Abstract: A power system includes a synchronous electrical generator having a rotor driven by a shaft; a permanent magnet signaling generator, coupled to the shaft; and an angle computation unit configured to calculate a rotor angle or load angle based on a voltage from the permanent magnet signaling generator and a voltage from the synchronous electrical generator.

Abstract: A device has a plurality of power converter groups and a control system. A power converter group has a group of power converters and is coupled between an input voltage source and a group of windings of a motor generator. The control system is configured to control currents of the windings such that the number of poles of and the number of phases in a pair of poles of the motor/generator are dynamically adjusted, and the number of poles and the strength of a magnetic field of the motor generator are controlled to reduce a power loss. The motor/generator has an air gap and a stator with a plurality of slots, where the windings are installed in. The windings are configured such that the number of poles and the number of phases in a pair of poles of the motor/generator can be dynamically adjusted.

Abstract: The present invention concerns a method of controlling a wind power installation having a generator with a stator, a pole wheel with at least two rotor poles with a respective pole winding for producing a magnetic field guided in the respective rotor pole, and an air gap between the stator and the pole wheel, including the steps— controlling a respective exciter current through each pole winding,— varying at least one of the exciter currents relative to at least one further one of the exciter currents, and/or— varying at least one of the exciter currents in dependence on the position of the pole wheel in relation to the stator.

Abstract: A system and method are disclosed for advantageously using field-controlled high-frequency alternators for the generation of controlled high-voltage DC power from variable speed mechanical power sources such as wind turbines, water wheels, and gas or steam turbines. The production of controlled high-voltage DC power without involving hard switching of the full output power is described.

Abstract: To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.

Abstract: 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.

Abstract: A method for operating a doubly fed permanent magnet synchronous machine and a system including such a machine and a converter for feeding and withdrawal of power. The machine has two or more winding groups where at least one winding group is connected directly to a grid and at least one winding group has the possibility to be connected to the grid via a power electronics converter or directly.

Abstract: A variable speed machine assembly includes an input shaft, a variable speed magnetically geared generator coupled to the input shaft, an electrical machine coupled to the input shaft, and a power converter coupled to the variable speed magnetically geared generator and the electrical machine. The power converter is configured to use electrical power output by the electrical machine to control a frequency of power output by the variable speed magnetically geared generator.

Abstract: 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.

Abstract: An exciter assembly for supplying a field current to the rotor windings of a superconducting synchronous machine includes a pulse transformer having a stationary primary winding and a secondary winding that is mounted to the rotor of the superconducting synchronous machine for rotation therewith. A switched mode power supply supplies a pulsed voltage to the primary winding of the pulse transformer. The pulsed voltage developed at the secondary winding of the pulse transformer is supplied to the rotor windings through a rectifier semiconductor device and a pair of transfer leads. The rotor windings and a flywheel semiconductor device are located inside a cryogenic chamber or cryostat. The flywheel semiconductor device is connected in parallel with the rotor windings and operates in unison with the rectifier semiconductor device in order to provide synchronous rectification of the switched mode power supply output.

Abstract: 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.

Abstract: 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.

Abstract: A wind power generation system includes an excessive current consumption device, an AC input of which is connected between a generator rotor and an excitation converter on a system failure to detect a DC voltage ascent of the excitation converter and operate a shunt circuit on the system failure.

Abstract: The present invention relates to a method and system for controlling a doubly-fed induction machine. In operation a rotor current vector is processed with a rotor position estimate vector. A scalar error quantity is the determined in dependence upon a stator current vector and the processed rotor current vector. The scalar error quantity is integrated and an estimate of the rotor angular frequency is determined in dependence upon the integrated scalar error quantity. To obtain a rotor position estimate, the estimate of the rotor angular frequency is integrated and a rotor position estimate vector is determined in dependence upon the rotor position estimate. The rotor position estimate vector is then provided for processing the rotor current vector. As output signals a signal indicative of the rotor position estimate vector and a signal indicative of the estimate of the rotor angular frequency are provided for controlling the doubly-fed induction machine.

