Method for controlling an electrical protection device, associated device and installation

Abstract

Method for controlling an electrical protection device, associated device and installation. The present invention relates to a method for controlling an electrical protection device, comprising: c) when an electrical fault of the short-circuit type is detected during a step b) and when the tripping energy is greater than or equal to the tripping energy threshold in step d), control (S118) in blocked configuration each switching module; e) when the reset time of the given circuit breaker has elapsed, control (S122) each switching module in on configuration; f) if a circuit breaker is connected immediately upstream of the given circuit breaker, a test time (Tt) has not elapsed and a short circuit is detected, repeat steps c) to f);and if no circuit breaker is connected immediately upstream of the given circuit breaker, the test time (Tt) has not elapsed and a short circuit is detected, command (S138) each switching module in blocked configuration. Figure for abbreviation: Figure 5;

Description

Title of the invention: Method for controlling an electrical protection device, associated device and installation

[0001] The present invention relates to a method for controlling an electrical protection device, as well as an associated device and installation.

[0002] In an electrical installation, it is common practice to connect one or more protective devices between a source and a load. The protective device protects the cables; therefore, it is common to find several electromechanical protective devices of different ratings in series, each protecting different cable cross-sections, from the largest cross-section connected to the source to the smallest connected to the load. The upstream protective device may, for example, be a hybrid or static circuit breaker associated with one or more electromechanical circuit breakers downstream. To ensure the tripping of the electromechanical circuit breakers, it is necessary to delay the tripping of the protective device so that the electromechanical circuit breaker has received sufficient energy to trip.

[0003] It is also possible to connect two electromechanical circuit breakers in series, with the downstream circuit breaker having a lower rating than the upstream one. In order to protect the installation and prevent damage to the downstream circuit breaker, the tripping threshold of the upstream circuit breaker must be equal to or less than the rating of the downstream circuit breaker. Therefore, an interruption of the current in the event of a short-circuit electrical fault depends on only one tripping threshold. However, in order to protect all cable cross-sections in an installation, it may be necessary to connect several electromechanical circuit breakers of different ratings and to ensure several tripping thresholds.

[0004] The aim of the invention is then to propose a method enabling the selective tripping of a plurality of electromechanical circuit breakers whose ratings are different.

[0005] To this end, the invention relates to a method for controlling an electrical protection device, configured to be connected between a source and a series of circuit breakers, the device comprising: - an interrupt cell, comprising at least one switching module, each switching module comprising: • at least one semiconductor element; and • a limiting element, connected in parallel with at least one semiconductor element, the limiting element having a voltage of limitation, the limiting tension(s), alone and / or summed together, forming one or a plurality of distinct levels,

[0006] each switching module being configured to switch between a passing configuration, in which a current flowing between the source and the series of circuit breakers flows in the or in one of the semiconductor elements, and a blocked configuration, in which, if the current flows in the switching module, it flows in the limiting element; - a current sensor, configured to measure an intensity and / or a derivative of the current; - a control unit comprising a processing module and a cell control module, configured to control each switching module in the on and off configurations,

[0007] each circuit breaker in the series being configured to switch between an armed and a tripped configuration, each circuit breaker in the series being associated with a fault current threshold, a trip energy threshold and a redeployment time, the circuit breakers being connected in series with each other and arranged from upstream to downstream in descending order of their respective fault current thresholds:

[0008] the process comprising at least the following steps:

[0009] a) measure the intensity and / or the derivative of the intensity as a function of time by the current sensor;

[0010] b) detect an electrical fault of the short-circuit type by the processing module, if the intensity measured by the current sensor is strictly greater than the fault current threshold and / or the derivative measured by the current sensor is strictly greater than a fault derivative threshold of a given circuit breaker, the given circuit breaker being the circuit breaker in the most downstream armed configuration of the series of circuit breakers;

[0011] c) when an electrical fault of the short-circuit type is detected, wait until the tripping energy becomes greater than or equal to a tripping energy threshold of the given circuit breaker;

[0012] d) when the tripping energy is greater than or equal to the tripping energy threshold of the given circuit breaker, control each switching module in blocked configuration by the cell control module;

[0013] e) when the renewal time of the given circuit breaker has expired, the given circuit breaker having switched to tripped configuration, command each switching module to pass-through configuration, whereas each switching module was commanded to block configuration in step d);

[0014] f) if a circuit breaker is connected immediately upstream of the given circuit breaker, if a test time has not elapsed and if a short circuit is detected, the fault current threshold, the tripping energy threshold and the reactivation time being those of the circuit breaker in armed configuration immediately upstream of the given circuit breaker, repeat steps c) to f); and

[0015] g) if no circuit breaker is connected immediately upstream of the given circuit breaker, if the test time has not expired and if a short circuit is detected, the fault current threshold being equal to a final fault current threshold, command each switching module in blocked configuration.

[0016] Thanks to the invention, it is possible to trip the circuit breakers sequentially, from the most downstream breaker, i.e., the one closest to the source, to the most upstream breaker, i.e., the one closest to the load. Thus, it is possible to obtain different fault current thresholds for different circuit breakers in the series, which makes it possible to interrupt the current only for the circuit breakers downstream of the fault from a single protective device, while leaving those upstream of the fault armed and functioning normally. This makes it possible to limit the interruption of the power supply to loads connected upstream of the electrical fault.

[0017] Furthermore, by waiting for the tripping energy to reach the tripping energy threshold before the switching modules are activated in the locked configuration, the control method makes it possible to limit the current and energy flowing between the source and the load to the minimum necessary to trip the upstream circuit breaker, while ensuring that the latter trips. This makes it possible to limit the electrical and thermal stresses in the installation and in the cables.

[0018] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations: - The method further comprises the following successive steps:

[0019] h) detecting an electrical fault of the short-circuit type by the processing module, if the intensity measured by the current sensor in step a) is strictly greater than a stealth fault current threshold and / or the derivative measured by the current sensor in step a) is strictly greater than a fault derivative threshold;

[0020] i) to control each switching module in blocked configuration by the cell control module if an electrical fault is detected in step h);

[0021] j) when a stealth fault recurrence period has elapsed, command each switching module to the on-state configuration; and

[0022] k) if the test time has not expired, perform steps b) to g), the given circuit breaker being the circuit breaker in armed configuration connected furthest downstream.

[0023] - The process further comprises the following step:

[0024] 1) when an electrical fault of the short-circuit type is detected by the module of processing, control in open configuration a mechanical switch, connected in parallel with the interrupt cell, the mechanical switch being configured to switch between a closed configuration, in which the mechanical switch conducts current, and an open configuration, in which the mechanical switch does not conduct current, via a mechanical switch control module included in the control unit,

[0025] and wherein step i) is carried out when a dielectric strength of the mechanical switch is greater than a sum of the limiting voltage of the limiting element of each switching module.

[0026] - If the test time has elapsed and no short circuit is detected, order the mechanical switch in closed configuration.

[0027] - This process further comprises the following step:

[0028] m) if the test time has expired, and the intensity is strictly greater than a stealth fault current threshold and / or the derivative measured by the current sensor is strictly greater than a fault derivative threshold, command each switching module in blocked configuration.

[0029] - Each circuit breaker is also associated with a minimum current threshold and a maximum intensity threshold and in which step c) further includes the following sub-steps:

[0030] cl) when an electrical fault of the short-circuit type is detected by the processing module in step b), and the tripping energy is less than or equal to the tripping energy threshold of the given circuit breaker and the current measured by the current sensor is less than or equal to the minimum current threshold, control, in on-mode configuration, by the cell control module, the switching module(s) whose limiting element voltages form a clipping plateau, the clipping plateau being the smallest plateau above a nominal network voltage; and

[0031] c2) when an electrical fault of the short-circuit type is detected by the module of processing in step b), that the tripping energy is less than or equal to the tripping energy threshold of the given circuit breaker and that the current measured by the current sensor reaches the maximum current threshold, control in blocked configuration, by the cell control module, the switching module(s) whose limiting voltages of the limiting elements form the clipping plateau.

[0032] - The device comprises a plurality of switching modules, connected to the substep c2) further includes, in addition, a control in passing configuration, by the cell control module, of the switching modules whose limiting voltages of the limiting elements do not form the clipping plateau.

