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

Abstract

Method for controlling an electrical protection device, associated electrical protection device and electrical installation The present invention relates to a method for controlling an electrical protection device, the device comprising an interruption cell, comprising at least one switching module, comprising a voltage limiting element having a limiting voltage, the method comprising: measuring (S102) the intensity (I); detecting (S104) an electrical fault; when an electrical fault is detected, the intensity is less than or equal to a minimum intensity threshold (Imin) and a tripping energy (Ed) is strictly less than an energy threshold (Eth), controlling (S114) the switching module(s) in the on-configuration;when an electrical fault of the short circuit type is detected, the current (I) reaches a maximum current threshold (Imax) and the tripping energy (Ed) is strictly lower than the energy threshold, control (S116) the switching module(s) in blocked configuration. Figure for the abstract: Figure 3;

Description

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

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

[0002] In order to protect a load included in an electrical installation against electrical faults such as short circuits, it is known to install an electromechanical circuit breaker upstream of the load, such that the electromechanical circuit breaker and the load are connected to each other, and to install an additional electrical protection device upstream of the electromechanical circuit breaker. The electromechanical circuit breaker comprises contacts and a trip device, which, when it receives sufficient energy, is responsible for separating the contacts. It is therefore necessary to wait until the trip device has received sufficient energy before the protection device interrupts the current and isolates the fault by separating the contacts.However, this generates an increase in the current flowing in the installation, due to the presence of the short circuit, which imposes significant constraints on the installation, in particular on the loads, as well as on the protection device, which must be able to withstand such a current. A known solution is to trigger the protection device when a current threshold is reached, in order to limit the constraints in the installation due to the current, without guaranteeing that the electromechanical circuit breaker receives sufficient energy to be triggered.

[0003] The aim of the invention is then to propose a method for controlling an electrical protection device making it possible to ensure the tripping of an electromechanical circuit breaker, while limiting the constraints in the installation caused by the current in the presence of a short circuit.

[0004] To this end, according to a first aspect, the invention relates to a method for controlling an electrical protection device, configured to be connected between a source and an electromechanical circuit breaker, the device comprising: - an interruption cell, comprising at least one switching module, each switching module comprising: • at least one semiconductor element; and • a voltage limiting element, connected in parallel with the at least one semiconductor element, the voltage limiting element having a limiting voltage, the limiting voltage(s) being at least one of the at least one semiconductor element. mitation, alone and / or combined, forming one or a plurality of distinct levels,

[0005] each switching module being configured to switch between a passing configuration, in which a current flowing between the source and the electromechanical circuit breaker 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 a current intensity; - a control unit comprising a processing module, and a cell control module, configured to control each switching module in the on configuration and in the off configuration,

[0006] the method comprising at least the following steps: a. measurement of current intensity by the current sensor; b. detection of an electrical fault of the short circuit type by the module of treatment, depending on the intensity measured by the current sensor;

[0007] According to the invention, the method further comprises the following successive steps: a. when an electrical fault of the short-circuit type is detected by the processing module in step b), when the intensity measured by the sensor is less than or equal to a minimum intensity threshold and a tripping energy received by the electromechanical circuit breaker is strictly less than an energy threshold, the tripping energy being calculated by the processing module as a function of the intensity measured by the current sensor, controlling in the on-configuration the switching module(s) whose limiting voltages of the limiting elements form the clipping level by the cell control module; b. when an electrical fault of the short-circuit type is detected by the processing module in step b), when the intensity measured by the sensor reaches a maximum intensity threshold and the triggering energy calculated by the processing module is strictly lower than the energy threshold, controlling in blocked configuration the switching module(s) whose limiting voltages of the limiting elements form the clipping level by the cell control module; and c. when the trigger energy is greater than or equal to the energy threshold, control each switching module in blocked configuration by the cell control module, independently of the intensity measured by the sensor.

[0008] Thanks to the invention, as long as the electromechanical circuit breaker has not received sufficient energy to trip, the device allows the current to flow. The intensity of the current is however limited, thanks to the switching modules, which are controlled in blocked configuration when the intensity reaches a maximum intensity threshold, which avoids excessively high intensities and risks of damage to the electromechanical circuit breaker, the protection device and the load. In addition, by controlling the switching modules in passing configuration when the intensity is less than or equal to the minimum intensity threshold, the device ensures that sufficient intensity flows in the electromechanical circuit breaker, ensuring that the latter receives enough energy to trip. Maintaining the intensity between the minimum intensity threshold and the maximum intensity threshold also ensures that the electromechanical circuit breaker receives energy continuously, without discharging, and therefore ensures the fastest possible tripping.This limits the constraints due to current intensity, while ensuring rapid tripping of the electromechanical circuit breaker.

[0009] According to other advantageous aspects of the invention, the method comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0010] - The method further comprises the following successive steps: a. controlling each switching module in the on-configuration, while the trigger energy is greater than or equal to the energy threshold and each switching module has been controlled in the off-configuration in step e); and b. each switching module having been controlled in the on-configuration in step f), if a short circuit is detected while a duration counted from a moment when each switching module is controlled in the on-configuration in step g) is less than a test duration, control each switching module in the blocked configuration.

[0011] - The method further comprises the following step: a. when an electrical fault of the short circuit type is detected by the processing module in step b), controlling in open configuration a mechanical switch, connected in parallel with the interruption cell, the mechanical switch being configured to switch between a closed configuration, in which the mechanical switch conducts the current, and an open configuration, in which the mechanical switch does not conduct the current, by a mechanical switch control module included in the control unit. - The method further comprises the following step: a. control the mechanical switch in the closed configuration if, when the duration of step g) is greater than or equal to the test duration, no short- circuit was detected.

[0012] - The device comprises a plurality of switching modules, connected to each other to the others, step d) further comprising a control in passing configuration of the switching modules whose limiting voltages of the limiting elements do not form the clipping level, by the cell control module.

[0013] According to a second aspect, the invention also relates to an electrical protection device, configured to be connected between a source and an electromechanical circuit breaker, the device comprising: - an interruption cell, comprising at least one switching module, each switching module comprising: • at least one semiconductor element; and • a voltage limiting element, connected in parallel with the at least one semiconductor element, the voltage limiting element having a limiting voltage, the limiting voltage(s), alone and / or summed together, forming one or a plurality of separate levels,

[0014] each switching module being configured to switch between a passing configuration, in which a current flowing between the source and the electromechanical circuit breaker 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 a current intensity; - a control unit comprising: • a processing module configured to detect an electrical fault of the short-circuit type as a function of the intensity measured by the current sensor and to calculate a tripping energy received by the electromechanical circuit breaker, as a function of the intensity measured by the current sensor; and • a cell control module, configured to control each switching module in the on-configuration and in the off-configuration,

[0015] the device being configured to implement the method described previously.

