Abstract: A lamp with a temperature-controlled automatically protecting circuit which includes a temperature induction circuit and a sampling circuit with its input end to connect with an output end of the temperature induction circuit, wherein the temperature control automatically protecting circuit further includes: a comparing circuit which has an input end to connect with an output end of the sampling circuit and when a positive voltage drop across the sampling resistance of the sampling circuit is lower than a reference voltage, the comparing circuit will have a high electrical level output; a trigger circuit which has an input end to connect with an output end of the comparing circuit and a thyristor which can be triggered by the high electrical level output of the comparing circuit to have the trigger circuit in the on state; and a maintaining circuit which has a capacitance in parallel with the thyristor in the trigger circuit and which, after being in series with a resistance, have a low electric level output

Abstract: The switchgear comprises a circuit breaker having an open position for isolating a generator from the network, and a closed position for connecting the generator to the network, together with a disconnector having a fixed pole connected to the generator and a contact connected to the fixed pole and movable relative thereto to occupy, when the circuit breaker is open, a first position connecting the generator to a starter circuit and a second position connecting the generator to ground. The moving contact of the disconnector also possesses a third position in which it forms an equipotential appendix for the fixed pole when the circuit breaker is closed. The moving contact does not carry the steady electric current of the generator, thus making it possible advantageously to reduce its dimensions so that they are capable merely of withstanding transient electrical conditions when in the first and third positions.

Abstract: A control apparatus controlling the operation of pulse width modulator for an electric clutch or electric motor in portable spray painting equipment having a pressure transducer for sensing the pressure, a manually adjustable pressure reference, a comparator type error detector, and a pressure deadband control for inserting a deadband in a pressure control loop with the deadband varying as the pressure reference varies. A fixed deadband is provided below a predetermined low pressure setting to avoid excessive cycling of the control apparatus during low pressure operation. The pulse width modulator control circuit includes compensation for improving input power factor. The clutch control includes an active alternative load circuit switched in when the alternator output voltage is above a predetermined value.

Abstract: A control circuit for the regulation of fan speed control in a computer power supply with software controlled shutdown and automatic restart for over-temperature protection. The control circuit overrides the control inputs when the temperature inputs indicate a temperature above a specific level.

Abstract: Disclosed is a floating gate neuron MOS transistor that may be incorporated into devices such as low voltage silicon control rectifiers for protection of internal circuits against electrostatic discharge. The transistor includes two or more input gates capacitively coupled to the floating gate. By adjusting the coupling ratio of the input gates, it is possible to control the transistor drain turn-on voltage very precisely and thereby turn on the rectifier without relying on avalanche breakdown of the transistor.

Abstract: An overvoltage protection circuit utilizes the fault current sensing capabilities of a differential protection circuit in combination with a shunting circuit to protect a power generating system against an overvoltage condition. The circuit offers the combined advantage of protecting attached load equipment from the harmful effects of an overvoltage condition while also ensuring rapid deexcitation of a generator.

Abstract: According to a field ground fault detector, a predetermined resistor is connected in series to a predetermined DC voltage. A DC voltage is applied between an N electrode side field circuit of a generator and a ground through the resistor. A voltage applied between terminals of the resistor is input to a low-pass filter. A voltage applied between the N electrode side field circuit and the ground is input to another low-pass filter. Output voltages of the low-pass filters are input to a level ratio determining circuit. The level ratio determining circuit outputs the determined result of the ground fault to the outside of the field ground fault detector corresponding to these voltages. Thus, even if the DC voltage varies or a higher harmonic voltage takes place in a generator of a thyristor exciting type, it does not affect the detecting sensitivity of the ground fault.

Abstract: An arrangement (1) for limiting the short-circuit current in a three-phase electric power line connected with one or more motors/generators (2) in which in each power line phase (3) leading to the generator/motor (2) at least one pair of series switches (4) are disposed, which are formed by semiconductor switch elements connected in anti-parallel, and in the section between the series switches (4) and the generator/motor (2) elements such as short-circuiting switches (6) are disposed which in case of a short-circuit cause the current of the generator (2) to be shunted away such that the operation of the series switches (4) is assured and the current cannot get into the power line. With the very simple structure of the system, very fast switching times are achieved.