[0033] The invention also relates to an electrical protection device configured to be connected between a source and a series of circuit breakers, each circuit breaker in the series being configured to switch between an armed configuration and an unarmed configuration triggered, each circuit breaker in the series being associated with a fault current threshold, a tripping energy threshold and a reset time, the circuit breakers being configured to be connected in series with each other and arranged from upstream to downstream in descending order of their respective fault current thresholds, the device comprising: - an interrupt cell, comprising at least one switching module, each switching module comprising: • at least one semiconductor element; and • a limiting element, connected in parallel with at least one semiconductor element, the limiting element having a limiting voltage, the limiting voltage(s), alone and / or summed together, forming one or a plurality of distinct stages,

[0034] each switching module being configured to switch between a forward configuration, in which a current flowing between the source and the series of circuit breakers flows in the or one of the semiconductor elements, and a blocked configuration, in which if the current flows in the switching module, it flows in the limiting element; - a current sensor, configured to measure the intensity of the current and / or a derivative of the current; - a control unit comprising: • a processing module configured to detect a short-circuit type electrical fault based on the current and / or derivative measured by the current sensor; and • a cell control module, configured to control each switching module in both the pass-through and block-out configurations,

[0035] the device being configured to implement the method described above;

[0036] Advantageously, this device comprises a single switching module, the limiting voltage of the voltage limiting element of the switching module then forming the clipping plateau.

[0037] The invention also relates to an electrical installation comprising a source, a load, a series of circuit breakers, connected between the source and the load, each circuit breaker in the series being configured to switch between an armed configuration and a tripped configuration, each circuit breaker in the series being associated with a fault current threshold, a tripping energy threshold and a redeployment time, the circuit breakers being connected in series to each other and arranged from upstream to downstream in descending order of their respective fault current threshold, and a device as described above, connected between the source and the series of circuit breakers.

[0038] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which: - [Fig.1] [Fig.1] is an electrical diagram of an electrical installation according to the invention; - [Fig.2] [Fig.2] is an electrical diagram of an electrical protection device according to a first embodiment of the invention; - [Fig.3] [Fig.3] is a graph of characteristic quantities of the device of [Fig.2], as a function of time; - [Fig.4] [Fig.4] is a detailed view of box IV in [Fig.3]; - [Fig. 5] [Fig. 5] is a logic diagram of a control process for the device of [Fig.3], according to the invention; - [Fig.6] [Fig.6] is an electrical diagram of an electrical protection device according to a second embodiment of the invention; - [Fig.7] [Fig.7] is an electrical diagram of an interrupt cell of the device in [Fig.6]; - [Fig.8] [Fig.8] is a graph of characteristic quantities of the device of [Fig.6], as a function of time; - [Fig.9] [Fig.9] is a detailed view of box X in [Fig.8]; - [Fig. 10] [Fig. 10] is a logic diagram of a control method for the device in [Fig. 6], according to the invention; and - [Fig.11] [Fig.11] is an electrical diagram of an interruption cell belonging to an electrical protection device according to a third embodiment of the invention.

[0039] Fig. 1 is a diagram of an electrical installation 1 comprising a source 3, a series of circuit breakers 4 and a load 5, electrically connected together by a phase conductor 7 and a neutral conductor 8.

[0040] Source 3 supplies electricity and is, for example, an electric generator or an electrical network, for example a mains electrical network.

[0041] The load 5 is a device that consumes electricity, such as a household electrical appliance, industrial equipment like an electric motor, or a server. Thus, an electric current, hereafter simply referred to as current, flows between the source 3 and the load 5 through the phase conductor 7, and returns to the source 3 via the neutral conductor 8.

[0042] The current is a low voltage or medium voltage current, that is to say that a nominal voltage Us of the current, also called mains voltage or nominal network voltage, is less than 52,000 V. The current is an alternating current or, alternatively, a direct current.

[0043] The series of circuit breakers 4 is connected between the source 3 and the load 5. The series of circuit breakers 4 comprises a plurality of circuit breakers, here three circuit breakers 4b 42 and 43.

[0044] In the example of [Fig.1], circuit breaker 4i is the most downstream circuit breaker, that is to say the closest to the load 5. Circuit breaker 43 is the most upstream circuit breaker, that is to say the closest to the source 3. Circuit breaker 42 is the intermediate circuit breaker, that is to say the circuit breaker located between the upstream and downstream circuit breakers.

[0045] Each circuit breaker 4b 42, 43 is configured to switch between an armed configuration, in which it conducts electric current, and a tripped configuration, in which it does not conduct electric current. Each circuit breaker 4b 42, 43 is associated with a distinct fault current threshold, Ib 42, 43 respectively, and a redeployment time, Trb 42 and Tr3 respectively. The circuit breakers 4b 42 and 43 are connected in series with each other such that they are arranged from upstream to downstream in descending order of their respective fault current thresholds. Thus, in the example of [Fig. 1], the fault current threshold I3 is greater than the fault current threshold I2, which is itself greater than the fault current threshold Ib

[0046] The series of circuit breakers 4 comprises at least two circuit breakers whose fault thresholds are distinct.

[0047] In an alternative not shown, the fault current thresholds of two adjacent circuit breakers may be equal.

[0048] Circuit breakers 4b 42 and 43 are electromechanical or static circuit breakers. In the example of [Fig. 1], circuit breakers 4b 42 and 43 are all electromechanical circuit breakers. Each electromechanical circuit breaker 4b 42, 43 is configured to trip and interrupt the current flowing from the source 3 to the load 5 when an electrical fault of the short-circuit type, hereafter referred to as a short circuit, is present in the electrical installation 1. Each electromechanical circuit breaker 4b 42, 43 includes contacts and a trip unit, which may be a coil, a magnetic paddle, or an electronic or electromechanical device (not shown), which, when it receives sufficient energy, is responsible for separating the contacts.

[0049] More specifically, when a short circuit occurs in the electrical installation 1, the current intensity I flowing between the source 3 and the load 5, expressed in amperes (A) in Figures 3 and 4, increases rapidly and significantly, for example by several tens of amperes per microsecond. Each circuit breaker 4b, 42, 43, is associated with a tripping energy threshold, Ethb, Eth2, and Eth3, respectively. When the circuit breaker 4i receives a tripping energy Edi equal to or greater than the tripping energy threshold Ethb, the trip of the circuit breaker 4i causes the contacts of the electromechanical circuit breaker 4i to open and interrupts the current between source 3 and load 5, more precisely between device 10 and load 5. In other words, when the tripping energy Ed i is greater than or equal to the tripping energy threshold Eth b, the electromechanical circuit breaker 4i trips. The tripping energy Edi is a function of time t and current I and is only received when the current I is strictly greater than a minimum current Iminb

[0050] The same applies to circuit breakers 42 and 43, which trip when they have respectively received a tripping energy Ed2 and Ed3 greater than or equal to the tripping energy threshold Eth2 and Eth3. The tripping energy Ed2 is received only when the current I is strictly greater than a minimum current Imin2 and the tripping energy Ed3 is received only when the current I is strictly greater than a minimum current Imin3.

[0051] The tripping energy Edi is less than the tripping energy Ed2, which is itself less than the tripping energy Ed3. Tripping energies are expressed in arbitrary units (AU). The electrical installation 1 also includes an electrical protection device 10, also referred to hereafter as the device, connected between the source 3 and the series of circuit breakers 4. The device 10 is detailed in [Fig. 2]. The device 10 is configured to switch between an armed configuration, in which the device 10 conducts the current flowing between the source 3 and the series of electromechanical circuit breakers 4, and a tripped configuration, in which the device 10 electrically isolates the source 3 from the series of electromechanical circuit breakers 4. The device 10 has a voltage U, expressed in volts (V), applied across its terminals, between conductors 7 and 8.

[0052] In the embodiment of Figures 1 to 4, the device 10 is a static circuit breaker, also called SSCB, from the English "Solid State Circuit Breaker". It comprises an interrupting cell 18 connected in series to the phase conductor 7 by an input 18a and an output 18b.

[0053] The interrupt cell 18 is configured to allow or interrupt the current passing through it, as explained later.

[0054] The device 10 advantageously comprises a first disconnector 23 and, optionally, a second disconnector 24, connected respectively to the phase conductor 7 and the neutral conductor 8. In particular, the disconnector 23 is connected to the phase conductor 7 in series with the interrupting cell 18. The disconnector 24 is connected in series with the neutral conductor 8. The disconnectors 23 and 24 are configured to switch between a closed configuration in which the disconnectors 23 and 24 conduct current, and an open configuration in which the disconnectors 23 and 24 do not conduct current. Advantageously, and as shown in [Fig. 2], the device 10 comprises an actuator 25 for the first disconnector 23 and a Actuators 26 of the second disconnector 24, when activated, interact respectively with the first disconnector 23 and the second disconnector 24 to switch them to the open configuration. Actuators 25 and 26 are, for example, coils and are activated when a current flows through the coil windings.