[0016] According to other advantageous aspects of the invention, the device comprises one or more of the following characteristics, taken individually or in all technically possible combinations:

[0017] - Each switching module comprises two semiconductor elements which are unidirectional in current and connected to each other in anti-series, and for each semiconductor element, a diode is connected in anti-parallel to the semiconductor element driver.

[0018] - The interrupt cell comprises two rectifier branches, the input and the output of the interruption cell respectively forming a midpoint of one of the rectifier branches, each rectifier branch comprising two diodes arranged on either side of the midpoint, connected in anti-series with respect to each other; - the switching modules are connected in parallel with the rectifier branches; and - each switching module comprises a single semiconductor element connected in parallel with the voltage limiting element.

[0019] - The device comprises a single switching module, the limiting voltage of the voltage limiting element of the switching module then forming the clipping level.

[0020] According to a third aspect, the invention also relates to an electrical installation comprising a source, a load, an electromechanical circuit breaker, connected between the source and the load, the electromechanical circuit breaker being configured to trip when it receives a tripping energy greater than or equal to an energy threshold, and a device as described previously, connected between the source and the electromechanical circuit breaker.

[0021] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which: - [Fig.l] [Fig.l] is an electrical diagram of an electrical installation according to a first embodiment of the invention; - [Fig.2] [Fig.2] is a graph of characteristic quantities of the installation of [Fig.l], as a function of time; - [Fig.3] [Fig.3] is a flowchart of a control process for a protective device belonging to the installation of [Fig.l]; - [Fig.4] [Fig.4] is an electrical diagram of an electrical installation according to a second embodiment of the invention; - [Fig.5] [Fig.5] is an electrical diagram of an interruption cell of the installation of [Fig.4]; - [Fig.6] [Fig.6] is a graph of characteristic quantities of the installation figures 4 and 5 in function; - [Fig.7] [Fig.7] is a flowchart of a control process for a protective device belonging to the installation of figures 4 and 5; and - [Fig.8] [Fig.8] is an electrical diagram of an ap interrupt cell participating in an installation according to a third embodiment of the invention.

[0022] [Fig.l] is a diagram of an electrical installation 1 comprising a source 3, an electromechanical circuit breaker 4 and a load 5, electrically connected to each other by a phase conductor 7 and a neutral conductor 8. The source 3 supplies electricity and is, for example, an electrical generator or an electrical network, for example a mains electrical network.

[0023] The load 5 is a device consuming electricity, such as a domestic electrical appliance, industrial equipment such as an electric motor, or even a server. Thus, an electric current, simply called current hereinafter, flows between the source 3 and the load 5 through the phase conductor 7, and returns to the source 3 through the neutral conductor 8.

[0024] The electromechanical circuit breaker 4 is connected between the source and the load 5. The electromechanical circuit breaker 4 comprises contacts, as well as a trigger which may be a coil, a magnetic blade, an electronic or electromechanical device, not shown, and is configured to trigger the interruption of the current flowing from the source 3 to the load 5 when an electrical fault of the short-circuit type is present in the electrical installation 1.

[0025] 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.

[0026] The electrical installation 1 also comprises an electrical protection device 10, also called a device hereinafter, connected between the source 3 and the electromechanical circuit breaker 4. 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 electromechanical circuit breaker 4, and a tripped configuration, in which the device 10 electrically isolates the source 3 from the electromechanical circuit breaker 4. The device 10 has a voltage U, expressed in volts (V) and applied to its terminals, between the conductors 7 and 8. In the embodiment of [Fig.l], the device 10 is a static circuit breaker, also called a SSCB, from the English "Solid State Circuit Breaker". It comprises an interruption cell 18 connected in series to the phase conductor 7 by an input 18a and an output 18b.

[0027] The interruption cell 18 is configured to allow or interrupt the current passing through it, as explained below.

[0028] The device 10 advantageously comprises a first disconnector 23 and, optionally, a second disconnector 24, connected respectively to the phase conductor 7 and to the neutral conductor 8. In particular, the disconnector 23 is connected to the phase conductor 7 in series with the interruption cell 18. The disconnector 24 is connected in series to 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.l], the device 10 comprises an actuator 25 of the first disconnector 23 and an actuator 26 of the second disconnector 24 which, when activated, interact respectively with the first disconnector 23 and the second disconnector 24 to switch them into the open configuration. The actuators 25 and 26 are, for example, coils and are activated when a current flows in the turns of the coils.

[0029] 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 interruption cell 18.

[0030] The interruption cell 18 comprises at least one switching module, here, a switching module 32. The switching module 32 comprises at least one switching-controllable semiconductor element, for example at least one thyristor or at least one transistor, such as a field effect transistor, also called FET (Field Effect Transistor), an insulated gate field effect transistor, also called MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an insulated gate bipolar transistor, also called IGBT (Insulated Gate Bipolar Transistor), or a combination of these different semiconductor elements. In the embodiment of [Fig.l], the interruption cell 18 comprises two semiconductor elements 34 and 35. The semiconductor elements 34 and 35 are unidirectional in current, and are for example two IGBT type transistors.The conduction direction of transistors 34 and 35 is indicated by an arrow on each transistor 34, 35. Transistors 34 and 35 are connected to each other in anti-series, that is, transistors 34 and 35 are connected in series but head to tail, so as not to conduct current at the same time. Two diodes 36 and 37 are connected respectively to transistors 34 and 35. Diode 36 is connected in anti-parallel to transistor 34, that is, diode 36 and transistor 34 do not conduct electric current at the same time: if transistor 34 is on, diode 36 is off and vice versa. In other words, transistor 34 and diode 36 are connected in parallel head to tail. The same applies to transistor 35 and diode 37. This arrangement allows each switching module 32 and 42 to conduct alternating current without interruption at each change of sign of the current.

[0031] The switching module 32 comprises a voltage limiting element 39, also called a limiting element. The voltage limiting element 39 is connected in parallel with an assembly formed by the transistors 34 and 35, and is by example a metal oxide varistor, or MOV (from the English Metal Oxide Varistor), a transil diode or a gas discharger. The voltage limiting element 39 has a limiting voltage Uiimi, which corresponds to a voltage at its terminals when it is crossed by the current flowing between the source 3 and the load 5. The limiting voltage Uiimi is higher than the nominal network voltage Us, for example of the order of 1.5 times the nominal network voltage Us.