Abstract: A brushless exciter diode wheel system includes a diode wheel and an electrical connection apparatus that is coupled to the diode wheel. The electrical connection apparatus includes a fuse support block, a diode support block, and a connector for electrically connecting the fuse support block to the diode support block. This connector permits the system to carry at least about 2000 amps of current, which is far in excess of the current capacity of conventional systems of this configuration.

Abstract: A system and method of protection against the passive loss of differential current fault protection is provided for an electric power generating system (EPGS). The EPGS utilizes a bus power control unit (BPCU) to control and protect bus configuration, and a generator control unit to control each of the generators. This system and method protection protects against perpetuation of a bus fault on a left air vehicle distribution bus, a right air vehicle distribution bus, or a air vehicle tie bus during passive loss of normal differential current fault protection within the BPCU, and comprises circuitry for monitoring parameters of the generator output power, circuitry responsive to these parameters for detecting a high generator current condition for generating an output overload signal when the parameters indicate the presence of a bus fault.

Abstract: According to a field ground fault detector, a predetermined resistor is connected in series to a predetermined DC voltage. A DC voltage is applied between an N electrode side field circuit of a generator and a ground through the resistor. A voltage applied between terminals of the resistor is input to a low-pass filter. A voltage applied between the N electrode side field circuit and the ground is input to another low-pass filter. Output voltages of the low-pass filters are input to a level ratio determining circuit. The level ratio determining circuit outputs the determined result of the ground fault to the outside of the field ground fault detector corresponding to these voltages. Thus, even if the DC voltage varies or a higher harmonic voltage takes place in a generator of a thyristor exciting type, it does not affect the detecting sensitivity of the ground fault.

Abstract: A three-phase alternator protection component is associated with a rectifying bridge. Three Shockley diodes and an avalanche diode are interconnected through three electrodes, of a first polarity, of the Shockley diodes, and the electrode, of the opposite polarity, of the avalanche diode to a common terminal that is connected to the output terminal, having a first polarity, of the rectifier. Each second electrode of the Shockley diodes is connected to each output of the alternator, and the second terminal of the avalanche diode is connected to the second output terminal of the rectifier.

Abstract: The stabilizer for power system is capable of suppressing power unstableness quickly and functioning effectively to a plurality of power disturbances even if the non-linearity of the power system becomes more intense because the stability point is moved from optimum stability. A phase difference calculating circuit calculates the phase difference between the internal phase angle of a generator and the voltage phase in a secondary bus line of a main transformer connected to a synchronous generator. A power system stabilizer produces an auxiliary signal based on the output of the phase difference calculating circuit. A first nonlinear compensating circuit and a second nonlinear compensating circuit produce compensating signals for compensating the non-linearity of the power system in order to compensate the output of the power system stabilizer.

Abstract: In a relay protective system a method of providing volts per Hz, loss of field, ground differential, phase distance and over voltage protective relay functions. In addition, the inventive method provides an improved method to selectively block any of the above functions in response to input contacts and selectively activate output contacts in response to operation of the above functions using programmable inputs and outputs.

Abstract: A fault current protection system for a traction vehicle propulsion system including a synchronous generator having armature and field windings and power conditioning circuitry connecting the generator armature windings to a traction motor employs a normally charged capacitor which, in response to a fault signal resulting from excess current in the generator armature windings, is electrically switched into parallel with the excitation current source connected to the generator field windings so as to discharge through the generator field windings and commutate the excitation current source.

Abstract: A shorted diode protection system for a traction vehicle propulsion system including a synchronous generator having armature and field windings and a bridge rectifier circuit coupling the generator armature windings to a traction motor employs a normally non-conducting solid-state controllable electric valve in parallel with the generator field windings. When a rectifier diode of the bridge rectifier circuit fails short, an a-c current is reflected into the generator field winding circuit. Upon detection of this reflected current, the valve is switched into a conducting state, thereby limiting the voltage on the generator field windings.

Abstract: A method and apparatus for avoidance of power-up current surge upon activation of a current supply device under inductive effect. An alternating-current switch is connected in series with the current supply device and a phase cut-in circuit is provided for enabling adjustable connection of the current supply device with the mains alternating voltage starting with the instant of powering up with equal-size unipolar phase segments. A switching unit is provided for activation of the phase cut-in circuit so that a predetermined number of the equal-size unipolar segments can be produced. An oppositely poled half wave which follows in time immediately is switched with an ignition signal of 170 to 180 degrees. In the phase cut-in circuit, respectively, an ignition signal is produced at the predetermined phase cut-in angle in the half waves following this half wave.

