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

Abstract

Method for controlling an electrical protection device, electrical protection device and associated 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: measurement (S102) of the current (I); detection (S104) of an electrical fault; when an electrical fault is detected, the current is less than or equal to a minimum current threshold (Imin) and a tripping energy (Ed) is strictly less than an energy threshold (Eth), controlling (S114) in the on-state configuration the switching module(s);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 less than the energy threshold, control (S116) in blocked configuration the switching module(s). Figure for the abbreviation: Fig 3;

Description

Title of the invention: Method for controlling an electrical protection device, electrical protection device and associated 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 includes contacts and a trip unit, which, when it receives sufficient energy, is responsible for separating the contacts. It is therefore necessary to wait until the trip unit 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 through the installation, due to the presence of the short circuit, which imposes significant stresses on the installation, particularly on the loads, as well as on the protective device, which must be able to withstand such a current. A known solution is to trip the protective device when a current threshold is reached, in order to limit the stresses on the installation due to the current, without any guarantee that the electromechanical circuit breaker will receive enough energy to trip.

[0003] The aim of the invention is therefore to propose a method of controlling an electrical protection device to ensure the tripping of an electromechanical circuit breaker, while limiting the stresses 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 interrupting 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 at least one semiconductor element, the voltage limiting element having a limiting voltage, the voltage(s) of mitation, alone and / or summed together, 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 in one of the semiconductor elements, and a blocking configuration, in which if the current flows in the switching module, it flows in the limiting element; - a current sensor, configured to measure current intensity; - a control unit comprising a processing module and a cell control module, configured to control each switching module in the on-state and off-state configurations,

[0006] the method comprising at least the following steps: a. measurement of the current intensity by the current sensor; b. detection of a short-circuit type electrical fault by the module processing, 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, control in the on-mode configuration the switching module(s) whose limiting voltages of the limiting elements form the clipping threshold by the cell control module; b. when a short-circuit type electrical fault is detected by the processing module in step b), when the current measured by the sensor reaches a maximum current threshold and the tripping energy calculated by the processing module is strictly less than the energy threshold, control in blocked configuration the switching module(s) whose limiting element voltages form the clipping threshold 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, regardless 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 current to flow. The intensity The current is limited, however, thanks to the switching modules, which are controlled in a blocked configuration when the current reaches a maximum threshold. This prevents excessive currents and the risk of damage to the electromechanical circuit breaker, the protective device, and the load. Furthermore, by controlling the switching modules in a forward configuration when the current is less than or equal to the minimum threshold, the device ensures that sufficient current flows through the electromechanical circuit breaker, guaranteeing that it receives enough energy to trip. Maintaining the current between the minimum and maximum thresholds also ensures that the electromechanical circuit breaker receives energy continuously, without discharging, and therefore ensures the fastest possible tripping.Thus, the constraints due to current intensity are limited, 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 features, taken individually or in all technically possible combinations:

[0010] - The process further comprises the following successive steps: a. command each switching module in the on-mode configuration, while the trip energy is greater than or equal to the energy threshold and each switching module was commanded in the off-mode configuration in step e); and b. each switching module having been ordered in the on-mode configuration in step f), if a short circuit is detected while a time counted from a time when each switching module is ordered in the on-mode configuration in step g) is less than a test time, order each switching module in the blocked configuration.

[0011] - The process further comprises the following step: a. when an electrical fault of the short-circuit type is detected by the processing module in step b), 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, by a mechanical switch control module included in the control unit. - The process also includes the following step: a. control the mechanical switch in the closed position if, when the duration of step g) is greater than or equal to the test duration, no short- No circuit was detected.

[0012] - The device comprises a plurality of switching modules, connected to each other to 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 plateau, 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 interrupt 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 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 distinct 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 in one of the semiconductor elements, and a blocking configuration, in which if the current flows in the switching module, it flows in the limiting element; - a current sensor, configured to measure current intensity; - a control unit comprising: • a processing module configured to detect a short-circuit type electrical fault based on the current measured by the current sensor and to calculate the tripping energy received by the electromechanical circuit breaker, based on the current 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,

[0015] the device being configured to implement the process described above.

[0016] According to other advantageous aspects of the invention, the device comprises one or more of the following features, 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 rectification branches, the input and the output of the interrupt cell forming respectively a midpoint of one of the rectification branches, each rectification 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 plateau.

[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 above, connected between the source and the electromechanical circuit breaker.