[0032] The switching module 32 is configured to switch between an on configuration and a off configuration. In the on configuration, the current flows in one of the transistors 34 or 35. More precisely, when the current passing through the device 10 is alternating, the current flows in the transistor 34 and in the diode 37, then when the current changes direction, in the transistor 35 and in the diode 36.

[0033] In the off configuration, transistors 34 and 35 do not conduct current and, if current flows in switching module 32, it flows through voltage limiting element 39.

[0034] 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 counter-voltage whose value is that of the limiting voltage Uiimi is applied across the terminals of the device 10.

[0035] The limiting voltage Uiimi forms a clipping level Pe, which is higher than the nominal network voltage Us.

[0036] The control device 10 also comprises a current sensor 52. The current sensor 52 is configured to measure an intensity I of the current, expressed in amperes (A), 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.

[0037] The control device 10 comprises 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. In the following, the term short-circuit is used to designate an electrical fault of the short-circuit type.

[0038] The control unit 60 also comprises a cell control module 66 and, advantageously, a disconnector control module 68, connected to the processing module 62 and respectively configured to control the interruption cell 18, more precisely the switching module 32, and the disconnectors 23 and 24.

[0039] The cell control module 66, also called the control module, is configured to control the switching module 32 in the on configuration and in the off configuration, as explained in more detail below, in particular by actuating the trigger of the transistors 34 and 35.

[0040] The disconnector control module 68 is advantageously configured to actuate the actuators 25 and 26 respectively, in order to switch the disconnectors 23 and 24 to the open configuration.

[0041] 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 the memories of registers or other types of display devices, transmission devices or storage devices.

[0042] 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 Specific Integrated Circuit).

[0043] In a variant not shown, the control unit 60 comprises an information processing unit formed for example by 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 produced in the form of software, or a software brick, 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 software among the processing software, the cell control software and the disconnector control software.

[0044] In a variant not shown, the processing module 62, the cell control module 66 and the disconnector control module 68 are each produced in the form of a programmable logic component, such as an FPGA (Field Programmable Gate Array), an integrated circuit, such as an ASIC (Application Specific Integrated Circuit) or even in the form of an analog component.

[0045] Advantageously, the device 10 also comprises a power supply module 70, connected to the 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 the conductors 7 and 8.

[0046] When a short circuit is present in the electrical installation 1, an intensity I of the current flowing between the source 3 and the load 5 increases rapidly and significantly, for example by several thousand amperes per microsecond. The intensity I of the current becomes strictly greater than a minimum current threshold Imin from from which the trip unit of the electromechanical circuit breaker 4 receives a tripping energy Ed, expressed in arbitrary units (AU) proportional to the time and to the square of the current I. When the tripping energy Ed is greater than or equal to an energy threshold Eth, the trip unit of the electromechanical circuit breaker 4 causes the contacts of the electromechanical circuit breaker 4 to open in order to interrupt the current between the source 3 and the load 5, more precisely between the device 10 and the load 5. In other words, when the tripping energy Ed is greater than the energy threshold Eth, the electromechanical circuit breaker 4 trips.

[0047] The trigger energy Ed is determined by the processing module 62 as a function of the intensity I measured by the current sensor 52.

[0048] In order to limit the constraints in the electrical installation, the intensity of the current I is limited, using the device 10, as explained below.

[0049] A method of controlling the device 10 according to the invention will now be explained, with reference to FIGS. 2 and 3.

[0050] Initially, advantageously, the device 10 is in the armed configuration, that is to say that the disconnectors 23 and 24 are in the closed configuration and the switching module 32 is in the passing configuration. The current flows from the source 3 to the mechanical circuit breaker 4, passing through the switching module 32.

[0051] The current sensor 52 measures the intensity I of the current flowing in the phase conductor 7, in step S102.

[0052] The control unit 60 receives the measurement of the intensity I and detects, via the processing module 62, whether a short circuit is present between the source 3 and the load 5, in step S104. If a short circuit is not detected, then the current sensor 52 performs step S102 again and continues to measure the intensity I of the current. An iterative operation is then implemented.

[0053] The short circuit is detected as a function of the intensity I measured by the current sensor 52, and is for example detected when the intensity I is strictly greater than a predetermined threshold, here, when the intensity is strictly greater than a fault threshold Icc. Alternatively, the short circuit is detected when a derivative of the intensity I is strictly greater than a predetermined threshold, or when a combination of conditions on the intensity I and its derivative are met. In the example of [Fig.2], a short circuit is detected at time CC.

[0054] If a short circuit is detected in step S104, the current is not immediately interrupted, which allows the intensity I to increase in the installation 1 in order to give the circuit breaker 4 time to receive the tripping energy Ed.

[0055] The processing module 62 begins a calculation of the tripping energy Ed received by the electromechanical circuit breaker 4 as soon as the intensity I becomes strictly greater than the minimum intensity threshold Imin, from which the electromechanical circuit breaker mechanical 4 receives the trigger energy Ed. The intensity I becomes strictly greater than the minimum intensity threshold Imin from the instant Ao in [Fig.2].

[0056] In a variant not shown, the minimum intensity Imin is lower than the fault intensity Icc. In this case, the calculation of the tripping energy Ed is started before the short circuit is detected in step 104.

[0057] During a step S108, the processing module 62 compares the calculated tripping energy Ed with the energy threshold Eth. The energy threshold Eth is advantageously indicated by the manufacturer of the device 10, or by the installer of the device 10, who thus indicates the energy threshold Eth corresponding to the electromechanical circuit breaker 4 downstream of the device 10.

[0058] If the trigger energy Ed is strictly lower than the energy threshold Eth, which is the case between times A and E of [Fig. 2], the processing module 62 performs a step S1010 in which it compares the intensity I with the minimum intensity threshold Imin. If the intensity I is strictly higher than the minimum intensity threshold Imin, as can be seen in [Fig. 2] between times A and B, the processing module 62 compares the intensity I with the maximum intensity threshold Imax in step S1012. If the intensity I is strictly lower than the maximum intensity threshold Imax, the processing module 62 performs step S108 again. An iterative operation is then implemented.

[0059] As can be seen in [Fig. 2], at time A, the trigger energy Ed is strictly lower than the energy threshold Eth and the intensity I has increased until it becomes equal to the maximum intensity threshold Imax. The control unit 60 controls the switching module 32 in the blocked configuration via the cell control module 66 at step SI 16, which corresponds to time A of [Fig. 2]. The voltage U across the terminals of the device 10 is then equal to the clipping level Pe, itself equal to the limiting voltage Uiimi.