Abstract: A shorted rectififing diode protection system for a synchronous generator having a stationary exciter field which induces a voltage in a rotating exciter armature when energized by an exciter drive current, the voltage being rectified by a plurality of rotating rectifiers and applied to a rotating field winding to induce an output voltage in a plurality of main stator output phase windings, the output voltage being controlled by a voltage regulator having peak excitation current protection means, comprises a circuit for detecting actuation of the excitation current protection and generating a field protection monitor signal, a circuit for discriminating a shorted exciter field and generating a protection lock-out signal, and a logic circuit responsive to the field protection monitor signal and the protection lock-out signal for generating a shorted rectifying diode protection signal.

Abstract: A system of protection for an electric power generating system having a poly-phase generator switchably coupled through a generator control breaker to a load distribution bus, wherein the generator output voltage is controlled by a generator control unit which utilizes isolated voltage and current sense signals having a magnitude proportional to the output voltage and current for each phase of the poly-phase generator, the isolated voltage and current sense signals being generated by isolated voltage and current sensors, comprises a first circuit for monitoring the magnitude of each of the isolated voltage sense signals and generating a first output control signal if the magnitude of any isolated voltage sense signal is below a first predetermined threshold.

Abstract: A portable power unit has a protective circuit for cutting off an output current from the power unit when the power unit is in an overload state. An amount of the output current is detected. An output voltage from the power unit is reduced when the amount of the output current detected reaches a first threshold value, thereby preventing the protective circuit from undesirably operating for one power unit when it is connected for another for parallel operation. When the amount of the output current decreases to a second threshold value which is smaller than the first threshold value, with the power unit being in a state in which the output voltage is reduced, the voltage-reducing operation is canceled.

Abstract: A protection system minimizing utilization equipment's exposure to, and power interruption resulting from, an under voltage condition in an electric power generating system includes generator current sensors, generator speed information, an exciter current sensor, voltage sensors, and a controller.

Abstract: A circuit for protecting the ac generator and/or load of a diesel-engine generator set is provided. Included is a circuit for measuring indications of the current in each phase of the ac generator, and a switching circuit for protecting the ac generator if the current in any phase is greater than a predetermined current for a predetermined length of time (overcurrent), or if the current in any phase is less than a predetermined function of the currents in each of the phases for the predetermined length of time (imbalance). The circuit which protects the ac generator preferably short circuits the field winding of the ac generator and thereby turns off the ac generator, and/or closes a fuel valve to effectively turn off the engine should the current imbalance or overcurrent be sensed. In conjunction with the protection circuit, a switch interlock and/or circuit breaker arrangement for shock protection is provided.

Abstract: The invention provides a zero phase sequence current zig-zag filter with adjustable zero phase sequence impedance and a method for adjusting the impedance of the filter. Impedance is adjusted in discrete increments by detuning the filter one phase at a time. Detuning is accomplished using taps or auxiliary windings, whereby the ratio of the effective number of turns of the first winding relative to the second winding on the same core leg is changed independently for each phase of a three phase power supply.

Abstract: An electrical generator system integrated controller device utilizing PID control and capable of regulating voltage or current, and frequency simultaneously. The device utilizes a micro-controller (30.1) to monitor the engine generator set (20), then determines the appropriate signal to deliver to the electrical generator set (20) to regulate the engine throttle (21) and the generator (22) field windings. The micro-controller (30.1) also provides for real and reactive load sharing with additional generator sets (40) while also providing for an integrated circuit interrupter module (500) to open the line from the generator (22) to the load bus (42). Additionally, serial communications (34) are provided as well as displays (35), meters (37), and operator input (36). Finally, the permissive paralleling module (700) provides that the engine electrical generator set (20) will not be allowed to be connected to the load bus (42) until standards of voltage and phase have been achieved for a set period of time.