[0055] The disconnectors 23 and 24 are configured to switch to the open position in particular when no current flows between the source 3 and the load 5, in other words, when the current has been interrupted by the interrupt cell 18.

[0056] The interrupt cell 18 comprises at least one switching module, here, a single switching module 32. The switching module 32 comprises at least one switchable semiconductor element, for example, at least one thyristor or at least one transistor, such as a field-effect transistor (FET), an insulated-gate field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), or a combination of these different semiconductor elements. In the embodiment of [Fig. 2], the interrupt cell 18 comprises two semiconductor elements 34 and 35. The semiconductor elements 34 and 35 are current-unidirectional and are, for example, two IGBT transistors.The direction of conduction of transistors 34 and 35 is indicated by an arrow on each transistor. Transistors 34 and 35 are connected to each other in anti-series, meaning they are connected in series but back-to-back, so they do not conduct current simultaneously. Two diodes, 36 and 37, are connected to transistors 34 and 35, respectively. Diode 36 is connected in anti-parallel to transistor 34, meaning that diode 36 and transistor 34 do not conduct current at the same time: if transistor 34 is conducting, diode 36 is blocking, and vice versa. In other words, transistor 34 and diode 36 are connected in parallel back-to-back. The same applies to transistor 35 and diode 37. This arrangement allows the switching module 32 to conduct alternating current without interruption at each change of sign of the current.

[0057] The switching module 32 includes a voltage limiting element 39, also called a limiting element. The voltage limiting element 39 is connected in parallel with a set formed by transistors 34 and 35, and is, for example, a metal oxide varistor (MOV), a transil diode, or a gas discharge tube. The voltage limiting element 39 has a limiting voltage Uiimi, which corresponds to the voltage across its terminals when it is traversed by the current flowing between the source 3 and the load 5. The limiting voltage Uiimi is greater than the nominal mains voltage Us, for example, on the order of 1.5 times the nominal network voltage Us. The limiting voltage Uiimi forms a clipping plateau Pe, which is therefore higher than the nominal network voltage Us.

[0058] The switching module 32 is configured to switch between a forward-biased and a reverse-biased configuration. In the forward-biased configuration, current flows through one of the transistors 34 or 35. More specifically, when the current through the device 10 is alternating, the current flows through transistor 34 and diode 37, and then when the current reverses direction, through transistor 35 and diode 36.

[0059] In the blocked configuration, transistors 34 and 35 do not conduct current and, if current flows in the switching module 32, it flows through the voltage limiting element 39.

[0060] Thus, in the blocked configuration, a voltage across the terminals of the switching module 32 is the limiting voltage Uiimi. This voltage across the terminals of the switching module 32 is then also the voltage U across the terminals of the device 10. In other words, a back voltage whose value is that of the limiting voltage Uiimi is applied across the terminals of the device 10.

[0061] The control device 10 also includes a current sensor 52. The current sensor 52 is configured to measure an intensity I of the current and / or a derivative of the intensity of the current flowing between the source 3 and the load 5, and in particular the current flowing in the phase conductor 7. The current sensor 52 is, for example, a Rogowski torus.

[0062] The control device 10 also includes a control unit 60, comprising a processing module 62, connected to the current sensor 52 and configured to detect an electrical fault of the short-circuit type as a function of the intensity I, measured by the current sensor 52.

[0063] The control unit 60 also includes a cell control module 66 and, advantageously, a disconnector control module 68, connected to the processing module 62 and respectively configured to control the interrupt cell 18, more specifically the switching module 32, and the disconnectors 23 and 24.

[0064] The cell control module 66, also called the control module, is configured to control the switching module 32 in the on-mode and off-mode configurations, as explained in more detail later, in particular by actuating the gate of transistors 34 and 35.

[0065] The disconnector control module 68 is advantageously configured to actuate actuators 25 and 26 respectively, in order to switch disconnectors 23 and 24 into open configuration.

[0066] The control unit 60 is an electronic circuit designed to manipulate and / or transform data represented by electronic or physical quantities in registers of the control unit 60 and / or memories, into other similar data corresponding to physical data in register memories or other types of display devices, transmission devices or storage devices.

[0067] As specific examples, the control unit 60 is implemented in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array), or an integrated circuit, such as an ASIC (Application Specified Integrated Circuit).

[0068] In an alternative variant not shown, the control unit 60 comprises an information processing unit consisting, for example, of a memory and a processor associated with the memory. The processing module 62, the cell control module 66, and the disconnector control module 68 are each implemented as software, or a software component, executable by the processor. The memory of the control unit 60 is then capable of storing processing software, cell control software, and disconnector control software. The processor is then capable of executing each of the following software programs: the processing software, the cell control software, and the disconnector control software.

[0069] In an alternative not shown, the processing module 62, the cell control module 66 and the disconnector control module 68 are each made in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array), or an integrated circuit, such as an ASIC (Application Specified Integrated Circuit).

[0070] Advantageously, the device 10 also includes a power supply module 70, connected to conductors 7 and 8 and to the control unit 60, in order to supply electricity to the control unit 60. Alternatively, the power supply module 70 is connected to an external circuit, not connected to conductors 7 and 8.

[0071] A method for controlling the device 10 according to the invention will now be explained, with reference to Figures 3 to 5.

[0072] Initially, and advantageously, the device 10 is in the armed configuration, that is, the disconnectors 23 and 24 are in the closed configuration and the switching module 32 is in the conducting configuration. Current flows from the source 3 to the mechanical circuit breaker 4, passing through the switching module 32. The voltage U across the device 10 is zero or substantially zero. All the circuit breakers 42, 43 are in the armed configuration and conduct current.

[0073] The current sensor 52 measures the intensity I of the current and / or the derivative I' of the intensity I flowing in the phase conductor 7, at step S102 of the method shown in [Fig.5].

[0074] In order to distinguish a short circuit from a stealthy fault, which can also cause a sudden and significant increase in the current I, caused for example by the dropping of a key on a busbar, or by a transient malfunction and which disappears by itself in a few hundred microseconds, the control method advantageously includes the steps S104 to SI 12.

[0075] The control unit 60 receives the current measurement I and / or the current derivative and detects, in step S104 and via the processing module 62, whether an electrical fault, corresponding to a short-circuit potential, is present between the source 3 and the load 5. To do this, the processing module 62 compares the measured current I to a stealth fault current threshold Io. If the current I is less than or equal to the stealth fault current threshold Io, the current sensor 52 repeats step S102 and continues to measure the current I. An iterative operation is then implemented.

[0076] If the current I is strictly greater than the stealth fault current threshold Io, then the cell control module 66 controls each switching module, here the single switching module 32, in blocked configuration at step S106, as seen in [Fig.4], at time A. The voltage U becomes equal to the clipping plateau Pe and the current I decreases until it becomes zero at time B. When the current I becomes zero, the voltage U across the device 10 becomes equal to the nominal network voltage Us.

[0077] In an alternative not shown, during step S106, the cell control module 66 controls each switching module, here the single switching module 32, in blocked configuration when the derivative I' of the current I as a function of time t is strictly greater than a predetermined fault derivative threshold, or if a combination of conditions on the current I and its derivative I' are met, for example the current I is strictly greater than the stealth fault current threshold Io and the derivative of the current I is strictly greater than the fault derivative threshold.

[0078] The control unit 60 waits at step S108 until the recurrence time of the stealth fault Tr0, calculated from the moment the cell control module 66 commands the switching module 32 in a blocked configuration, has elapsed. The recurrence time of the stealth fault Tr0 is advantageously predetermined and programmed in advance by the manufacturer of the device 10. It is, for example, less than or equal to 500ps.

[0079] When the Tr0 stealth fault recurrence time has expired, the switching module 66 performs step SI 10 during which it commands in configuration Each switching module, here switching module 32, is switched on at time C. Current then flows again between source 3 and load 5, and the voltage U becomes zero. This switching configuration of module 32 allows testing whether the fault detected in step S104 has disappeared or is still present.

[0080] The processing module 62 determines whether a test time Tt, measured from time C, has elapsed at step SI 12. If the test time Tt has not elapsed, the processing module 62 considers, at step SI 14, that a short circuit is detected if the current intensity I measured by the current sensor 52 is strictly greater than the fault current threshold h of the circuit breaker 4b which is the circuit breaker of the series of circuit breakers 4 in the most downstream armed configuration.

[0081] Alternatively, the short circuit is considered to be detected at step SI 14 if the derivative F of the current I is strictly greater than a predetermined threshold, or if a combination of conditions on the current I and its derivative are met, for example the current I is strictly greater than the fault current threshold L and the derivative I' of the current I is strictly greater than the predetermined threshold.

