Abstract: A high power factor AC/DC converter is disclosed. In the AC/DC converter in which a rectifying circuit RC1 rectifies a commercially available AC power supply Ei, a switching device turns on and off so that the rectified voltage is applied across the primary winding n1 of the transformer Tr1 to provide a high frequency voltage across the secondary winding n2, and the high frequency voltage is rectified by means of a rectifying circuit connected across the secondary winding so as to generate a predetermined DC output, a choke coil (L1) and a diode (D1) are interposed between the rectifying circuit (RC1) and a smoothing capacitor (C1) and a capacitor (C3) is interposed between a first junction and a second junction. The first junction connects the choke coil (L1) to the diode (D1) and the second junction connected the switching device (Q1) to the primary winding (n1) of the transformer (Tr1).

Abstract: The performance of AC to DC and DC to DC boost preregulators, and the performance of the equipment of which they form a part, can be improved by means of an adaptive boost switching preregulator which can, when used with a load capable of operating over a range of load voltages, increase or optimize the conversion efficiency and reliability of both the preregulator and the load by adaptively controlling the load voltage as a function of the voltage of the input source. Also, a gain-variable current controller can be provided which allows for accurately controlling the waveform and magnitude of the input current of a switching preregulator as the preregulator load (and hence the input current) varies over a wide dynamic range, yet does so by comparing signals whose magnitudes are essentially independent of the magnitude of the load. In this way, second order effects, which cause degradation in control of power factor in other preregulators as load is decreased, are rendered less significant.

Abstract: A power generation system is constituted by an induction generator and a converter. An output current waveform of the induction generator is determined by the magnetic flux, speed, winding impedance, DC output voltage, and load of the induction generator. In particular, the output current waveform is changed in accordance with a change in speed (i.e., change in slip). Switching elements in the converter are ON/OFF-controlled in accordance with changes in current waveform, thereby controlling power generation of the induction generator.

Abstract: A AC to DC power converter unit includes an AC/DC converter section operable to convert an AC input into a plurality of unregulated internal DC outputs and a pair of positive and negative switching DC/DC converter sections connected to said AC/DC converter section and receiving a pair of positive and negative unregulated internal DC outputs therefrom being of a first voltage level and generating a pair of dual positive and negative regulated external DC outputs being of a second voltage level different from said first voltage level.

Abstract: A high power-factor converter (50) for use with motor drives and power supplies. A first and "buck"-type converter section (62) is connected to an a.c. voltage source. This section provides an output voltage having preselected voltage characteristics. This section is operational during that portion of an input voltage cycle in which the input voltage level exceeds that of the output voltage level. A second and "boost"-type converter section (70) is also connected to the voltage source. This second section also provides the output voltage, and is operational during that portion of the input voltage cycle in which the output voltage level exceeds that of the input voltage level.

Abstract: Procedure for regulating the d.c. voltage of a pulse-width modulated rectifier bridge controlled by self-commutated semiconductor components and provided with filtering coils, in which procedure the phase voltages of the supplying three-phase mains and the d.c. voltage of the rectifier are measured. The modulation references needed for the pulse-width modulation are produced using pure sine and cosine curves synchronized with the mains voltages, with spatial vectors formed from them or with components of such vectors, by means of a phase-locked loop. The regulation is effected in a coordinate system tied to the spatial vector of the mains voltages.

Abstract: An improved electric power conversion system comprising a multi-phase bridge circuit composed of semiconductors such as thyristors and an associated firing circuit. It is so constructed that: if the AC input current Iac flowing in the bridge circuit is equal to or larger in value that the DC output current Idc flowing out of the bridge circuit, it will be decided than an inner defect or fault is caused, and possible expansion of inner defect will be prevented by disabling the firing circuit to extinguish the thyristors in the bridge circuit, and if the AC input current Iac is smaller than the DC output current Idc in value, the bridge is permitted to continue the operation of power conversion, thus eliminating unnecessary interruption which otherwise would be caused by exterior disturbances. Also, an improved electric power conversion system may be equipped with a device to prevent an adverse effect from being caused by abnormal rise of thyristors' temperature.

