Detecting process of switchgear degradation

Abstract

It is proposed a process for detecting degradation of a switching device (30) comprising:-a moving contact (10); -a control mechanism (4) comprising:-a drive element (9) of the moving contact (10); -an elastic member (7) linked to the drive element (9); and-an unlocking member (8) configured to release the resilient member (7) to move the contact (10) so as to open the circuit (50), and-an actuator (1) configured to displace the unlocking member (8), the process comprising the steps of: (i) commanding the actuator (1), the method comprises the steps of (i) determining a predetermined position (P1) of the unlocking member (8), (ii) determining a duration (D) between a first moment (t1) corresponding to the predetermined position (P1) of the unlocking member (8) and a second moment (t2) corresponding to the predetermined position (P2) of the driving member (9), (v) executing a set of consecutive commands of the actuator (1) in order to obtain a set (E) of values for the duration (D), and (vi) determining a degradation of the unlocking member (8) of the switching device (30) as a function of an evolution of the values of the set (E) of values.

Description

Technical Field

[0001] The present invention relates to the field of switchgear for electrical equipment, for example for low voltage and medium voltage electrical equipment. For example, the switchgear may be a circuit breaker. Background Art

[0002] A low or medium voltage switchgear may include one or more actuators, for example of the electromagnetic type, for triggering the opening of an electrical circuit. To this end, the actuator may unlock a spring control mechanism, allowing the movable contact to be displaced, thereby opening or closing the electrical circuit. In the case of a circuit breaker, the electrical circuit is opened when a fault occurs in the electrical circuit. For example, the fault may be a short circuit between two phases, or a short circuit between one phase and ground.

[0003] When the actuator is of electromagnetic type, it consists of a moving magnetic core and a control coil. Under the action of the current flowing through the control coil, the magnetic core is displaced. The magnetic core is mechanically coupled to a drive element acting on a moving contact so as to be able to open or close the circuit. A closed circuit allows the load to be energized.

[0004] In order to ensure the safety of the electrical network and individuals, it is important to be able to check the correct operation of the switchgear throughout its service life. Switchgear often experiences the effects of aging, which gradually degrades its electrical or mechanical functionality, eventually rendering it inoperable. It is therefore important for the user to be able to monitor changes in the state of the switchgear. In particular, it is desirable to be able to monitor the state of the control mechanism between the actuator and the moving contact, and in particular to be able to detect any degradation in this control mechanism. The user can thus intervene in order to repair or change the control mechanism at an appropriate time in the management of the electrical network. Summary of the invention

[0005] To this end, the present invention proposes a process for detecting degradation of a switch device, the switch device comprising:

[0006] - electrical contacts movable between a closed position for an electrical circuit and an open position for an electrical circuit;

[0007] - Control bodies, including:

[0008] -- an actuating element configured to displace the movable contact, thereby opening the circuit;

[0009] - an elastic member connected to the drive element;

[0010] - an unlocking member configured to switch from a locking position, in which the elastic member is held in a tensioned state, to a releasing position, in which the elastic member is free to release, thereby shifting the electrical contact from a closed position of the circuit to an open position, or from an open position to a closed position;

[0011] - an actuator configured to displace the unlocking member from the locked position to the released position,

[0012] The process includes the following steps:

[0013] (i) commanding an actuator to displace an unlocking member from a locked position to a released position;

[0014] (ii) determining a first moment corresponding to a predetermined position of the unlocking member;

[0015] (iii) determining a second time instant corresponding to a predetermined position of the drive element;

[0016] (iv) determining a duration that elapses between the first moment and the second moment;

[0017] (v) repeating steps (i) to (iii) for a set of consecutive commands of the actuator so as to obtain a set of values ​​of the duration elapsed between the first instant and the second instant;

[0018] (vi) Determination of the degradation of the unlocking member of the switching device from the variation in the value of the set during successive commands of the actuator.

[0019] The process for detecting switchgear degradation is a process for detecting changes in the behavior of the control mechanism of the switchgear due to aging of its components. Aging of components includes, for example, the effects of wear, deformation, corrosion and changes in the friction characteristics of the components.

[0020] The duration elapsed between the first and second moments corresponds to the reaction time of the unlocking member. Monitoring changes in the duration value, ie how the duration changes during the service life of the switchgear, allows monitoring any changes in the behavior of the control mechanism of the switchgear during use of the switchgear.

[0021] When the unlocking device operates normally, the values ​​of the set are substantially constant during successive actuations of the switching device. In other words, the various values ​​of the set are substantially constant. In contrast, a gradual degradation of the control mechanism tends to cause the values ​​to change during successive actuations, in particular to cause fluctuations in these values. The values ​​of the set are no longer substantially constant, but fluctuate significantly. This gradual change allows the degradation of the unlocking member to be detected.

[0022] The process used to detect switchgear degradation is also a process that allows the prediction of the occurrence of faults in the switchgear.

[0023] In fact, uncorrected degradation of the switching device will eventually lead to the occurrence of failure, and such failure is therefore predictable.

[0024] The functions listed in the following paragraphs may be implemented independently of each other or in any technically feasible combination:

[0025] In step (vii), the variation of the set of values ​​may be a fluctuation of the value of the set during successive commands of the electromagnetic actuator.

[0026] According to one embodiment, the electrical contact is movable between a closed position of the circuit and an open position of the circuit, and releasing the resilient member shifts the electrical contact from the closed position of the circuit to the open position.

[0027] Thus, the control mechanism allows the flow of current through the circuit to be interrupted.

[0028] According to another embodiment, the electrical contact is movable between an open position of the circuit and a closed position of the circuit, and releasing the resilient member shifts the electrical contact from the open position of the circuit to the closed position.

[0029] Thus, the control mechanism allows current flow to be established through the circuit.

[0030] The set of values ​​for the duration elapsed between the first instant and the second instant is obtained by a series of consecutive actuations of the switching device.

[0031] Each value in the set of values ​​of the duration elapsed between the first instant and the second instant corresponds to a separate actuation of the switching device.

[0032] Each actuation of the switching device corresponds to a command of the actuator.

[0033] The switching device may be a circuit breaker.

[0034] The switching device may be a switch.

[0035] The switching device may be an isolator.

[0036] According to one embodiment, the actuator is an electromagnetic actuator.

[0037] The electromagnetic actuator includes an electromagnet.

[0038] The electromagnetic actuator includes a control coil and a magnetic core configured to be displaced under the influence of a magnetic field generated by a current flowing through the control coil.

[0039] For example, the core may be moved in translation.

[0040] The unlocking member is connected to the magnetic core of the electromagnetic actuator.

[0041] According to another embodiment, the actuator comprises a button which can be manually activated by an operator.

[0042] The unlocking member includes a position indicator.

[0043] The position indicator provides a signal at two levels.

[0044] The position indicator is a contactor with two electrical states.

[0045] The predetermined position of the unlocking member for determining the first moment may be a balance position of the unlocking member.

[0046] The predetermined position of the unlocking member used for determining the first moment in time may be an instantaneous position of the unlocking member.

[0047] The predetermined position of the drive element used for determining the second moment in time may be an instantaneous position of the drive element.

[0048] The elastic member is configured to apply a driving force to the electrical contact.

[0049] The elastic member may be a spring, for example a helical spring or a spiral spring.

[0050] The drive member can rotate freely.

[0051] The drive element may be connected to the moving contact via a connecting rod.

[0052] Measuring the current flowing through the electromagnetic actuator is understood to be measuring the intensity of the current flowing through the electromagnetic actuator.

