Abstract: A generator control unit for fast field discharge of a field coil is disclosed. The generator control unit comprises a control domain for detecting an excessive generator output voltage, a buck regulator with a feedback pin fed from the control domain, and an over-voltage protection switch connected in a field coil return path which is bypassed by a voltage limiting device. The control domain receives a point of regulation voltage feedback and upon detection of an over-voltage, emits a disable signal to cause the buck switch shut off along with the over-voltage protection switch. Thus dual breaking points are created at two ends of the field coil to dissipate the field charge quickly through the voltage limiting device. When the buck switch experiences a shorting failure, the over-voltage protection switch provides a second breaking point to allow the field discharge through the voltage limiting device, thereby controlling the field discharge with directly controlled over-voltage protection switch.

Abstract: A generator control unit for fast field discharge of a field coil is disclosed. The generator control unit comprises a control domain for detecting an excessive generator output voltage, a buck regulator with a feedback pin fed from the control domain, and an over-voltage protection switch connected in a field coil return path which is bypassed by a voltage limiting device. The control domain receives a point of regulation voltage feedback and upon detection of an over-voltage, emits a disable signal to cause the buck switch shut off along with the over-voltage protection switch. Thus dual breaking points are created at two ends of the field coil to dissipate the field charge quickly through the voltage limiting device. When the buck switch experiences a shorting failure, the over-voltage protection switch provides a second breaking point to allow the field discharge through the voltage limiting device, thereby controlling the field discharge with directly controlled over-voltage protection switch.

Abstract: An electric generator with a rotating diode fault detection device built in that operates by comparing a voltage buildup across the exciter DC supply with a preset threshold value and determining if a fault condition is present based on the comparison.

Abstract: Conventional electric power generation system employ a solid state electronically controlled IM that may be capable of self-start motoring and power generation, but, when the DC bus voltage collapses upon a failure, an additional external source of DC voltage is not available for IM excitation. The present invention provides an internal bus that does not collapse when the main DC bus is shorted. This internal or auxiliary bus may be used to excite the IM to provide generation function. The power generation systems of the present invention may play a significant role in the modern aerospace and military industries.

Abstract: A wound field synchronous (WFS) dynamoelectric machine comprises: a rotor assembly; an exciter generator section comprising a stationary multiphase exciter stator winding for receiving excitation power from a multiphase alternating current (AC) source to generate an exciter stator magnetic field, a multiphase exciter rotor winding in the rotor assembly for generating multiphase AC excitation power as it cuts through the exciter stator magnetic field and a rotating rectifier assembly in the rotor assembly for converting the multiphase AC excitation power to direct current (DC) excitation power; a synchronous machine section comprising a DC main rotor winding in the rotor assembly for generating a main rotor magnetic field and a stationary multiphase main stator winding for receiving a multiphase AC control signal to generate a rotating main stator magnetic field that interacts with the main rotor magnetic field to rotate the rotor assembly; and an impedance that selectively connects one phase of the exciter st

Abstract: A rotating electrical machine, such as an aircraft starter-generator, that may be operated in either a DC motor mode or an AC generator mode. The machine includes a conventionally wound main stator that is selectively configurable as a multi-pole AC stator and a multi-pole DC stator. The machine also includes rotor windings that are configured to be selectively coupled to either an exciter or a plurality of commutator segments, and DC brushes that are selectively moveable into, and out of, electrical contact with the commutator segments, to thereby electrically couple and decouple a DC power source to and from, respectively, the rotor windings.

Abstract: A system and method for electrically coupling windings of a main generator rotor to a plurality of DC sources on an exciter that each have respective first-voltage and second-voltage terminals is disclosed. The system includes first and second conductive plates supported by the rotor that respectively define first and second apertures that surround a rotor shaft. The first plate includes a first rotor winding terminal by which the plate is electrically coupled to the windings, and a first plurality of terminals configured to be respectively coupled to the first-voltage terminals of the DC sources. The second plate is electrically insulated from the first plate, includes a second rotor winding terminal by which the second plate is electrically coupled to the windings, and includes a second plurality of terminals configured to be respectively coupled to the second-voltage terminals of the DC sources.

Abstract: An alternator for use in an automotive vehicle includes a circuit for detecting initiation of rotation of an engine. Upon detecting the initiation of rotation, excitation current supply to a field winding is started, and thereafter an alternator output is controlled by controlling the excitation current. A resistor is connected to one phase winding of an armature to obtain a voltage indicating initiation of rotation during a period in which no excitation current is supplied to the field winding, and a capacitor is connected to another phase winding to raise the indicating voltage level. Since the indicating voltage induced by a small amount of residual magnetism is increased to a sufficient level by the capacitor, the initiation of rotation can be accurately detected.