Abstract: A reactive power controller for controlling a reactive power output from a self-commutated inverter capable of eliminating an uncontrolled reactive power at the starting moment of its operation. The reactive power controller includes a device for producing a signal indicating amounts to be adjusted of an amplitude and a phase of an output AC voltage of the self-commutated inverter, in accordance with a DC voltage over a DC capacitor and an AC voltage of an AC system power source, and a device for adjusting the amplitude and the phase of the output AC voltage of the self-commutated inverter in accordance with the indication of the producing device.

Abstract: A power factor correction circuit in which a divided-down version of a rectified input waveform is sampled approximately at its peak by a sample-and-hold circuit. The peak value is then processed to produce a correction signal which is subtracted from the original divided down rectified signal. This produces a reference signal which is then multiplied by the output of an error amplifier to produce a sinusoidal reference signal for the input current. The output of the error amplifier which is used is that which is sampled periodically when the divided-down rectified signal approaches zero volts. The sinusoidal reference is used by peak and valley comparators whose other inputs come from a current sense amplifier. The outputs of the comparators are used to switch a shunting transistor which controls the input current to achieve near unit y power factor.

Abstract: A regulated voltage converter circuit includes a storage inductor and a controlled semiconductor switch connected in series circuit to a pair of input terminals that supply a full wave rectified voltage of a sinusoidal 60 Hz AC input voltage. A power factor amplifier receives a divided part of the rectified voltage and produces an output control voltage V.sub.M of a predetermined waveform (FIG. 2c). A comparison circuit compares the control voltage V.sub.M with a ramp voltage that is proportional to the current flowing through the semiconductor switch. The comparison circuit supplies PWM pulses to a control electrode of the semiconductor switch so as to regulate the output voltage of the converter circuit. The control voltage (V.sub.M) waveform is chosen so as to produce near unity power factor correction at the input of the converter circuit.

Abstract: An AC to DC power converter comprises an imput filter for filtering the alternating current input and an output filter for filtering and smoothing the direct current power output to a load. The output alternating current of the input filter is rectified and electronically switched by buck and boost switching circuits at a frequency much higher than the frequency of the alternating line current input. The rectified line current is sensed and provided to a control circuit which controls the operation of the buck and boost switching such that the power line current will follow a predetermined reference voltage waveform.

Abstract: An AC to DC power converter comprises an input filter for filtering the alternating current input and an output filter for filtering and smoothing the direct current power output to a load. The output alternating current of the input filter is rectified and electronically switched at a frequency much higher than the frequency of the alternating line current input. The rectified line current is sensed and provided to an integrator circuit whose output provides one control signal input of a pulse width modulator circuit. The pulse width modulator circuit drives the electronic switching an at the same time, provides an output to a discharge circuit for discharging the integrator circuit.

Abstract: In a voltage-source PWM step-up converter connected to an a.c. power supply through a reactor, even in the case where a reactor voltage drop V.sub.L changes in dependence upon a load current, it is required to compensate such a change to control a d.c. voltage so that it is equal to a predetermined value. Since this reactor voltage drop V.sub.L has a phase shift of substantially 90 degrees with respect to an a.c. power supply voltage, a control signal for compensating such a phase shift, resulting in the possibility that is exceeds above a linear control range of the control circuit to reach the saturation range. In view of this, in accordance with this invention, control signal means for compensating a reactor voltage drop V.sub.L is provided in the control circuit, thereby making it possible to perform a stable control to provide a stable d.c. output.

Abstract: An automatic line monitor for use in conjunction with a power supply for electronic components automatically accommodates either of two voltage ranges. Since the power supply may operate in domestic voltage ranges of about 100 volts or in international voltage ranges of about 120, the automatic line monitor senses and automatically switches to a voltage-doubling mode for the domestic range or a non-voltage-doubling mode for the higher international range. A latch may latch the line monitor in a non-voltage doubling mode once the higher voltage range is sensed. A monitor of a preferred embodiment eliminates almost all of the high-power-handling elements of the switch so that almost all of the operative elements of the switch may be incorporated on a single integrated circuit chip.