[0082] If the current intensity I measured by the current sensor 52 is less than or equal to the fault current threshold F of the circuit breaker 4b, the processing module 62 performs step SI 12 again. An iterative operation is then implemented.

[0083] If the test duration Tt has elapsed without the current I becoming strictly greater than the fault current threshold Ib, then the electrical fault detected in step S104 was a transient fault. The process is reset, and the device 10 performs step S102 again. An iterative operation is then implemented.

[0084] If the current intensity I measured by the current sensor 52 at step SI 14 is strictly greater than the fault current threshold F of the circuit breaker 4b as shown at a time D in [Fig.4], then the control unit 60 determines that the fault current threshold F used at step SI 14 is different from a fault current threshold I2 at a step SI 15. The control unit 60 then estimates the tripping energy Edi and compares it to the tripping energy threshold Ethi at step SI 16.Advantageously, the tripping energy Edi is estimated only when the current I is strictly greater than the minimum current Iminb. Advantageously, and as shown in Figures 3 and 4, the minimum current Imini is equal to the tripping threshold Ib. If the tripping energy Edi is less than the tripping energy threshold Ethb, then the control unit 60 performs step SI 12 again, and an iterative operation is implemented. If the tripping energy Edi is greater than or equal to the tripping energy threshold Ethi, which is the case at an instant E in [Fig. 4], then circuit breaker 4i trips, and if the fault is downstream of circuit breaker 4b, it isolates the fault. The control module of... Cell 66 then commands module 32 in a locked configuration at step SI 18, visible at time E in [Fig. 4]. The voltage U becomes equal to the clipping threshold Pe and the current I decreases until it becomes practically zero at time F. When the current I becomes zero, the voltage U becomes equal to the nominal network voltage Us.

[0085] The control unit 60 waits until a renewal time Trb, measured from time E, has elapsed at step S120. The renewal time Trb is advantageously predetermined and programmed in advance by the manufacturer of the device 10.

[0086] When the redeployment time Tr i has elapsed, the cell control module 66 commands module 32 to switch to the on-mode configuration at step S122, corresponding to an instant G in [Fig. 4]. Current therefore flows again between the source 3 and the circuit breaker 42, circuit breaker 4i has tripped if the fault was downstream of it, and the voltage U across the device 10 becomes zero. This switching of module 32 to the on-mode configuration makes it possible to test whether the fault detected in step SI 14 has disappeared, i.e., whether it was located between circuit breaker 4i and the load 5, or whether it is still present and is therefore located upstream of circuit breaker 4b.

[0087] With circuit breaker 42 connected immediately upstream of circuit breaker 4b, the processing module 62 then performs a second iteration of steps SI 12 to S122. The fault current threshold, trip energy threshold, and re-energization time used in the remainder of the process described below become those associated with circuit breaker 42, which is the circuit breaker in its armed configuration immediately upstream of circuit breaker 4b, i.e., the fault current threshold I2, the trip energy threshold Eth2, and the re-energization time Tr2. Circuit breaker 42 is the new circuit breaker in the series of 4 circuit breakers in its armed configuration and is the furthest downstream connected.

[0088] The processing module 62 determines in step SI 12 whether the test time Tt, measured from time G, has elapsed. If the test time Tt has not elapsed, the processing module 62 detects in step SI 14 whether the current intensity I measured by the current sensor 52 is less than, equal to, or strictly greater than the fault current threshold I2 of the circuit breaker 42, in other words, whether the short circuit is still present.

[0089] If the current intensity I measured by the current sensor 52 is less than or equal to the fault current threshold I2 of the circuit breaker 42, the processing module 62 performs step SI 12 again, and an iterative operation is then implemented.

[0090] If the current intensity I measured by the current sensor 52 is detected at step SI 14 as strictly greater than the fault current threshold I2 of the circuit breaker 42, which corresponds to an instant H on [Fig. 4], this means that the fault is located upstream of the circuit breaker 4b and is still present. The control unit 60 determines that the fault current threshold 12 is different from a final fault current threshold If and the device 10 performs step SI 16, calculating the tripping energy Ed2 and comparing it with the tripping threshold Eth2. The tripping energy Ed2 is represented by dashed lines in Figures 3 and 4 on the energy graph Ed.

[0091] When the tripping energy Ed2 is greater than or equal to the energy threshold Eth2, steps SI 18, S120 and S122 are performed successively. As the circuit breaker 43 is connected immediately upstream of the circuit breaker 42, the processing module 62 then performs a third iteration of steps S112 to S122, using the fault current threshold I3 of the circuit breaker 43 and, if necessary, calculating the tripping energy Ed3 and using the tripping threshold Eth3, the maximum current Imax3 and minimum current Imin3 and the re-energization time Tr3.

[0092] In the example of Figures 3 and 4, during the third iteration of the step SI 141' The current intensity I measured by the current sensor 52 is strictly greater than the fault current threshold I3 of the circuit breaker 43, corresponding to an instant L on [Fig. 3]. The fault is therefore located upstream of the circuit breaker 42 and is still present. The device 10 therefore performs steps SI 15, S320 and SI 18 to S122. The tripping energy Ed 3 is represented by a solid line in [Fig. 3] on the energy graph Ed. [Fig. 5] represents the control method of the device 10, with Ix, Edx, Ethx and Trx respectively the fault current, the tripping energy, the tripping threshold and the re-energization time for iteration x, with x equal to 1, 2 or 3.

[0093] In an alternative not shown, the installation 1 comprises more than three circuit breakers. In this case, steps SI 12 to S122 continue to be iterated as long as circuit breakers are connected immediately upstream of the last tripped circuit breaker.

[0094] When the third iteration is carried out, following step S122, the processing module 62 then carries out step SI 12 in which the processing module 62 determines whether the test time Tt, measured from the instant or the renewal time Tr3 has elapsed, corresponding to an instant P, has elapsed.

[0095] If the test time Tt has not elapsed, the processing module 62 detects at step SI 14 whether the intensity I of the current measured by the current sensor 52 is strictly greater than the final fault current threshold If, in other words, whether the short circuit is still present.

[0096] If the test time Tt has elapsed without the current intensity I measured by the current sensor 52 becoming strictly greater than the final fault current threshold If, then the process is reset, and step S102 is performed again.

[0097] If the current intensity I measured by the current sensor 52 is less than or equal to the final fault current threshold If, the processing module 62 performs step SI 12 again, and an iterative operation is then implemented.

[0098] If the current intensity I measured by the current sensor 52 is strictly greater than the final fault current threshold If, which corresponds to an instant Q in [Fig. 4], this means that the fault is located between the circuit breaker 43 and the device 10, and that it is still present. During step SI 15, the control unit 60 determines that the fault current threshold used in the preceding step SI 14 is equal to the final fault current threshold If.

[0099] The cell control module 66 then performs a step S138, in which it commands all the switching modules, here module 32, into a blocked configuration. The current is thus interrupted by the device 10.

[0100] Optionally, once the current intensity I has become zero following step S138, the disconnector control module 68 controls the disconnectors 23 and 24 in blocked configuration, in order to achieve galvanic isolation of the device 10.

[0101] In an unshown variant, the final fault current threshold If is equal to the fault current threshold I3. In this case, during step SI 15, the control unit 60 determines the number of times the same fault threshold is used and only performs step S138 if this number is greater than one.

[0102] Advantageously, if during step SI 12 the test time elapses without the current threshold Ib I2,13 or If being exceeded, the control unit 60 performs step S140, in which it compares the current I to the stealth fault current threshold Io. If the current is strictly greater than the stealth fault threshold Io, then the cell control module 66 performs step S138. Otherwise, the process is reset, and step S102 is performed again.

[0103] In an alternative not shown, during step S140, the control unit 60 compares the derivative I' of the current I as a function of time t to a predetermined fault derivative threshold, or alternatively determines whether a combination of conditions on the current I and its derivative I' are met, for example, the current I is strictly greater than the stealth fault current threshold Io and the derivative of the current I is strictly greater than the fault derivative threshold. In this case, the cell control module 66 performs step S138 if the derivative I' is strictly greater than the predetermined fault derivative threshold or if the conditions on the current I and its derivative I' are met.

[0104] [Fig.6] represents an electrical installation 1, which differs from the electrical installation of [Fig.1] by its device 100, which replaces the device 10. The elements of the device 100 identical to those of the device 10 or identified in [Fig.6] by the same reference signs are similar, at least functionally, to those of the device 10 and are not described in detail.

