Abstract: A system for monitoring maintenance information in a hydroelectric power generation facility comprises sensors coupled to a controller. The sensors detect actual levels of operating parameters for a desired operating period at an operating condition. The detected parameters include a stressor capable of affecting a life span, or mean time between failures, of the turbine or one of its components. The controller determines the amount of the life span used up. A method for monitoring maintenance information in a power generation facility includes the steps of monitoring levels of operating parameters including a stressor for a desired operating period at an operating condition. The stressor affects the life span of the turbine or one of its components, and the amount of the life span used up over the operating period is calculated.

Abstract: An electronic device capable of increasing the braking torque applied to an electric power generator without causing a significant reduction in electric power generated by the electric power generator. The electronic device, which may be embodied in an electronically controlled mechanical clock, includes an electric power generator for converting mechanical energy transmitted from a spring via a wheel train to electrical energy, and a rotation controller for controlling the rotation period of the electric power generator.

Abstract: An improved motor vehicle electrical system includes a flexible topology DC-to-DC converter for coupling an engine-driven alternator to vehicle electrical loads at a mode-dependent transfer ratio. The output voltage of the alternator is regulated based the load voltage, and the converter is operable in one of a number of different modes based on engine speed, including a forward boost mode, a forward unity mode, and a forward buck mode. In the forward boost mode, the converter output voltage is boosted above that of the alternator to enable battery charging at low engine speeds; in the forward unity mode, the alternator output voltage is transferred to the battery and electrical loads at a unity transfer ratio; and in the forward buck mode, the converter output voltage is reduced below that of the alternator to enhance the alternator power output at medium-to-high engine speeds.

Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a minimal number of current sensors and controlling at least one of a machine flux, an output voltage and generator torque, based on the stator or rotor flux magnitude and position.

Abstract: The present invention features a voltage-limiting regulator for use with an AC generator having DC-excited fields. The AC output voltage from the generator is sensed and compared to a fixed reference voltage. An algebraic difference voltage representative of the sensed difference is amplified and applied to the DC field excitation input of the AC generator. As the DC voltage supplied to the field varies, the AC output voltage from the generator may be held constant under varying load conditions. The voltage-limiting regulator is particularly useful for vehicle-mounted, high power, single phase AC generators.

Abstract: A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a plurality of flux sensing coils and controlling at least one of a machine flux and an output voltage based on the stator or rotor flux magnitude and position. One embodiment of the invention only uses flux sensing coils without requiring current sensors or position sensors.

Abstract: An AC generator control apparatus for automobiles includes a car battery charged by the rectified output from an AC generator for automobiles; a voltage regulator circuit for intermittently controlling the exciting current flowing through the field coil of the AC generator and adjusting the generated output voltage into a set value; and a set signal output unit for outputting to the voltage regulator circuit an output voltage value set signal of the AC generator depending on the detection results of various operation states of automobiles.

Abstract: A method and apparatus for compensating, consistent with variations in cooling conditions, protection and limit functions of a generator. Limits of the capability curve of the generator, including the overexcited region, underexcited region and region limited by stator current heating, are modified in response to changes in coolant pressure or temperature depending on the type of generator being compensated. Feedback signals and setpoints being provided to fixed protection and limit functions are intercepted and modified in accordance with the relationship between generator rated values and generator performance in view of altered coolant conditions. Protection and limit functions are automatically coordinated. As a result, overall generator performance is improved.

Abstract: A marine power distribution arrangement utilizes generators driven at standard or higher than normal speeds and/or having a number of poles to produce electric power at a standard 50/60 Hz frequency or substantially higher than the standard 50/60 Hz frequency, such as 400 Hz. Each generator is a multi-phase, multi-circuit generator supplying isolated outputs on a plurality of lines to a propulsion power converter having isolated inputs to provide variable frequency, variable voltage power to a ship propulsion motor and to a service power converter to provide ship service power at a standard AC frequency or DC and at standard voltage for a service load. With this arrangement, power conversion transformers can, for the most part, be eliminated, thereby reducing the size and weight of the distribution system.

Abstract: An alternator having a sensorless power angle control includes a three phase stator winding and three stator winding outputs connected to a controlled full wave rectifier bridge with a dc output. The controlled full wave rectifier bridge includes upper MOSFET switches and lower MOSFET switches with body diodes. Operation of the alternator results in a three phase back EMF generated in the stator windings and phase voltages across each of the stator windings. The output of the alternator is increased by introducing a phase shift between the back EMF and the phase voltages, resulting in an optimized power angle. In order to provide a reference for the phase of the back EMF, a zero crossing detector is provided which monitors the zero voltage crossings across the body diodes of the lower MOSFET switches. The negative to positive zero voltage crossings across the body diodes of the lower MOSFET devices correspond to the negative to positive zero crossings of the three phase back EMF.