[0053] The current flowing through the electromagnetic actuator may be detected by a sensor for measuring the current flowing through the electromagnetic actuator.

[0054] The current flowing through the electromagnetic actuator may be sampled, for example, at a sampling frequency in the range between 1 kHz and 100 kHz.

[0055] The actuator is configured to trigger displacement of the moving contact in order to open or close the circuit.

[0056] When the switchgear is a circuit breaker, the electromagnetic actuator is configured to trigger opening of the circuit if a fault is present on the circuit.

[0057] According to one embodiment of the proposed detection process, wherein the actuator is an electromagnetic actuator, the process comprises the following sub-steps:

[0058] - measuring the current flowing through the electromagnetic actuator when the switching device is actuated;

[0059] - determining a first instant corresponding to a predetermined position of the unlocking member from the measured variation of the current over time.

[0060] Therefore, the proposed process does not require the installation of any additional sensors, such as electrical contact displacement sensors or displacement sensors for elements of the actuating mechanism.

[0061] The proposed procedure comprises a sub-step of determining the variation of the measured current over time.

[0062] The electromagnetic actuator includes a control coil and a magnetic core, the magnetic core being configured to be displaced under the effect of a magnetic field generated by a current flowing through the control coil. The predetermined position of the unlocking member corresponding to the first moment is a maximum displacement position of the magnetic core.

[0063] According to one aspect of the detection process, the first moment corresponding to the predetermined position of the unlocking member is a moment corresponding to a local minimum of the current flowing through the electromagnetic actuator.

[0064] The first time can be determined from the temporal variation of the intensity of the current flowing through the control coil and coincides with the time at which the current passes through a local minimum.

[0065] According to another embodiment of the proposed detection process, wherein the actuator comprises a button manually activatable by an operator, and wherein the unlocking member comprises a position indicator, the process comprises the following sub-steps:

[0066] - measuring the electrical signal from the position indicator;

[0067] - determining a first moment corresponding to a predetermined position of the unlocking member based on the variation over time of the electrical signal from the position indicator.

[0068] This moment corresponds to a change in the electrical state of the position indicator.

[0069] This moment is the time reference, indicating that the action exerted on the button has been clearly transmitted to the unlocking member.

[0070] According to one embodiment of the detection process, the predetermined position of the drive element corresponding to the second moment is an intermediate displacement position of the drive element. The intermediate displacement position is located between a first end position, in which the movable contact is in a closed position, and a second end position, in which the movable contact is in an open position.

[0071] The angular displacement travel range of the drive element is, for example, between 40° and 60°.

[0072] According to one embodiment of the detection process, the range of the displacement travel of the drive element between the first end position and the predetermined position corresponding to the second moment is between 5% and 15% of the total displacement travel of the drive element.

[0073] Thus, the initial part of the displacement travel of the drive element is used to determine the second instant as a reference. Thus, the detection sensitivity of the proposed process is improved.

[0074] The detection process may include the following sub-steps:

[0075] - measuring the position of the drive element when the switching device is actuated;

[0076] - determining a second time instant corresponding to a predetermined position of the drive element from the measured position of the drive element.

[0077] According to one embodiment of the proposed detection process:

[0078] - the control mechanism comprises a position sensor configured to detect a magnetic field;

[0079] The drive element comprises a plurality of magnetic elements which are arranged to pass successively in front of the position sensor during a displacement stroke of the drive element.

[0080] The magnetic element may be a permanent magnet.

[0081] The position sensor may be a Hall Effect sensor.

[0082] The magnetic element is provided, for example, on a portion of the periphery of the drive element.

[0083] The magnetic element may be arranged in a plane perpendicular to the axis of rotation of the drive element.

[0084] The magnetic elements may be identical.

[0085] The angular spacing between two consecutive magnetic elements may be constant.

[0086] For example, the drive element includes four magnetic elements.

[0087] According to one embodiment, the unlocking member comprises a freely rotatable half-moon.

[0088] The half-moon is actuated by the core of an electromagnetic actuator.

[0089] The unlocking member may include an intermediate lever including a first portion configured to engage with the half-moon and a second portion configured to engage with the drive element.

[0090] According to one embodiment, the detection process includes the following sub-steps:

[0091] - calculating a value of a statistical parameter representing the fluctuation of the value of a set of values ​​of the duration elapsed between a first moment and a second moment;

[0092] - Determining the degradation of the unlocked member from the calculated values ​​of the statistical parameters.

[0093] According to one embodiment of the detection process, the statistical parameter representative of the fluctuation of the value of the set of values ​​of the duration elapsed between the first moment and the second moment comprises the difference between:

[0094] - a current value of the duration elapsed between the first instant and the second instant, the current value being determined for the current actuation of the switching device; and

[0095] - a mean value of the duration values ​​that elapse between the first instant and the second instant, the mean value being obtained for a predetermined number of actuations preceding the current actuation of the switching device.

[0096] The average value may be a sliding average value calculated from values ​​corresponding to actuations preceding the current actuation and comprising a number of values ​​equal to a predetermined number of actuations.

[0097] According to one embodiment of the detection process, the statistical parameter representing the fluctuation of the values ​​of a set of values ​​of the duration elapsed between a first moment and a second moment includes a standard deviation of the values ​​of the duration elapsed between the first moment and the second moment, the standard deviation being determined for a set of actuations of the switching device performed under reference conditions corresponding to a new state of the circuit breaker.

[0098] A set of actuations of the switching device performed under reference conditions comprises, for example, 20 consecutive actuations of the switching device.

[0099] The proposed procedure therefore comprises a calibration phase which allows quantifying the nominal variations in the values ​​of the duration elapsed between a first moment and a second moment when the switching device is actuated. These nominal variations correspond to the variations observed in a reference state in which the switching device exhibits neither a fault of assembly nor degradation due to wear.

[0100] For example, the reference state corresponds to the new state of the switching device.

[0101] The proposed procedure comprises a measurement phase, in which the change in the value of the duration elapsed between a first moment in time and a second moment in time is analyzed.

[0102] The calibration phase is followed by the measurement phase.

[0103] The measurement phase is carried out over the entire operating life of the switchgear.

[0104] According to one embodiment of the proposed detection process, the statistical parameter representing the fluctuation of the duration of time elapsed between a first moment and a second moment is equal to the following ratio:

[0105] - the difference between a current value of the duration elapsed between a first moment and a second moment and an average value of the duration elapsed between the first moment and the second moment, the average value being obtained for a predetermined number of actuations preceding the current actuation; and

[0106] a standard deviation of the values ​​of the duration elapsed between the first instant and the second instant, the standard deviation being determined for a set of actuations of the switching device performed under reference conditions corresponding to the new state of the switching device.

[0107] The proposed statistical parameters allow reliable detection of any degradation of the unlocking member of the switching device while being easy to implement. In particular, the necessary calculations can be easily performed in real time, which allows fast degradation detection.

[0108] Therefore, the statistical parameter representing the fluctuation of the duration of time elapsed between the first moment and the second moment can be equal to:

[0109] [Formula 1]

[0110]

[0111] Where D i is the determined value of the duration D of the actuation of rank i, P(i) is the calculated value of the statistical parameter P of the actuation of rank i, M is the number of actuations considered to determine the mean value, K is the number of actuations performed under reference conditions corresponding to the new state of the switching device.

[0112] According to one aspect of the proposed detection process, degradation of the unlocking member is determined when the absolute value of a statistical parameter representative of fluctuations of the duration elapsed between a first moment and a second moment is greater than a first positive predetermined threshold.