[0060] The passage of current in the voltage limiting element 39 makes it possible to limit an increase in the intensity I caused by the short circuit, according to the following formula:

[0061] TA-L^

[0062] with: - TA the growth rate of intensity I; - U the voltage across the terminals of the device 10; and - Us the nominal network voltage.

[0063] 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 1-^.. U 5

[0064] The voltage U being here equal to the limiting voltage Uiimi which is higher than the nominal network voltage Us, the intensity I decreases until it reaches the intensity threshold minimum Imin, as visible in [Fig.2] between times A and B.

[0065] As visible in [Fig.2], at time B, the triggering energy Ed is strictly lower than the energy threshold Eth and the intensity I has decreased until it becomes equal to the minimum intensity threshold Imin. In a variant not shown, at time B, the intensity I has decreased until it becomes equal to the minimum intensity threshold Imin. Thus, from time B and following step SI 10, a step SI 14 is carried out, during which the control module 66 controls the switching module 32 in the on configuration. The voltage U across the terminals of the device 10 drops suddenly and becomes substantially zero at the same time as the intensity I increases, until it reaches the maximum intensity threshold Imax again, which corresponds to time C in [Fig.2]. The processing module 62 then performs steps S108, S1010 and S12 again, and determines that the intensity I has reached the maximum intensity threshold Imax.The control module 66 then controls the switching module 32 in the blocked state in step SI 16. The voltage U across the terminals of the device 10 again becomes equal to the limiting voltage Uiimi and the current I decreases.

[0066] The intensity I measured by the sensor 52 decreases until it becomes equal to the minimum current threshold Imin, this corresponds to the instant D of [Fig.2]. The cell control module 66 again performs step SI 14 and controls the switching module 32 in the on state. The voltage U becomes zero again and the intensity I increases again.

[0067] In a variant not shown, at time D, the intensity I has decreased until it becomes strictly lower than the minimum intensity threshold Imin.

[0068] Maintaining the intensity I between the minimum intensity threshold Imin and the maximum intensity threshold Imax continues as long as the tripping energy Ed is strictly lower than the energy threshold Eth. When the tripping energy Ed becomes greater than or equal to the energy threshold Eth, which corresponds to the instant E of [Fig.2], the electromechanical circuit breaker 4 trips. The processing module 62 performs step S118 following step S108. During step S118, the switching module 32 is controlled by the cell control module 66 in blocked configuration, independently of the intensity I measured by the sensor 52. Thus, the current is interrupted both by the electromechanical circuit breaker 4 and by the device 10. The voltage U becomes equal to the limiting voltage Uiimi and the intensity I decreases until it becomes zero.When the intensity I has become zero, the voltage U at the terminals of the device 10 becomes equal to the nominal voltage of the network Us.

[0069] Advantageously, and as shown in [Fig.2], while the triggering energy Ed is greater than or equal to the energy threshold E* and the control of the switching module 32 in the blocked configuration at step SI 18 has been carried out, a reactivation sequence is implemented.

[0070] The renewal sequence comprises step S120, in which the processing module 62 waits for a minimum duration Dmin, calculated from the moment when the control module 66 controls the switching module 32 in the blocked configuration in step S118, to elapse. For this, during step S328, the processing module 62 compares a duration T”, measured from the instant E, and the duration Dmin. When the duration Dmin has elapsed, that is to say, when the duration T” is greater than or equal to Dmin, the control module 66 controls the switching module 32 in the on-configuration during step S122, corresponding to the instant F of [Fig.2]. The processing module 62 compares a duration T, measured from the command of the switching module 32 in the on-configuration in step S122, to a test duration Dt, during a step S124.If the duration T is strictly less than the test duration Dt, in other words, if the test duration Dt has not elapsed, the processing module 62 detects whether a short circuit is still present, at step S126. In the example of Figures 2 and 3, the processing module 62 detects a short circuit at step S126 if the current I is strictly greater than a fault current Icc- If the processing module 62 detects a short circuit while the duration T is strictly less than the test duration Dt, this means that, despite the tripping of the electromechanical circuit breaker 4, the short circuit has not been isolated. This is due, for example, to the fact that the short circuit is located between the electromechanical circuit breaker 4 and the device 10. The cell control module 66 then controls the switching module 32 in the blocked configuration at step S128, corresponding to the instant G of [Fig.2].The voltage U across the device is then equal to the limiting voltage Uiimi, until the current I becomes zero. The voltage U then becomes equal to the nominal network voltage Us.

[0071] Advantageously, when the intensity I has become zero following step S128, the disconnector control module 68 activates the actuators 25 and 26, in order to switch the disconnectors 23 and 24 to the open configuration. The device 10 is then in the triggered configuration.

[0072] As is clear from the preceding explanations, the disconnectors 23 and 24 switch to the open configuration only once the current has been interrupted and serve to galvanically isolate the source 3 and the load 5, but do not participate in the interruption of the current as such.

[0073] If the processing module 62 does not detect a short circuit in step S126, then the processing module 62 performs step S124 again and an iterative operation is implemented. If the duration T is greater than or equal to the test duration Dt, in other words, if the test duration Dt has elapsed, no short circuit having been detected, this means that the tripping of the electromechanical circuit breaker 4 has made it possible to isolate the short circuit. The cell control module 66 then maintains the control module mutation 32 in passing configuration and the device 10 resumes its normal operation and performs step S102 again.

[0074] [Fig.4] represents an electrical installation 1, which differs from the installation electrical system of [Fig.l] 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.4] by the same reference signs are similar, at least functionally, to those of the device 10 and are not described in detail.

[0075] The device 100 is a hybrid circuit breaker, and comprises a mechanical switch 112, also known as a bypass switch, or a fast mechanical switch, also called FMS (from the English Fast Mechanical Switch). The mechanical switch 112 is connected in series to the phase conductor 7, by 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. 4], the mechanical switch 112 is shown in the open configuration. The device 100 advantageously comprises an actuator 116 which, when activated, switches the mechanical switch 112 to the open configuration.

[0076] The device 100 comprises an interruption 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 to an input 118a and an output 118b of the interruption cell 118, respectively. More specifically, the input 112a of the mechanical switch 112 and the input 118a of the interruption cell 118 are connected by an electrical connection 119a, which is uninterruptible, and the output 112b of the mechanical switch 112 is connected to the output 118b of the interruption cell 118 by an electrical connection 119b, which is also uninterruptible. In other words, the electrical connections 119a and 119b are each an electrical cable or wire; none of the electrical connections 119a and 119b include a switch or more generally a means of interrupting the electric current.The interrupt cell 118 is configured to pass or to interrupt the current passing through it, as explained below.

