EP0883145B1 - Method of controlling and diagnosing the operation of a high voltage electrical apparatus - Google Patents

Abstract

The method involves comparing a pressure signal received from a detector (21) with a standard reference signal. The detector is outside a circuit breaking chamber (5) but in communication with the pressurised, dielectric gas within the chamber. The pressure signal is recorded during the movement of one of the contacts (9) to represent the temporal evolution of pressure inside the circuit breaking chamber during the opening or closure of the electrically insulated apparatus. The signal is recorded with the aid of a detector (25) on the outside of the chamber, designed to detect the movement of a rod (11) linked to the moving contact (9).

Description

The invention relates to a control and diagnostic method. the operation of high voltage electrical equipment which includes, inside a switching chamber containing a gas under pressure, contacts of which at least one mobile is moved by an operating rod.

The invention applies more particularly to the control and diagnostic of the operation of so-called new circuit breakers low-energy control generation, and can be applied to other devices such as a disconnect switch or a disconnect switch earth if the technology of these devices is similar to this! so-called new generation circuit breakers.

So far, to control the operation of the part active of a circuit breaker, the breaking chamber is dismantled which immobilizes this circuit breaker for a certain time.

The aim of the invention is to propose a non-intrusive method for checking and diagnosing the operation of a circuit breaker, to say not requiring the disassembly of the cut-off chamber this one.

i) enregistrer un signal représentatif de l'évolution temporelle de la pression dans la chambre de coupure à l'aide d'un capteur disposé à l'extérieur de la chambre de coupure et monté pour communiquer avec le gaz sous pression dans cette chambre,

ii) comparer le signal précédent avec un signal de référence, correspondant à un bon fonctionnement de l'appareillage électrique à haute tension pour contrôler le bon fonctionnement ou détecter un dysfonctionnement de l'appareillage électrique.

To this end, the subject of the invention is a method of checking and diagnosing the operation of a high-voltage electrical apparatus which comprises, inside a switching chamber containing a gas under pressure, contacts of which the '' at least one is mobile and is moved by an operating rod, consisting, when opening or closing the electrically insulated switchgear, at:

i) recording a signal representative of the time evolution of the pressure in the interrupting chamber using a sensor placed outside the interrupting chamber and mounted to communicate with the gas under pressure in this chamber,

ii) compare the previous signal with a reference signal, corresponding to the proper functioning of the high voltage electrical equipment to check the proper functioning or detect a malfunction of the electrical equipment.

A malfunction can for example result from a blockage in open or closed position of a shut-off chamber valve circuit breaker, or an abnormally high mechanical shock - movable contacts when the circuit breaker opens or closes.

Advantageously, in the method according to the invention, records in addition to the signal representative of the time evolution of pressure, a signal representative of the time evolution of the displacement of the movable contact using a sensor arranged at outside of the switching chamber and mounted to detect the displacement of the operating rod.

The simultaneous recording of the two pressure signals and displacement can detect a malfunction with a increased safety, the signal representative of the movement being used to confirm the diagnosis based on the pressure representative signal.

Other characteristics and advantages of the invention will appear on reading the description of an embodiment of the method according to the invention illustrated by the drawings.

Figure 1 shows a sectional cut-off chamber transverse with a pressure sensor and a position sensor mounted outside this room.

Figures 2a and 2b illustrate a pressure record and a position record corresponding to an operation of reference of a circuit breaker respectively to closing and to the opening.

Figures 3a and 3b illustrate a malfunction of the circuit breaker assigned to a blocking in the open position of valves arranged on a rear ring of the circuit breaker respectively at the closing and opening.

Figures 4a and 4b illustrate a malfunction of the circuit breaker assigned to a blocking in the closed position of valves arranged on a rear ring of the circuit breaker respectively at the closing and opening.

Figures 5a and 5b illustrate a malfunction of the circuit breaker assigned to a blocking in the open position of valves arranged on a front ring of the circuit breaker respectively at the closing and opening.

Figures 6a and 6b illustrate a malfunction of the circuit breaker assigned to a blocking in the closed position of valves arranged on a front ring of the circuit breaker respectively at the closing and opening.

Figures 7a to 7c illustrate a pressure record reflecting respectively normal mechanical shock, abnormally high at the end of opening, and abnormally high during opening of the circuit breaker.

The invention provides a method for monitoring and diagnosing the operation of high voltage electrical equipment, and particular of a circuit breaker.