Abstract: A method is disclosed for arranging and exciting the stator, rotor and various windings of a multi-stage brushless high frequency alternator so that the resulting multiple high frequency sub-phase armature winding outputs can be rectified and commutated into desired phases of power-frequency alternating current (AC) electrical output, including single-phase, split-phase, three-phase and other multiple phase output. Power frequency currents in field windings control output amplitude, output frequency, and output phase. If desired, DC power output can be accommodated as zero power-frequency operation. Devices incorporating this arrangement are suitable of generating fixed frequency electrical power while accommodating variable speed rotation of a generator shaft and offer multiple advantages over existing techniques. The capability to generate speed independent electric power allows natural power sources such as windmills and hydro-power stations to be efficiently coupled to fixed frequency power grids.

Abstract: A variable rotational speed wind turbine includes a doubly-fed induction generator, a rotor current controller for controlling the rotor currents of the generator, a compensation mechanism having a computation mechanism, and an input mechanism for providing input to the compensation mechanism, the input being representative of at least the instantaneous angular speed of the rotor of the generator. The computation mechanism is arranged to compute an instantaneous compensation control output in dependency of the instantaneous angular speed of the rotor of the generator and feed the compensation control output to the rotor, and to compute the compensation control output during operation of the wind turbine to compensate at least partly for dependencies on the rotor angular speed of the locations of poles of a generator transfer function, thus making a resulting generator transfer function substantially independent of variations in the rotor angular speed during operation of the wind turbine.

Abstract: In a method and an apparatus for controlling the output or drawn active and reactive power of a double-fed asynchronous machine (5), the maintenance of a maximum permissible current (16) of the machine—without the use of a subordinate current controller—is ensured by virtue of the fact that, during the operation of the double-fed asynchronous machine, a maximum permissible desired value for the active power (10a) to be output or to be drawn and a maximum permissible desired value for the reactive power (10b) to be output or to be drawn are calculated with the aid of a model of the asynchronous machine from the maximum permissible current (16), preferably corrected at least using the actual value of the current to be limited of the machine, in such a way that the maximum permissible current (16) is not exceeded; The predetermined active and reactive power desired values are then limited to the calculated maximum permissible values.

Abstract: When driven by a variable speed prime mover, a 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 and located in a common core as the main rotor windings to provide two-phase excitation current to the main rotor windings. The exciter stator winding is also located in a common core as the main generator stator 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 and rotor position of the generator, to maintain a constant output frequency.

Abstract: In a wind power generation system, an AC input of a unit for coping with system faults is connected to an excitation converter and a DC port of the unit for coping with system faults is connected to a DC port of a converter through resistors. A plurality of energy consumptive circuits each constructed of a resistor and switching units are provided for the DC port of the unit for coping with system faults.

Abstract: A method and a damping device are proposed for damping a torsional oscillation in a rotating drive train. Arranged on the drive train is an electrical machine (13), which is connected to an electrical multipole (31). A damping torque is generated in the electrical machine (13) by an electrical damping member connected to the electrical machine (13). It is proposed that the damping torque has a predetermined damping frequency and is antiphase to the angular velocity of the torsional oscillation.

Abstract: An electromechanical power transfer system that transfers power between a prime mover and a direct current (DC) electrical system, comprises: a permanent magnet machine (PMM) that has a permanent magnet (PM) rotor coupled to the prime mover, a stator with a multiphase alternating current (AC) winding coupled to an AC bus and a control coil with a winding that has a configuration to generate a magnetic field with flux that varies the reactance of the stator winding with the application of control coil current; a control coil current sensor for generating a control coil current signal that is representative of the level of electrical current in the control coil; an electrical current sensor for generating a DC bus current signal that is representative of the level of DC current through the DC bus; an electrical potential sensor for generating a DC bus potential signal that is representative of the level of DC potential on the DC bus; a fixed pattern active rectifier and inverter system coupled between the AC bu

Abstract: A control apparatus for a vehicular AC generator analyzes, at least, a “HIGH” logic continuation time, a “LOW” logic continuation time and the pulse width duty of an external signal, for the external signal pulse inputted from an external unit. In a case where the “HIGH” logic or “LOW” logic of the external signal pulse has continued for a predetermined time period, the control apparatus controls a generator control voltage as either of adjustment voltages consisting of the two values of an ordinary voltage and a voltage lower than the ordinary voltage. On the other hand, in a case where the “HIGH” logic or “LOW” logic of the external signal pulses are iterated within a predetermined time period, and where the pulse width duty of the external signal falls within a predetermined range, the control apparatus controls the generator control voltage as a multistage or linear adjustment voltage which is the function of the pulse width duty ratio.