[0077] The interrupt cell 118 comprises N switching modules; for example N is equal to 2 in the example of the figures. The interrupt cell 118 comprises two switching modules 132 and 142, as seen in [Fig. 5]. Alternatively, there are three or more switching modules, as symbolized by the dotted line in [Fig. 5].

[0078] The switching modules 132 and 142 are connected in series to each other.

[0079] In the example of [Fig.5], the switching module 132 is similar, at least functionally, to the switching module 32 and as such comprises two transistors 134, 135 connected in anti-series, two diodes 136 and 137 respectively connected in anti-parallel to the transistors 134 and 135, and a limiting element 139, having a limiting voltage Uiimn. The transistors 144, 145 and the diodes 146 and 147 of the switching module 142 are respectively similar, at least functionally, to the transistors 134, 135 and the diodes 136 and 137 of the switching module 132. In particular, the transistors 134, 144, 135 and 145 are, in the example of [Fig. 5], current unidirectional transistors, the direction of which is indicated by an arrow on each transistor. The switching module 142 comprises a limiting element 149, connected in parallel with an assembly formed by the transistors 144 and 145 and has a limiting voltage Uiimi2, which is different from the limiting voltage U limll-

[0080] 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.

[0081] Thus, in the blocked configuration, the voltages across the switching modules 132 and 142 are respectively the limiting voltage Uiimn and the limiting voltage Uiimi2.

[0082] The limiting voltages Uiimn and Uiimi2 form at least 2N-1 steps, distinct from each other. Here, the number Np of switching steps is equal to Np= 2N-1, where N is the number of switching modules. The steps are formed by the limiting voltages Uiimn and Uiimi2 taken alone, or summed together. The list of steps obtained is shown in the table below. For N=2 switching modules, three distinct steps PI, P2, P3 are obtained, with 3 = 22-1. Here, PI is the step with the lowest value, equal to Uiimn which is for example 0.5Us, P2 is greater than PI, and has a value equal to Uiimi2 which is for example 1.5US, and P3 is greater than P2, with a value equal to the sum of Uiimn and Uiimi2, for example 2US.

[0083] [Tables 1] Level Value PI Uiimii P2 Ulim12 P3 Uiimn + Uiimi2

[0084] The P2 level is the smallest level above the nominal network voltage, and is called the clipping level Pe.

[0085] The control device 100 comprises a control unit 160, which differs from the control unit 60 in that it further comprises a mechanical switch control module 164.

[0086] A method of operating the device 100 will now be explained, in look at figures 3 and 4.

[0087] Initially, advantageously, the device 100 is in the armed configuration, that is to say that 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. Because of an internal resistance lower than that of the transistors 134, 135, 144 and 145, the mechanical switch 112 conducts all of the electric current flowing in the device 100. A voltage U across the terminals of the device 100 is zero, or substantially zero.

[0088] The current sensor 52 measures the intensity I of the current flowing in the phase conductor 7, at step S302.

[0089] The control unit 160 receives the measurement of the intensity I and detects, via the processing module 62, whether a short circuit is present between the source 3 and the load 5, in step S304.

[0090] In the example of [Fig.6], a short circuit is detected when the intensity I is strictly greater than the fault intensity Icc-

[0091] If a short circuit is not detected, then the current sensor 52 performs step S304 again and continues to measure the current intensity I. An iterative operation is then implemented.

[0092] If a short circuit is detected, then the control unit 160 controls the mechanical switch 112 to switch into the open configuration, via the mechanical switch control module 164, during step S306. The opening of the mechanical switch 112 corresponds to the instant J in [Fig.6]. In addition, if a short circuit is detected, the processing module 62 begins a calculation of the tripping energy Ed received by the electromechanical circuit breaker 4. Indeed, the fault threshold Icc being greater than the minimum current threshold Imin, the trip unit of the electromechanical circuit breaker 4 receives the tripping energy Ed.

[0093] Alternatively, the processing module 62 begins calculating the triggering energy Ed as soon as the intensity I exceeds the minimum intensity threshold Imin, which corresponds to the instant Jo in [Fig.6], and before the short circuit is detected, i.e. before step S304.

[0094] When the mechanical switch 112 is in the open configuration, the electric current is transferred from the mechanical switch 112 to the interruption cell 118. However, the opening of the mechanical switch 112 generates an electric arc and an ionization of the medium between contacts of the mechanical switch 112. This reduces a dielectric strength of the mechanical switch 112. Thus, before reducing or interrupting the current flowing between the source 3 and the load 5, it is necessary to wait for a restoration of a sufficient dielectric strength of the mechanical switch 112, failing which a re-breakdown may occur at the terminals of the switch. mechanical 112, that is to say a reappearance of an electric arc between contacts of the mechanical switch 112, while the latter is in the open configuration, which causes damage to the mechanical switch 112. The device 100 will then be unable to reduce or interrupt the current.

[0095] The dielectric strength of the mechanical switch 112 increases over time, until it becomes greater than one or more levels PI, P2, P3. In the example described here, PI is the smallest level. Thus, the dielectric strength of the mechanical switch 12 becomes greater than or equal to level PI while being less than levels P2 and P3. PI is then the largest level less than or equal to the dielectric strength of the mechanical switch 112.

[0096] Preferably, the time required between the moment when the mechanical switch 12 switches to the open configuration and the moment when the dielectric strength of the mechanical switch 12 becomes equal to the level PI is equal to a first waiting threshold Tb

[0097] The processing unit 62 compares a waiting time T' with a first waiting threshold Ti in step S308. As long as the waiting time T' is less than the first waiting threshold Tb, the processing unit 62 continues to perform step S308. An iterative operation is then implemented.

[0098] When the waiting time T' is greater than or equal to the first waiting threshold Tb, the dielectric strength of the mechanical switch 12 is equal to or greater than the level PL. Advantageously, the cell control module 166 controls the switching module 132 in the blocked configuration at step S310, which corresponds to the instant K in [Fig. 6], and the other switching modules, here the switching module 142, in the passing configuration. The transistors 134 and 135 are blocked and do not conduct the current, which then flows in the voltage limiting element 139 and in the switching module 142. The voltage U at the terminals of the device 100, and therefore at the terminals of the mechanical switch 112 is then equal to the limiting voltage. The passage of the current in the voltage limiting element 139 makes it possible to limit an increase in the intensity I caused by the short circuit and the level PI is also called the limiting level.Steps S308 and S310 make it possible to limit the increase in intensity I as early as possible, by applying a voltage equal to the PI level, as soon as the dielectric strength of the mechanical switch 112 allows it.