[0105] The circuit breakers 4b 42, 43 are furthermore each associated with the minimum intensity, respectively Imin, Imin2 and Imin3, here equal to the respective fault current thresholds L, I2,13 and with a maximum intensity, respectively Imaxi, Imax2 and Imax3.

[0106] The device 100 is a hybrid circuit breaker and includes a mechanical switch 112, also known as a bypass switch or fast mechanical switch (FMS). The mechanical switch 112 is connected in series to the phase conductor 7 via an input 112a and an output 112b, and is configured to switch between a closed configuration, in which it conducts the current flowing between the source 3 and the load 5, and an open configuration, in which it does not conduct the current. In [Fig. 6], the mechanical switch 112 is shown in the open configuration. The device 100 advantageously includes an actuator 116 which, when activated, switches the mechanical switch 112 to the open configuration.

[0107] The device 100 includes an interrupt cell 118, connected in parallel with the mechanical switch 112, such that the input 112a and the output 112b of the mechanical switch 112 are connected respectively to an input 118a and an output 118b of the interrupt cell 118. More specifically, the input 112a of the mechanical switch 112 and the input 118a of the interrupt cell 118 are connected by an electrical link 119a, which is uninterruptible, and the output 112b of the mechanical switch 112 is connected to the output 118b of the interrupt cell 118 by an electrical link 119b, which is also uninterruptible. In other words, the electrical links 119a and 119b are each an electrical cable or wire; Neither of the electrical connections 119a and 119b includes a switch or more generally a means of interrupting the electric current.Interrupt cell 118 is configured to allow or interrupt the current flowing through it, as explained below.

[0108] The interrupt cell 118 comprises N switching modules; for example, the interrupt cell 118 comprises N=2 two switching modules 132 and 142, as shown in [Fig. 7]. Alternatively, there are three or more switching modules, as symbolized by the dashed line in [Fig. 7].

[0109] The switching modules 132 and 142 are connected in series with each other.

[0110] In the example of [Fig. 5], the switching module 132 is similar to Functionally, at least, the switching module 32 comprises two transistors 134 and 135 connected in anti-series, two diodes 136 and 137 connected in anti-parallel to transistors 134 and 135 respectively, and a limiting element 139, having a limiting voltage Uiimn. The transistors 144 and 145 and the diodes 146 and 147 of the switching module 142 are respectively similar, at least functionally, to transistors 134, 135 and diodes 136 and 137 of the switching module 132. The switching module 142 includes a limiting element 149, connected in parallel with a set formed by transistors 144 and 145 and has a limiting voltage Uiimi2, which is different from the limiting voltage Uiimn.

[0111] The limiting voltage Uiimn is, for example, equal to 0.5 times Us and the limiting voltage Uiimi2 is, for example, equal to 1.5 times Us

[0112] Thus, in the blocked configuration, the voltages across the switching modules 132 and 142 are respectively the limiting voltage Uiim ii and the limiting voltage Uiim i 2.

[0113] The limiting voltages Uiim i and Uiim i 2 form at least 2N-1 distinct steps. Here, the number Np of steps is equal to Np = 2N-1, where N is the number of switching modules. The steps are formed by the limiting voltages Uiim ii and Uiim 12 taken individually, or summed together. The list of steps obtained is shown in the table below. For N=2 switching modules, three distinct steps P1, P2, P3 are obtained, with P3 = 22-1. Here, PI is the level with the lowest value, equal to Uiim ii which is for example 0.5Us, P2 is greater than PI, and has a value equal to Uiim i 2 which is for example 1.5US, and P3 is greater than P2, with a value equal to the sum of Uiim ii and Uiim i 2, for example 2US.

[0114] [Tables 1] Level Value PI Uliml 1 P2 Ulim 1 2 P3 Ulim 1 1 + Ulim 1 2

[0115] The PI level is also called the limiting level. The P2 level is the smallest level above the nominal network voltage Us, and is called the clipping level Pe.

[0116] The control device 100 includes a control unit 160, which differs from the control unit 60 in that it further includes a mechanical switch control module 164.

[0117] A method for controlling the device 100 will now be explained, with reference to Figures 8 to 10. The steps identical to the control method previously described are referenced with the same reference symbols.

[0118] Initially, and advantageously, the device 100 is in the armed configuration, that is, the disconnectors 23 and 24 are in the closed configuration, the mechanical switch 112 is in the closed configuration, and the transistors 134, 135, 144, and 145 are conducting. Due to an internal resistance lower than that of the transistors 134, 135, 144, and 145, the mechanical switch 112 conducts the entire electric current circulating in device 100. A voltage U across the terminals of device 100 is zero, or substantially zero.

[0119] The current sensor 52 measures the intensity I of the current flowing in the phase conductor 7, during a step S102.

[0120] The control unit 160 receives the current measurement I and detects, via the processing module 62, whether an electrical fault, corresponding to a short-circuit potential, is present between the source 3 and the load 5, at step S104. To do this, the processing module 62 compares the measured current I to a stealth fault current threshold Io. If the current I is less than or equal to the stealth fault current threshold Io, the current sensor 52 repeats step S102 and continues to measure the current I. An iterative operation is then implemented.

[0121] If the intensity I is strictly greater than the stealth fault current threshold Io, which corresponds to an instant Al on the [Fig.9], then the mechanical switch control module 164 controls the mechanical switch 112 to switch to the open configuration at step S306.

[0122] When the mechanical switch 112 is in the open position, the electric current is transferred from the mechanical switch 112 to the interrupt cell 118, with transistors 134, 135, 144, and 145 being controlled in the forward position. However, the opening of the mechanical switch 112 generates an electric arc and ionization of the medium between the contacts of the mechanical switch 112. This reduces the dielectric strength of the mechanical switch 112. Therefore, before reducing or interrupting the current flowing between the source 3 and the load 5, it is necessary to wait for the dielectric strength of the mechanical switch 112 to be restored to a sufficient level. Otherwise, the mechanical switch 112 may fail, i.e. become conductive while in the open configuration, which will damage the mechanical switch 112. The device 100 will then be unable to reduce or interrupt the current.This waiting time corresponds to the isolation time Ti0 after which the dielectric strength of the mechanical switch 112 has increased sufficiently to become greater than the P3 threshold. The isolation time Ti0 is advantageously predetermined and programmed by the manufacturer of the device 10.

[0123] Alternatively, during step S306, the cell control module 166 controls the switching module forming the largest lower step below the dielectric strength of the mechanical switch 112. Thus, the switching modules forming steps P1 and then P2 are controlled in a blocked configuration as soon as the dielectric strength exceeds these steps. This limits the increase in current I until the dielectric strength exceeds step P3.

[0124] The control unit 160 therefore waits until the isolation time Ti0 has elapsed at step S308.

[0125] When the isolation time Ti0 has elapsed, which corresponds to an instant B1 on the [Fig.9], the cell control module 66 commands all the switching modules 132, 142 in a locked configuration at step S106. The voltage U becomes equal to the third step P3, in other words to the clipping step Pe, and the current I decreases until it becomes zero, at an instant CL. When the current I has become zero, the voltage U becomes equal to the nominal network voltage Us.

[0126] The control unit 160 waits until the duration of the stealth fault renewal T^, counted from the instant Al, has elapsed at the step S108.

[0127] When the duration of the transient fault Tr0 has expired, the cell control module 66 commands modules 132 and 142 into the conducting state, corresponding to the instant DI on the [Fig.9] at step SI 10. The current therefore flows again between the source 3 and the load 5 and the voltage U becomes zero.

[0128] In an unrepresented variant, at time Dl, the cell control module 66 controls the modules forming the PI limiting bearing in the blocked state and the others in the passing state.

[0129] The processing module 62 determines whether the test time Tt, measured from the instant Dl, has elapsed at step SI 12. If the test time Tt has not elapsed, the processing module 62 detects at step SI 14 a short circuit, if the current intensity I measured by the current sensor 52 is less than or equal to or strictly greater than the fault current threshold L of the circuit breaker 4b which is the circuit breaker in the most downstream armed configuration of the series of circuit breakers 4.

[0130] Alternatively, the short circuit is detected if the derivative I' of the current I with respect to time t is strictly greater than a predetermined fault derivative threshold, or if a combination of conditions on the current I and its derivative F are met, for example the current I is strictly greater than the fault current threshold h and the derivative I' of the current I is strictly greater than the fault derivative threshold.

[0131] If the current intensity I measured by the current sensor 52 is less than or equal to the fault current threshold h of the circuit breaker 4b, the processing module 62 performs step SI 12 again. An iterative operation is then implemented.