Abstract: A generation control apparatus for vehicles is provided, in which a drastic change in the drive torque of a generator, which occurs with the cancellation of gradual excitation immediately after starting an internal combustion engine, can be suppressed to prevent stoppage of the internal combustion engine. The generation control apparatus includes an engine-start detection circuit, a gradual excitation circuit, a comparator for gradual-excitation cancellation, and a masking circuit for gradual-excitation cancellation. After detecting an engine start by the engine-start detection circuit, an instruction for gradual-excitation cancellation is released during an initial gradual excitation performed by a gradual excitation circuit, based on an output from the masking circuit for gradual-excitation cancellation. The drastic change in the drive torque occurring with the cancellation of the gradual excitation immediately after the engine start, can thus be suppressed, thereby preventing the engine stop.

Abstract: When drive control of a generator is performed, PWM control of a switching circuit comprising an FET and a diode connected to the opposite ends of a winding is performed. In the vicinity of a moment in time Lmax where the winding has a maximum inductance L, an alternating mode for repeating a supply mode and a reflux mode alternately is performed through PWM control. After the alternating mode is performed, the reflux mode is performed temporarily in order to increase the quantity of current, and then a regenerative mode is performed. The regenerative mode is performed by increasing the current level as much as possible when the reflux mode is started while suppressing the brake force of the rotor in the alternating mode. From a position advancing in angle by a time Tah from the moment in time Lmax where the winding has a maximum inductance L, a first alternating mode C1 for repeating the supply mode P and the reflux mode Q alternately is performed.

Abstract: A fixed frequency electrical generation system includes an induction coupler. The system includes an electricity generator with no rings or brushes, and an induction speed regulator, mechanically coupled, so as to transform mechanical energy input from a shaft rotating at a variable speed into output electricity in the form of at least one alternating voltage with a constant rms value and constant frequency.

Abstract: A vehicle power generation control apparatus that has a power supply circuit, a rotation detecting circuit, an exciting current detecting circuit, an exciting current control circuit, a torque detecting/maximum exciting current determining circuit and a power transistor. When a speed of rotation of a vehicle generator is detected by the rotation detecting circuit and an exciting current flowing through an exciting winding of the vehicle generator is detected by the exciting current detecting circuit, the torque detecting/maximum exciting current determining circuit calculates an upper limit value of the exciting current so that a rate of change of a generator torque does not exceed a predetermined value, and the exciting current control circuit controls the exciting current so that the exciting current becomes below the limit value. This can prevent the engine revolution from becoming unstable due to variation of load or variation of engine revolution.

Abstract: The generator includes an asynchronous machine with a wound rotor driven mechanically and a stator connected to the network. The rotor is excited by a constant DC voltage source via an inverter controlled by a pulse width modulation control circuit. In accordance with the invention, the following are generated: a stator frequency set point, a rotor frequency set point which is a function of the stator frequency set point and the rotation speed of the machine, an rms stator voltage set point, an error signal which is a function of the difference between the rms stator voltage set point and the actual rms stator voltage. A rotor voltage set point is imposed on the control circuit which is a function of the error signal and the rotor frequency set point.

Abstract: An excitation control system for a generator includes a silicon controlled rectifier bridge having an input interconnected with a plurality of alternating current (AC) phases of positive and negative polarity, an output interconnected with the field input of the generator in order to provide an excitation voltage thereto, and an SCR segment for each of the positive and negative polarities of the AC phases. Each of the SCR segments has an SCR responsive to a control signal in order to control current conduction within the segment between the input and the output of the SCR bridge. A regulator circuit requests a maximum value of the excitation voltage for the generator. The auxiliary contacts of a generator circuit breaker determine when the generator is on-line and connected to a power circuit. A phase lock loop provides an error signal from the AC phases. A control circuit outputs control signals to the SCR segments in order to control current conduction within the segments.

