scispace - formally typeset
Search or ask a question

Showing papers by "Hydro-Québec published in 1979"


Journal ArticleDOI
TL;DR: In this paper, the amplitude of the pressure wave generated by an AC arc with current from 10 A to 80 kA and with arc length from 8 mm to 15 m, burning in air for up to one second.
Abstract: The collapse of the building housing a large substation following an arcing fault motivated the measurements of the amplitude of the pressure wave generated by an AC arc with current from 10 A to 80 kA and with arc length from 8 mm to 15 m, burning in air for up to one second. At low arc power there is a correspondance between the pressure amplitude and the rate of change of the power which is not true for high arc power due to absorption. However, the pressure is very large and should be taken into account in the design of substations. An empirical formula is given relating the pressure variation amplitude to the short-circuit current and the response time of the protection system.

56 citations


Journal ArticleDOI
TL;DR: In this paper, a particle charging and detachment into a compressed SF6 coaxial electrode gap energized with high direct voltage have been investigated using the charge simulation technique and dimensional analysis.
Abstract: Conducting particle charging and detachment into a compressed SF6 coaxial electrode gap energized with high direct voltage have been investigated using the charge simulation technique and dimensional analysis.

40 citations


Journal ArticleDOI
TL;DR: In this article, a general framework for the formulation of the generation planning problem is presented which serves to illustrate the underlying structure of the problem, which rests on the occurrence of two different types of decisions in generation planning problems in general.

35 citations


Journal ArticleDOI
TL;DR: In this paper, sensitive clay from the Outardes 2 hydroelectric project is characterized and studied with respect to the effect of chemical changes on the development of the remoulded strength of the soil.

22 citations


Book ChapterDOI
R Bartnikas1

20 citations


Journal ArticleDOI
M. Duval1, H. St-Onge1
TL;DR: In this article, high performance liquid chromatography (HPLC) has been used to simultaneously determine the amounts of antioxidant(Santonox(R) R), peroxide, acetophenone and?-methylstyrenepresent in crosslinked polyethylene cable samples andmolded specimens, as well as to detect some other peroxidedecomposition products.
Abstract: High performance liquid chromatography (HPLC) has beenused to simultaneously determine the amounts of antioxidant(Santonox(R) R), peroxide, acetophenone and ?-methylstyrenepresent in crosslinked-polyethylene cable samples andmolded specimens, as well as to detect some other peroxidedecomposition products.It was found that the antioxidant is grafted to thepolymer chains after curing (even after partial curing).Results also seem to suggest that a reduction of the phenoliccharacter and perhaps of the effectiveness of thentiantioxidant might result from this grafting process. Peroxidedecomposition products were found to depend on the curingconditions used and to affect the dielectric behavior insome cases.Various XLPE and EPR materials have also been examined bydifferential scanning calorimetry (DSC), and experimentalprocedures were developed for evaluating the degree ofcrosslinking by DSC.This work was part of a program supported by the Electric Power Research Institute.

16 citations


Patent
19 Oct 1979
TL;DR: In this paper, a variable inductor for three-phase circuits is described, where the first magnetic circuits are closed towards the outside of the magnetic circuit of control so as to present no common point between them and are formed by respective ferromagnetic cores.
Abstract: L'inductance variable pour circuit triphase comporte un premier circuit magnetique pour chacune de ses phases, chaque premier circuit magnetique etant forme d'un materiau anisotrope a travers lequel circule un champ magnetique alternatif. Variable inductor for three-phase circuit comprises a first magnetic circuit for each phase, each first magnetic circuit being formed of an anisotropic material through which flows an alternating magnetic field. L'inductance comprend en outre un circuit magnetique de controle ferme, egalement forme d'un materiau anistrope, a travers lequel circule un champ magnetique a courant continu reglable. The inductor further comprises a magnetic circuit closed control, also formed of an anisotropic material through which flows an adjustable direct current magnetic field. Ce circuit magnetique de controle est dispose par rapport a chacun des premiers circuits magnetiques de facon a definir pour chaque phase au moins un espace magnetique (D3, D4, D5) dans lequel les champs magnetiques alternatif et continu respectifs se superposent orthoganalement. This magnetic control circuit is arranged with respect to each of the first magnetic circuits so as to define for each phase at least one magnetic gap (D3, D4, D5) wherein the respective AC and DC magnetic fields are superimposed orthoganalement. Les premiers circuits magnetiques sont fermes vers l'exterieur du circuit magnetique de controle de sorte a ne presenter aucun point commun entre eux et sont formes de noyaux ferromagnetiques respectifs (MA, MB, MC) couples chacun a une phase (PA, PB, PC) d'une source a courant alternatif triphase. The first magnetic circuits are closed towards the outside of the magnetic circuit of control so as to present no common point between them and are formed by respective ferromagnetic cores (MA, MB, MC) each coupled to a phase (PA, PB, PC ) from a source to three-phase alternating current. Le circuit magnetique de controle est egalement forme d'un noyau de controle ferromagnetique (N), et chaque noyau de phase est dispose par rapport au noyau de controle de facon a definir entre eux l'espace magnetique commun. The magnetic control circuit is also formed of a ferromagnetic control core (N), and each phase core is arranged relative to the control ring so as to define therebetween the common magnetic space.