Abstract: A system and method for controlling operation of a diesel electric traction vehicle of the type including a synchronous generator driven by a diesel engine for producing alternating current (AC) electric power, the AC electric power being converted to direct current (DC) electric power and transferred over a DC link to a plurality of DC to AC inverters, and each of the inverters being coupled to transfer controlled frequency power to at least one AC electric traction motor coupled in driving relationship to at least one wheel-axle set of the vehicle. A computer-based control system controls operation of the engine, generator and inverters in response to a power command signal. The control system computes power supplied by the generator from calculated torque developed by the AC traction motors and electric power losses in the inverters and other circuit elements coupling power from the generator to the motors.

Abstract: A power supply for delivering voltage for use in an internal-combustion engine includes an onboard d.c. power source; an alternator connected to the d.c. power source and having an output for supplying a normal, onboard-network voltage during engine run; a step-up transformer having a primary winding and a secondary winding; and an inverter having an input connected to the d.c. power source and an output. There is further provided a change-over switch that has a first input connected to the output of the alternator, a second input connected to the output of the inverter and an output connected to the primary winding of the transformer. The change-over switch has a first switching state connecting the output of the alternator with the primary winding and a second switching state connecting the inverter with the primary winding. An rpm-responsive arrangement sets the change-over switch into the second switching state from the first switching state when the engine-rpm falls below a predetermined magnitude.

Abstract: A boosting switch circuit is constituted by a plurality of MOSFETs of which drains are respectively connected to a plurality of output terminals of an AC magneto and sources are connected to each other or together. The MOSFETs each have a parasitic diode in a drain-source circuit thereof. The parasitic diodes and a plurality of rectification diodes are subjected to bridge connection, to thereby provide a rectifying circuit for rectifying an AC output voltage of the AC magneto. The MOSFETs are fed at a gate thereof with a drive signal of a rectangular waveform, resulting in being concurrently subjected to on-off operation. This permits the output voltage of the AC magneto to be boosted and then rectified through the rectifying circuit. The output voltage thus boosted and rectified is then fed to a load.

Abstract: A motor generator system (120) in accordance with the invention includes a prime mover (21) for driving an output shaft (18), a main motor generator (105), having a rotor driven by the output shaft, for producing electrical power on at least one output winding (36a-36c) in response to the prime mover rotating the output shaft and for driving the output shaft in response to operation as a motor; an exciter (102) for applying excitation to a field winding (34) of the main motor generator during operation for producing electrical power on the at least one output winding and for applying current to the field winding of the main motor and generator to produce a magnetic field in the field winding during operation of the main motor generator as a motor; circuitry (122), responsive to current in a field winding (204) of the exciter, for producing an output signal representing a position of the rotor of the main motor generator driven by the output shaft; and a main inverter (114), responsive to the output signal, fo

Abstract: A control voltage setting circuit 31 provides one of a pair of control voltages when one of a pair of command signals are transmitted from an upper control unit 4 which is disposed outside the alternator. The command signals correspond respectively to upper and lower desired output voltages of the alternator. A voltage regulation circuit 32 makes the alternator provide an alternator output voltage according to one of the control signal. When a pair of the command signals are generated alternately at a cycle shorter than a cycle decided by the response time of the alternator, the control voltage setting circuit 31 provides an alternating control signal so that the alternator 2 generates a middle voltage between the upper and lower desired voltages.

Abstract: A generating apparatus includes a generator, a first and a second rectifiers, and a voltage regulator. The generator has three-phase star-connected armature windings which generate three-phase high-output voltage at phase-terminals and low-output voltage at a neutral point. The first rectifier is a three-phase full-wave rectifier connected between the phase-winding and a high-voltage load, and the second rectifier is a diode connected between the neutral point and a low-voltage load with a battery. The regulator regulates the high output voltage to energize the high-voltage load and, at the same time, the low-output voltage to become an optimum voltage level for charging battery. MOSFETs may be used for the first rectifier to short-circuit the armature windings thereby supplying them with leading currents which are respectively ahead of the high-output voltages, so as to increase the generator output power.

Abstract: A generator according to the disclosure includes a control system for regulating the output of the generator. The generator, such as a permanent magnet generator, includes multiple windings. For high current applications, the windings are connected in parallel. For high voltage applications, each three-phase set of windings is connected in series. The various windings may be selectively and individually activated by the control system to achieve a desired output current or voltage.

