Abstract: A method of measuring the density of a dielectric gas under pressure in a buried metal-clad electricity line consists in measuring the pressure and the temperature of the dielectric gas by means of a sensor mounted on the case of the line, and in compensating the pressure measurement as a function of the temperature measurement using constant density curves that have been corrected on the basis of a curve representing the difference between the temperature at the surface of the case of the line and the mean temperature of the gas inside the line for increasing amounts of current carried by the line conductor.

Abstract: The hybrid high-voltage substation comprises firstly equipment implemented using metal-clad technology and constituted by at least one single or double busbar set, and secondly equipment implemented using conventional air-insulated technology so as to form feeders disposed in bays approximately perpendicular to said busbar set. The substation incorporates at least one air-insulated backup line approximately parallel to the busbar set and performing the function of backup phase to enable the substation to operate in “degraded” manner.

Abstract: The 4 mA-20 mA type or 0-20 mA type current loop connects an analog sensor (1) to an acquisition system (3), respectively carrying a sensor current (Ic) and an acquisition current (Ia). A test circuit is connected in parallel with the current loop to inject a superposition current (Is) into said loop, which current is superposed on the sensor current (Ic) or on the acquisition current (Ia). In a first embodiment, a variable voltage generator (7) injects the superposition current (Is) by adding it to the acquisition current (Ia), thereby making it possible to check a low-current threshold of the acquisition system (3). In a second embodiment, a variable current regulator injects the superposition current (Is) by adding it to the sensor current (Ic), thereby making it possible to check a high-current threshold of the acquisition system. The high- and low-current thresholds of the acquisition system are tested without opening the current loop.

Abstract: The method relates to discriminating between an internal arc and a circuit-breaking arc established in the enclosure of a circuit breaker in a bay of a medium or high voltage metal-clad substation. The appearance of an internal arc is detected by a protection system which responds by transmitting a disengagement order to the circuit breaker, thereby causing a circuit-breaking arc to appear. The pressure of the dielectric gas inside the enclosure of the circuit breaker, is continuously measured and recorded so that after the instant at which the disengagement order is transmitted, it is possible to recover a first pressure value measured before the instant. The first pressure value is then compared with a second pressure value measured after the said instant in order to identify whether the internal arc was struck in the circuit breaker enclosure.

Abstract: A density sensor for monitoring a rate of leakage from the case of electrical switchgear filled with dielectric gas under pressure, the sensor comprising a fixing support mounted from the outside in the thickness of the case and communicating with the dielectric gas. A radiator is placed around the fixing support of the density sensor, thereby enabling a measurement artifact that is due to the exposure of the case and of the sensor to solar radiation to be transformed in such a manner that any risk of untimely crossing of a low density threshold is eliminated.

Abstract: During opening or closing of the apparatus, in particular a circuit breaker while it is electrically isolated, the method consists in:i) recording a signal representative of the variation over time of the pressure inside the interrupter chamber by means of a sensor disposed outside the interrupter chamber and mounted to be in communication with the gas under pressure inside said chamber;ii) recording a signal representative of the variation over time of the position of the moving contact by means of a sensor disposed outside the interrupter chamber and mounted to detect movement of a drive rod; andiii) comparing the above signals with corresponding signals representative of reference operation of the high voltage electrical apparatus for the purpose of monitoring proper operation thereof or of detecting faulty operation of the electrical apparatus, particularly in the event of a valve in the interrupter chamber of the circuit breaker becoming jammed.

Abstract: The present invention relates to a method of monitoring electrical wear on selector switch disconnectors in a bay of a high voltage station that includes a set of distribution busbars connected to at least three electrical circuits constituted by an inlet bay, an outlet bay, and a bay for coupling together the busbars.

Abstract: A method of discriminating an arc detected in metal-clad equipment includes detecting an arc, generating an arc-appearance signal, transmitting the arc-appearance signal to a computer, and determining a time lapse T. The time lapse T is determined according to the formula t.sub.o -t.sub.a ; t.sub.o is an instant at which the computer receives a circuit breaker trigger order, and t.sub.a is an instant at which the arc-appearance signal is first acquired by the computer. The arc is determined to be an internal arc (1) if the time lapse T is positive, or (2) if the time lapse T is negative and its absolute value is less than or equal to 10 ms. On the other hand, if the time lapse T is negative and its absolute value is greater than 10 ms, variation of the arc-appearance signal is analyzed to discriminate the arc.