Abstract: An AC generator whose field winding (4) on the rotor is excited by AC so that the resultant speed of the rotating field is the algebraic sum of the rotor speed and the speed of the field relative to the rotor itself. This makes it possible to generate AC at a frequency different from that of conventional DC excited generators by the appropriate choice of the frequency of the AC input to the rotor field circuit. It enables the stabilization of the output frequency of the alternator when speed changes occur, by the adjustment of the AC frequency of the rotor input. The AC fed to the rotor is from an auxiliary winding (3) which may be housed on the rotor itself, thereby eliminating the need for any brushes or slip rings. The AC is induced in the auxiliary rotor winding by having an auxiliary winding on the stator (2), distinct from the main stator winding (1). The input to the stator auxiliary winding may be from an inverter (5) whose frequency may be adjustable.

Abstract: An induction machine used as a power generator for an internal combustion engine, and which generates a predetermined power regardless of a rotation speed of a rotor of the induction machine and the engine. A power P to be generated is controlled so as to be equal to an upper limit value Pmax or less, a lower limit value or more or, equal to a target value Pc. The power generation control is achieved in the following manner. A speed N2 of the rotating magnetic field electrically generated with a three-phase winding of the rotor 1R is controlled in accordance with the mechanical rotation speed N1 of the rotor 1R in order that a relative speed N of the rotating magnetic field generated in the rotor with respect to a stator coil is kept at an upper limit speed Nmax or less, a lower limit speed Nmin or more, or a target relative speed Nc.

Abstract: Loss of excitation and control and subsequent damage to exciter windings in an excitation system for dynamoelectric machines wherein one or more rotating diodes fail in a shorted mode is prevented through the use of an RC circuit for detecting AC voltages in an exciter field winding for the purpose of directly operating a circuit breaker to remove excitation to the field windings and supply or to activate a timer for such purposes while temporarily shorting the AC current through the exciter field winding.

Abstract: An excitation system for a brushless generator having a main generator portion including a field winding disposed on a rotor and an armature winding disposed in a stator includes an exciter portion having a set of polyphase exciter field windings disposed in the stator and an armature winding disposed on the rotor and coupled to the main generator portion field winding. A first power converter is coupled to the main generator armature winding and a second power converter is coupled to the set of polyphase exciter field windings. Contactors are operable in a starting mode of operation to couple a source of electrical power to the first and second power converters and are operable in a generating mode to disconnect the source of electrical power from the first and second power converters.

Abstract: A starter generator system is provided with a dynamoelectric machine having a stator and a rotor which is mounted for rotation with respect to the stator. The rotor carries a main field winding, an exciter armature winding and means for rectifying the output of the exciter armature winding to provide DC excitation for the main rotating field winding. A main armature winding is mounted on the stator and magnetically coupled to the main field winding. An exciter portion of the stator supports both a multiple phase AC exciter field winding and a distributed DC exciter field winding, both of which are mounted to be magnetically coupled to the exciter armature winding. A variable voltage, variable frequency power converter is capable of being alternatively connected to drive the dynamoelectric machine as a starting motor or to receive power from the machine during generator operation.

Abstract: A generator providing both tachometer and synchro outputs and comprising a magnetic stator and a corresponding armature structure. The generator stator structure produces a composite magnetic field of both constant (DC) and alternating (AC) flux. The rotor directs the composite flux field through a plurality of sensing coils, each producing a signal from the sensed composite magnetic field and rotor motion, and which coil signal is separated into separate signal components. The components are processed to produce a synchro output which preferrably has standard Hall-effect equivalent signals, as well as providing a tachometer output voltage proportional to the rotor rotational velocity and direction.

Abstract: A variable-speed constant-frequency alternator compensating for changes in speed of the prime mover by electromagnetically rotating the rotor's magnetic poles around the rotor. If the prime mover has a rotational speed above or below that required to produce the desired output frequency, the magnetic poles rotate about the rotor in a forward or reverse direction, respectively. To connect the alternator to an external a.c. source, the alternator's controls match its output to the precise amplitude frequency, and phase of the external source. The rotor, for each magnetic pole pair, includes three windings. Three-phase power in these windings, produces the magnetic pole pair and rotates it relative to the rotor. Each winding couples to a flopper circuit having k sets of resistances. The resistances, taken in turn, have an inverse proportionality to the magnitude of the desired sine wave for the three-phase current in the rotor's windings.