[0113] The value chosen for the first predetermined threshold allows adjusting the sensitivity of the proposed detection process.

[0114] For example, the first predetermined threshold ranges between 2 and 3.

[0115] According to one embodiment of the detection process, degradation of the unlocking member is classified as a first type of degradation, called slight degradation, when the absolute value of a statistical parameter representative of the fluctuation of the duration elapsed between a first moment and a second moment is greater than a first positive predetermined threshold and less than a second positive predetermined threshold.

[0116] For example, the second predetermined threshold ranges between 4 and 5.

[0117] According to one embodiment of the detection process, degradation of the unlocking member is classified as a second type of degradation, called major degradation, when the criterion representative of the fluctuation of the duration elapsed between the first moment and the second moment is greater than a second predetermined threshold.

[0118] Thus, the statistical parameter P used allows quantifying the degradation, not just the presence or absence of degradation.

[0119] The detection process may include the step of sending a warning signal if degradation of the unlocking member has been determined.

[0120] The transmitted warning signal allows the user to plan and perform maintenance or replacement operations on the switchgear.

[0121] When it is determined that there is no degradation, no warning signal is sent. In other words, when the proposed process indicates that the unlocking member is not degraded, no warning is sent.

[0122] The present invention also relates to a switch device, comprising:

[0123] - electrical contacts movable between a closed position for an electrical circuit and an open position for an electrical circuit;

[0124] - Control bodies, including:

[0125] -- an actuating element configured to displace the movable contact, thereby opening the circuit;

[0126] - an elastic member connected to the drive element;

[0127] an unlocking member configured to switch from a locking position, in which the elastic member is held in a tensioned state, to a releasing position, in which the elastic member is free to release, thereby shifting the electrical contacts from a closed position of the circuit to an open position;

[0128] - an actuator configured to displace the unlocking member from the locked position to the released position;

[0129] - An electronic control unit configured to implement the degradation detection process as described above.

[0130] Switchgear can be circuit breakers, switches or isolators. BRIEF DESCRIPTION OF THE DRAWINGS

[0131] Further features, details and advantages will become apparent by reading the following detailed description and referring to the accompanying drawings, in which:

[0132] Figure 1 is a schematic diagram of an electric circuit equipped with a switching device, the circuit being in the closed position;

[0133] Figure 2 is a schematic diagram of an electrical circuit equipped with a switching device, with the circuit in the open position;

[0134] Figure 3 is a schematic diagram of a control mechanism of a switchgear according to a first embodiment, wherein the circuit is in a closed position;

[0135] Figure 4 yes Figure 3 Schematic diagram of the control mechanism of the switching device, in which the circuit is in the open position,

[0136] Figure 5 It is shown that when the switch device is actuated, Figure 3 and Figure 4 Changes of some operating parameters of switchgear over time;

[0137] Figure 6 is a timing diagram illustrating a process according to the present invention;

[0138] Figure 7 is a block diagram showing the various steps of a process according to the present invention;

[0139] Figure 8 is a schematic diagram of a control mechanism of a switchgear according to a second embodiment, wherein the circuit is in a closed position;

[0140] Fig. 9 yes Figure 7 Schematic diagram of the control mechanism of a switching device with the circuit in the open position. DETAILED DESCRIPTION

[0141] In order to make the drawings easier to read, various elements are not necessarily shown to scale. In these figures, the same elements use the same reference numerals. Some elements or parameters can be indexed, that is, for example, referred to as the first element or the second element, or even referred to as the first parameter and the second parameter, etc. The purpose of this index is to distinguish similar but not identical elements or parameters. This index does not mean that one element or parameter takes precedence over another element or parameter, and the names can be interchanged. When a specified subsystem includes a given element, this does not exclude the presence of other elements in the subsystem. Similarly, when a specified subsystem includes a given element, it should be understood that the subsystem includes at least this element.

[0142] Figure 1 There is schematically shown an electric circuit 50. The electric circuit 50 comprises three electric conductors 20, 21, 22, each conductor corresponding to a phase of a three-phase medium voltage network.

[0143] The circuit 50 includes a switching device 30 .

[0144] The switchgear 30 may be a circuit breaker. As an alternative embodiment, the switchgear 30 may be a switch. According to another example of application, the switchgear 30 may be an isolator.

[0145] Figure 1 and Figure 2 Two states of the switching device 30 are respectively schematically shown.

[0146] The switching device 30 comprises an electrical contact 10 movable between a closed position F of an electrical circuit 50 and an open position O of the electrical circuit 50 .

[0147] The switch device 30 further includes a control mechanism 4, which includes:

[0148] an actuating element 9 configured to displace the movable contact 10 in order to open the circuit 50 ;

[0149] - an elastic member 7 connected to a drive element 9;

[0150] - an unlocking member 8 configured to switch from a locking position V, in which the elastic member 7 is kept in a tensioned state, to a releasing position L, in which the elastic member 7 is free to relax, thereby shifting the electrical contact 10 from the closed position F of the circuit 50 to the open position O.

[0151] The switching device 30 further comprises an actuator 1 which is configured to displace the unlocking member 8 from the locking position V to the releasing position L.

[0152] The switchgear 30 further comprises an electronic control unit 25 which is configured to implement a degradation detection process which will be described in detail below.

[0153] The elastic member 7 is configured to apply a driving force to the electrical contact 10 .

[0154] The elastic member 7 may be a spring, for example, a helical spring or a spiral spring.

[0155] The actuator 1 is configured to trigger the displacement of the moving contact 10 in order to open or close the circuit 50 .

[0156] In practice, the actuator 1 allows the control member 4 to be unlocked in order to displace the moving contact 10 and thus open or close the circuit 50 .

[0157] exist Figure 1 In the embodiment, the movable contacts 10, 11, 12 are in the closed position, that is, the current can flow through the circuit 50. The reference symbol F indicates the closed position of the movable contact 10.

[0158] The elastic member 7 is in a tensioned state. The elastic member 7 is held in a tensioned state by the unlocking member 8. The drive element 9 is blocked by the unlocking member 8.

[0159] The circuit 50 is disconnected as follows:

[0160] Under the action of the actuator 1, the unlocking member 8 is displaced to the release position L, in which the drive element 9 is no longer blocked by the unlocking member 8. The drive element 9 can be displaced under the action of the drive force applied by the elastic member 7, which is in a tensioned state and can be released freely. The drive element 9 thus displaces the electrical contact 10 from the closed position F of the circuit 50 to the open position O.

[0161] The three moving contacts 10 , 11 , 12 are mechanically coupled so that when the control mechanism 4 is unlocked, the three contacts 10 , 11 , 12 are switched to the disconnected position together.

[0162] Figure 2The position of the various elements once the movable contacts 10 , 11 , 12 have been displaced into the open position of the electrical circuit 50 is schematically shown.

[0163] according to Figure 1 and Figure 2 In the embodiment shown, the actuator 1 is an electromagnetic actuator.

[0164] The electromagnetic actuator 1 includes an electromagnet.

[0165] The electromagnetic actuator 1 includes a control coil 2 and a magnetic core 3 configured to be displaced by a magnetic field generated by a current flowing through the control coil 2 .

[0166] For example, the magnetic core 3 may be moved in translation.

[0167] The unlocking member 8 is connected to the magnetic core 3 of the electromagnetic actuator 1 .

[0168] Therefore, displacement of the magnetic core 3 of the electromagnetic actuator 1 results in displacement of the unlocking member 8 .