15 citations


Journal ArticleDOI
Ashok K. Vijh1
TL;DR: In this article, the relationship between molecular properties and electric strength of dielectric gases has been further examined and a molecular basis of Paschen's law has been suggested and it has been shown that under comparable experimental conditions (i.e., temperature and pressure of the gas, electrode material, geometry and interelectrode spacing etc.).

15 citations


Proceedings ArticleDOI
H. St-Onge1, C. de Tourreil, M. Braunovic, Michel Duval, Ray Bartnikas 
01 Apr 1979
TL;DR: A study of the temperature behavior of chemically cross-linked polymer materials used in conventional extruded cables and the use of those materials at elevated termperatures is discussed as regards to satisfactory cable operation under emergency conditions.
Abstract: This paper describes a study of the temperature behavior of chemically cross-linked polymer materials used in conventional extruded cables. An extensive :study has been carried out into the electrical, mechanical, thermal and physico-chemical behavior of extruded dielectric materials as a function of temperature. Materials studied include XLPE filled XLPE, EPR compounds and semiconducting XLPE and data was obtained on specimens cut from full size extruded cables as well as laboratory molded specimens. The results are presented in a form that emphasizes differences and similarities between the behavior of XLPE and EPR materials at elevated temperatures. The use of those materials at elevated termperatures is discussed as regards to satisfactory cable operation under emergency conditions.

13 citations


Journal ArticleDOI
L. Masson1
TL;DR: In this paper, a new technique using the characteristics of asymmetrical fault currents, has been developed in order to achieve a dynamic control of the core flux, thus allowing a significant reduction of the required cross-section.
Abstract: Incorrect relay operation has often been related to saturation of current transformers. In many cases, the obvious solution to this saturation problem is an increased core cross-section of the current transformers, in order to allow a larger flux amplitude. In this respect, the transient asymmetrical component of fault currents is one of the most determining factors governing the dimensioning of the core cross-section of current transformers. A new technique using the characteristics of asymmetrical fault currents, has been developed in order to achieve a dynamic control of the core flux, thus allowing a significant reduction of the required cross-section. It is shown theoretically and experimentally that, taking into account all accuracy requirements and overvoltage limitations, the flux control circuit achieves a net reduction of the core crosssection by a factor of at least 3, even in the worst conditions imposed by C.T. or system parameters.

10 citations



Journal ArticleDOI
TL;DR: In this paper, a short-cavity single-longitudinal mode mini TEA-CO 2 laser is described and an experimental study of the effect of cavity length tuning on the mode intensity rejection is presented.

Journal ArticleDOI
R. Roberge1, J. L. Fihey
TL;DR: In this article, the "In Situ" technique for fabricating superconducting multifilamentary composites is reviewed and a casting technique for larger scale production is described.
Abstract: The "In Situ" technique for fabricating superconducting multifilamentary composites is reviewed. The casting technique is described. Our previously reported observation of a sharp transition in the critical current density at a critical concentration is supplemented by the observation of a sharp increase in the hardness for a niobium concentration of around 15 wt %. Also observed is a sharp transition in the J c at 12 Tesla as a function of Nb concentration again at about 15 wt %. The "In Situ" technique has now achieved overall J c 's comparable to those of commercial multifilamentary composites. Furthermore the mechanical properties of "In Situ" materials have improved strength. We are exploring production at larger scale by a continuous casting process.