[0099] The dielectric strength of the mechanical switch 112 continues to increase, and becomes equal to and then greater than the level P2. Preferably, the duration between the instant when the mechanical switch 12 switches to the open configuration and the instant when the dielectric strength of the mechanical switch 12 becomes equal to the level P2 is equal to a second waiting threshold T2.

[0100] The processing unit 62 compares the waiting time T' to the second waiting threshold T2 in step S312. As long as the waiting time T' is less than the second waiting threshold T2, the processing unit 62 continues to perform step S312. An iterative operation is then implemented.

[0101] When the waiting time T' is greater than or equal to the second waiting threshold T2, which is the case at time L, then during a step S316, the processing module 62 compares the calculated trigger energy Ed to the energy threshold Eth.

[0102] If the trigger energy Ed is strictly less than the energy threshold Eth, the processing module 62 performs a step S318 in which it compares the intensity I with the minimum intensity threshold Imin. If the intensity I is strictly greater than the minimum intensity threshold Imin, the processing module 62 compares the intensity I with the maximum intensity threshold Imax in step S320. If the intensity I is strictly less than the maximum intensity threshold Imax, the processing module 62 performs step S316 again. At time L, the trigger energy Ed is strictly less than the energy threshold Eth and the intensity I is greater than the maximum intensity threshold Imax. The control module 66 then controls the switching module 142 in the blocked configuration and the switching module 132 in the passing configuration in step S324.In other words, the cell control module 66 controls the switching module 142 whose limiting voltage Uiimi2 of the limiting element 149 forms the clipping level Pe, and controls the switching modules whose limiting voltages do not form the clipping level Pe in the on configuration. The transistors 146 and 147 are blocked and do not conduct the current, which then flows in the voltage limiting element 149 and in the switching module 132. The voltage U at the terminals of the device 100, and therefore at the terminals of the mechanical switch 112 is then equal to the level P2, equal to the limiting voltage Uiimi2, in other words, to the clipping level Pe. The processing module 62 performs step S316 again and an iterative operation is implemented.

[0103] If the trigger energy Ed is strictly lower than the energy threshold Eth, which is the case between times L and P of [Fig. 6], the processing module 62 performs step S318 in which it compares the intensity I with the minimum intensity threshold Imin. If the intensity I is strictly higher than the minimum intensity threshold Imin, which is the case between times L and M of [Fig. 6], the processing module 62 compares the intensity I with the maximum intensity threshold Imax in step S320. If the intensity I is strictly lower than the maximum intensity threshold Imax, the processing module 62 performs step S316 again. An iterative operation is then implemented. Steps S316, S318 and S320 are respectively similar to steps S108, S110 and S112 of the first embodiment.

[0104] As visible in [Fig.6], at time M, the trigger energy Ed is strictly lower than the energy threshold Eth and the intensity I has decreased until it becomes equal to the minimum intensity threshold Imin. Thus, following step S318, a step S322 is carried out, during which the control module 66 controls the switching module 142 in the on configuration and, advantageously, the switching module 132 in the off configuration. The voltage U at the terminals of the device 10 becomes equal to the level PI, in other words, to the limitation level, and the intensity I increases, until it reaches the maximum intensity threshold Imax, corresponding to the instant N in [Fig.6].

[0105] The processing module 62 then performs steps S316, S318 and S320, and determines that the intensity I is greater than or equal to the maximum intensity threshold Imax. The control module 66 then controls the switching module 142 in the blocked configuration and the switching module 132 in the on-configuration at step S324. In other words, the control module 66 controls the switching module 142 in the blocked configuration, the limiting voltage Uiim2i of the limiting element 149 of which forms the clipping level Pe, and controls the switching module 132 in the on-configuration, the limiting voltage Uiimn of the limiting element 139 of which does not form the clipping level Pe. The voltage U across the terminals of the device 10 again becomes equal to the limiting voltage Uiimi2, in other words, to the clipping level Pe, and the intensity I decreases.

[0106] Maintaining the intensity I between the minimum intensity threshold Imin and the maximum intensity threshold Imax continues as long as the trigger energy Ed is strictly lower than the energy threshold Eth. Thus, controlling the switching module 132 in the blocked configuration at step S322 makes it possible to limit the increase in the intensity I and limits the number of commands of the switching modules 132 and 142.

[0107] When the tripping energy Ed becomes greater than or equal to the energy threshold Eth, which corresponds to the instant P of [Fig.6], the electromechanical circuit breaker 4 trips. The processing module 62 performs step S326 following step S316. During step S326, the dielectric strength of the mechanical switch 112 is greater than the level P3, and each switching module 132, 142 is controlled by the cell control module 66 in the blocked configuration, independently of the intensity I.

[0108] Thus, the current is interrupted both by the electromechanical circuit breaker 4 and by the device 10. The voltage U becomes equal to the level P3 and the intensity I decreases until it becomes zero, at an instant Po which follows the instant P. When the intensity I has become zero at the instant Po, the voltage U at the terminals of the device 10 becomes equal to the nominal voltage of the network Us.

[0109] In the example of figures 4 to 6, controlling each switching module 132, 142 in step S326 makes it possible to accelerate the reduction of the intensity I, compared to a variant where only the switching modules whose limiting voltages form the clipping stage Pe, here the switching module 142, are used.

[0110] Advantageously, and as shown in [Fig.6], following the command of all the switching modules in blocked configuration at step S326, a re-energization sequence is implemented, similar to the re-energization sequence described for the device 10.