Abstract: Circuit configuration for degradation of the stored magnetic energy of a field winding of a generator, where a battery voltage is applied to the field winding, having a power switch that is in operative connection with the field winding and is controllable by timed pulses from a clock control and which controls the storage and degradation of energy of the field winding. A zener diode is arranged between the field winding and a control input of a power switch for control of the energy degradation of the field winding, in particular of the power switch.

Abstract: A power device including a magneto and a rectification circuit for rectifying an output of the magneto is provided which is capable of adjusting an output of the magneto without any specific control circuit. A field adjusting excitation coil is arranged on a side of a stator of the magneto so as to generate a field adjusting magnetic flux when it is excited, resulting in a magnet field of the magneto being varied by means of the magnetic flux. The field adjusting excitation coil is connected to an intermediate portion of a current flow circuit for a load current, to thereby be excited by the load current, so that a magnet field of a rotor of the magneto is varied depending on the load current, leading to adjustment of an output of the magneto.

Abstract: A brushless three-phase synchronous generator includes a stator having primary generating windings and stator excitation windings whose number of poles is odd-number times the number of poles of the primary generating windings. The generator further includes a cylindrical rotor on which a plurality of field windings are wound in a full-pitch concentrated winding form. The plurality of field windings are respectively short-circuited by the corresponding diodes. A plurality of field windings in which voltages of the same phase are induced based on the odd-order spatial higher harmonic magnetic fields are connected in parallel and further connected in parallel to the central field windings which effectively produce primary field magnetic fluxes. A circulating rectifier element is connected in parallel to the central field windings.

Abstract: An electrical generator provides an output at a main stator winding which is excited by a main rotor winding. The main rotor winding is connected via a rectifier to a main exciter rotor winding which is excited by a main exciter field winding. A control circuit controls excitation of the main exciter field winding so as to stabilise the generator output voltage. The control circuit includes a detector for detecting excessive generator output voltage and a transistor switch for connecting a resistor in the current recirculation path of the main exciter field winding so as to prevent transient over-voltages caused by sudden load reductions.

Abstract: A brushless synchronous machine, for example a synchronous generator, having an exciter, whose field excitation winding is powered via a regulator connected to a separate auxiliary winding in the stator of the main machine in which the auxiliary winding has a number of phases that differs from the harmonic number of the harmonic wave that is the strongest in the event of a short circuit. In the case of a strong third harmonic wave, the auxiliary winding has a four- or five-phase design.

Abstract: A self-excited brushless AC generator as a single or polyphase main winding, a generator field winding, an exciter device for drawing current from the main winding for energizing the generator field winding when the main winding is under no load and normal load conditions and an auxiliary exciter system responsive to the generation of a harmonic of the generator fundamental flux to supply current to the exciter device for energizing the field winding when the main winding is under short circuit conditions. The auxiliary exciter system has an auxiliary winding wound with the main winding so as to be responsive to generation of the harmonic flux and an automatic voltage regulator. The regulator has a first input coupled to the auxiliary winding, a second input coupled to an output of the generator and an output coupled to an exciter field winding which is inductively coupled to an armature winding of the exciter device.

Abstract: In case of short circuit the overcurrent which passes through a detecting resistance in series with the excitation winding of the alternator operates a threshold current generator, which reduces the voltage of the central node of a voltage divider. A trigger interposed between said central node and an actuator circuit (for example a Darlington circuit) placed in series with the excitation winding of the alternator and with the above mentioned resistance turns off said actuator circuit, thus interrupting the current passage through the excitation winding. A filtering condenser associated to the voltage divider restores with delay the initial condition. The cycle is periodically repeated until the short circuit condition remains.

Abstract: An electric power generator which includes a component, for example, a Zener diode, connected in series with the usual return diode which is connected in parallel to the excitation winding of the alternator. The Zener diode makes it possible to set the discharging voltage due to the energy stored in the magnetic field associated with the inductance of the excitation winding at a relatively high level during high-voltage transients caused by the accidental disconnection of the wire connecting the alternator to a load or a terminal of the motor vehicle battery while it is in the charging stage. The result is a more rapid dissipation of the energy stored in the excitation circuit, and therefore results in an output transient having a reduced energy content. Thus, it is possible to construct a voltage regulator and such other devices as may be powered by the alternator in the form of low-voltage integrated circuits.

Abstract: A device of indicating the charging state of a battery including a series combination of a diode and an indicating lamp connected between an output terminal of a rectifying means of an alternator and a battery. A first switching means activates the indicating lamp when the battery voltage is less than a first lower predetermined value. A second switching means turns the first switching means off when the battery voltage rises above the first predetermined value. A third switching means reactivates the indicating lamp when the battery voltage exceeds a second higher predetermined value.