Journal ArticleDOI
TL;DR: In this paper, the measured levels of RIV for EHV apparatus may be unrealistically high at 1 MHz due to an internal resonance in the test circuit, which cannot be corrected by the application of the Circuit RIV Factor "p" since the circuit responses of the calibration and test set-ups are different.
Abstract: North American practice for the measurement of Radio Interference Voltage, (RIV), on EHV apparatus is specified by the NEMA 107 Standard. The recommended measurement frequency is 1 MHz but at this frequency physically large test circuits do not represent the service condition. The measured levels of RIV for EHV apparatus may be unrealistically high at 1 MHz. This phenomenon is caused by an increase of RIV signals due to an internal resonance in the test circuit. This increased reading cannot be corrected by the application of the Circuit RIV Factor "p" since the circuit responses of the calibration and test set-ups are different.

Journal ArticleDOI
TL;DR: In this paper, a theory for the simultaneous generation of noise from both the load and generator sides and a method for determining all the coefficients is proposed, which is being implemented on-line on a mini/micro computer based system.
Abstract: Various studies to determine the response of power system loads to voltage and frequency fluctuations, have generally neglected the feed back from the load to the generation side as well as the dynamics. These effects become very significant when the fluctuation originating from the load side is of the same order as those from the generation side. The effect may be negligible if large perturbations are staged to determine the response. However, methods based on small variations should take into account the fact that the variations in the load itself may lead to a bias in the model parameters due to feed back. This paper formulates a theory for the simultaneous generation of noise from both the load and generator sides and proposes a method for determining all the coefficients. The method described is being implemented on-line on a mini/ micro computer based system.

Patent
17 Apr 1979
TL;DR: In this paper, an analog simulation of the parameters and operating characteristics of three-phase rotating machines is presented. Butler et al. use a generator and control circuit to simulate the parameters of a machine in function of those currents of direct and quadrature axes, and feed another circuit for generating diphase voltages.
Abstract: The invention concerns the analog simulation of the parameters and the operating characteristics of three-phase rotating machines. The system comprises a unit for transforming the three-phase armature currents of a machine into equivalent diphase currents and a further unit for transforming the diphase currents into currents so-called of direct and quadrature axes. A generator and control circuit simulates the parameters and operating characteristics of the machine in function of those currents of direct and quadrature axes, and feeds another circuit for generating diphase voltages. These diphase voltages are then transformed into three-phase voltages from which the dynamic characteristics of the machine are generated.

Journal ArticleDOI
TL;DR: In this article, the degradation reaction of polyethylene, poly(tetrafluoroethylene), and an expoxy resin resulting from the action of a 13.56MHz radio-frequency (rf) discharge in SF6 was studied.
Abstract: Studies were conducted on the degradation reaction of polyethylene, poly(tetrafluoroethylene), and an expoxy resin resulting from the action of a 13.56-MHz radio-frequency (rf) discharge in SF6. The curves showing the temperature variations of the samples during the experiment suggest that this degradation process occurs in two distinct stages: in the first, the heat released by the electric discharge causes the thermal degradation of the polymers, whereas in the second, the volatile degradation products react in the gas phase with the excited SF6. Analysis of the reaction products shows consistency with this two-step degradation model. The main degradation products have been identified as C2H2, C2H4, SOF2, and CS2 in the case of polyethylene; as CF4, C2F4, and SOF2 in the case of poly(tetrafluorethylene); and finally as CO2 and SOF2 in the case of the epoxy resin. Furthermore, it is interesting to note the formation of polymers of the di(trifluoromethyl) polysulfane type, CF3-Sn-CF3, among the reaction products. The more volatile members, n = 2, 3, and 4, were identified by mass spectrometry, whereas the heavier members, identified by infrared spectrophotometry, often took the form of a whitish powder deposited on the walls of the reactor.