[0111] The renewal sequence comprises step S328, in which the processing module 62 waits for the minimum duration Dmin, calculated from the control of the switching modules 132 and 142 in the blocked configuration, which takes place in step S326, to have elapsed. For this, during step S328, the processing module 62 compares a duration T”, measured from the instant P and the duration Dmin. When the duration Dmin has elapsed, that is to say, when the duration T” is greater than or equal to Dmin, the cell control module 66 controls all the switching modules 132, 142 in the passing configuration during step S330, corresponding to the instant Q of [Fig. 2]. The processing module 62 determines during a step S332 whether the test duration Dt has elapsed. For this, during step S332, the processing module 62 compares the duration T, measured from the control of the switching modules 132 and 142 in the on-configuration at time Q, with the test duration Dt.If the duration T is strictly less than the test duration Dt, in other words, if the test duration Dt has not elapsed, the processing module 62 detects whether a short circuit is still present, in step S334, by comparing the intensity I with the fault intensity Le- If the processing module 62 determines that the intensity I is strictly greater than the fault intensity Icc while the test duration Dt has not elapsed, this means that, despite the tripping of the electromechanical circuit breaker 4, the short circuit has not been isolated. The cell control module 66 then controls the switching module 32 in blocked configuration in step S336. The voltage U across the terminals of the device is then equal to the level P3, until the intensity I becomes zero. The voltage U then becomes equal to the nominal network voltage Us.

[0112] Advantageously, when the intensity I has become zero following step S336, the disconnector control module 68 activates the actuators 25 and 26, in order to switch the disconnectors 23 and 24 to the open configuration. The device 10 is then in the triggered configuration.

[0113] If the processing module 62 does not detect a short circuit in step S334, then the processing module 62 performs step S332 again and an iterative operation is implemented. If the duration T is greater than or equal to the test duration Dt, in other words, if the test duration Dt has elapsed, no short circuit having been detected, this means that the tripping of the electromechanical circuit breaker 4 has made it possible to isolate the short circuit. This is shown in [Fig.6], between the times Q and R, between which the intensity I remains below the fault threshold Le- The cell control module 66 then maintains the switching modules 132 and 142 in the on configuration and the mechanical switch control module 164 controls the mechanical switch 112 in the closed configuration in step S338. The device 10 then resumes its normal operation and performs step S302 again.

[0114] In a particularly advantageous manner, when the processing module 62 calculates the triggering energy Ed, if the intensity I becomes substantially lower than the minimum intensity Imin, for example equal to 90% of the minimum intensity threshold Imin before the switching modules 132 and 142 are controlled in the blocked configuration at step S326, then the processing module 62 cancels the calculation of the triggering energy Ed, or decreases the triggering energy Ed.

[0115] In a variant 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 interruption cell connected in parallel with the mechanical switch.

[0116] In a variant not shown, the interruption cell 118 comprises only a single switching module, for example the switching module 132. The method for controlling the device 100 is then similar to the method for controlling the device 10, with the following differences. Initially, when the device 100 is in the armed configuration, the mechanical switch 112 is in the closed configuration. The mechanical switch control module 164 controls the mechanical switch 112 in the open configuration as soon as a short circuit is detected in step S104. The cell control module 66 only controls the switching module 132 in step S116 if the dielectric strength of the mechanical switch 112 is greater than or equal to the clipping level Pe.If the dielectric strength of the mechanical switch 112 is lower than the clipping level Pe, the cell control module 66 waits for the dielectric strength of the mechanical switch 112 to become greater than or equal to the clipping level Pe to perform step S116. If, during step S124, the test duration Dt has elapsed without a short circuit having been detected, the mechanical switch control module 164 controls the mechanical switch in the closed configuration, then the device 100 resumes its normal operation and performs step S302 again.

[0117] Optionally, a mechanical switch is connected to the neutral conductor, an interruption cell being connected in parallel with the mechanical switch.

[0118] [Fig.8] is a diagram of an interrupt cell 218 according to a third embodiment of the invention, as an alternative to interrupt cell 18 or 118.

[0119] When the interruption cell 218 is integrated into the device 10, it replaces the interruption cell 18 and is connected in series to the phase conductor 7 by an input 218a and an output 218b.

[0120] 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 to the input 218a and the output 218b of the interrupt cell 218, respectively. More specifically, the input 112a of the mechanical switch 112 and the input 218a of the interrupt cell 218 are connected by the uninterruptible electrical connection 119a, and the output 112b of the mechanical switch 112 is connected to the output 218b of the interruption cell 218 by the electrical connection 119b also uninterruptible.

[0121] The interruption cell 218 comprises two rectifier branches 220 and 222. Each rectifier branch 220 and 222 comprises two diodes, respectively 236 and 237 for the rectifier branch 220, and 246 and 247 for the rectifier branch 222. The diodes 236 and 237 are connected in anti-series with respect to each other, that is to say that the diodes 236 and 237 are connected in series and never conduct current at the same time. The same is true for the diodes 246 and 247.

[0122] The input 218a and the output 218b of the interruption cell 218 correspond respectively to the midpoint of the rectification branch 220, between the diodes 236 and 237 and to the midpoint of the rectification branch 222, between the diodes 246 and 247. Thus, the interruption cell 218 is connected in parallel with the mechanical switch 112 by the midpoint of each rectification branch 220 and 222.

[0123] The interrupt cell 218 comprises two interrupt modules 232 and 242. The interrupt modules 232 and 242 are connected in parallel to 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 dotted line in [Fig. 8].

[0124] The interrupt modules 232 and 242 respectively comprise a switching-controllable 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 the transistor 234 and the voltage-limiting element 249 is connected in parallel with the transistor 244. The voltage-limiting elements 239 and 249 are similar, at least functionally, to the voltage-limiting elements 139 and 149 and have a limiting voltage Uiim2i and Uiim22 respectively. The limiting voltage Uiim2i is different from the limiting voltage Uiim22 and these voltages form three levels, similarly to the limiting voltages Uiimn and Uiimi2.

[0125] The interrupt cell 218 is configured to receive alternating current and to convert it into direct current by means of the diodes 236, 237, 246 and 247, such that direct current flows in the switching modules 232 and 242. The arrangement of the diodes 236, 237, 246 and 247 makes it possible to limit the number of diodes in the interrupt cell 218 to four. Thus, even when the interrupt cell 218 comprises 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 relative to the interrupt cell 118.

[0126] The method for controlling the protection device 10 comprising an interruption cell 218 and the method for controlling the protection device 100 comprising an interruption cell 218 are similar to those described respectively for the protection device 10 comprising the interruption cell 18 and for the protection device 100 comprising the interruption cell 118 and are not described again in detail.

[0127] In a variant not shown applicable to all embodiments, the electrical installation 1 does not include a neutral conductor 8.

[0128] Any feature described for one embodiment or variation in the foregoing may be implemented for the other embodiments and variations described above, as long as technically feasible.