[0169] When the switchgear 30 is a circuit breaker, the electromagnetic actuator 1 is configured to trigger the opening of the circuit 50 if a fault is present on the circuit 50 .

[0170] according to Figure 8 and 9 In another embodiment shown, the actuator 1 comprises a button 32 which can be manually operated by an operator. When the operator wishes to trigger the opening of the circuit 50, the operator presses the button 32, which is mechanically connected to the unlocking member 8. Thus, the unlocking member 8 is unlocked by the operator's action on the button 32.

[0171] In this embodiment, the unlocking member 8 comprises a position indicator 33 .

[0172] The proposed procedure aims to detect degradation of the switching device 30, i.e. to detect changes in the behavior of the control mechanism 4 of the switching device 30, in particular the unlocking member 8, due to aging of its components. Aging of components includes, for example, wear, deformation, changes in magnetic properties and changes in the friction characteristics of the components.

[0173] Therefore, a process for detecting degradation of a switchgear 30 is proposed, the switchgear comprising:

[0174] - an electrical contact 10 movable between a closed position F of the electrical circuit 50 and an open position O of the electrical circuit 50;

[0175] - Control mechanism 4, comprising:

[0176] - an actuating element 9 configured to displace the movable contact 10 in order to open the circuit 50;

[0177] - an elastic member 7 connected to a drive element 9;

[0178] - an unlocking member 8, configured to switch from a locking position V, in which the elastic member 7 is kept in a tensioned state, to a releasing position L, in which the elastic member 7 is free to release, thereby shifting the electrical contact 10 from the closed position F of the circuit 50 to the open position O, or from the open position O to the closed position F;

[0179] an actuator 1 configured to displace the unlocking member 8 from the locking position V to the releasing position L,

[0180] The process includes the following steps:

[0181] (i) command actuator 1;

[0182] (ii) determining a first moment t1 corresponding to a predetermined position P1 of the unlocking member 8;

[0183] (iii) determining a second time t2 corresponding to a predetermined position P2 of the drive element 9;

[0184] (iv) determining a duration D that elapses between a first instant t1 and a second instant t2;

[0185] (v) repeating steps (i) to (iii) for a set of consecutive commands of the actuator 1 so as to obtain a set E of values ​​of the duration D elapsed between the first instant t1 and the second instant t2;

[0186] (vi) Determination of the degradation of the unlocking member 8 of the switching device 30 from the variation of the set of values ​​E during successive commands of the actuator 1 .

[0187] The duration D elapsed between the first and second instants t1 and t2 corresponds to the reaction time of the unlocking member 8. Monitoring changes in the value of the duration D, i.e. how it changes during the service life of the switching device 30, allows monitoring any changes in the behavior of the unlocking member of the control mechanism 4 during its use.

[0188] When the unlocking member of the control mechanism 4 operates normally, the values ​​of the set E are substantially constant during the continuous actuation of the switching device 30. In other words, the various values ​​of the set E are substantially constant. On the contrary, during the service life of the switching device 30, the gradual degradation of the unlocking member of the control mechanism 4 tends to cause the values ​​of the set E to change during continuous actuation, in particular to cause fluctuations in these values. Therefore, the values ​​of the set E are no longer substantially constant, but fluctuate greatly. This gradual change allows the degradation of the unlocking member 8 of the control mechanism 4 to be detected.

[0189] The process for detecting degradation of the switchgear 30 is also a process that allows for detection of faults in the switchgear 30 .

[0190] In fact, uncorrected degradation of the switching device 30 may eventually lead to the occurrence of a fault, which may also be detected.

[0191] The opening and closing movements of the moving contact can be performed in a similar manner.

[0192] According to one embodiment, the electrical contact 10 is movable between a closed position F of the electrical circuit 50 and an open position O of the electrical circuit 50; and

[0193] Releasing the resilient member 7 displaces the electrical contact 10 from the closed position F to the open position O of the electrical circuit 50 .

[0194] The control mechanism 4 thus allows the flow of current through the circuit 50 to be interrupted.

[0195] According to another embodiment, the electrical contact 10 is movable between an open position O of the electrical circuit 50 and a closed position F of the electrical circuit 50; and

[0196] The release of the elastic member 7 displaces the electrical contact 10 from the open position O to the closed position F of the electrical circuit 50 .

[0197] The control mechanism 4 thus allows a current flow to be established through the electrical circuit 50 .

[0198] The set E of values ​​of the duration D elapsing between the first instant t1 and the second instant t2 is obtained by a series of consecutive actuations of the switching device 30 .

[0199] Each value of the set E of values ​​of the duration D elapsing between the first instant t1 and the second instant t2 corresponds to a separate actuation of the switching device 30 .

[0200] Each actuation of the switching device 30 corresponds to a command from the actuator 1 .

[0201] “Actuation of the switching device 30 ” is understood to mean that, in response to a command from the actuator 1 , the electrical contact 10 is switched from the closed position F of the electrical circuit 50 to the open position O of the electrical circuit 50 .

[0202] When the actuator 1 is an electromagnetic actuator, actuation of the switching device 30 is achieved by causing current to flow through the control coil 2. When the actuator 1 is a push button, actuation of the switching device 30 is achieved by an operator pressing the push button.

[0203] The predetermined position P1 of the unlocking member 8 is a first characteristic position for defining a first time reference characterizing the operation of the control mechanism 4 .

[0204] The predetermined position P2 of the drive element 9 is a second characteristic position for defining a second time reference characterizing the operation of the control mechanism 4 .

[0205] More specifically, the duration separating the two time references may be a parameter for determining the degradation of the control mechanism 4 of the switching device 30 .

[0206] According to the example shown, the predetermined position P1 of the unlocking member 8 for determining the first time instant t1 may be an equilibrium position of the unlocking member 8 .

[0207] In other words, when the unlocking member 8 is in the predetermined position P1 for determining the first time instant t1 , the speed of the unlocking member 8 is zero.

[0208] According to an embodiment not shown, the predetermined position P1 of the unlocking member 8 for determining the first time t1 may be an instantaneous position of the unlocking member 8 .

[0209] In this case, the speed of the unlocking member 8 is non-zero when the unlocking member 8 is in a predetermined position P1 for determining the first moment t1. The first moment t1 corresponds to the unlocking member 8 passing through the first position P1.

[0210] The predetermined position P2 of the drive element 9 for determining the second time instant t2 may be an instantaneous position of the drive element 9 .

[0211] In other words, the speed of the drive element 9 is non-zero when the drive element 9 is in the predetermined position P2 for determining the second instant t2. The second instant t2 corresponds to the drive element 9 passing through the second position P2.

[0212] The duration D that elapses between the first instant t1 and the second instant t2 corresponds to the duration that separates the first instant t1 and the second instant t2.

[0213] The way of determining the first instant t1 depends on the type of actuator 1 . When the actuator 1 is an electromagnetic actuator, the determination of the first instant t1 is based on current measurement in the electromagnetic actuator 1 .

[0214] “Measuring the current C flowing through the electromagnetic actuator 1” is understood to mean measuring the intensity of the current flowing through the electromagnetic actuator 1.

[0215] The current C flowing through the electromagnetic actuator 1 may be detected by a sensor 6 for measuring the current flowing through the electromagnetic actuator 1 .

[0216] The current C flowing through the electromagnetic actuator 1 may be sampled, for example, with a sampling frequency ranging between 1 kHz and 100 kHz.