Journal ArticleDOI
TL;DR: In this paper, the principle of operation and physical details of a device for measuring electric fields and ionic currents caused by very high voltage d.c. transmission lines are described.
Abstract: Describes the principle of operation and the physical details of a device for measuring electric fields and ionic currents caused by very high voltage d.c. transmission lines. The authors present results of measurements made under different conditions, and compare them with theoretical results. The measuring apparatus was subjected to testing for a period of about a year and a half, under different climatic conditions, under the experimental line at IREQ. The results obtained show the suitability of this equipment for long-term tests under all climatic conditions.

Patent
05 Jul 1979
TL;DR: In this paper, the authors describe an apparatus for measuring the concentration of gaseous hydrogen dissolved in a liquid substance, which consists of an electrochemical cell constituted of a polymeric membrane in contact with a sample of the liquid substance and which is permeable to hydrogen, of an electrolyte capable of causing an oxydation reaction of the hydrogen diffused through the polymeric membranes, at first electrode, and a reduction reaction of an oxygenated gas at a second electrode, so as to deliver an electric current proportional to the hydrogen concentration to be measured.
Abstract: The invention relates to an apparatus for measuring the concentration of gaseous hydrogen dissolved in a liquid substance. The apparatus comprises an electrochemical cell constituted of a polymeric membrane in contact with a sample of the liquid substance and which is permeable to hydrogen, of an electrolyte capable of causing an oxydation reaction of the hydrogen diffused through the polymeric membrane, at a first electrode, and a reduction reaction of an oxygenated gas at a second electrode, so as to deliver an electric current proportional to the hydrogen concentration to be measured. An electrovalve operates, when activated, to exhaust the liquid substance sample at a predetermined instant in the measuring process. Moreover, the circuit amplifies a voltage corresponding to the value of the current proportional to the concentration, which current flows through a load resistance mounted in parallel across the first and second electrodes and the input of the amplifying circuit. A display device is connected to the output of the amplifying circuit and supplies a digital measure of the hydrogen concentration in the liquid substance. A control unit determines the operation times of the electrochemical cell, of the electrovalve as well as of the digital display device pursuant to a predetermined sequence.

Proceedings ArticleDOI
C. T. Nguyen1, H.H. Le1, Y. Robichaud1, K. Srinivasan1, G. Santerre1 
15 May 1979
TL;DR: A real-time digital data-acquisition and processing system has been operating continuously since late May 78 in an Hydro-Quebec 735 kV substation and the actual implementation is described and the operating experience is reported.
Abstract: A real-time digital data-acquisition and processing system has been operating continuously since late May 78 in an Hydro-Quebec 735 kV substation. This paper describes the actual implementation and reports the operating experience. The prototype was developped in the first stage of a research project on computer-based line protection. The software is designed to accomodate (i) relaying algorithm (ii) auto verification (iii) self-evaluation and (iv) communication functions. All these functions are performed on line. Relaying algorithm consists of a one-cycle Fourier analysis and a continuous calculation of impedances. The sampling rate is controlled by the computer to synchronize to the power system frequency. Upon detection of a perturbation, five to fifty cycles of rel evant voltage and current waveform samples are "frozen" and transmitted via a phone link to IREQ main computer for permanent storage and further processing. Performances of the protection algorithm are evaluated auto matically against the actual protection system. An auto-answer modem allows the control of the remote system.

Journal ArticleDOI
TL;DR: In this article, the status of the development of multifilamentary high-field A15 superconductors is reviewed briefly and alternative techniques to circumvent the basic difficulty of fabricating a conductor with a brittle material are described and evaluated.

Journal ArticleDOI
J. L. Lachambre1, Z. Szili1
TL;DR: A retroreflection system is described that produced a 64-fold increase in the brightness of a N/sub 2/ laser.
Abstract: A retroreflection system is described that produced a 64-fold increase in the brightness of a N/sub 2/ laser. (AIP)

Patent
19 Nov 1979
TL;DR: In this article, a filtering circuit consisting of an input circuit for receiving a voltage input signal to be filtered, a summator circuit is provided for monitoring the input signal relative to an analog output signal from an accumulator circuit and providing an error signal representative of the difference of the input and output signals.
Abstract: A filtering circuit having the behavior of a low-pass filter capable of having a long time constant. The filtering circuit comprises an input circuit for receiving a voltage input signal to be filtered. A summator circuit is provided for monitoring the input signal relative to an analog output signal from an accumulator circuit and providing an error signal representative of the difference of the input and output signals. The error signal is fed to a voltage controlled oscillator to generate a frequency signal proportional to the error signal. The accumulator has a frequency dividing circuit is provided to divide the frequency signal by a predetermined division factor to control the low cut-off frequency of the filtering circuit whereby to increase the response time thereof. The accumulator also integrates the divided frequency signal. An output circuit provides an output of the stored integrated frequency signal to constitute the analog output signal.