Abstract: A method and apparatus for determining the quenching angle in inverter valves, in which the pulse-shaped deviations, which occur in the valve voltages due to the current commutations as compared to the corresponding fundamental waveforms, are blanked out in the form of voltage blocks. For the duration of the quenching angle, a binary measuring signal is generated which is triggered by an end-of-conduction pulse and is terminated by a zero voltage crossing pulse. The end-of-conduction pulse indicating the completion of the commutation is formed by the flank at the end of the voltage shift caused by the preceeding commutation in the valve voltage as compared to the fundamental waveforms.

Abstract: An electronic power supply converts alternating current to a regulated DC voltage with high efficiency. A switch connects the input AC to a DC output capacitor when the input voltage is greater than the output voltage and the output voltage is less than a set point value. The switch receives the input AC and rectifies the input voltage and applies the switch rectified voltage to the output. The voltage difference between the input voltage and the output voltage level at which the switch closes varies in accordance with the input and output voltages.

Abstract: A power supply control system controls at least two variable power supplies feeding a common load connected to a common output terminal. A sensor monitors the current drawn by each power supply in dependence upon the difference detected in a sense to reduce the difference to zero. A summing circuit sums the outputs of all the comparators. Another comparator compares the output of the summing circuit with a zero level and produces an output to modify the reference signal. The loops comprising each comparator and the further comparator each act in a sense to reduce the output of the summing circuit to zero and in this way the system tends to maintain a balanced output from all supplies so that each supply shares the power requirement of the load according to its capacity while at the same time maintaining the output voltage at a level corresponding to the average of the nominal voltages of the individual supplies.

Abstract: An apparatus for controlling power conversion from alternating current (A.C.) to direct current (D.C.) by a converter has a D.C. voltage detector connected to receive a D.C. output of the converter for detecting the D.C. side voltage of the converter, a phase detector connected to an A.C. power source for detecting the phase of the A.C. power source, and calculating means for making a first calculation of a first current command value based on the output of the D.C. voltage detector, a second calculation of a phase angle of the A.C. power source voltage based on the first current command value, and a third calculation of second current command values based on the phase angle of the A.C. power source voltage and the output of the phase detector.

Abstract: A circuit for regulating the output of a DC power supply that substantially eliminates turn-on transients induced by the switching of a silicon-controlled rectifier (SCR). A zero-crossover detector senses the AC voltage waveform of an applied power source and provides a trigger signal at the zero-crossing point. The trigger signal is applied to cause induction of the SCR's and raise the output voltage when the power supply output drops below a regulated value, and is interrupted so as to inhibit conduction of the SCR's and decrease the output voltage when the power supply output exceeds the regulated value.

Abstract: An improved switching arrangement for a direct coupled switching power supply is provided by utilizing a gate turn off SCR as the primary switching element and a second SCR as the turn-off control such that upon detection of any of a fully charged storage element, an excessive current through the gate turn off SCR, or an insufficient input voltage, the switch is turned off.

Abstract: In order to produce direct voltages with greater flexibility, a rectifier (1) according to the invention comprises an alternating voltage measuring sensor (25), a comparator (22), controllable switches (160 to 183) and a switch control (20), through which the switching states of the switches are alterable in dependence on the output signal of the comparator, in order so to connect at least one of the direct voltage outputs (11, 12, 13) for certain time spans during each alternating voltage phase one after the other with the alternating voltage inputs of the rectifier that a pulsating direct voltage drops at it relative to a fixed or variable direct voltage potential. The switching instants are determined through constant measurement of the instantaneous alternating voltage values and their comparison with predeterminable direct voltage levels or alternating voltages, which serves as reference values.

Abstract: A regenerative d-c power supply comprises a bridge rectifier, a series-connected smoothing choke, a shunt-connected filter capacitor and a switching circuit consisting of a first diode disposed in a positive line of the d-c power supply between the smoothing choke and one terminal of the capacitor, a second diode disposed in a negative line of the power supply between another terminal of the capacitor and the rectifier and a pair of converter valves in the form of transistors connecting the cathodes of the diodes to one another and the anodes of the diodes to one another. Each converter valve is operated in the forward energy transmission direction by a respective first pulse sequence having pulses staggered in time with respect to the pulses of the other first pulse sequence. The converter valves are operated in the reverse energy transmission direction by respective second pulse sequences each having pulses staggered in time with respect to the pulses of the other second pulse sequence.