Abstract: An apparatus for controlling an output from an AC generator for a vehicle is provided which enables wiring from an external control unit to a voltage regulator by using only one wiring line, and which is capable of adjusting an output voltage of the AC generator to a usual value in accordance with a duty ratio of a control signal supplied from the external control unit, and linearly controlling the generator output voltage to a desired value in relation to a change in the level of the control signal.

Abstract: An output voltage control system for an electric generator having two field windings, wherein a rotary shaft of the generator is rotated by a power source such as an engine, for producing an output voltage. According to the invention, the control system includes a first control unit for supplying an electric current inversely proportionate to the output frequency of the generator to one of the field windings of the generator to produce a substantially constant output voltage for a stationay (fixed) load, and a second control unit for supplying an electric current derived from a portion of the output voltage produced at the generator output to the other of the field windings of the generator in the event of fluctuations in the generator load.

Abstract: In a system comprising an asynchronous generator rotatable at variable speeds, and a main electrical network carrying power at a substantially constant voltage and frequency, the improvement comprising a synchronizer having an electronic optimization controller connected in circuit between the generator and the network, the synchronizer being capable of receiving electrical power at variable voltages and frequencies from the generator and controllably and continuously injecting the power into the network at substantially constant voltage and frequency. A method for optimizing the generation of electrical power into the mains is also claimed.

Abstract: An induction system of the invention is adapted to apply coordinate transformation to the excitation current reference vector corresponding to the primary interlinkage magnetic flux vector reference value and the primary current vector so that they exist in the same coordinate system, thereafter to control the secondary current vector so that the primary interlinkage magnetic flux vector is in correspondence with the primary interlinkage magnetic flux vector, thereby allowing the primary side of the wound-rotor induction machine to function apparently as a voltage source.

Abstract: A permanent magnet generator and rectifier is connected to the exciter of an alternator and a separate rectifier provides a D.C. voltage supply to a voltage regulator. A thyristor is connected in series with a second fuse across the exciter rectifier to short circuit the supply in series with a main external fuse. If the main fuse fails to open, the second fuse opens. The second fuse is potted in the regulators to prevent tampering. An overexcitation and a low voltage demand signal are sensed. The two signals are coupled to a NAND logic gate to produce an output shut-down signal. If either even is established and the first produces a signal, a shut-down signal is generated to a second comparator amplifier of latch circuit. A delay circuit connects the shut-down signal to a triggered oscillator for firing the thyristor.

Abstract: An induction generator system is disclosed for utilization with an oil producing well having casing gas available at the wellhead and an existing electrical power system. An electric motor is coupled to the existing electrical power system and is utilized as a generator to drive a submersible pump or other electrical load. A gas engine which is powered by the casing gas is mechanically coupled to the electric motor by means of a drive belt and is utilized to drive the electric motor at a speed greater than the synchronous speed of the motor. While the electric motor is driven at a speed greater than its synchronous speed it will generate electrical energy which can be utilized to carry the electrical load. A novel control system is utilized to control the operation of the engine/motor generator system in response to variations in motor speeds, engine operating parameters and load/voltage conditions.

Abstract: An electronic voltage regulator for an ac electric generator precisely controls the generator output voltage and enhances motor starting ability. A filtered dc representation of the output voltage of the generator is produced by circuitry sensing the output voltage of the generator and rectifying to dc and filtering the voltage sense to obtain a relatively smooth dc voltage which is directly proportional to the output voltage of the generator and has on it a small amount of ripple voltage. A dc voltage which is proportional to the frequency of the generator is also produced by circuitry means which senses the frequency of the generator and produces a dc voltage proportional to the frequency of the generator up to a predetermined maximum frequency, not increasing above that maximum, and for amplifying the voltage produced. A comparator circuit compares the dc voltages.

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: A voltage regulator for a generating system having a main generator and an exciter for providing field current to the main generator includes means coupled to the main generator for sensing at least two operating parameters thereof. Means are coupled to the sensing means for generating pulse width modulated (PWM) signals based upon the first and second sensed operating parameters. Means are coupled to the first and second PWM signals for comparing the pulse widths thereof. The PWM signal having the narrower pulse width is coupled to a switch for controlling the current delivered to the exciter. The exciter current is therefore controlled in accordance with one of the sensed parameters at any particular time.

