Abstract: In this paper the assumption of a localized voltage response due to reactive power disturbances is analyzed. Conditions on transmission line parameters, given its normal operating point, are stated which explicitly define directions of voltage changes so that the line is subject to the localized voltage response. We show that it is not possible to give an exclusive answer to the question of the localized response (tier-wise) in the decoupled Q - V network. The answer is network and operating point dependent. The operating regions in which this property is satisfied even under large changes in reactive power injections are derived on the SE graph based decoupled Q- V network. We first define a no-gain operating mode of this network and then claim that the power no-gain operating mode always implies a localized voltage response. These results cannot be used to demonstrate a voltage gain. We develop algebraic type statements to show that a system may have response which is system wide. More definite answers on the localized response are established for the echelon structure of a given network.

Abstract: A regulating A.C. power controller regulates the selected levels of power to be applied to a plurality of loads by producing a digital signal directly from the A.C. voltage with a pulse duration representative of load power which can be applied as an input to the microprocessor without the need for prior analogue to digital conversion. The load power level is displayed in terms of percentage of power source. Remote control units, such as a computer, can be connected with the power controller to program it for power level settings and warm up time.

Abstract: A semiconductor device comprising a plurality of circuits driven by at least one external power source, and at least one voltage converter transforming the voltage of the external power source into another voltage. At least a part of the plurality of circuits are driven by the output voltage of the at least one voltage converter, which is provided with a controller for controlling its load driving power, corresponding to the operation of the part of the plurality of circuits. The voltage converter includes a voltage limiter which is used exclusively for each of the different natures of the loads, and its operation and load driving power are controlled, depending on the operations of each of the loads.

Abstract: A 3-phase-to-3-phase power converter is intended to control the output voltage and current so as to provide a 3-phase sinusoidal wave which is controlled in compliance with the input voltage. The main circuit has a switching period shorter than 30° of the power voltage waveform and it is controlled so that switching of lines takes place in alternate fashion, whereby the input power factor is improved.

Abstract: The system includes: a voltage conversion circuit (11a, 11b) selectively obtaining at least three kinds of conversion voltages, i.e., a first conversion voltage which is double the input voltage (AIN), a second conversion voltage which subtracts a reference voltage (VR) from the first conversion voltage, and a third conversion voltage which adds the reference voltage to the first conversion voltage; a comparison circuit (CPR1, CPR2) setting at least two decision level voltages (-¼VR, +¼/VR) and comparing the converted) voltage (VCMP) with each of the decision level voltages; then outputting a command signal as a result of a comparison to the voltage conversion circuit so that the voltage conversion circuit outputs one of the conversion voltages in response to the command signal; and a control circuit (SGT) for changing the connections of switches (S1A...S7B) provided in the voltage conversion circuit in response to the result of the comparison by the comparison circuit.

Abstract: Upon the occurrence of a change of an a.c. voltage amplitude of an a.c. power network line in one station A, a computing element generates a first pilot control variable by means of which the control angle of the respective static converter is shifted in terms of a reduction of its d.c. output voltage. In the other station a voltage correction regulator generates a correction variable by compensating the voltage drop in the HVDC transmission line, by means of which the control voltage of the respective static converter is corrected, which, for example, is generated by a pilot control voltage and the output signal of a marginal current or extinction angle regulator. Thus, even in case of an a.c. power network fault-induced voltage dip of the HVDC voltage, a preset value can be maintained for the HVDC current and the voltage dip in the power transmission be reduced. This procedure is independent of which station is operated as rectifier and which as inverter.

Abstract: An image intensifier with an internal power supply that produces 20,000-25,000 Hz. noise in the output screen voltage is provided with an additional power supply coupled to the output screen through an R-C filter which removes that noise. The additional power supply produces the screen voltage at a current that is a large multiple of the current produced by the output screen voltage of the internal power supply, so that the screen voltage from the additional power supply prevails over the screen voltage from the internal power supply. The additional power supply is regulated by an optical coupler which responds to the light input level to the image intensifier, as follows: at light inputs above about 5×10 -5 footcandle, the screen voltage from the additional power supply is less than the usual screen voltage from the internal power supply; at light levels higher than that the screen voltage from the additional power supply increases with decreasing light input and it is higher than the usual screen voltage from the internal power supply throughout the light input range below about 10 -5 footcandle.

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: A method and apparatus for detecting voltage losses in a power distribution line wherein a plurality of voltage sensing devices are used to generate an alarm signal which identifies the phases and locations corresponding to points at which voltage losses are detected.

