Hydro-quebec

Ireq - Institut De Recherche De L'hydro-quebec

Institut De Recherche De L'hydro-quebec

Gilles Missout

Guy Belanger

Jean-Marc Bourgeois

Francois Lalonde

Marius Cloutier

Marcel Dery

Jacques Belanger

Fran&ccedil;ois Lalonde

A non-contact measuring method and apparatus for producing a signal representative of a distance between facing surfaces of first and second parts, which are closely spaced apart such as the rotor and stator of an electric rotating machine. The method resides in positioning a sensor on the surface of the first part. The sensor includes first and second parallel, superimposed conductive plates electrically insulated from one another. The second plate is located in between the first plate and the surface of the first part. The first plate is fed with a high frequency signal through a resistance. A high impedance, low input capacity, unitary gain voltage amplifier is fed with the high frequency signal through the resistance. The second plate is fed with an output signal of the amplifier. The output signal of the amplifier is directly proportional to the distance between the two surfaces.

Non-contact measuring method and apparatus for producing a signal representative of a distance between facing surfaces

The current surge indicator (10) has a ferromagnetic member (12) held about a conductor (15) with the ends of the member (12) in proximity and facing each other such that the ends are attracted to one another with a given force as current passes through the conductor (15). When the force exceeds a given threshold, a signal is created to help in locating where the current surge took place. The member may be spring loaded to open up, and the signal may be provided by the member being released by the current surge such that the member falls from the conductor. The conductor may be an anchor cable of an insulator or tower beam for a power transmission line.

Current surge indicator

An apparatus for sensing and measuring a DC or AC current on an LV or HV power circuit. The apparatus comprises a shunt element having an input connected to the transmission line. The current flowing through the shunt is measured by an electronic circuit which is located in a conductive housing connected in series with the shunt element. The housing conducts the current from the shunt back to the power circuit. The housing is dimensioned to contain therein the electronic circuit whereby to shield the circuit from thermal effects of the shunt element, the magnetic field effect of the measured current, and environmental electrostatic interference.

Apparatus for sensing and measuring a current on power transmission line

A system and a method for sensing and reproducing a measured current value on a high voltage transmission line. An input shunt means senses a current to be measured. A transmitter circuit transmits a sampled current value of the current passing through the shunt means. The transmitter has converter circuits for reproducing a composite output digital coded signal representative of the sample current value. A light transmitting output means is provided for transmission of the composite output digital coded signal on an optical fiber transmission line to a receiver circuit. The receiver circuit has decoding circuit means for decoding and reconstituting the coded signal to a usable form to determine the sampled current value.

System and method of sensing current in high voltage transmission lines

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.

Electronic low-pass filter circuit with an adjustable long time base

Discloses is an improved device to facilitate detecting and measuring the concentration of gaseous hydrogen dissolved in a fluid. A polymeric membrane is in contact with the fluid and permeable to the hydrogen gas. An electrolyte is provided which is capable of producing oxidation of the hydrogen diffused through the membrane at a first electrode, and reduction of an oxygen-containing gas such as air, at a second electrode. The connection of a measuring device across the electrodes measures the intensity of the current generated by the electrochemical reaction of oxidation of the hydrogen gas. The electrodes and the electrolyte are mounted in an electrode mounting unit which includes a first, tightly sealed enclosure encased within a second, tightly sealed enclosure. The mounting unit is tightly mounted into a hollow housing. This housing is fixed to a base across one extremity of which extends the polymeric membrane.

Device for detecting and measuring the concentration of gaseous hydrogen

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 oxidation 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.

Apparatus for detecting and measuring the hydrogen content in a liquid

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.

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Saint-Bruno, Canada

Gilles Missout