Abstract: An electrical distribution system has parallel connected generators powered by variable speed engines. Loads connected with each generator are interconnected through an electrical distribution bus. Constant speed drives have inputs connected with the engines and outputs directly connected with the generators. The connections between the constant speed drive outputs and the generators are characterized by the absence of overrunning clutches used in prior systems. An improved electrical protective circuit senses a flow of electrical power from the distribution bus to a generator, driving the generator as a motor. If the power flow to the generator is excessive, the bus tie breaker is opened disconnecting the generator from the bus.

Abstract: An output voltage of an AC generator is produced through a full-wave rectifier and converted into a digital signal by an A/D converter. This digital signal is compared with a reference signal, and in accordance with the difference therebetween, the firing angle of a thyristor is controlled to regulate the field current. Synchronous point detectors detect a synchronous point of the output voltage of the AC generator. A microprocessor computes a firing angle of the thyristor in accordance with the difference between the digital signal and the reference signal and produces a signal representing the computed firing angle upon detection of the synchronous point. The thyristor is fired at the firing angle computed by the microprocessor.

Abstract: The input signal corresponding to the respective frequency or power variation is supplied both to the inputs of the discrete filters and to angle measuring devices assigned to them, of which only the tuned filter in conjunction with its angle measuring device actuates a switch which sends the filter output via angle rotating and matching elements to a MAX selector element, from which the supplementary damping signal for the excitation is tapped. For low oscillation frequencies a low-press filter is provided which, via mean value formers and time delay multivibrator stages, permits a regulator signal to become operative for the excitation, delayed or undelayed, when certain limit values are exceeded.

Abstract: There is disclosed a system for predicting desynchronization of a synchronous machine by detecting a phenomenon of radical variation of the magnetic flux in the gap of a synchronous machine immediately before falling in an asynchronous state. For example, a functional value of the fundamental harmonic component and that of the higher harmonic component of the flux in the gap are detected for comparing the variation of each functional value with a predetermined reference level to predict desynchronization of the synchronous machine.

Abstract: A control circuit for supplying power to the heater of an electrically heatable windshield of an automotive vehicle while simultaneously providing the requisite current for the standard electrical system of the vehicle includes a resistive heating element connected in series between the vehicle alternator output and the high voltage terminal of the vehicle battery, so that current conducted through the heating element is supplied to both the battery and the load circuit. A control circuit, responsive to the alternator output voltage and the battery voltage, controls a voltage regulator to regulate the alternator output voltage within a first narrow band corresponding to the rated battery voltage and within a second narrow band corresponding to a given power rating for the heater.

Abstract: A field control apparatus for a generator having a field winding comprises a terminal voltage control unit for controlling a field current of the generator in accordance with a difference between a terminal voltage signal of the generator and a reference voltage signal, which control unit has at least one of a line drop compensation function, an under-excitation limitation function, an over-excitation limitation function, a power factor regulation function, an armature winding over-current compensation function and a cross-current compensation function. The field control apparatus includes a detector as a common signal source for detecting active power and reactive power components at an output terminal of the generator and means responsive to the output of the detector for performing scalar operation in accordance with a function of the added compensation/control function described above.

Abstract: A constant frequency a.c. generating system includes an alternator driven at a variable speed. A rectifier provides a d.c. supply for a rotary inverter. To maintain the voltage and frequency of the inverter output constant, the frequency is monitored and used to control the alternator field current and the voltage is monitored and used to control the inverter field current in a regulator circuit.

Abstract: A voltage regulator for a magneto AC generator comprising a battery charging generator coil and a loading generator coil, said voltage regulator comprising a first voltage divider to detect a voltage proportional to a terminal voltage of a battery; a second voltage divider to detect a voltage proportional to an output voltage of the loading generator coil; and a controlled rectifier arranged to short-circuit the battery charging generator coil and adapted to be conductive when either of the voltages detected by the first and second voltage dividers is greater than a predetermined value, the battery charging and loading generator coils being arranged to be magnetically bonded with each other.

Abstract: In a power system, control signals derived from a measurement of dynamoelectric machine output voltage and current are selectively applied to an exciter to control the current in a field winding of the machine to control the machine reactive volt-amperes and output voltage.

Abstract: A device for automatic excitation of brushless electrical machines, comprising: an A.C. exciter feeding a power converter built around controlled rectifiers disposed on a machine shaft; a converter control circuit employing optoelectronic elements with light-emitting diodes, composed of a booster unit, an inverter unit, and a unit intended for transfer of the converter into a non-controlled rectifier mode; and a photodetector receiving light signals from a stationary light source and located on the machine shaft. The device permits continuous control from boosting modes to inversion.