[0217] In an embodiment where the actuator 1 is an electromagnetic actuator, the process comprises the following sub-steps:

[0218] - measuring the current C flowing through the electromagnetic actuator 1 when the switching device 30 is actuated;

[0219] - determining a first instant t1 corresponding to a predetermined position P1 of the unlocking member 8 from the measured variation of the current C over time.

[0220] Therefore, the proposed process does not require the installation of any additional sensors, such as electrical contact displacement sensors or displacement sensors for elements of the actuating mechanism.

[0221] Therefore, the proposed procedure may comprise a sub-step of determining the variation of the measurement current C over time.

[0222] The electromagnetic actuator 1 includes a control coil 2 and a magnetic core 3 configured to be displaced by a magnetic field generated by a current flowing through the control coil 2 .

[0223] The predetermined position P1 of the unlocking member 8 corresponding to the first time t1 is the maximum displacement position of the magnetic core 3 .

[0224] In other words, the first instant t1 corresponds to the instant when the magnetic core 3 reaches its maximum displacement position.

[0225] The first time t1 corresponding to the predetermined position P1 of the unlocking member 8 is a time corresponding to a local minimum value of the current flowing through the electromagnetic actuator 1 .

[0226] Therefore, the first time t1 can be determined according to the change of the current intensity flowing through the control coil 2 with time, and coincides with the time when the current passes through the local minimum.

[0227] Figure 5 The changes of several parameters when the switching device is actuated are shown. Figure 5 In FIG. 1 , curve G2 shows the change of the current in the electromagnetic actuator 1 over time when the electromagnetic actuator 1 is controlled. Curve G2 includes a first continuously increasing portion z1, a second continuously decreasing portion z2, and a third continuously increasing portion z3, the second portion z2 follows the first portion z1, and the third portion z3 follows the second portion z2. The time t1 corresponding to the local minimum value of the current corresponds to the time separating the third portion z3 from the second portion z2.

[0228] The control of the electromagnet is deactivated at instant tf and the portion z4 corresponds to a phase in which the current decreases until it reaches zero. The current remains zero until the next activation or control of the electromagnet.

[0229] At a time tm between a time t0 corresponding to when the current starts to flow through the electromagnetic actuator 1 and a time t1 corresponding to a local minimum value of the current flowing through the electromagnetic actuator 1 , a local maximum value i1 of the current is obtained.

[0230] The local maximum i1 of the current is a current value obtained when switching from the first section z1 to the second section z2.

[0231] The decrease in current between instant tm and instant t1 is related to the variation in the gap between the moving part and the fixed part. As soon as the gap no longer varies, the current starts to increase again, which corresponds to the portion z3 of the curve G2.

[0232] From the time t1, the electromagnetic actuator 1 has reached its maximum displacement stroke and the position of the magnetic core 3 no longer changes. However, in order to provide a holding force, the electrical control is maintained until the time tf.

[0233] When the actuator 1 is a purely mechanical actuator of the push-button type, the determination of the first instant t1 is based on a signal from a position indicator (also called a position sensor).

[0234] Therefore, the unlocking member 8 comprises a position indicator 33 .

[0235] The position indicator 33 may provide a signal at two levels.

[0236] The position indicator 33 is a contactor having two electrical states.

[0237] In other words, when the locking member reaches a certain threshold position, the signal from the position indicator 33 switches from the first level to the second level.

[0238] Thus, in the embodiment of the proposed detection process, in which the actuator 1 comprises a button 32 manually activatable by an operator, and in which the unlocking member 8 comprises a position indicator 33, the process comprises the following sub-steps:

[0239] - measuring the electrical signal from the position indicator 33;

[0240] - From the variation over time of the electrical signal from the position indicator 33 , a first instant t1 corresponding to the predetermined position P1 of the unlocking member 8 is determined.

[0241] The time t1 corresponds to a change in the electrical state of the position indicator 33 .

[0242] The time t1 is a time reference, indicating that the action applied by the operator to the button has been transmitted to the unlocking member 8 .

[0243] Figure 3 and Figure 4 An exemplary embodiment of a control mechanism 4 of a switching device 30 is shown, in which the actuator 1 is an electromagnetic actuator.

[0244] In order to simplify the drawings, the elastic member 7 is shown in the form of a helical spring. The elastic member 7 may also be a spiral spring.

[0245] exist Figure 3 In the embodiment, the unlocking member 8 is in the locking position V, and the spring 7 is kept in a compressed state. One end of the spring 7 exerts a force on the fixed stop 18, and the other end of the spring exerts a force on the drive element 9.

[0246] In this case, the drive element 9 is free to rotate. The drive element 9 is connected to the moving contact 10 via a connecting rod 19 .

[0247] The connecting rod 19 is rigid. The connecting rod 19 is pivotably connected to the drive element 9 .

[0248] The link 19 is pivotably connected to the moving contact 10 .

[0249] The unlocking member 8 comprises a freely rotatable half-moon 16. The half-moon 16 presents the general shape of a semi-cylinder and comprises a flat surface 16-1 extending parallel to the axis of the semi-cylinder.

[0250] The half-moon 16 is actuated by the magnetic core 3 of the electromagnetic actuator 1 .

[0251] “Actuated” is understood to mean that the half-moon 16 can pivot in response to a displacement of the magnetic core 3 .

[0252] The electromagnetic actuator 1 comprises a connecting element 13 connecting the moving magnetic core 3 and the half-moon 16 .

[0253] The unlocking member 8 further comprises an intermediate lever 17 comprising a first portion 17 - 1 configured to engage with the half-moon 16 and a second portion 17 - 2 configured to engage with the drive element 9 .

[0254] exist Figure 3 , the unlocking member 8 is in the locked position V, and the driving force applied by the elastic member 7 to the drive element 9 is transmitted to the intermediate rod 17 of the unlocking member 8. The half-moon 16 is in the locked position and the rotation of the intermediate rod 17 is blocked because the first part 17-1 of the intermediate rod 17 interferes with the surface 16-1 of the half-moon 16. The second part 17-2 blocks the drive element 9, which is thus held in place. The spring 7 remains compressed between the drive element 9 and the fixed stop 18.

[0255] When the half-moon 16 leaves its locking position, the first portion 17-1 is no longer held and the force applied to the second portion 17-2 causes the intermediate lever 17 to pivot. Thus, the intermediate lever 17 can pivot under the action of the driving force of the elastic member 7. The drive element 9 can thus be displaced under the action of the driving force of the elastic member 7. The connecting rod 19 rigidly connected to the drive element 9 pivots the contact 10.

[0256] exist Figure 4In the embodiment, the unlocking member 8 is in the release position L. The spring 7 is in the released state, and the moving contact 10 is in the disconnected position O after the drive element 9 has been pivoted and thus displaced.

[0257] exist Figure 4 , the half-moon 16 of the unlocking member 8 is shown in a position P1 for defining a first time reference t1.

[0258] According to the embodiment shown, the predetermined position of the drive element 9 corresponding to the second instant t2 is an intermediate displacement position of the drive element 9. The intermediate displacement position is located between a first end position B1, in which the movable contact 10 is in the closed position F, and a second end position B2, in which the movable contact 10 is in the open position O.

[0259] Figure 3 The first end position B1 is schematically shown, Figure 4 The second end position B2 is schematically shown.

[0260] According to the example shown, the displacement travel of the drive element 9 between the first end position B1 and the predetermined position P2 corresponding to the second instant t2 is between 5% and 15% of the total displacement travel CT of the drive element 9 .

