque produced by the main generator.