[0132] If the test duration Tt elapses without the current I exceeding the fault current threshold Ib, then the control unit 60 performs step S140, in which it compares the current I to the stealth fault current threshold Io. If the current I is strictly greater than the stealth fault threshold Io, then the cell control module 66 performs step S138, in which it commands all the switching modules, here modules 132 and 134, to operate in a blocked configuration. The current is The process was thus interrupted by device 10. Otherwise, the electrical fault detected in step S104 was a transient fault and disappeared. The mechanical switch control module 164 then commands the mechanical switch 112 to switch to the closed position in step S317. The process is then reset, and device 10 performs step S102 again.

[0133] If the current intensity I measured by the current sensor 52 at step SI 14 is strictly greater than the fault current threshold Ii of the circuit breaker 4b as represented at an instant Fl, then the control unit 160 determines that the fault current threshold used at step SI 14 is different from the final fault threshold at step SI 15. The control unit 160 then estimates a tripping energy Edi and compares it to a tripping energy threshold Ethi at a step S320. Step S320 comprises a plurality of substeps S322 to S330.

[0134] During substep S322, the processing module 62 determines whether the tripping energy Edb represented by solid line in figures 8 and 9 on the energy graph Ed is strictly less than the tripping energy threshold Ethb then the processing module 62 determines whether the intensity I measured by the current sensor 52 is strictly greater than the minimum intensity Imini, here equal to the fault current threshold L, during substep S324.

[0135] If the intensity I is strictly greater than the minimum intensity threshold Iminb, which is the case between time Fl and time Gl, then the processing module 62 determines whether the intensity I is greater than or equal to a maximum intensity threshold Imaxl, during substep S326. If the intensity I is strictly less than the maximum intensity threshold Imaxl, then the processing module 62 performs substep SI 12 again and an iterative operation is then implemented.

[0136] If during substep S322, the processing module 62 determines that the Edi trigger energy is greater than or equal to the Ethb trigger energy threshold then the control unit performs steps SI 18 to S122 as described above for the first embodiment.

[0137] In particular, the cell control module 66 commands module 32 in blocked configuration at step SI 18 corresponding to time Gl, the processing module waits until the renewal time Trb measured from time Gl has elapsed at step S120, and once the renewal time Tri has elapsed, commands modules 132 and 142 in passing configuration at time HL. Times Gl and H1 are visible on [Fig.9].

[0138] With circuit breaker 42 connected upstream of circuit breaker 4i, the processing module 62 performs a second iteration of steps SI 12 to SI 15, S320 and SI 18 to S122 using the fault current threshold I2 of circuit breaker 42 and, where applicable, calculating the tripping energy Ed 2, the maximum intensity Imax 2 and minimum intensity Imin 2, using the tripping threshold E* 2 and the re-enactment time Tr 2. If the test time Tt has not elapsed, the processing module 62 detects at step SI 14 whether the current intensity I measured by the current sensor 52 is less than or equal to or strictly greater than the fault current threshold I2 of the circuit breaker 42, in other words, whether the short circuit is still present.

[0139] If the current intensity I measured by the current sensor 52 is less than or equal to the fault current threshold I2 of the circuit breaker 42, the processing module 62 performs step SI 12 again, and an iterative operation is then implemented.

[0140] If the test time Tt has elapsed without the current intensity I measured by the current sensor 52 becoming strictly greater than the fault current threshold I2 of the circuit breaker 42, then the control unit 60 performs step S140. If the current intensity I is strictly greater than the stealth fault threshold Io, then the cell control module 66 performs step S138; otherwise, the mechanical switch control module 164 commands the mechanical switch 112 to the closed position during step S317, the process is reset, and step S102 is performed again.

[0141] In the example of Figures 8 and 9, during step SI 14, the processing module 62 determines at time J1 that the current I is strictly greater than the fault current threshold I2 of the circuit breaker 42. The control unit 60 determines in step SI 15 that the fault current threshold I2 is different from the final fault current threshold If. The device 10 performs steps S320 and SI 18 to S122, using the tripping energy Ed2, the tripping energy threshold Eth2, the re-energization time Tr2, the maximum current Imax2, and the minimum current Imin2, the latter being equal to the fault current threshold I2. The tripping energy Ed2 is represented by a dashed line in Figures 8 and 9 on the energy graph Ed.

[0142] At time K1, the processing module 62 performs substep S322 and determines that the trigger energy Ed2 is strictly less than the energy threshold Eth2. The processing module 62 then performs substep S324 and determines that the current I is strictly greater than the minimum current Imin2, and performs substep S326 and determines that the current I has reached the maximum current Imax2, in other words, is greater than or equal to the maximum current Imax2. The cell control module 66 then performs substep S328 in which it controls the switching module 142 in a blocked configuration at time K1, in other words, it controls the switching modules whose limiting element voltages form the clipping threshold Pe, here the switching module 142.Advantageously, during substep S328, the cell control module 66 controls in forward configuration the switching modules whose limiting voltages. Limiting elements do not form the clipping threshold Pe. The voltage U becomes equal to the clipping threshold Pe. This prevents an excessive current I that could damage the electrical installation 1.

[0143] Alternatively, the cell control module 66 controls each switching module 132, 142 in a blocked configuration

[0144] In an alternative not shown, where the number N of steps is greater than three, the cell control module 66 controls the switching modules whose limiting element voltages form a threshold higher than the nominal network voltage Us, so as to reduce the current I according to the formula:

[0145] TA^l-#

[0146] with - TA the growth rate of intensity I; - U the voltage across the terminals of device 10; and - Us the nominal network voltage.

[0147] In practice, the voltages induced by the resistance of conductors 7 and 8, and by the fault are considered negligible, and the rate of increase TA is thus considered equal to i--g.

[0148] The current decreases until a time L1 at which the current I becomes equal to or less than the minimum current Imin2. During substep S326, the processing module 62 therefore determines that the current I is less than or equal to the minimum current Imin2, and the control module 66 performs substep S330, in which it switches on the modules whose limiting element voltages form the clipping plateau Pe, here, module 142. The current I increases again, and the voltage U becomes zero. Substep S322 is then performed again, and an iterative operation is implemented. This ensures that the current I is sufficiently high for the triggering energy Ed2 to continue increasing.

[0149] In an unrepresented variant, during substep S330, the cell control module 66 controls the modules forming the PI limiting bearing in the blocked state and the others in the conducting state.

[0150] In an unrepresented variant, during substep S330, the cell control module 66 controls all modules in the passing state.

[0151] At time M1, the processing module 62 determines during step S322 that the trigger energy Ed2 has reached the energy threshold Eth2. The cell control module 66 commands all the switching modules 132, 142 in blocked configuration during step SI 18. Following step SI 18, the control unit 60 performs steps S120 to S122.

[0152] The processing module 62 waits until the renewal time Tr2 has elapsed at step S120 and commands the switching modules 132, 142 into the on-mode configuration at step S122.

[0153] The processing module 62 then performs a third iteration of steps SU2, at S115, S320 and SI 18 to S122, using the fault current threshold I3 of the circuit breaker 43 and, where applicable, calculating the tripping energy Ed 3, the maximum current Imax3 and minimum current Imin3, using the tripping threshold Eth3 and the re-energization time Tr3. If, at step SI 12, the test time Tt has elapsed without the current intensity I measured by the current sensor 52 becoming strictly greater than the fault current threshold I3, the control unit 60 performs step S140. If the intensity is strictly greater than the stealth fault threshold Io, then the cell control module 66 performs step S138, otherwise, step S317 is performed, in which the mechanical switch 112 is controlled in the closed configuration, the process is reset, and step S102 is performed again.

[0154] In the example of [Fig.8], the processing module 62 determines that the test time Tt has not elapsed, performs step SI 14 and detects at an instant Q1 that the intensity I of the current measured by the current sensor 52 is strictly greater than the fault current threshold I3 of the circuit breaker 43, in other words, that the short circuit is still present.

[0155] The control unit 160 then performs steps SI 15, S320 and SI 18 to S122. The tripping energy Ed 3 is shown as a solid line in [Fig. 8] on the energy graph Ed. [Fig. 10] represents the control method of device 100, with L, Iminx, Imaxx, Edx, Ethx and Trx respectively representing the fault current, minimum current, maximum current, tripping energy, tripping threshold and re-energization time for iteration x, with x equal to 1, 2 or 3. In an alternative not shown, the installation 1 includes more than three circuit breakers and steps SI 12, to SI 15, S320 and SI 18 to S122 continue to be iterated as long as a circuit breaker is connected immediately upstream of the last tripped circuit breaker.