[0261] Thus, the initial part of the displacement travel of the drive element 9 is used to determine the second moment serving as a reference. Thus, the detection sensitivity of the proposed process is improved.

[0262] The total displacement travel CT is the distance between the first end position B1 and the second end position B2 of the drive element 9 .

[0263] In the case of free rotation of the drive element 9, the total displacement travel CT is the angular spacing.

[0264] The angular displacement travel CT of the drive element 9 is, for example, between 40° and 60°.

[0265] Reference numeral L0 denotes a reference indicating an initial position B1 of the drive element 9, and reference numeral L1 denotes the position of the reference after the drive element 9 has completed a rotation when the drive element is in position B2. The difference between L0 and L1 denotes a rotation stroke CT.

[0266] Reference L2 denotes a position with reference to L0 when the drive element 9 is in a predetermined position P2 corresponding to a second moment t2.

[0267] The detection process may include the following sub-steps:

[0268] - measuring the position of the drive element 9 when the switching device 30 is actuated;

[0269] - Determining a second instant t2 corresponding to a predetermined position P2 of the drive element 9 from the measured position of the drive element 9 .

[0270] According to the embodiments described herein:

[0271] - the control mechanism 4 comprises a position sensor 14 configured to detect a magnetic field;

[0272] The drive element 9 comprises a plurality of magnetic elements 15 which are arranged to successively pass in front of the position sensor 14 during the displacement stroke of the drive element 9 .

[0273] When the drive element 9 is transferred from the first end position B1, in which the movable contact 10 is in the closed position F, to the second end position B2, in which the movable contact 10 is in the open position O, the passage of the magnetic element 15 in front of the position sensor 14 generates a change in the electrical state of the position sensor 14. When this magnetic element 15 moves away from the sensor 14, the position sensor 15 returns to the initial electrical state. Thus, the rotation of the drive element 9 generates a signal comprising a series of slots, each slot corresponding to a separate magnetic element 15.

[0274] The magnetic element 15 may be a permanent magnet.

[0275] The position sensor 14 may be a Hall Effect sensor.

[0276] The magnetic element 15 is provided on a portion of the periphery of the driving element 9 .

[0277] In this case, the magnetic element 15 is arranged in a plane which is perpendicular to the axis of rotation of the drive element 9 .

[0278] In the example shown, the magnetic elements 15 are identical. The magnetic elements 15 may also be different.

[0279] In this case, the angular spacing T between two consecutive magnetic elements 15 is constant. The magnetic elements can also be mounted with an angular spacing between two consecutive magnetic elements 15 which is not the angular spacing from one magnetic element to another.

[0280] In the example shown, the drive element 9 comprises four magnetic elements 15. The four magnetic elements 15 are permanent magnets.

[0281] exist Figure 3 and Figure 4 In the figure, four permanent magnets are indicated by reference numerals 15-1, 15-2, 15-3, and 15-4.

[0282] Of course, different numbers of magnetic elements may be used.

[0283] exist Figure 5In FIG. 2 , curve G3 shows the signal provided by the position sensor 14 during the displacement of the drive element 9 .

[0284] The time t2 corresponds to the beginning of the passage of the first magnet 15 - 1 in front of the position sensor 14 .

[0285] The time t3 corresponds to the beginning of the passage of the second magnet 15 - 2 in front of the position sensor 14 .

[0286] Similarly, time t4 corresponds to the beginning of the passage of the third magnet 15 - 3 , and time t5 corresponds to the beginning of the passage of the fourth magnet 15 - 4 .

[0287] The duration between two consecutive magnet passes is not constant, because the displacement speed is not constant.

[0288] exist Figure 5 In FIG. 1 , curve G1 represents the signal provided by the high-resolution position sensor.

[0289] In other words, the sensor delivers a substantially continuous signal, rather than a discrete signal. The sensor was installed only experimentally in order to verify the proposed process and does not form part of the switchgear 30 when said switchgear is used normally. Therefore, the signal from curve G1 is not used in the proposed process.

[0290] Until the time td, the signal is constant, which indicates that the drive element 9 is stationary. The drive element 9 starts to pivot at the time indicated by td.

[0291] Due to the passage of the magnet 15 - 1 , the time t2 at which the position sensor 14 changes its electrical state is later than the time td due to the displacement stroke required for the magnet 15 - 1 to be in a position opposite to the position sensor 14 .

[0292] like Figure 5 As shown, the predetermined position of the drive element 9 defining the second moment t2 corresponds to the position at which the first magnet 15 - 1 passes in front of the position sensor 14 .

[0293] The predetermined position P1 of the unlocking member 8 defining the first moment t1 is the end of the pivoting position of the half-moon 16 .

[0294] The time shift between the instant t1 and the instant t2 defines the duration D.

[0295] Figure 8 and Fig. 9 An embodiment of a control mechanism 4 of a switching device 30 is shown, in which the actuator 1 is a mechanical actuator of the pushbutton type.

[0296] This embodiment differs from the embodiment described above in the nature of the actuator 1 and in the presence of a position indicator 33. Figure 3 and 4 Embodiment of the invention.

[0297] The button 32 is connected to the half-moon 16 via the connecting element 13B. For example, the button 32 is rigidly connected to the connecting element 13B, which is connected to the half-moon 16.

[0298] The connecting element 13B can be similar to Figure 3 and 4 The half-moon 16 is displaced in the manner described within the scope of the embodiment shown with an electromagnetic actuator.

[0299] The time t1 is determined by the electrical signal delivered by the position indicator 33. The position indicator 33 comprises a pivoting lug 34 which is held at a distance from a contactor 35 by a spring (not shown).

[0300] When the half-moon-shaped member 16 is away from the pivoting protrusion 34, as shown in FIG. Figure 8 As shown, the tab itself is away from the contact 35 in the "released" state. The position indicator 33 delivers a first signal level.

[0301] Once the half-moon 16 is fully pivoted, it displaces the pivot tab 34 which presses on the contact 35 and moves it out of the released state.

[0302] The position indicator 33 then delivers a second signal level.

[0303] The instant corresponding to the transition between the first signal level and the second signal level allows the first instant t1 to be determined.

[0304] In this embodiment, the rest of the control mechanism 4 is Figure 3 and 4 The embodiments are the same and the second time t2 is determined in the same way.

[0305] The determined time period D is the physical parameter on which the process for detecting degradation of the control device 4 is based.

[0306] The physical parameters are statistically processed.

[0307] Therefore, the detection process includes the following sub-steps:

[0308] - calculating the value of a statistical parameter P representing the fluctuations of the value of a set E of values ​​of a duration D elapsing between a first instant t1 and a second instant t2;

[0309] - From the calculated value of the statistical parameter P, the degradation of the unlocking member 8 is determined.

[0310] According to one embodiment of the detection process, the statistical parameter P representative of the fluctuations of the values ​​of the set E of values ​​of the duration D elapsed between the first instant t1 and the second instant t2 comprises the difference between:

[0311] a current value of the duration D which elapses between the first instant t1 and the second instant t2 , which is determined for the current actuation of the switching device 30 ; and

[0312] a mean value Moy of the values ​​of the duration D which elapses between the first instant t1 and the second instant t2 , which is obtained for a predetermined number M of actuations preceding the current actuation of the switching device 30 .

[0313] The mean value Moy may be a sliding mean value calculated from the values ​​corresponding to actuations preceding the current actuation and comprising a number of values ​​equal to a predetermined number M of actuations.