Abstract: A device for exciting a synchronous machine, comprises an exciter electrically connected to an exciting winding of the synchronous machine, a starting unit connected in parallel with the exciter and comprising at least one branch having a resistor and a thyristor switch placed in series. The control circuit of the thyristor switch has a threshold element. A protective thyristor is placed parallel to the branch of the starting unit and its control electrode is connected via the commutator of a current sensor of the starting unit branch to the control circuit of the protective thyristor. A safety device is inserted in series into the starting unit branch circuit.

Abstract: In a synchronous generator-motor, having both its main armature windings and exciter winding located on the stator and both the main field winding and the exciter armature windings including a rectifier for providing DC current to the main field located on the rotor and also including a voltage regulator responsive to the main armature voltage for regulating the current applied to the exciter field; the effects of transient currents in the main field windings resulting from load removal during the generator mode of operation and the voltages induced during motor start-up are substantially reduced by utilizing a resistive circuit operatively controlled by a transistor switching network that is in turn responsive to the exciter voltage and the induced voltage in the main field windings.

Abstract: An apparatus for protecting a synchronous machine from a field overvoltage is disclosed. The apparatus comprises a field excitation control circuit which is impressed with the armature voltage of the synchronous machine so as to provide a DC power supply for producing a DC output to excite the field winding of the synchronous machine, a first discharge circuit which is adapted to discharge the stored energy of the field winding when the synchronous machine is to be tripped under predetermined conditions, and a second discharge circuit for reducing the field voltage by allowing a field current to flow therethrough in response to generation of an overvoltage whose absolute value is higher than a predetermined level, across the field winding.

Abstract: In a protective arrangement for protecting a brushless synchronous machine against overvoltage at a field winding which is connected to a rotating excitation rectifier which is fed from an exciter machine, in which the field winding is short circuited by means of a solid state switching element when overvoltages occur, a voltage comparison means is provided to which are fed as respective first and second inputs, a first input voltage proportional to the primary voltage of the exciter machine and a second input voltage proportional to the primary current of the exciter machine with the proportionality constant chosen such that for normal operation of the synchronous machine the absolute value of the second input voltage is lower than the first input voltage and for operation when the field winding is short circuited, the absolute value of the second input voltage is greater than the first input voltage.

Abstract: In a brushless synchronous generator with an exciter, in which the three phase armature winding of the generator is coupled through a series regulator to the field winding of the exciter, and in which the rotating armature of the exciter feeds the rotating field winding for the synchronous generator through rectifiers, the series regulator being coupled in series between the three phase windings of the generator and the field winding of the exciter and including a control element, and in which there is a bypass diode across the exciter field winding, in order to protect the control element, a protective device is disposed between the control element and the three phase winding and an overvoltage arrester is placed in parallel across the exciter field winding and the bypass diode, the overvoltage arrester operating if an overvoltage occurs, thereby causing increased current to be drawn to actuate the protective device in series with the control element thereby preventing the synchronous generator from reaching

Abstract: A generating system employing a generator having a self-excited field winding the excitation of which is achieved by supplying a bridge circuit with signals which are, respectively, proportional to the generator terminal voltage and the load current further includes means to selectively short-circuit the field winding during each cycle of normal generator operation. The system further includes a feedback path or loop for controlling the time during which the field winding is short-circuited which feedback path develops a control signal by comparing a signal representing the voltage supplied to the bridge circuit with a reference signal to develop an error signal which is then modified by a further signal proportional to the Thevenin equivalent voltage of the bridge circuit to thus linearize the feedback loop.

Abstract: A voltage regulator for a separately excited generator including a main generator unit having generating winding means and exciting winding means and an exciter comprising a magnet field type generator with the output connected through a rectifier to said exciting winding means, said voltage regulator comprising thyristor means connected to said output of said exciter to short the AC output from said exciter from being supplied to said exciting winding means of said main generator unit characterized by further comprising a voltage divider including first electric resistance means non-linear in voltage to current characteristic, and second electric resistance means said voltage divider connected to the output of said generating winding means of said main generator, with the output voltage across said first electric resistance means of said voltage divider connected through a Zener diode to the gate of said thyristor means.

Abstract: This invention is directed to an automatic voltage regulator for a seperately excited generator comprising a main AC generator including an armature winding and an exciting winding and an exciter of an AC magneto generator associated with the exciting winding of the main AC generator. The regulator comprises a single controlled semiconductor switching device disposed in parallel to the exciting winding of the main AC generator and an output voltage detecting and control signal generating circuit which is adapted to detect the output voltage of the main AC generator and to apply a control signal to the controlled electrode of the controlled semiconductor switching device when the output voltage of the main AC generator reaches more than a predetermined value. The exciter of the AC magneto generator has an operating frequency higher than that of the main AC generator whereby the output voltage of the main generator can be regulated in a minute manner.