[0156] The processing module 62 performs step SI 12 again and determines whether the test time Tt, measured from the instant or the re-enactment time Tr3 has elapsed, corresponding to instant RI, has elapsed. If the test time Tt has not elapsed, the processing module 62 detects in step SI 14 whether the current intensity I measured by the current sensor 52 is less than, equal to, or strictly greater than the final fault current threshold If, in other words, whether the short circuit is still present.

[0157] If the current intensity I measured by the current sensor 52 is less than or equal to the final fault current threshold If, the processing module 62 performs step SI 12 again, and an iterative operation is then implemented.

[0158] If the test time Tt has elapsed without the current intensity I measured by the current sensor 52 becoming strictly greater than the final fault current threshold If, then the control unit 60 performs step S140. If the intensity is strictly greater than the stealth fault threshold Io, then the cell control module 66 performs step S138; otherwise, the mechanical switch 112 is controlled in the closed position in step 317, the process is reset, and step S102 is performed again.

[0159] If the current intensity I measured by the current sensor 52 is strictly greater than the final fault current threshold If, which corresponds to time V1 in [Fig. 4], this means that the fault is located upstream of the circuit breaker 43 and is still present. The control unit determines in step SI 15 that the current threshold used in the preceding step SI 14 is equal to the final fault current threshold If. The cell control module 66 then performs step S138, in which it commands all the switching modules, here modules 132 and 134, to operate in a blocked configuration and interrupts the current in the device 10.

[0160] Optionally, once the current intensity I has become zero following step S138, the disconnector control module 68 controls the disconnectors 23 and 24 in blocked configuration, in order to achieve galvanic isolation of the device 10.

[0161] In an alternative not shown, the source 3 and the load 5 are connected to each other by several phase conductors, for example three. In this case, the device 10 advantageously comprises, for each phase conductor, a mechanical switch and an interrupt cell connected in parallel with the mechanical switch.

[0162] Optionally, a mechanical switch is connected to the neutral conductor, with an interruption cell connected in parallel with the mechanical switch.

[0163] The [Fig. 11] is a diagram of an interrupt cell 218 according to a third embodiment of the invention, as a variant to interrupt cell 18 or 118.

[0164] When the interrupt cell 218 is integrated into the device 10, it replaces the interrupt cell 18 and is connected in series to the phase conductor 7 by an input 218a and an output 218b.

[0165] When the interrupt cell 218 is integrated into a device 100, the interrupt cell 218 replaces the interrupt cell 118. In this case, the interrupt cell 218 is, similarly to the interrupt cell 118, connected in parallel with the mechanical switch 112, such that the input 112a and the output 112b of the mechanical switch 112 are connected respectively to the input 218a and to the output 218b of the interrupt cell 218. More specifically, the input 112a of the mechanical switch 112 and the input 218a of the interrupt cell 218 are connected by the electrical link 119a, which is non-interruptible, and the output 112b of the mechanical switch 112 is connected to the output 218b of the interrupt cell 218 by the electrical link 119b, which is also non-interruptible.

[0166] The interrupt cell 218 comprises two rectifier branches 220 and 222. Each rectifier branch 220 and 222 comprises two diodes, 236 and 237 for rectifier branch 220, and 246 and 247 for rectifier branch 222. Diodes 236 and 237 are connected in anti-series with respect to each other, that is, diodes 236 and 237 are connected in series and never conduct current at the same time. The same is true for diodes 246 and 247.

[0167] The input 218a and the output 218b of the interrupt cell 218 correspond respectively to the midpoint of the rectifier branch 220, between diodes 236 and 237 and to the midpoint of the rectifier branch 222, between diodes 246 and 247. Thus, the interrupt cell 218 is connected in parallel with the mechanical switch 112 by the midpoint of each rectifier branch 220 and 222.

[0168] The interrupt cell 218 comprises two interrupt modules 232 and 242. The interrupt modules 232 and 242 are connected in parallel with the rectifier branches 220 and 222 and in series with each other. Alternatively, the interrupt cell 218 comprises more than two interrupt modules, connected in series with the interrupt module 242 and in parallel with the branches 220 and 222, as symbolized by the dashed line in [Fig. 11].

[0169] The interrupt modules 232 and 242 respectively comprise a switchable semiconductor element, which is here a transistor 234 and 244, and a voltage limiting element 239 and 249. The voltage limiting element 239 is connected in parallel with transistor 234, and the voltage limiting element 249 is connected in parallel with transistor 244. The voltage limiting elements 239 and 249 are similar, at least functionally, to the voltage limiting elements 139 and 149 and have limiting voltages Uiim21 and Uiim2, respectively. The limiting voltage Uiim21 differs from the limiting voltage Uiim2, and these voltages form three steps, similarly to the limiting voltages Uiimn and Uiimi2.

[0170] The interrupt cell 218 is configured to receive alternating current and convert it to direct current using diodes 236, 237, 246, and 247, such that direct current flows through the switching modules 232 and 242. The arrangement of diodes 236, 237, 246, and 247 limits the number of diodes in the interrupt cell 218 to four. Thus, even when the interrupt cell 218 includes more than two switching modules, only the four diodes 236, 237, 246 and 247 are necessary for their operation, thus limiting the number of diodes required compared to the interrupt cell 118.

[0171] The method of controlling the protection device 10 comprising an interrupt cell 218 and the method of controlling the protection device 100 comprising an interrupt cell 218 are similar to those described respectively for the protection device 10 comprising the interrupt cell 18 and for the protection device 100 comprising the interrupt cell 118 and are not described again in detail.

[0172] Advantageously, the control methods described and shown in Figures 3 to 5, and 8 to 10 last 10 ms or less.

[0173] As an alternative applicable to all embodiments, in the case where one of the circuit breakers in the series of circuit breakers 4 is a static or hybrid circuit breaker, an isolation time is associated with this circuit breaker, corresponding to a time required to trip the circuit breaker.

[0174] As an alternative applicable to all embodiments, each circuit breaker in the series of circuit breakers 4 is associated with a test duration, which may be different for one or more of the 4b 42, 43 circuit breakers. In this case, the test duration used is updated at step S126, in addition to the values ​​of the fault current threshold, the renewal duration, and where applicable, the maximum and minimum currents.

[0175] In an alternative applicable to all embodiments, the device 10 is arranged upstream of a medium-voltage to low-voltage transformer, and the series of circuit breakers 4 is downstream of the medium-voltage to low-voltage transformer.

[0176] In an alternative not shown applicable to all embodiments, the electrical installation 1 does not include a neutral conductor 8.

[0177] Any feature described for an embodiment or variant in the foregoing may be implemented for the other embodiments and variants described above, provided that it is technically feasible.

