Abstract: A locked state for a movable part (11) of switchgear is created by deflected spring wires (15) entering a recess (12). Said device is reversible and has the advantage of being safe since it is completely passive, and it improves the dynamics of the movement of the movable part in particular by damping impacts when entering the abutment state. The invention can be applied to the drive rod of a vacuum circuit-breaker.

Abstract: The movable portion (35) of a vacuum circuit-breaker comprises a circular spring (46) sliding on an outer bearing surface (41) in most positions, that is suitable for entering a recess (40) on relaxing in order to define a maximally open position for the vacuum circuit-breaker in which locking is thus provided. The movable portion (35) may be made up of two sections (38, 39), of which one, made of copper, is a very good electrical conductor, and is directed towards the stationary contact (37) and receives a connection element for connection to an outside electrical circuit; the section (38) may be made of steel in order to promote sliding of the spring without wear.

Abstract: A control apparatus for controlling electrical switchgear, the control apparatus being designed such that it is capable of performing the following in succession: during an opening stage for opening the moving contact, causing the connection end for connection to the moving contact and provided on an output member to go from the point P1 to the point P2, under the effect of an opening mechanical spring moving a moving abutment element that drives the output member by abutment; during a re-cocking stage for re-cocking the spring, moving the moving abutment element under the effect of switching on a motor, while keeping the connection end at the point P2; and during a closure stage for closing the moving contact, causing the connection end to go from the point P2 to the point P1, also under the effect of switching on the motor.

Abstract: A control device for controlling electrical switchgear such as a circuit breaker or the like includes an actuating arm having a connection point suitable for being moved along a closed line including points P1, P2 and P3. The connection point thus moves during an opening stage for opening the moving contact, under the effect of a mechanical spring from point P1 to point P2. It also moves during a re-cocking stage for re-cocking the mechanical spring under the effect of a motor being switched on, and while keeping the moving contact in the open position, from point P2 to point P3. It also moves during a closure stage for closing the moving contact, also under the effect of the motor being switched on, from point P3 to P1. In this manner it is possible to successively perform three distinct stages of putting the actuating arm in motion, between the instant at which the moving contact leaves its closed position and the instant at which it returns thereto after having occupied its open position.

Abstract: A control apparatus for controlling electrical switchgear, the control apparatus being designed such that it is capable of performing the following in succession: during an opening stage for opening the moving contact, causing the connection end for connection to the moving contact and provided on an output member to go from the point P1 to the point P2, under the effect of an opening mechanical spring moving a moving abutment element that drives the output member by abutment; during a re-cocking stage for re-cocking the spring, moving the moving abutment element under the effect of switching on a motor, while keeping the connection end at the point P2; and during a closure stage for closing the moving contact, causing the connection end to go from the point P2 to the point P1, also under the effect of switching on the motor.

Abstract: The current transformer comprises at least two partial circuits (CBn) each comprising a Rogowski type winding (Cn), each of said the partial circuits being made in the form of an angular portion of a complete circuit (CB) which surrounds at least one primary conductor (10, 10A, 10B, 10C) of the transformer over 360°. The winding (Cn) of each partial circuit (CBn) is constituted by a go winding (Cn0) and by a return winding (Cn1) which extend over the angular extent (?n) of the partial circuit (CBn). For each partial circuit (CBn), the go and return windings are electrically connected in series, both having turns wound in the same direction so as to form a single winding (Cn) which presents a pair of adjacent electrical terminations (T1n, T2n) connected to an acquisition system (7, 7?).

Abstract: A device for controlling a circuit-breaker intended for opening and closing this electric power cut-off device comprising a mobile contact, this control device comprising a motor with a rotary output shaft and being connected to power supply means and actuating means transforming the output displacement of the motor into a displacement of the contact, this device also comprising a mechanical spring arrangement involved in opening and closing the contact. The actuation means include a set of jointed elements providing the connection of the rotary shaft and of the ring, and, in the closed position of the contact, the set of jointed elements is near a dead centre position, a so-called open dead centre, the opening spring being only able to drive it towards the open position upon moving past this dead centre during opening.

Abstract: A highly temperature-stable capacitor for taking measurements on a high-voltage line, said capacitor having a high-voltage electrode (HT), an annular printed circuit (CI) surrounding said high-voltage electrode (HT) coaxially and having at least one electrically conductive track that forms a low-voltage electrode (BT), said capacitor being characterized in that the printed circuit (CI) also has at least one temperature-sensitive resistor (TH).

Abstract: A method for determining the reclose time of a circuit breaker on a three-phase high-voltage electric network after separation of contacts 7A, 8A, 7B, 8B, 7C, 8C in the presence of a fault on one of the three phases A, B or C includes measuring voltages ULA0, ULBO and ULCO, measuring voltage USAO,determining the voltage USA0, USB0, and USCO, calculating the differences ULAB, ULAC and ULBC, calculating the differences USAB, USAC, and USBC. From these measurements and calculations, a determination of the reclose time is made on the basis of the voltage differences.

Abstract: A highly temperature-stable capacitor for taking measurements on a high-voltage line, said capacitor having a high-voltage electrode (HT), an annular printed circuit (CI) surrounding said high-voltage electrode (HT) coaxially and having at least one electrically conductive track that forms a low-voltage electrode (BT), said capacitor being characterized in that the printed circuit (CI) also has at least one temperature-sensitive resistor (TH).