Abstract: A power supply apparatus for a radar system of the type which has a control box including signal processing means and a source of electrical power, an antenna unit remote from the control box and including an antenna, a transmitter, a receiver and an IF amplifier, and a coupling cable of variable length between the control box and the antenna unit, the coupling cable coupling signals to and from the antenna unit as well as a power supply voltage and a tuning control voltage. The power supply apparatus comprises a switching mode power supply circuit having an input supplied with the power supply voltage and an output for providing a substantially stable output supply voltage for the receiver. A feedback circuit is responsive to the output supply voltage and is coupled to a control input of the switching mode power supply circuit for adjusting the operation of that circuit so as to maintain the output supply voltage substantially stable. A voltage regulator is coupled to receive the output supply voltage and respond thereto for supplying an IF power supply voltage to the IF amplifier. The power supply voltage that is supplied to the switching mode power supply circuit also is used as a transmitter power supply voltage.

Abstract: In this article, the authors present the design and realisation of a DC/AC inverter. The power cell described is reversible and thus enables the handling of highly reactive loads. A state variable feed-back study leads to the large signal mastery of the power cell. The adaptation of the feedback loop for load variations and source voltage variations are also considered. The article concludes with the presentation of measurements made on a breadboard realisation which testifies as to why this power cell and its control law become a focus of interest.

Abstract: An improved power supply for power switches arranged in a totem pole configuration is disclosed. A single power supply, having an output voltage substantially less than the voltage applied to the upper power switch, periodically charges a capacitor within a flying capacitor circuit. Microprocessor based control circuitry controls the charging and discharging of the capacitor and the periodic operation of the power switches resulting in the voltage at the output of the power switches being at system common or at the voltage applied to the upper power switch.

Abstract: Improvement of power quality is frequently necessary to insure proper operation of sensitive electronic equipment. Power quality improvement involves the use of combinations of ac regulators, transient limiters and/or power filters. Traditional ac regulators have multiple-cycle response and cannot actively attenuate voltage transients and harmonics, and may generate low-order harmonics. The Electronic Power Conditioner (EPC) developed by Powertronic Systems, Inc. (PSI) has much shorter response time and regulates the instantaneous value of output voltage. The EPC generates no low-order harmonics, has low output impedance and actively attenuates voltage transients and harmonics. It provides superior performance and is competitive with traditional regulators in cost, size and weight.

Abstract: A power interface circuit includes a low voltage control chip and a separate, high voltage power chip contained in a common package. The high voltage power chip includes a power switching semiconductor device, such as a thyristor or power MOSFET, and is controlled under the influence of the control chip. Operating power for the low voltage control chip is provided from an auxiliary portion of the high voltage power chip. Such auxiliary portion comprises a voltage regulator, which derives its power from a high voltage lead in the power device. The high voltage lead may comprise a lead on which high voltage power is supplied for power switching purposes. The low voltage control chip may include a high degree of "intelligence", or logic functions, for controlling the power switching device, since the low voltage device may be a microprocessor or other device that can be fabricated with a high density of control elements.

Abstract: A very low drop voltage regulator with a new vertical (collector insulated) power PNP transistor is presented. An antisaturation circuit prevents the current peak at the start-up of the device. A zener-zap trimmed reference makes possible a ± 1% output voltage tolerance.

Abstract: As t h e puabpull self-excited power oacilator with feelbaok f r o m ceramic transformer is ueed aa a driving oircruit, the pieroeleotric cerraic tmnaformer high voltage power upp ply oan be s tabi l ized t o mrk i n wide temperature range (ovelc20 t o 60'0) and oan have high effeoieney (up t o 87%). t o a regulated c i r cu i t , t he hi@ voltage power sup ply haa vezy good load oharaoteristica and is used i n some fields. Adding

Abstract: A power device for an axial-flow-type CO 2 laser tube in which a high DC voltage is applied to the cathode side of the laser tube, a ballast resistance is connected to the anode side, and power at a high voltage pulse is applied to this anode side so that laser oscillations occur. In addition, the output of the high voltage pulsed power on the anode side is adjusted by PWM control of the switching circuit, controlling the output of the laser. In this way, the cathodes becomes a common structure, cross discharge is prevented, and the response speed of the power feedback is increased.