Abstract: The problems of minimizing size and weight in an aircraft and avoiding requirements for custom design are minimized in a generator control unit (22) provided with separate digital control circuits (74 and 76) for implementing voltage regulation and speed control. These circuits (74 and 76) are manufactured using custom very large scale integration (VLSI) technology to reduce size, weight, life cycle costs and improve reliability.

Abstract: A synchronous machine is protected from closely spaced instances of excessive field current and an excessive volts/hertz ratio by a control system which models rotor and stator cooling to provide memory of recent periods of excessive heating. Maximum excitation limiting and volts/hertz ratio limiting modules in a microprocessor based automatic voltage regulator for the machine generate time delayed limit signals which override voltage feedback control when the respective parameters exceed threshold values. The limiters each increment a count when the associated threshold value is exceeded and generate the associated limit signal when a predetermined count is reached. The predetermined counts and the counting rates are selected such that the delay intervals are inversely proportional to the amount by which the threshold values are exceeded. The counts are decremented at a rate which models rotor and stator cooling when the respective parameters return below the threshold values.

Abstract: In a thermal overload protection system three system variables are sensed and provide the inputs required for a calculation conducted in real time at one second intervals. The system variables include ambient inlet air temperature to the alternator, alternator stator winding embedded sensor temperature, and traction motor armature current. A traction motor current limit is calculated using the inlet air temperature and the sensor temperature. The thermal overload is then controlled in response to the traction motor current.

Abstract: A scheme for counteracting subsynchronous resonance in an AC power system that comprises a passive device in combination with a line inductive shunt reactor (L10). The device is connected from the neutral end (N) of the reactor (L10) to ground and comprises a plurality of circuit branches: one of those branches comprises a condenser (C10), another one includes an inductor (L12) in series with at least one tank circuit (C14, L14). The combination of these elements results in circuit paths from the AC line to ground of selected admittance values for at least one selected frequency as well as in a solid grounding of the shunt reactor neutral at synchronous frequency.

Abstract: An auxiliary stranded copper conductor carries the fault currents generated by a diode failure about the periphery of a brushless exciter diode wheel. The auxiliary conductor is constructed with a lower high-frequency impedance than the adjacent diode wheel, so that AC fault currents in particular are diverted to the auxiliary conductor. The auxiliary conductor carries the fault currents to equalize both AC and DC fault currents among the fuse-legs of the same phase. In a preferred embodiment, the auxiliary conductor is circular and is mounted between all of the diode fuse bases at one end of the diode wheel and the diode wheel itself.

Abstract: A circuit for protecting the ac generator and/or load of a diesel-engine generator set is provided. Included is a circuit for measuring indications of the current in each phase of the ac generator, and a switching circuit for protecting the ac generator if the current in any phase is greater than a predetermined current for a predetermined length of time, or if the current in any phase is less than a predetermined function of the currents in each of the phases for the predetermined length of time. For diesel-engine generator sets which generate three phase 460 V at up to thirty amperes continuously, the preferred predetermined overcurrent for any phase of the ac generator is thirty-five amperes, and the predetermined length of time (to permit inrush currents) is five seconds. Preferably the current in any phase should be less than fifty percent of the average of the current in the three phases.

Abstract: A connection control device for controlling the connection of a small generator unit, which is installed at the consumer's location, to an electric power system. The connection control device detects variations in frequency components which result from interruptions in the distribution of electric power to the consumer from the electric power system. When a significant variation in a frequency component is present, the connection control device disconnects the consumer from the electric power system in order to prevent injury to line workers.

Abstract: A variable speed, constant frequency aircraft power system uses current sensing diodes to rectify the power generator output. The current flow through pairs of diodes is compared to generate phase currents to detect feeder faults.

Abstract: A protection system (80) for a first generator unit (12) connectible by a first switch (24) to a power generating system having at least one additional generator unit with the at least one additional generator unit being connectible in parallel to the first generator unit with the first switch being opened in response to a first control signal to enable the first generator unit to be disconnected from the parallel connection to the at least one additional generator unit in accordance with the invention includes a signal generator (12) for generating a reference signal having a frequency proportional to a frequency of a voltage generated by the first generator unit; a sensor (14) for sensing a common frequency at a point of reference of voltage generated by the generator units of the power generating system; and a controller (14) responsive to the signal generator and the sensor, for calculating a difference between the frequency of the reference signal and the common frequency and for generating the first con

Abstract: A permanent magnet generator system is provided with a permanent magnet generator having a multiple phase armature that includes several circuit branches which are electrically connected to provide a multiple phase output voltage to the output terminals of the generator. At least two of the circuit branches include an armature phase winding and a switching device electrically connected in series with the winding. The switching devices are opened and closed in response to a control signal to disconnect the generator from the remainder of the electrical system and to simultaneously de-energize the individual phase windings of the generator armature to protect against a fault occurring within the generator housing.