Abstract: A power supply for providing multiple operating potentials to a load switching controller is capable of providing constant voltage d.c. outputs from any of a plurality of a.c. voltage sources including the full range of power supply voltages and frequencies commonly used in various geographic locations throughout the world. The power switching element on-time is controlled by sensing the output voltage levels and providing feedback control of the switching element. A status circuit provides an indication of either an overvoltage of an undervoltage condition.

Abstract: The input terminals of a PWM converter are connected to the a-c power supply via a reactor. A capacitor C as well as a load 11 are connected to the d-c output terminals of the PWM converter. An apparent phase of the power supply voltage E is shifted depending upon the difference between a d-c voltage detected across both terminals of the capacitor and a set voltage, and a control signal for the PWM converter is prepared, with the shifted voltage as a reference. When the detected voltage is greater than the set voltage, the PWM converter is so controlled as to be operated with a lagging power factor, and the a-c voltage at the input terminals of the PWM converter becomes smaller than the power supply voltage. Accordingly, the d-c voltage can be maintained at a value smaller than the set voltage.

Abstract: A method and apparatus for controlling power to a precipitator 27. After each spark the power to the precipitator is reduced to zero, increased along a fast ramp 15 for a fixed period of time and then increased along a slow ramp 17 until a spark occurs. The fast and slow ramp data is computed and stored (memory 48) and then retrieved after each spark. The data retrieved is the data corresponding to the firing angle at the last spark. Means are provided (selector 51 and memory 52) for dividing (frequency divider 45) the retrieved slow ramp data by a number to select the number of sparks per minute. Also the AC current and the AC voltage in the power to the precipitator are detected and the RMS values are obtained (32 and 34) and compared 35 and if the difference is above a predetermined value the power is disconnected (relay 36 and contacts 23 and 24).

Abstract: A control apparatus for a thyristor converter which supplies electric power to a load generating a changeable electromotive force, wherein, in response to a load current being changed from an intermittent load current mode to a continuous load current mode, an actual main circuit constant of the load is calculated on the basis of a pregiven main circuit constant of said load, a predetermined minimum value of a DC average motor current at which a compensation control angle is zero, a DC average load current and a set control angle at a time when the load current just changed from the intermittent load current mode to the continuous load current mode.The compensation control angle is obtained on the basis of the calculated actual main circuit constant and the DC average load current.The calculated compensation control angle is added to the set control angle to thereby apply the added angle to the thyristor converter as a firing control angle.

Abstract: A multi-loop control system for convertors of the kind used in h.v.d.c. transmission and industrial applications. The invention consists in a control circuit which effects transfer between two or more control loops, e.g. a constant-current loop and a constant .alpha. loop, in a smooth and precise manner, without extra smoothing lags, even in the presence of ripple in the controlled quantities.

Abstract: A phase-controlled ac-to-dc rectifying circuit includes a pair of alternately conducting main controllable electric valves and cyclically operative forced commutation means for turning off the main valves. The forced commutation means comprises a pair of auxiliary controlled rectifiers respectively connected, in circuit with a commutating capacitor, across the main valves, and the auxiliary rectifiers are alternately turned on in response to periodic trigger signals that are normally produced by associated control means. Protective means is provided for inhibiting the trigger signals when the magnitude of voltage across the commutating capacitor is lower than a critical level which depends on the magnitude of the current being conducted by the main valves, thereby avoiding a risk of commutation failure due to low capacitor voltage.

Abstract: A DC power plant system has the operation of its individual rectifiers controlled by a stored program control system for the purpose of optimizing power efficiency. Load power requirements are compared with rated capacities of operating rectifiers of the system and individual rectifiers are turned on or off so that the plant efficiency is always maximized. Rectifiers are selected for turn on and off in the basis of their rated power capacity and their accumulated operating times.

Abstract: A polyphase rectifier power circuit with single phase regenerative capability provides motoring power from a polyphase supply and returns single phase regenerative power to the supply. One embodiment uses pulse width modulation of the regenerative rectifier to limit line-to-line current flow through the regenerative rectifier during regeneration while another embodiment uses 180.degree. conduction in the regenerative rectifier with the substitution of two thyristors for two diodes in the rectifier.