Abstract: The method consists in: i) making a series of recordings of the density of the gas at regular time intervals during a nighttime period by means of a temperature-compensated pressure sensor fixed on the outside of the envelope and communicating with the gas via a duct formed through the thickness of the envelope; ii) processing the density recordings of the gas acquired during the nighttime period in hourly intervals, each hourly interval giving rise to an hourly mean value for the density of the gas; iii) processing the hourly mean values obtained at the end of each hourly interval to give a daily mean value for the density of the gas at the end of the nighttime period; and iv) determining the leakage rate from the envelope by taking the difference between mean densities obtained at the ends of two different nighttime periods.

Abstract: A control device for high-voltage equipment includes a computer adapted to receive status information from the equipment via at least one transmission cable. A display system includes a support device carrying on its visible face an equipment status mimic diagram associated with indicator lamps and at least one connector connected directly to the transmission cable, incorporating the indicator lamps and removably connected to the computer at a connection face thereof. The support device and the connector are so disposed that the latter presents the indicator lamps in a manner associated with the mimic diagram of the support device whether it is connected to the computer in a normal position or disconnected from the computer in an emergency position.

Abstract: A system for actuating electrical equipment, in particular a high-voltage section switch or a high-voltage grounding section switch includes, in a control box, a rotary drive unit for driving the contacts of the equipment. A control circuit includes "end-of-stroke" contacts associated with the contacts of the equipment. The system includes a portable electric motor having a self-contained power supply. The motor is equipped with a mechanical coupling for mechanically coupling the motor to the rotary drive unit, and is provided with an electrical connector for connecting the motor to the control circuit.

Abstract: The invention relates to a method of protecting against circuit breaker failure, said circuit breaker having contacts capable of moving between a closed position and an open position, and vice versa, and being fitted with protection apparatus including fault detector apparatus for putting into operation an opening electromagnetic coil that actuates circuit breaker contact drive apparatus, with position-indicator contacts of monitor apparatus being changed over as soon as the circuit breaker contacts start to move. According to the invention, in the event of a fault being detected, a time delay is generated from the indicator contacts changing over, and at the end of said time delay it is verified whether the fault current has become zero, and if not an alarm is generated.

Abstract: A drive mechanism for driving a rotary signalling switch of a high voltage electrical apparatus, in particular a disconnector or a grounding switch, the mechanism connecting the rotary shaft of the signalling switch to a rotary actuator shaft of an actuator mechanism for actuating the contacts of the apparatus so that the contacts of the signalling switch are opened or closed when the contacts of the apparatus are opened or closed, the actuator shaft being displaced at an angular velocity .omega..sub.ht during an operation to open or close the contacts of the apparatus. The drive mechanism constitutes a positive action mechanism connected between said drive shaft and said rotary shaft, and includes drive device for driving the rotary shaft of the signalling switch at the beginning and at the end of an operation at a velocity .omega..sub.cs greater than .omega..sub.ht.

Abstract: A metal-clad modular power-supply station comprising a main set of busbars interconnecting at least two pairs of components, such as overhead feedthroughs or cable boxes, in an H-station configuration. The components are connected together in pairs by respective rectilinear groups of metal-clad electrical apparatuses that are parallel to and connected to the main set of busbars. Preferably, the groups of electrical apparatuses are in alignment. The length of the set of busbars is thus reduced while complying with the laid-down isolation distances and a station is provided of minimum size and of reduced cost.

Abstract: A switching component for a metal-clad station provides the equivalent of three three-phase section switches respectively disposed on two outlets powering sets of three-phase busbars and allowing grounding of the section switches upstream therefrom. The section-switching and grounding are performed by first contact parts engagable with second contact parts electrically connected together and to ground, and third contact parts. The second contact parts and the third contact parts are carried by a common shaft rotatable about the shaft axis.