Abstract: A system for detecting load has a first detector for detecting load on a generator based on the voltage in a circuit of an armature of the generator, and a second detector for detecting the load on the generator based on the voltage in a circuit inductively coupled to the armature circuit. An output of the first detector is compared with a first reference value by a first comparator and a first overload signal is produced when exceeding the first reference value. A second comparator is provided for producing a second overload signal when exceeding a second reference value. In response to the first and second overload signals alarm lamps are turned on for providing an alarm of the overload.

Abstract: A control apparatus of an AC generator for use in vehicles is disclosed which includes an AC generator having a field coil, a storage battery to be charged by a rectified output of the AC generator, a voltage regulator for regulating the output voltage of the AC generator and an excessive temperature controller that includes a triangular wave generator, a temperature detection circuit and a comparator. The controller controls the on-time ratio of a power transistor so that the field current flowing through the field coil is changed in accordance with output of the comparator which compares the output level of the temperature detection circuit and the triangular wave output of the triangular wave generator.

Abstract: There is disclosed a power regulating system for portable engine generator wherein overcurrent protection is provided by connecting the AC output of an AC generator driven by an engine to a rectifier for conversion to a DC current, supplying the DC current so obtained to an inverter to obtain an AC current of an arbitrary frequency, and providing for stopping of the driving signal to the inverter when an overcurrent state is detected in the inverter.

Abstract: A voltage regulator circuit for an AC generator of an automobile is disclosed. The circuit comprises, in addition to the conventional elements, a transistor turned on and off in phase with the power transistor by the control transistor of the voltage detecting circuit. The collector of this additional transistor is coupled to the positive terminal of the battery through a resistor, while the emitter thereof is grounded. A serial circuit of a resistor and a capacitor forming a positive feedback circuit is coupled across the collector of this additional transistor and the base of the control transistor, a biasing resistor being coupled across the base and emitter of the control transistor. Thus, when the control transistor is turned on, the charging current of the capacitor produces a forward bias across the base and emitter of the control transistor; when the control transistor is turned off, the discharging current of the capacitor produces a reverse bias thereacross.

Abstract: A short-circuit protective device for a motor-driven and generator-driven electrical machine fed by a pulse-controlled a.c. converter has reverse-parallel circuitry that is switching dependent on a monitoring device. The monitoring device detects short circuits and is provided in a d.c. current supply line. Using the reverse-parallel circuitry and the monitor, an intermediate circuit capacitor of the pulse-controlled a.c. converter feeding the machine is isolated from the short circuit location.

Abstract: A predetermined unsymmetry of a bipolar waveform is detected by apparatus which includes a circuit which generates a pulse for each zero crossing of the waveform. Each zero crossing pulse triggers a first retriggerable one-shot for a first interval T.sub.1. Timing out of the first one-shot triggers a second retriggerable one-shot for a second interval T.sub.2. If both the first and second one-shots have timed out a third one-shot is triggered for a third interval T.sub.3. The intervals are selected such that twice T.sub.1 plus T.sub.2 is equal to the period of one cycle of the bipolar waverform so that triggering of the third one-shot is an indication of a predetermined unsymmetry determined by relative values of T.sub.1 and T.sub.2 of the bipolar waveform. T.sub.3 is selected such that two symmetrical cycles of the bipolar waveform are required to clear the unsymmetry indication.

Abstract: A voltage regulator that reduces the voltage output of a generator to make it appropriate for use with an external load. The voltage regulator includes a starting unit for use with on-demand generators to cause the on-demand generator to start without presenting a risk to the external load.