Journal ArticleDOI
Ashok K. Vijh1
TL;DR: In this article, a new class of electrode materials for vacuum insulation is suggested, constituted by a variety of the so-called hard metals which are basically metallic materials composed of WC and cobalt, but they would be expected to be very resistant to erosive and evaporative losses.

Journal ArticleDOI
TL;DR: In this paper, the well-known Schwarz-Christoffel transformation and the free streamline theory are used to solve the problem of flow past a lateral outlet housed in a two-dimensional conduit.
Abstract: The well-known Schwarz-Christoffel transformation and the free streamline theory are used to solve the problem of flow past a lateral outlet housed in a two-dimensional conduit. The solution presented can be applied to lateral outlets which are fitted with a barrier that can be set at arbitrary inclinations. For the more general case, where the barrier inclination is arbitrary, numerical techniques were used to obtain the solution. The contraction coefficient and the inclination of the flow issuing out of the outlet are obtained as functions of the velocity ratios.

01 Jan 1979
TL;DR: Hydro Quebec has developed and is now using a time dissemination system which uses a modified IRIG B code transmitted on its own telecommunication network.
Abstract: The ever increasing complexity of electrical networks combined with the increasing cost of power losses during a network failure has led public utilities to become equipped with more powerful and precise tools for pinpointing the causes of such a fault. Hydro Quebec has developed and is now using a time dissemination system which uses a modified IRIG B code transmitted on its own telecommunication network. The reasons for using such a system and the way it was carried out are discrete.

Proceedings ArticleDOI
01 Apr 1979
TL;DR: In this paper, a new element meterial was developed, made from zinc and aluminum bonded together in a composite form, which has a slow melting characteristic and a size improvement permits direct replacement for the expulsion fuse tube in distribution cutout supports.
Abstract: Results of a research program leading to the development of a new current limiting fuse device are described. The electrothermal properties of various metals were determined for optimal analysis. A new element meterial was developed. It is made from zinc and aluminum bonded together in a composite form. The composite fuse, rated general purpose, has a slow melting characteristic. A size improvement permits direct replacement for the expulsion fuse tube in distribution cutout supports.

Proceedings ArticleDOI
C. de Tourreil1
01 Oct 1979
TL;DR: In this paper, various electrode systems are evaluated for the dielectric strength measurements of solid Dielectric plates and it is found that the breakdown test results obtained with metal electrodes embedded in filled epoxy resin yield a better evaluation of the properties of the material investigated than those obtained with bare metal electrodes directly immersed in oil.
Abstract: Various electrode systems are evaluated for the dielectric strength measurements of solid dielectric plates. It is found that the breakdown test results obtained with metal electrodes embedded in filled epoxy resin yield a better evaluation of the properties of the dielectric material investigated than the results obtained with bare metal electrodes directly immersed in oil.

Journal ArticleDOI
TL;DR: The cathodic polarization curves of a series of Nb-Ni alloys were measured in a 25 wt.% KOH solution at 25 °C as mentioned in this paper, and it was found that a sharp decrease in the hydrogen overpotential occurred when the nickel content of the alloy was increased in the δ + γ region.

Journal ArticleDOI
Michel G. Drouet1
TL;DR: In this paper, it was shown that the measurements of Edwards et al. do not demonstrate the existence of two independent self-generated magnetic fields in the laser-target interaction region.
Abstract: It is shown that the measurements of Edwards et al. do not demonstrate the existence of two independent self-generated magnetic fields in the laser-target interaction region. On the contrary, these results illustrate, once more, the two-phase expansion of the magnetic fields spatial configuration: diffusion within the photoionized background followed by convection with the laser plasma.