Figure 1, a circuit breaker called new generation with low control energy comprises, in a breaking chamber defined by a sealed envelope 5 filled with a dielectric gas such as SF ₆ under a pressure of a few bars, a fixed tubular main contact 1 which cooperates with a movable tubular main contact 3, the contact 3 being movable in the axial direction D. The fixed main contact 1 is secured to a fixed arcing contact 7 which cooperates with a movable arcing contact 9 secured to the contact main movable 3. The movable contacts 3 and 9 are moved in the direction D by an operating rod 11 which exits through the side 5A of the casing 5. The operating rod is guided in sliding by a support block 13 mounted fixed at inside the envelope resting on side 5A.

The movable main contact 3 and the movable arcing contact 9 are coaxial and arranged parallel to the longitudinal direction D. A front crown 15 is disposed between the two movable contacts 3 and 9 in a plane perpendicular to the longitudinal direction D. It holds secured to the two movable contacts 3 and 9 and opens via of valves 151 and 152 on a blowing volume V1 closed by a blowing nozzle 17.

A rear crown 19 is arranged between the two contacts mobile 3 and 9 in a plane perpendicular to the longitudinal direction D. It slides in relation to the two movable contacts and opens by through two valves 191 and 192 on a volume of compression-depression V2 closed by the front crown 15.

A spring 20 is supported by one end on the block of support 13 and by the other end on the face of the rear crown 19 which does not carry the valves 191 and 192.

The method according to the invention uses a first sensor which records the time evolution of the pressure prevailing in the cut-off chamber when opening or closing the breaker.

Figure 1, a pressure sensor 21 to record the evolution pressure in the cut-off chamber is by example an elastic membrane sensor. Advantageously, we use a temperature compensated pressure sensor which behaves like a pressure sensor when changing rapid pressure inside the interrupting chamber due to the thermal inertia of such a sensor, and which also makes it possible to monitor the density of the dielectric gas 6. The pressure sensor is fixed from the outside to the metal casing 5 of the circuit breaker. The gas 6 present in the switching chamber is connected with the pressure sensor 21 via a conduit 23 formed in the thickness of the metal casing 5.

According to a particularly advantageous mode, the method according to the invention uses a second sensor which records the time evolution of the position of the mobile contact (s) during opening or closing the circuit breaker.

Figure 1, a position sensor 25 to record an evolution position of the mobile contact (s) in the break is for example an optical cell, or a sensor of inductive or Hall effect displacement. It is attached to the outside of the metal casing 5 for example on the side 5A of the casing to detect the displacement of the rod 11 in the direction D.

The P and L signals produced by the two pressure sensors 21 and position 25 are supplied to a unit 30. Unit 30 can be a display and / or data processing unit. By comparing P and L signals recorded during an opening and closing of the electrically isolated circuit breaker with reference records we can check the correct circuit breaker malfunction or operation as explained below.

Figure 2a, a reference operation when the circuit breaker results in a pressure reference record 2a1 flat-shaped and a position reference record 2a2 in the form of a rising ramp as indicated by the arrow Fm.

When closing, the compression-depression volume V2 is initially zero, the front 15 and rear 19 crowns being in contact. The pressure record 2a1 is explained by the fact that the displacement of the movable contact 9 in the direction indicated by the arrow f of Figure 1, causes the opening of the valves 191 and 192 of the rear crown 19 which allow the dielectric gas to circulate freely so that no depression is created in the chamber cut. At the end of the stroke, the valves close the circuit breaker being ready for opening.

Note that the 2a1 recording ends with relatively fast pressure oscillations that reflect the wave sound generated by the mechanical shock of the moving main contact 3 with the main contact fixed 1.

Figure 2b, a reference operation at the opening of the circuit breaker results in a pressure reference record 2b1 curved and a position reference record 2b2 in shape of a descending ramp as indicated by the arrow Fd.

When opening, the compression-depression volume V2 is initially maximum, the front 15 and rear 19 crowns being separated by a maximum distance. Pressure recording 2b1 is explained by the fact that the displacement of the movable contact 9 in the direction indicated by the arrow o in Figure 1, is accompanied by a compression of the gas contained in the compression-depression volume V2 which corresponds to a depression in the shutdown, and compression of the gas contained in the volume of blowing V1 defined by the blowing nozzle 17. About halfway through, the valves 151 and 152 of the front crown 15 open to equalize gas pressure in the two compression-depression volumes V2 and blowing V1, and let out part of the gas compressed through the blowing nozzle to extinguish a possible arc electric when the opening is made under load.