Claims

Claims

1. Method for controlling an electrical protection device (10; 100), configured to be connected between a source (3) and an electromechanical circuit breaker (4), the device (10; 100) comprising: - an interruption 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 voltage limiting element (39; 139, 149; 239, 249), connected in parallel with the at least one semiconductor element (34, 35; 134, 135, 144, 145; 234, 244), the voltage limiting element (39; 139, 149; 239, 249) having a limiting voltage (Uiimi, Ulimll, Uliml2, Ulim21, Uüm22)» 1^ OR the limiting voltages, 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 electromechanical circuit breaker (4) flows in the or 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; - 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 on configuration and in the off configuration, the method comprising at least the following steps: a. measurement (S 102; S302) of the intensity (I) of the current by the current sensor (52); b. detection (S 104; S304) of a short-type electrical fault circuit by the processing module (62), depending on the intensity (I) measured by the current sensor (52); characterized in that the method further comprises the following successive steps: has. when a short-circuit type electrical fault is detected by the processing module in step b), when the current (I) measured by the sensor (52) is less than or equal to a minimum current threshold (Imin) and a tripping energy (Ed) received by the electromechanical circuit breaker (4) is strictly less than an energy threshold (Eth), the tripping energy (Ed) being calculated by the processing module (62) as a function of the current (I) measured by the current sensor (52), controlling (S 114; S322) in the on-configuration the switching module(s) (32; 132, 142; 232, 242) whose limiting voltages (Uiimi; Uiimn, Uiimi2; Uiim2i, Uiim22) of the limiting elements (39; 139, 149; 239, 249) form the clipping stage (Pe) by the cell control module (66); b. when a short-circuit type electrical fault is detected by the processing module in step b), when the intensity (I) measured by the sensor (52) reaches a maximum intensity threshold (Imax) and the triggering energy (Ed) calculated by the processing module (62) is strictly lower than the energy threshold (Eth), controlling (SI 16; S324) in blocked configuration the switching module(s) (32; 132, 142; 232, 242) whose limiting voltages (Uiimi; U limii, Uiimi2; Uiim2i, Uiim22) of the limiting elements (39; 139, 149; 239, 249) form the clipping level (Pe) by the cell control module (66); and c. when the trigger energy (Ed) is greater than or equal to the energy threshold (Eth), control each switching module (32; 132, 142; 232, 242) by the cell control module (66), independently of the intensity (I) measured by the sensor (52).

2. The method of claim 1, further comprising the following successive steps: a. controlling (S 122 ; S330) each switching module (32 ; 132, 142 ; 232, 242) in the on-configuration, while the trigger energy (Ed) is greater than or equal to the energy threshold (Eth) and each switching module (32 ; 132, 142 ; 232, 242) has been controlled in the off-configuration in step e); and b. each switching module (32; 132, 142; 232, 242) having been controlled in the on-configuration in step f), if a short circuit is detected while a duration (T) counted from a moment when each switching module (32; 132, 142; 232, 242) is controlled in the on-configuration in step g) is less than a test duration (Dt), controlling (S 128; S336) each switching module (32; 132, 142; 232, 242) in the blocked configuration.

3. Method according to any one of claims 1 and 2, wherein the method further comprises the following step: a. when an electrical fault of the short circuit type is detected by the processing module (62) in step b), controlling in open configuration a mechanical switch (112), connected in parallel with the interruption cell (118; 218), the mechanical switch (112) being configured to switch between a closed configuration, in which the mechanical switch (112) conducts the current, and an open configuration, in which the mechanical switch (112) does not conduct the current, by a mechanical switch control module (164) included in the control unit (160).

4. The method of claims 2 and 3, further comprising the following step: a. controlling (S338) the mechanical switch (112) in confi- closed configuration if, when the duration (T) of step g) is greater than or equal to the test duration (Dt), no short circuit has been detected.

5.

6. A method according to any preceding claim, in wherein the device comprises a plurality of switching modules (132, 142; 232, 242), connected to each other, step d) further comprising a control in the on-configuration of the switching modules (132, 142; 232, 242) whose limiting voltages (Uiimii, Uiimi2; Uiim2i, Un™??) of the limiting elements (139, 149; 239, 249) do not form the clipping level (Pe), by the cell control module (66) Electrical protection device (10; 100), configured to be connected between a source (3) and an electromechanical circuit breaker (4), the device (10; 100) comprising: - an interruption 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 voltage limiting element (39; 139, 149; 239, 249), connected in parallel with the at least one semiconductor element (34, 35; 134, 135, 144, 145; 234, 244), the voltage limiting element (39; 139, 149; 239, 249) having a limiting voltage (Uiimi , Uiimi 1, Unmi2 , Unm21, Unm22X the OR 1OS limiting voltages (Uiimi ; Uiimn, Uiimi2 ; Uiim2i, U lim22), 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 electromechanical circuit breaker (4) flows in the or one of the semiconductor elements (34, 35; 134, 135, 144, 145; 234, 244), and a confi- 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; - a control unit (60; 160) comprising: • a processing module (62) configured to detect an electrical fault of the short-circuit type as a function of the intensity (I) measured by the current sensor (52) and to calculate a tripping energy (E d) received by the electromechanical circuit breaker (4), as a function of the intensity (I) 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 on configuration and in the off configuration, the device (10; 100) being configured to implement the method of any one of the preceding claims.

7. A device (10; 100) according to claim 6, wherein each switching module (32; 132, 142) comprises two semiconductor elements (34, 35; 134, 135, 144, 145) which are current unidirectional and connected to each other in anti-series, and for each semiconductor element (34, 35; 134, 135, 144, 145), a diode (36, 37; 136, 137, 146, 147) is connected in anti-parallel to the semiconductor element (34, 35; 134, 135, 144, 145).

8. Device (10; 100) according to claim 6, wherein: - the interruption cell (218) comprises two rectifier branches (220, 222), the input (218a) and the output (218b) of the interruption cell (218) respectively forming a midpoint of one of the rectifier branches (220, 222), each rectifier branch (220, 222) comprising two diodes (236, 237, 246, 247) arranged on either side of the midpoint, connected in anti-series with respect to each other; - the switching modules (232, 242) are connected in parallel of the rectifier branches (220, 222); and - each switching module (232, 242) comprises a single semiconductor element (234, 244) connected in parallel with the voltage limiting element (239, 249).

9. Device according to claim 7, 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 level (Pe).

10. Electrical installation (1) comprising a source (3), a load (5), an electromechanical circuit breaker (4), connected between the source (3) and the load (5), the electromechanical circuit breaker (4) being configured to trip when it receives a tripping energy (Ed) greater than or equal to an energy threshold (Eth), and a device (10; 100) according to any one of claims 7 to 9, connected between the source (3) and the electromechanical circuit breaker (4).

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