Abstract: A rotating electric machine comprising a stator 1 and a rotor 5 which is adapted to be rotated about an axis and which is disposed opposite said stator 1. Normally, the magnetic field of the rotor is excited by a direct current which is supplied via sliding contacts. In order to avoid wear of the sliding contacts, the invention employs the measure that the exciting current for the magnetic field of the rotor is supplied via a second stator 13 and a second rotor 9 by means of induction.

Abstract: An excitation system for a brushless synchronous alternator includes an exciter having a stator which includes first and second sets of field coils respectively coupled to a source of DC power and in series with polyphase AC output current developed by the main generator. A base level of exciter field current is provided by the DC current delivered to the first set of field coils while a second variable amount of field current is provided by the AC output current delivered to the second set of field coils. The exciter also includes a rotor structure having first and second sets of armature windings which develop first and second exciter currents in response to movement of the rotor structure within the magnetic fields set up by the first and second sets of exciter field coils. The first and second exciter currents are added, rectified and delivered to a set of main generator field windings.

Abstract: An automatic feedback and control system for operating a load off of a multi-phase rectified rotary field system of a motor vehicle and for increasing the voltage and current to the load upon demand. The multi-phase rectified rotary field system comprises a rotatable coil for forming the rotary field when excited and stationary windings having an output coupled thereto by way of rectifier means. A DC power supply is coupled to said output. A regulator is provided having an input coupled to the DC power supply and and output coupled to the rotatable coil. Non-polarized capacitors are provided and a switch is coupled to the capacitors and to the DC power supply. The switch when closed, electrically connects the capacitors between the stationary windings and the rotatable coil and electrically connects the DC power supply to the rotatable coil.

Abstract: A substantially constant frequency self-regulated generator produces in one embodiment 120 volts or the like single phase output or in another embodiment 120 or 240 volts or the like single phase output. The generator employs an exciter stator and a stationary rectifier assembly with the former being a six pole exciter stator alternately wound with three shunt poles and three series poles with two separate windings on each series pole. The three shunt poles of the exciter stator are connected in series making, in effect, one shunt winding. The series circuit consists of two separate windings on each series pole, which are respectively parallel connected and wound on all three series poles. Each series pole then has two separate isolated coils. With the exciter stator there is employed a stationary diode assembly utilizing three diodes as rectifiers for the shunt and isolated series windings.

Abstract: A double induction dynamo electric machine of the exciter-generator type provides an AC electrical output that has a substantially constant frequency characteristic by using a closed frequency loop arrangement without requiring electronic controls or, in most instances, continuous application of an externally derived AC excitation signal. Moreover, the machine preferably provides such AC electrical output with a substantially constant voltage characteristic as the load current varies, without electronic voltage feedback controls.

Abstract: This invention relates to a generator system for generating a readily controllable A.C. of a selected potential and of a substantially constant selected frequency, which system comprises a first, or master, rotary generator producing an A.C. potential of substantially constant frequency and at least one other, or slave, rotary generator producing an A.C. potential of a frequency identical to that of the first generator, the A.C. potential outputs of all the generators being combined in series, and electrical means for shifting the phase of the A.C. potential of the slave generator with respect to the phase of the A.C. potential master generator whereby the resultant combined A.C. outputs constitute an A.C. potential of the selected value and being of the substantially constant selected frequency.

Abstract: An inductor-type high frequency generator with alternating current field excitation and frequency changing output means. An excitation winding provides current for the field winding by way of a rectifier, and automatic voltage regulator and an inverter. In response to generator output the A.V.R. controls the d.c. voltage fed to the inverter.

Abstract: A generator providing both tachometer and synchro outputs and comprising a magnetic stator and a corresponding armature structure. The generator stator structure produces a composite magnetic field of both constant (DC) and alternating (AC) flux. The rotor directs the composite flux field through a plurality of sensing coils, each producing a signal from the sensed composite magnetic field and rotor motion, and which coil signal is separated into separate signal components. The components are processed to produce a synchro output which preferrably has standard Hall-effect equivalent signals, as well as providing a tachometer output voltage proportional to the rotor rotational velocity and direction.