Claims

1. Demands Method for controlling an electrical protection device (10; 100), configured to be connected between a source (3) and a series (4) of circuit breakers (4b 42, 43), the device (10; 100) comprising: - an interrupt cell (18;118;218), comprising at least one switching module (32; 132, 142; 232, 242), each switching module (32; 132, 142; 232, 242) comprising: • at least one semiconductor element (34, 35; 134, 135, 144, 145; 234, 244); and • a limiting element (39; 139, 149; 239, 249), connected in parallel with at least one semiconductor element (34, 35; 134, 135, 144, 145; 234, 244), the limiting element (39; 139, 149; 239, 249) having a limiting voltage (Uiimi , Uiimii, Uiimi2, Uiim2i, Uiim22), the limiting tension(s), alone and / or summed together, forming one or a plurality of distinct levels (PI, P2, P3), each switching module (32; 132, 142; 232, 242) being configured to switch between a passing configuration, in which a current flowing between the source (3) and the series of circuit breakers (4) flows in the or in one of the semiconductor elements (34, 35; 134, 135, 144, 145; 234, 244), and a blocking configuration, in which, if the current flows in the switching module (32; 132, 142; 232, 242), it flows in the limiting element (39; 139, 149; 239, 249); - a current sensor (52), configured to measure an intensity (I) and / or a derivative (!') of the current; - a control unit (60; 160) comprising a processing module (62), and a cell control module (66), configured to control each switching module (32; 132, 142; 232, 242) in the passing configuration and in the blocked configuration, each circuit breaker (4b 42, 43) in series (4) being configured to switch between an armed configuration and a configuration tripped, each circuit breaker (4b 42, 43) of the series (4) being associated with a fault current threshold (Ib I2,I3), a tripping energy threshold (Ethb Eth2, Eth3) and a re-establishment time (Trb Tr2 , Tr3), the circuit breakers (4b 42, 43) being connected in series with each other and arranged from upstream to downstream in descending order of their respective fault current threshold (Ib I2,I3): the process comprising at least the following steps: a) measure (S 102) the intensity (I) and / or the derivative (!') of the intensity (I) as a function of time by the current sensor (52); b) detect (SI 14) an electrical fault of the short-circuit type by the processing module (62), if the current (I) measured by the current sensor (52) is strictly greater than the fault current threshold (Ib I2,13) ​​and / or the derivative (I') measured by the current sensor (52) is strictly greater than a fault derivative threshold of a given circuit breaker, the given circuit breaker being the circuit breaker in the most downstream armed configuration of the series of circuit breakers (4); c) when an electrical fault of the short-circuit type is detected, wait (SI 16; S320) until the tripping energy (Edb Ed2, Ed3) becomes greater than or equal to a tripping energy threshold (Ethb Eth 2, Eth 3) of the given circuit breaker; d) when the tripping energy (Edb Ed2, Ed3) is greater than or equal to the tripping energy threshold (Ethb Eth 2, Eth 3) of the given circuit breaker, control (SI 18) in blocked configuration each switching module (32; 132, 142; 232, 242) by the cell control module (66); e) when the renewal time (Trb Tr2, Tr3) of the given circuit breaker has expired, the given circuit breaker having switched to tripped configuration, command (S 122) each switching module (32; 132, 142; 232, 242) in passing configuration, while each switching module (32; 132, 142; 232, 242) has been commanded in blocked configuration in step d); (f) if a circuit breaker is connected immediately upstream of the given circuit breaker, if a test time (Tt) has not elapsed and if a short circuit is detected, the fault current threshold, trip energy threshold and reset time being those of the circuit breaker in the armed configuration immediately upstream of the given circuit breaker, repeat steps (c) to (f); and (g) if no circuit breaker is connected immediately upstream of the given circuit breaker, if the test time (Tt) has not elapsed and if a short circuit is detected, the fault current threshold being equal to a final fault current threshold (If), control (S 138) each switching module (32; 132, 142; 232, 242) in blocked configuration.

2. A control method according to claim 1, wherein the method further comprises the following successive steps: h) detect (S 104) an electrical fault of the short-circuit type by the processing module (62), if the current (I) measured by the current sensor (52) in step a) is strictly greater than a stealth fault current threshold (10) and / or the derivative (!') measured by the current sensor (52) in step a) is strictly greater than a fault derivative threshold; i) control (S 106) in blocked configuration each switching module (32; 132, 142; 232, 242) by the cell control module (66) if an electrical fault is detected in step h); j) when a recurrence time (Tr0) of the stealth fault has elapsed, command each switching module (32; 132, 142; 232, 242) in the on-mode configuration;and k) if the test time (Tt) has not elapsed, perform steps b) to g), the given circuit breaker being the circuit breaker in armed configuration connected furthest downstream.;

3. A method according to claim 2, wherein the method further comprises the following step: 1) when a short-circuit type electrical fault is detected by the processing module (62) in step h), controlling (S306) in an open configuration a mechanical switch (112), connected in parallel with the interrupt cell (118; 218), the mechanical switch (112) being configured to switch between a closed configuration, in which the mechanical switch (112) conducts current, and an open configuration, in which the mechanical switch (112) does not conduct current, by a mechanical switch control module (164) included in the control unit (160), and wherein step i) is carried out when a dielectric strength of the mechanical switch (112) is greater than a sum of the limiting voltage (Uiimn, Uiimi2 ; Un™?!, Un™??) of the limiting element of each switching module (132, 142 ; 232, 242).

4. Method according to claim 3, wherein if the test time (Tt) has elapsed and if a short circuit is not detected, control (S317) the mechanical switch (112) in closed configuration.

5. A method according to any one of claims 2 to 4, further comprising the following step: m) if the test time (Tt) has elapsed, and the intensity (I) is strictly greater than a stealth fault current threshold (Io) and / or the derivative (!') measured by the current sensor (52) is strictly greater than a fault derivative threshold, command (S 138) each switching module (32; 132, 142; 232, 242) in blocked configuration.

6. A method according to any one of the preceding claims, wherein each circuit breaker (4b 42, 43) is further associated with a minimum current threshold (Imini, Imin2, Imin3) and a maximum current threshold (Imaxi, Imax2, Imaxs), and wherein step c) further comprises the following substeps: c) when a short-circuit type electrical fault is detected by the processing module (62) in step b), and the tripping energy (Edi, Ed2, Ed3) is less than or equal to the tripping energy threshold (Ethi, E*2, E*3) of the given circuit breaker, and the current (I) measured by the current sensor (52) is less than or equal to the minimum current threshold (Imini, Imin2, Imin3), the cell control module (66) controls the switching module(s) whose limiting voltages of the elements of limitations form a clipping plateau,the clipping threshold being the smallest threshold above a nominal network voltage (Pe); and c2) when an electrical fault of the short-circuit type is detected by the processing module (62) in step b), that the tripping energy (Edi, Ed2, Ed3) is less than or equal to the tripping energy threshold (Ethi, Eth 2, Eth 3) of the given circuit breaker and that the current (I) measured by the current sensor (52) reaches the maximum current threshold (Imaxi, Imax2, Imaxs), command (S328) in blocked configuration, by the cell control module (66), the switching module(s) whose limiting voltages of the limiting elements form the clipping threshold (Pe).

7. A method according to claim 6, wherein the device (100) comprises a plurality of switching modules (132, 142; 232, 242), connected to each other, substep c2) further comprises a control in on-configuration, by the cell control module (66), of switching modules whose limiting voltages of the limiting elements do not form the clipping plateau (Pe).

8. Electrical protection device (10; 100) configured to be connected between a source (3) and a series (4) of circuit breakers (4b 42, 43), each circuit breaker (4b 42, 43) in the series (4) being configured to switch between an armed and a tripped configuration, each circuit breaker (4b 42, 43) in the series (4) being associated with a fault current threshold (Ib I2,13), a tripping energy threshold (Ethb Eth2, Eth3) and a re-energization time (Trb Tr2, Tr3), the circuit breakers (4b 42, 43) being configured to be connected in series with each other and arranged from upstream to downstream in descending order of their respective fault current thresholds (Ib I2,13), the device (10; 100) comprising: - an interrupting cell (18;118;218), comprising at least one switching module (32; 132, 142; 232, 242), each switching module (32; 132, 142; 232, 242) comprising: • at least one semiconductor element (34, 35;134, 135, 144, 145; 234, 244); and • a limiting element (39; 139, 149; 239, 249), connected in parallel with at least one semiconductor element (34, 35; 134, 135, 144, 145; 234, 244), the limiting element (39; 139, 149; 239, 249) having a limiting voltage (Uiimi, Unmib, Uiimi2, Uiim2b, Uiim22), the limiting voltage(s), alone and / or summed together, forming one or a plurality of distinct steps (PI, P2, P3), each switching module (32; 132, 142; 232, 242) being configured to switch between a forward configuration, in; in which a current flowing between the source (3) and the series of circuit breakers (4) flows in the or in one of the semiconductor elements (34, 35; 134, 135, 144, 145; 234, 244), and a blocked configuration, in which if the current flows in the switching module (32; 132, 142; 232, 242), it flows in the limiting element (39; 139, 149; 239, 249); - a current sensor (52), configured to measure an intensity (I) of the current and / or a derivative (!') of the current; - a control unit (60; 160) comprising: • a processing module (62) configured to detect a short-circuit type electrical fault based on the current (I) and / or the derivative (!') measured by the current sensor (52); and • a cell control module (66), configured to control each switching module (32; 132, 142; 232, 242) in the passing and blocking configurations, the device (10; 100) being configured to implement the method of any one of the preceding claims.

9. Device (10) according to claim 8, comprising a single switching module (32), the limiting voltage (Uiimi) of the voltage limiting element (39) of the switching module (32) then forming the clipping bearing (Pe).

10. An electrical installation (1) comprising a source (3), a load (5), a series (4) of circuit breakers (4b 42, 43) connected between the source (3) and the load (5), each circuit breaker (4b 42, 43) in the series (4) being configured to switch between an armed and a tripped configuration, each circuit breaker (4b 42, 43) in the series (4) being associated with a fault current threshold (Ib I2,13), a tripping energy threshold (Ethb Eth 2, Eth 3) and a re-establishment time (Trb Tr2, Tr3), the circuit breakers (4b 42, 43) being connected in series with each other and arranged from upstream to downstream in descending order of their respective fault current thresholds (Ib I2,13), and a device (10; 100) according to any one of claims 8 and 9, connected between the source (3) and the series of circuit breakers (4).

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