Abstract: The invention relates to a device for controlling a circuit-breaker intended for opening and closing this electric power cut-off device comprising a mobile contact, this control device comprising a motor (3) with a rotary output shaft (12) and being connected to power supply means (4-9) and actuating means transforming the output displacement of the motor into a displacement of the contact, this device also comprising a mechanical spring arrangement involved in opening and closing the contact. According to the invention, the actuation means include a set of jointed elements providing the connection of the rotary shaft and of the ring, and, in the closed position of the contact, the set of jointed elements is near a dead centre position, a so-called open dead centre, the opening spring (15) being only able to drive it towards the open position upon moving past this dead centre during opening.

Abstract: The invention relates to a control device for controlling electrical switchgear, the control device including an actuating arm (8) having a connection point (8b) suitable for being moved along a closed line (L) including points P1, P2, and P3: during an opening stage for opening the moving contact, under the effect of a mechanical spring (12), from point P1 to point P2; during a re-cocking stage for re-cocking the mechanical spring (12), under the effect of a motor (10) being switched on, and while keeping the moving contact in the open position, from point P2 to point P3; and during a closure stage for closing the moving contact, also under the effect of the motor being switched on, from point P3 to P1.

Abstract: A method and system of non-intrusively monitoring the proportion of a component in a gaseous mixture having at least two components and contained in an electrical switchgear enclosure includes measuring the pressure, the temperature, and the density of the gas mixture by using sensors mounted on said enclosure, and in determining said proportion by processing the measured values in a data-processing unit.

Abstract: The invention concerns a method for determining the reclose time of a circuit breaker on a three-phase high-voltage electric network after separation of contacts 7A, 8A, 7B, 8B, 7C, 8C in the presence of a fault on one of the three phases A, B or C, the determination of the reclose time comprising the following steps: measuring the voltages ULA0, ULBO and ULCO, measuring voltage USAO, determining the voltage USA0, USB0, and USCO, calculating the differences ULAB, ULAC and ULBC, calculating the differences USAB, USAC, and USBC, determining the reclose time on the basis of the voltage differences.

Abstract: The capacitor of high thermal stability includes a high-voltage electrode (HT) extending in a longitudinal direction (AX), a cylindrical printed circuit (CI) coaxially surrounding said high-voltage electrode and including an electrically conductive track forming a low-voltage electrode (BT), and a frame (CH) having a cylindrical inside surface (SI) coaxially surrounding said cylindrical printed circuit (CI). The printed circuit is slit along a generatrix (G1) of the cylinder that it forms and it is rigidly fixed to the inside surface by a fixing point (F1, F2). The frame includes guide means (A1, A2) for holding said printed circuit (CI) near the inside surface (SI) whilst allowing it to expand along said inside surface of the frame. This provides a capacitor of high thermal stability and very simple construction which is suitable for carrying out measurements on a gas-insulated high-voltage electrical line.

Abstract: The current transformer comprises at least two partial circuits (CBn) each comprising a Rogowski type winding (Cn), each of said the partial circuits being made in the form of an angular portion of a complete circuit (CB) which surrounds at least one primary conductor (10, 10A, 10B, 10C) of the transformer over 360°. The winding (Cn) of each partial circuit (CBn) is constituted by a go winding (Cn0) and by a return winding (Cn1) which extend over the angular extent (?n) of the partial circuit (CBn). For each partial circuit (CBn), the go and return windings are electrically connected in series, both having turns wound in the same direction so as to form a single winding (Cn) which presents a pair of adjacent electrical terminations (T1n, T2n) connected to an acquisition system (7, 7?).

Abstract: The capacitor of high thermal stability includes a high-voltage electrode (HT) extending in a longitudinal direction (AX), a cylindrical printed circuit (CI) coaxially surrounding said high-voltage electrode and including an electrically conductive track forming a low-voltage electrode (BT), and a frame (CH) having a cylindrical inside surface (SI) coaxially surrounding said cylindrical printed circuit (CI). The printed circuit is slit along a generatrix (G1) of the cylinder that it forms and it is rigidly fixed to the inside surface by a fixing point (F1, F2). The frame includes guide means (A1, A2) for holding said printed circuit (CI) near the inside surface (SI) whilst allowing it to expand along said inside surface of the frame. This provides a capacitor of high thermal stability and very simple construction which is suitable for carrying out measurements on a gas-insulated high-voltage electrical line.

Abstract: The method of non-intrusively monitoring the proportion of a component in a gaseous mixture having at least two components and contained in an electrical switchgear enclosure consists in measuring the pressure, the temperature, and the density of the gas mixture by means of sensors mounted on said enclosure, and in determining said proportion by processing the measured values in a data-processing unit.

Abstract: In the method, pairs of pressure and temperature values are recorded using a pressure sensor and a temperature sensor fixed to a case from the outside and communicating with a dielectric gas, thereby enabling a density value to be calculated for the dielectric gas corresponding to each recorded pair of values. Simultaneously with making the pressure and temperature records, an electric current flowing through an electrical apparatus located inside the case and a climate parameter relating to the medium in which the case is located are also recorded for the purpose of giving each density value an index, thereby enabling a leakage rate to be determined with improved accuracy on the basis of indexed leakage rates, each of which is obtained from density values all having the same index.

Abstract: A method and a system for determining the density of an insulating gas in electrical apparatus in the vicinity of parts carrying electrical current, the method comprising the following steps:a) a reference temperature is measured outside the apparatus and in the vicinity thereof;b) the current passing through the apparatus is measured, and the temperature rise of the gas above the reference temperature is determined on the basis of gas temperature rise values as a function of current values and of various reference temperatures, said temperature rise values having been previously determined by testing or by a mathematical model;c) the gas temperature is computed by adding the reference temperature and the temperature rise;d) the gas pressure inside the apparatus is measured; ande) the density .rho. of the gas is computed on the basis of equations of state of the gas .rho.=F(T,P) which equations are tabulated data.