Note that the 2b1 recording ends with relatively fast oscillations carried by a slower oscillation pressure reflecting the sound wave generated by the shock mechanical of the front crown 15 with the rear crown 19.

Figures 3a, 4a, 5a, 6a show recordings of pressure and position when closing a circuit breaker under control. Figures 3b, 4b, 5b, 6b show pressure records and position at the opening of this circuit breaker under control. These records reflect a breaker malfunction.

Thus Figure 3a, the closing of the circuit breaker under control is translated by two records of pressure 3a1 and position 3a2 similar to reference records 2a1 and 2a2. On the other hand, Figure 3b, the opening of the circuit breaker under control results in a pressure record 3b1 different from the pressure record reference 2b1 indicated in dotted lines, recording of position 3b2 being similar to the reference record 2b2. The difference between records 2b1 and 3b1 reflect a blockage in the open position of the valves 191 and 192 of the rear crown 19. This difference can easily be detected automatically by a program in the data processing unit 30.

Figures 4a and 4b illustrate a malfunction of the circuit breaker assigned to a blockage in the closed position of the valves 191 and 192 of the rear crown 19. We have also shown on these figures the reference records in dotted lines. We see that the detection of the malfunction is done by detecting a difference between records 4a1 and 2a1 and 4a2 and 2a2.

Note that when closing, the position record 4a2 reflects the existence of a significant retaining force exerted by a depression created in the compression-depression volume V2, and is used to confirm the diagnosis of blocking in the closed position of valves 191 and 192.

Figures 5a and 5b illustrate a malfunction of the circuit breaker assigned to a blockage in the open position of the valves 151 and 152 of the front crown 15. We see that the detection of the malfunction occurs by detecting a difference between the records 5b1 and 2b1, 5b2 and 2b2.

Figures 6a and 6b illustrate a malfunction of the circuit breaker assigned to a blocking in the closed position of the valves 151 and 152 of the front crown 15. We see that the detection of the malfunction occurs by detecting a difference between the records 6b1 and 2b1, 6b2 and 2b2.

Again, it should be noted that during the opening, the recording of position 6b2 indicates the existence of a significant retaining force exerted by a compression created in the compression-depression volume V2 and used to confirm the diagnostic of blocking in position closed valves 151 and 152.

It is thus understood that the method according to the invention makes it possible to locate the faulty element of the circuit breaker if we refer to examples of Figures 3a-3b to 6a-6b. These figures illustrate records of typical time trends which may vary depending on the topology of the circuit breaker or switchgear high voltage electric.

In addition, a frequency and amplitude analysis of oscillations in pressure records at the end or in progress opening or closing the circuit breaker allows you to control a normal mechanical shock or diagnose mechanical shock abnormally high between moving and stationary contacts or between front and rear crowns.

Figure 7a shows a pressure record representative of a normal mechanical shock in an operation of circuit breaker reference. Figures 7b and 7c are given pressure records showing by comparison with the previous recording respectively a mechanical shock abnormal high at the end of opening and a mechanical shock or abnormal vibration during opening.

Claims (3)

1. A method of monitoring and diagnosing the operation of high voltage electrical apparatus which includes an interrupter chamber (5) filled with a dielectric gas under pressure, which apparatus is fitted with a sensor (21) disposed on the outside of said chamber and mounted to communicate with the gas under pressure inside said chamber, the chamber containing contacts (1, 3, 7, 9) at least one of which is a moving contact that is moved by a drive rod (11), in which method a pressure signal (P) delivered by the sensor (21) is compared with a reference signal corresponding to a satisfactory operation of the electrical apparatus, the method being characterized in that the pressure signal (P) is recorded during movement of said moving contact to be representative of the variation over time in the pressure inside the interrupter chamber (5) during opening or closing of the apparatus while it is electrically isolated, and is compared with a reference recording, the difference between said recordings making it possible to locate a defective element within the apparatus.
2. The method according to claim 1, further consisting in recording a signal (L) representative of the variation over time in the position of the moving contact, by means of a sensor (25) also disposed outside the interrupter chamber and mounted to detect movement of the drive rod, and in comparing said signal (L) with a reference signal corresponding to a satisfactory operation of the high voltage electrical appliance.
3. The method according to claim 1 or 2, further consisting in analyzing pressure oscillations in the pressure signal for the purpose of monitoring or diagnosing mechanical shocks between elements of the apparatus.

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