Abstract: Results are presented for reduced order models of power systems as large as 254 generators, 2500 buses, based on the modal coherency method of model reduction. Extension of order estimation, based on balanced realizations, to larger systems is discussed. An alternative order estimation approach based on the intergenerator coherency ranking table is introduced and compared to the balanced realization approach. The alternative approach is consistent with the balancing results and two orders of magnitude faster.

Abstract: A number of limitations surround the JET pulse load and its impact upon the high voltage network in order not to decrease quality and reliability of the electrical supply to other consumers. According to the present agreement with the Central Electricity Generating Board (CEGB) the active and reactive power swing at the 400kV point of supply should not exceed 575MW and 375MVAr. The voltage drop should be less than 1.5% and the rise and decay of JET load should not exceed 200MW/s. There are also limitations in load power steps the purpose being to protect components of the CEGB power system.

Abstract: PURPOSE: To attain the maximum output power with the maximum power voltage rating of a monolithic IC by providing a power voltage limit section limiting a power voltage in a range of the maximum power voltage rating of the monolithic IC. CONSTITUTION: A power voltage limit section 5 acts like limiting a power voltage in a range of the maximum power voltage rating of the monolithic IC at no load. Further, the power voltage limit section 5 acts like supplying a power voltage to the monolithic IC with low loss at the maximum output power. In setting the power voltage within the maximum power voltage rating of a monolithic IC voltage amplifier section 2 through the constitution of the power voltage limit section 5, the power voltage is increased near the maximum power voltage rating of the monolithic IC. COPYRIGHT: (C)1987,JPO&Japio

Abstract: In the case of a power controller for mains-operated low-voltage apparatuses, the voltage amplitude of the mains voltage and the gradient of the mains-voltage behaviour are determined, and the triggering time of the power component is defined with the aid of these variables.

Abstract: This note describes the modeling of the power and voltage control loop of a thermal power plant of 180 MW. The modeling is based upon full-scale measurements at the Flevo power plant of the PGEM. A relatively simple ninth-order mathematical model of one unit for several working points has been developed. Based on this model the existing controller structure has been analyzed and an improved voltage control system designed. The design method is based on a state-feedback technique and pole placement. By means of computer simulations in an extended nonlinear model of this unit, including the grid, the existing and the newly developed control algorithms are compared. Field tests have been carried out to verify the results of the designed control algorithms.

Abstract: New technological advances in the area of power electronics are having an increasing impact on the design of aerospace control systems. These next generation power components promise improved system performance through increased electronic efficiencies. Applying state-of-the-art packaging concepts as an integral part of the system design will allow these devices to be utilized in a space efficient and reliable manner. The first portion of this paper looks at two such next generation components. The first is a High Voltage Integrated Circuit (HVIC) that provides a bridge between the low voltage controller logic and the high voltage motor winding invertor. This device achieves size reduction and an increase in reliability through integration of low and high voltage logic networks on a single integrated circuit. The second is the Insulated Gate Transistor (IGT). This device provides a high voltage switch with MOS-like drive characteristics. The present and future expectations of these power devices are discussed. This paper then looks at new packaging techniques for power devices. The impact of parasitic circuit effects have significant impact on power circuit performance. Finally, this paper looks at an example control application. The design is that of a permanent magnet motor driven actuator. The drive motor uses 270 vdc for supply voltage. Within the intelligent system controller, is the capability to control the current demands of the motor. The new power electronics devices are making the design feasible in both thermal and volume efficiency. This topic includes projected controller sizing into the 1990s.

Abstract: It is the objective of this paper to determine the levels at which Normal and Common Mode AC powerline disturbances affect the operation and integrity of microprocessor based equipment. These disturbances impact on system operation in varying degrees, from disruption of logic to actual degradation and component failure. The results summarized in this paper are based on observations of the DC output voltage variation of typical power supplies when subjected to surge testing based on ANSI/IEEE C62.41-1980 Voltage Waveforms. It can be concluded from these observations that AC powerline transients in the range of magnitude of 100 volts peak or greater, have a significant effect on the DC output voltages of typical power supplies. It was also determined that transients in the Normal Mode were more disruptive to DC power supply operation than those in the Common Modes.

Abstract: This paper describes the propagation of harmonic voltages and currents, generated by solid state power converters and nonlinear resistive loads in power systems. After establishing accurate harmonic models for a six pulse bridge rectifier and a nonlinear resistor supplied from non sinusoidal sources, a harmonic power flow technique, "Q-HARM", is used to compute the harmonic propagation in a sample power system. Design of appropriate filters to reduce the deleterious effects of injected harmonics, with special reference to communication line interference is also included.