[0314] According to one embodiment of the detection process, the statistical parameter P representing the fluctuation of the values ​​of the set E of values ​​of the duration D elapsed between the first moment t1 and the second moment t2 includes the standard deviation of the values ​​of the duration D elapsed between the first moment t1 and the second moment t2, the standard deviation being determined for a set of actuations of the switching device 30 performed under reference conditions corresponding to the new state of the circuit breaker 30.

[0315] For example, a set of actuations of the switching device 30 performed under reference conditions includes 20 consecutive actuations of the switching device 30 .

[0316] The proposed process thus comprises a calibration phase for quantifying nominal variations in the value of the duration D that passes between a first instant t1 and a second instant t2 when the switching device 30 is actuated. These nominal variations correspond to variations observed in a reference state in which the switching device 30 exhibits neither an assembly fault nor degradation due to wear. For example, the reference state corresponds to a new state of the switching device 30.

[0317] The proposed procedure comprises a measurement phase, in which the change in the value of the duration D which elapses between a first instant t1 and a second instant t2 is analyzed.

[0318] The calibration phase is followed by the measurement phase.

[0319] The measuring phase takes place during the entire operation of the switching device 30 .

[0320] The values ​​obtained under these reference conditions are used to determine a nominal variation of the duration D elapsed between the first instant t1 and the second instant t2. In this case, this nominal variation is characterized by a mathematical quantity equal to the standard deviation of the duration D elapsed between the first instant t1 and the second instant t2, this standard deviation being calculated for all measurements made under the reference conditions. This nominal variation is characterized by a predetermined number of values ​​corresponding to a predetermined number of actuations. For example, 20 consecutive actuations performed when the switching device 30 is new can be used to characterize a nominal variation of the quantity used to determine the degradation of the switching device 30.

[0321] Figure 6 The values ​​of the duration D between a first instant t1 and a second instant t2 are shown for various actuations of the switching device 30. Part A schematically shows a measurement made at a first instant t_A. Part B of the diagram schematically shows a measurement made at a second instant t_B later than t_A.

[0322] The measurement points framed by the frame denoted J0 are those obtained under reference conditions corresponding to the new state of the switching device 30. To simplify the figure, only 7 measurement points are shown. It can be seen that the dispersion of the values ​​of the quantity D is very low.

[0323] Reference Ec0 denotes the standard deviation of the values ​​corresponding to a set of actuations of the switching device 30 performed under reference conditions and taken into account for the calibration phase.

[0324] exist Figure 6 In part A of FIG. 1 , the measurement point circled by the box marked J1 is the point used at time t_A of the measurement phase. As mentioned above, in order to simplify the drawing, only 10 measurement points of duration D are shown. The value D determined at time t_A n is the current value at time t_A, i.e., the most recent value.

[0325] The horizontal dashed line represents the mean value moy_A of the values ​​considered, ie the values ​​appearing in box J1.

[0326] The arrow denoted as e_A shows the current value D n The difference between the average value moy_A, in this example, the average value moy_A is calculated from the current measurement D n Calculated for the previous 10 measurement points.

[0327] exist Figure 6 In part B of FIG. 1 , the measurement point enclosed by the box indicated as J2 is the point used at time t_B in the measurement phase. As mentioned above, 10 measurement points are used in the figure.

[0328] The value determined at time t_B is the current value at time t_B, ie the most recent value. Compared to time t_A, 4 new measured values ​​have been acquired and the 4 oldest values ​​in block J1 are not used at time t_B and do not form part of block J2.

[0329] The horizontal dashed line represents the mean value moy_B of the values ​​considered, ie those occurring in box J2.

[0330] Arrow e_B indicates the current value D n+4 The difference between the average value moy_B.

[0331] More specifically, the statistical parameter P representing the fluctuation of the duration D elapsed between the first instant t1 and the second instant t2 is equal to the following ratio:

[0332] - the difference between the current value Di of the duration D elapsed between the first instant t1 and the second instant t2 and the mean value Moy of the values ​​of the duration D elapsed between the first instant t1 and the second instant t2, the mean value Moy being obtained for a predetermined number M of actuations preceding the current actuation; and

[0333] the standard deviation Ec of the values ​​of the duration D elapsed between the first instant t1 and the second instant t2 determined for a set of actuations of the switching device 30 carried out under reference conditions corresponding to a new state of the switching device 30 .

[0334] The proposed statistical parameter P allows reliable detection of any degradation of the unlocking member 8 of the control mechanism 4 of the switching device 30 while being easy to implement. In particular, the necessary calculations can be easily performed in real time, which allows fast degradation detection.

[0335] Therefore, the statistical parameter P representing the fluctuation of the duration D elapsed between the first instant t1 and the second instant t2 is equal to:

[0336] [Formula 1]

[0337]

[0338] Where D i is the determined value of the duration D of the actuation of rank i, P(i) is the calculated value of the statistical parameter P of the actuation of rank i, M is the number of actuations considered to determine the average value, K is the number of actuations performed under reference conditions corresponding to the new state of the switching device 30.

[0339] The calculations carried out for the statistical parameter P allow conclusions to be drawn about the state of the control device 4 .

[0340] Degradation of the unlocking member 8 is determined when the absolute value of a statistical parameter P representative of the fluctuations of the duration D elapsing between the first instant t1 and the second instant t2 is greater than a first positive predetermined threshold S1 .

[0341] The value chosen for the first predetermined threshold S1 allows adjusting the sensitivity of the proposed detection process.

[0342] For example, the first predetermined threshold S1 ranges between 2 and 3.

[0343] According to one embodiment of the detection process, when the absolute value of the statistical parameter P representative of the fluctuation of the duration D elapsed between the first moment t1 and the second moment t2 is greater than the first positive predetermined threshold S1 and less than the second positive predetermined threshold S2, the degradation of the unlocking member 8 is classified as a first type of degradation, called slight degradation.

[0344] For example, the second positive predetermined threshold S2 ranges between 4 and 5.

[0345] When the absolute value of the parameter P representative of the fluctuation of the duration D elapsed between the first instant t1 and the second instant t2 is greater than a second positive predetermined threshold S2 , the degradation of the unlocking member 8 is classified as a second type of degradation, called major degradation.

[0346] Thus, the statistical parameter P used allows quantifying the degradation, not just the presence or absence of degradation.

[0347] The detection process may include the step of sending a warning signal if degradation of the unlocking member 8 has been determined.

[0348] The transmitted warning signal allows the user to plan and perform maintenance or replacement operations of the switchgear 30 .

[0349] The warning signal may be, for example, a code stored in the electronic control unit.

[0350] As an alternative or in addition, the warning signal may include turning on an indicator light.

[0351] As a further alternative or in addition, the warning signal may comprise displaying a message on the control screen.

[0352] Of course, other types of warnings are possible.

[0353] When it is determined that there is no degradation, no warning signal is sent. In other words, when the proposed process indicates that the control mechanism 4 is not degraded, no warning is sent.