Abstract: A method for nondestructively electronically detecting a short circuit in a conductor system which is composed of two parallel inductor groups connected together to form a selected current path when no short circuit exists, by the steps of: disposing a current probe at a selected location of the current path for sensing changes in the current flowing in the path at the selected location; and injecting a fast rate-of-rise current pulse into the path; and monitoring the response of the current probe to provide an indication of the existence of a short circuit.

Abstract: A method by which a turbine generator (1, 2, 3) can be protected against sub-synchronous frequencies occurring in an electric network which is connected to the turbine generator and which incorporates capacitors. The method is based on de-equalizing the subsynchronous natural frequencies of the three phases, so as to weaken the coherence of the frequencies. This is achieved by incorporating in each of two of the phases a respective inductance L of mutually different size and by changing the capacitance equivalently with a series capacitance C such as to fulfill the condition 1/LC=.omega..sub.o.sup.2, where .omega..sub.o is the network frequency.

Abstract: An alternator regulator includes a status sensor connected to monitoring the connection of a voltage sensor to the alternator and a separate current limited monitor unit to regulate the output in accordance with the alternator current output. The sensor monitor unit includes a continuity circuit detector coupled to the voltage sensor and operable to continuously monitor the state of the connection to the alternator. A fault in the circuit connection such as a loose terminal, a broken lead or other such faults, opens the continuity circuit and generates a signal which drive the regulator off and terminates operation of the alternator, thereby protecting the alternator from possible destruction. A voltage/current mode selector receives a voltage related signal and a current related signal. A signal comparator is coupled to the voltage related signal and the sensed current related signal and generates a logic control signal applied to the selector to transmit one of the two signals.

Abstract: The power system stabilizer is provided at an individual power system to be separated due to an accident cutting off a link line which interconnects a number of power systems to form a large-scale power system. The power systems include power stations such as power plants and transformer substations. A simplified arithmetic processing unit of the stabilizer performs an arithmetic processing by a simple linear equation using an output frequency of a representative power station belonging to the separated power system immediately after the accident has been cleared, so that a total load drop of the separated power system can be assumed. Based on the assumption amount, balance control of demand and supply in the separated system is made.

Abstract: "Doorbelling" in a generating system including a fault detecting circuit is prevented without the use of auxiliary power supply for a generator control unit. The generating system includes a permanent magnet generator (14) driving an exciter winding (18) and a relay (26) is utilized for interconnecting the two. Control of the relay (26) is exercised by a microcomputer (32) including a non-volatile memory (48) and programmed to remember the occurrence of a fault and thereafter prevent the relay (26) from cyclically opening and closing in response to power changes occurring as a result of connection and disconnection of the exciter winding (18) from the permanent magnet generator (14).

Abstract: The present invention relates to an automatic device for depressing low frequency oscillation of power system. It consists of an electronic circuit incorporated in the original excitation regulator of a synchronous generator. This circuit can turn the input deviation of voltage .DELTA.V into simulating state variable deviations of angular frequency .DELTA..omega., of power .DELTA.P and of power angle .DELTA..delta., and then outputs the sum of them according to the principle of optimal control. With the device of the present invention, the output capability of a remote power station may double, a whole set of measurement and feedback devices may be spared and the distortions in measurement may be avoided. The present device has further advantages of being small in size, cheap in cost, easy to establish and high in reliability.

Abstract: An AC generator control status detecting device having an AC generator with a plurality of stator coils, a field coil and a plurality of rectifying diodes connected to the stator coils; a regulator connected to the field coil to control field current; a field current state output terminal connected to the junction of the field coil and the regulator; and a current limiting element between the junction and the field current state output terminal. Normal operation of the generator is maintained even when the field current state output terminal is short-circuited to ground.

Abstract: The circuit utilizes combinational logic and latching circuits to prevent damage to the regulator or to the battery of an automotive ignition system due to a serious fault such as the ignition being turned "on" but the engine/alternator not rotating. A fixed duty cycle control signal is added to the control signal for the field excitation current only when a serious fault is detected, thus limiting battery drain and excessive temperature in the regulator module but not shutting the whole system down. The system thus provides the desirable "limp-home" capability.

Abstract: A protection circuit for a charging generator against a short-circuit of a field winding of an a.c. generator included therein is disclosed, in which an output transistor of a voltage regulator of the charging generator is on-off controlled when a collector current of said output transistor exceeds a predetermined high value.