Abstract: A three-phase regenerative rectifier provides power flow from ac to dc using a three-phase rectifier bridge. The reversal of the input ac voltage at the input frequency commutates current in the rectifier devices. A power transistor or field-effect transistor is coupled in inverse parallel with each rectifier device to provide a path for current from the dc output of the rectifier back to the ac supply during regeneration. The rectifier devices can be phase controlled thyristors or diodes. Control means sense the three-phase voltage and switch the transistors in phase with the ac supply. Commutation of the transistors is provided by their self-contained turn-off capabilities.

Abstract: A rectifier controller for controlling bridge connected silicon control rectifiers (SCRs) (1 to 6) of a three-phase rectifier which is used to supply a direct current (DC) voltage to an inverter (314) used for injecting pulse coded audio frequency signals on a power line. The controller supplies gate control signals to the SCRs (1 to 6) of the rectifier bridge in accordance with the envelope of the three-phase supply voltages and provides for protection of the inverter (314) when shoot-through conditions occur in the inverter (314) and provides for output DC voltage adjustment by controlling the firing time of the rectifier bridge SCRs.

Abstract: An AC to DC converter utilizes a first power converter for converting an AC signal to a DC signal under the control of a control signal. The control signal is generated by a control circuit that includes a first analog generator that provides a first signal that is analogous to the voltage of the AC signal that is to be converted. A second analog generator generates a second signal that is analogous to the current of the AC signal that is to be converted and a third analog generator generates a third signal that is analogous to the voltage of the DC output signal. The third signal and the first signal are multiplied together to obtain a fourth signal. The control signal is generated from the fourth signal and the second signal and is used to control the power converter such that the waveform of the current of the AC signal is limited to a sinusoidal waveform of the same frequency and phase as the AC signal.

Abstract: A regulated DC power supply has a converter having a plurality of switches which, upon proper regulation of their conduction, rectify an AC current. The converter produces a current feedback signal. A reference generator produces a plurality of adjustable reference signals each representative of one value of a load current and produces a predetermined, standby, reference signal representative of a standby load current. One of the adjustable reference signals, the standby reference signal, and the current feedback signal are added to produce a control signal. The control signal is compared to a signal representative of the AC source voltage. Firing signals, used to regulate the conduction of the switches, are produced in response to the existence of a predetermined relationship therebetween. In the event that all of the adjustable reference signals have a value of zero for a predetermined period of time, the firing signals will be inhibited from regulating the conduction of the switches.

Abstract: A controlled rectifier inverter system of the type in which the inverter circuit has capacitors across which voltages are developed as a function of the current output of the inverter, such voltages being utilized to commutate the rectifiers of the inverter circuit, includes means to limit the magnitude of the rise in output current between successive commutations of the rectifiers of a group to prevent the achievement of a current in excess of that which can be commutated by the voltages on the capacitors.

Abstract: A system, for supplying electrical power from a source to a load, of the type employing phase controlled rectifiers for controlling the power from a polyphase source to the load includes circuitry to detect the existence of a rectifier which is conducting at an improper time and to provide appropriate corrective action to terminate such improper conduction.

Abstract: An electronic power supply utilizes a full wave bridge rectifier circuit whose alternating current voltage source is derived from a multi-primary and multi-secondary winding transformer whose windings are selectively disposed in series or parallel circuits, thereby enabling the apparatus to be effectively employed on a wide variety of A.C. voltage sources. Two adjacent legs of the bridge rectifier employ S.C.R.'s gated simultaneously symetrically by pulses obtained from a unijunction transistor driven by the output of an operational amplifier whose input terminals are coupled to voltage and current sensing networks located at the output terminals of a filter coupled to the D.C. side of the full wave bridge.

Abstract: The amplitude of the rectified voltage applied to the filter capacitor of a power supply is varied by selecting different taps in the secondary winding as a function of the output voltage and current so that the supply provides a wide range of operating voltages and currents in a minimum volume and at reduced cost.

Abstract: A power supply system is disclosed wherein redundant D.C. power supplies are provided for a single load, each of the supplies being capable of providing full load current so that one of the supplies may be removed without interrupting power to the load. Each of the power supplies has a differential amplifier type of voltage regulator that includes a resistor in series with the output lead so that it is capable of varying the output voltage to compensate for lead and OR-ing rectifier drops.