Claims

1. A process for detecting degradation of a switchgear (30), the switchgear (30) comprising: - an electrical contact (10) movable between a closed position (F) of the electrical circuit (50) and an open position (O) of the electrical circuit (50); - a control mechanism (4), comprising: - a driving element (9) configured to displace the moving contact (10) so as to open the circuit (50); - an elastic member (7) connected to the drive element (9); - an unlocking member (8) configured to switch from a locking position (V) to a releasing position (L), in which the elastic member (7) is kept in a tensioned state, and in which the elastic member (7) is free to release, thereby shifting the electrical contact (10) from the closed position (F) of the circuit (50) to the open position (O), or from the open position (O) to the closed position (F); - an actuator (1) configured to displace the unlocking member (8) from the locking position (V) to the releasing position (L), The process includes the following steps: (i) commanding the actuator (1) to shift the unlocking member (8) from the locking position (V) to the releasing position (L); (ii) determining a first moment (t1) corresponding to a predetermined position (P1) of the unlocking member (8); (iii) determining a second moment (t2) corresponding to a predetermined position (P2) of the drive element (9); (iv) determining a duration (D) that elapses between said first moment (t1) and said second moment (t2); (v) repeating steps (i) to (iii) for a set of consecutive commands of said actuator (1) so as to obtain a set (E) of values ​​of the duration (D) elapsed between said first instant (t1) and said second instant (t2); (vi) determining the degradation of the unlocking member (8) of the switching device (30) from the variation in the value of the set (E) during successive commands of the actuator (1).

2. The detection process according to claim 1, wherein the actuator (1) is an electromagnetic actuator, and wherein the process comprises the following sub-steps: - measuring the current (F) flowing through the electromagnetic actuator (1) when the switching device (30) is actuated; - determining a first moment (t1) corresponding to a predetermined position (P1) of the unlocking member (8) from the measured variation of the current (F) over time.

3. The detection process according to claim 2, The electromagnetic actuator (1) comprises a control coil (2) and a magnetic core (3), wherein the magnetic core (3) is configured to be displaced under the action of a magnetic field generated by a current flowing through the control coil (2). And wherein the predetermined position (P1) of the unlocking member (8) corresponding to the first moment (t1) is the maximum displacement position of the magnetic core (3).

4. A detection process according to claim 2 or 3, wherein the first moment (t1) corresponding to the predetermined position (P1) of the unlocking member (8) is a moment (tm) corresponding to a local minimum of the current flowing through the electromagnetic actuator (1).

5. The detection process according to claim 1, wherein the actuator (1) comprises a button (32) which can be manually activated by an operator, and wherein the unlocking member (8) comprises a position indicator (33), wherein the process comprises the following sub-steps: - measuring the electrical signal from the position indicator (33); - determining a first moment (t1) corresponding to a predetermined position (P1) of the unlocking member (8) based on the variation over time of the electrical signal from the position indicator (33).

6. A detection process according to any one of the preceding claims, wherein the predetermined position of the drive element (9) corresponding to the second moment (t2) is an intermediate shift position of the drive element (9), and the intermediate shift position is located between a first end position (B1) and a second end position (B2), in which the moving contact (10) is in the closed position (F) and in which the moving contact (10) is in the open position (O).

7. The detection process according to claim 6, wherein the displacement stroke of the drive element (9) between the first end position (B1) and the predetermined position (P2) corresponding to the second moment (t2) is between 5% and 15% of the total displacement stroke (CT) of the drive element (9).

8. The detection process according to any one of the preceding claims, comprising the following sub-steps: - measuring the position of the drive element (9) when the switching device (30) is actuated; - determining a second moment (t2) corresponding to a predetermined position (P2) of the drive element (9) based on the measured position of the drive element (9).

9. A detection process according to any one of the preceding claims, wherein: - the control mechanism (4) comprises a position sensor (14) configured to detect a magnetic field; The drive element (9) comprises a plurality of magnetic elements (15) which are arranged to successively pass in front of the position sensor (14) during a displacement stroke of the drive element (9).

10. The detection process according to any one of the preceding claims, comprising the following sub-steps: - calculating the value of a statistical parameter (P) representative of the fluctuations of the value of a set (E) of values ​​of a duration (D) elapsed between said first instant (t1) and said second instant (t2); - determining the degradation of the unlocking member (8) based on the calculated value of the statistical parameter (P).

11. A detection process according to claim 10, wherein the statistical parameter (P) representative of the fluctuations in the values ​​of the set (E) of values ​​of the duration (D) elapsed between the first instant (t1) and the second instant (t2) comprises the difference (X) between the following values: - a current value of the duration (D) elapsed between said first instant (t1) and said second instant (t2), the current value being determined for a current actuation of said switching device (30); and - a mean value (Moy) of the values ​​of the duration (D) elapsed between the first instant (t1) and the second instant (t2), the mean value being obtained in a predetermined number (M) of actuations preceding the current actuation of the switching device (30).

12. A detection process according to claim 10 or 11, wherein the statistical parameter (P) representing the fluctuation of the values ​​of the set (E) of values ​​of the duration (D) elapsed between the first moment (t1) and the second moment (t2) includes the standard deviation of the values ​​of the duration (D) elapsed between the first moment (t1) and the second moment (t2), the standard deviation being determined for a set of actuations of the switching device (30) performed under reference conditions corresponding to the new state of the circuit breaker (30).

13. The detection process according to any one of claims 10 to 12, wherein the statistical parameter (P) representing the fluctuation of the duration (D) elapsed between the first instant (t1) and the second instant (t2) is equal to the following ratio: - a difference (X) between a current value (Di) of the duration (D) elapsed between said first moment (t1) and a second moment (t2) and a mean value (Moy) of the duration (D) elapsed between said first moment (t1) and said second moment (t2), the mean value being obtained for a predetermined number (M) of actuations prior to the current actuation; and - a standard deviation (Ec) of the values ​​of the duration (D) elapsed between said first instant (t1) and said second instant (t2), the standard deviation being determined for a set of actuations of the switching device (30) performed under reference conditions corresponding to a new state of said switching device (30).

14. A detection process according to any one of claims 10 to 13, wherein the statistical parameter (P) representing the fluctuation of the duration (D) elapsed between the first instant (t1) and the second instant (t2) is equal to: [Formula 1] 15. A detection process according to any one of claims 10 to 14, wherein degradation of the unlocking member (8) is determined when the absolute value of a statistical parameter (P) representing the fluctuation of the duration (D) elapsed between the first moment (t1) and the second moment (t2) is greater than a first positive predetermined threshold (S1).

16. The detection process according to claim 15, wherein: - degradation of the unlocking member (8) is classified as a first type of degradation, called slight degradation, when the absolute value of a statistical parameter (P) representative of the fluctuation of the duration (D) elapsed between the first moment (t1) and the second moment (t2) is greater than a first positive predetermined threshold (S1) and less than a second positive predetermined threshold (S2); and wherein: - when the absolute value of the statistical parameter (P) representative of the fluctuations of the duration (D) elapsed between the first moment (t1) and the second moment (t2) is greater than a second positive predetermined threshold (S2), the degradation of the unlocking member (8) is classified as a second type of degradation, called significant degradation.

17. Detection process according to claim 15 or 16, comprising the step of sending a warning signal if degradation of the unlocking member (8) has been determined.

18. A switch device (30), comprising: - an electrical contact (10) movable between a closed position (F) of the electrical circuit (50) and an open position (O) of the electrical circuit (50); - a control mechanism (4), comprising: - a driving element (9) configured to displace the moving contact (10) so as to open the circuit (50); - an elastic member (7) connected to the drive element (9); - an unlocking member (8) configured to switch from a locking position (V) in which the elastic member (7) is maintained in a tensioned state to a releasing position (L) in which the elastic member (7) is free to release, thereby shifting the electrical contact (10) from a closed position (F) of the circuit (50) to an open position (O); - an actuator (1) configured to displace the unlocking member (8) from the locking position (V) to the releasing position (L); - an electronic control unit (25) configured to implement a degradation detection procedure according to any one of the preceding claims, the switching device (30) being a circuit breaker, or a switch, or an isolator.

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