[0021] 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 a first embodiment of the invention; - [Fig.2] [Fig.2] is a graph of characteristic quantities of the installation of the [Fig.1], as a function of time; - [Fig.3] [Fig.3] is a logic diagram of a control process for a protective device belonging to the installation of the [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 interrupt cell the installation of the [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 logic diagram of a control process for a protective device belonging to the installation shown in Figures 4 and 5; and - [Fig.8] [Fig.8] is an electrical diagram of an interrupt cell. starting with an installation according to a third embodiment of the invention.

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

[0023] 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 called current, 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 includes contacts, as well as a trip unit which may be a coil, a magnetic paddle, an electronic or electromechanical device, not shown, and is configured to trip 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 includes an electrical protection device 10, also referred to hereafter as the device, 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), applied across its terminals between conductors 7 and 8. In the embodiment of [Fig. 1], the device 10 is a solid-state circuit breaker, also called an SSCB. It comprises an interrupting cell 18 connected in series to the phase conductor 7 by an input 18a and an output 18b.

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

[0028] 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. 1], the device 10 includes 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 to the open configuration. The actuators 25 and 26 are, for example, coils and are activated when a current flows through 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 interrupt cell 18.

[0030] The interrupt cell 18 comprises at least one switching module, here, a 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. 1], 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 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 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 by 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 carries 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, by about 1.5 times the nominal network voltage Us.

[0032] 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.

[0033] 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.

[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 back 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 plateau Pe, which is higher than the nominal network voltage Us.

[0036] The control device 10 also includes 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 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. 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 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.

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

[0040] 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.

[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 register memories 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 Specified Integrated Circuit).

[0043] 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.

[0044] 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), an integrated circuit, such as an ASIC (Application Specified Integrated Circuit) or in the form of an analog component.

[0045] 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.

[0046] When a short circuit occurs in the electrical installation 1, the current intensity I flowing between the source 3 and the load 5 increases rapidly and significantly, for example by several thousand amperes per microsecond. The current intensity I becomes strictly greater than a minimum current threshold Imin from from which the tripping device of the electromechanical circuit breaker 4 receives a tripping energy Ed, expressed in arbitrary units (AU) proportional to 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 tripping device 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 for controlling the device 10 according to the invention will now be explained, with reference to figures 2 and 3.

[0050] Initially, and advantageously, the device 10 is in the armed configuration, that is to say, the disconnectors 23 and 24 are in the closed configuration and the switching module 32 is in the conducting 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, at step S102.

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

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

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

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

[0056] In an alternative not shown, the minimum current Imin is less than the fault current 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 to 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 less than the energy threshold Eth, as is the case between times A and E in [Fig. 2], the processing module 62 performs a step SI 10 in which it compares the intensity I to the minimum intensity threshold Imin. If the intensity I is strictly greater than the minimum intensity threshold Imin, as seen in [Fig. 2] between times A and B, the processing module 62 compares the intensity I to the maximum intensity threshold Imax in step SI 12. If the intensity I is strictly less than the maximum intensity threshold Imax, the processing module 62 performs step S108 again. An iterative operation is then implemented.

[0059] As shown in [Fig. 2], at time A, the triggering energy Ed is strictly less than the energy threshold Eth, and the current I has increased until it equals the maximum current threshold Imax. The control unit 60 commands the switching module 32 in the blocked configuration via the cell control module 66 at step SI 16, which corresponds to time A in [Fig. 2]. The voltage U across the device 10 is then equal to the clipping plateau Pe, itself equal to the limiting voltage Uiimi.

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

[0061] TA-L^

[0062] with: - TA the growth rate of intensity I; - U is the voltage across the terminals of device 10; and - Us is 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] Since the voltage U here is equal to the limiting voltage Uiimi, which is greater than the nominal network voltage Us, the current I decreases until it reaches the current threshold minimal Imin, as seen in [Fig.2] between times A and B.

[0065] As shown in [Fig. 2], at time B, the triggering energy Ed is strictly less than the energy threshold Eth, and the current I has decreased until it equals the minimum current threshold Imin. In an alternative not shown, at time B, the current I has decreased until it equals the minimum current threshold Imin. Thus, starting from time B and following step SI 10, a step SI 14 is performed, during which the control module 66 commands the switching module 32 to the forward-biased configuration. The voltage U across the device 10 drops sharply and becomes substantially zero at the same time as the current I increases, until it again reaches the maximum current threshold Imax, which corresponds to time C in [Fig. 2]. The processing module 62 then performs steps SI 108, SI 10, and SI 12 again and determines that the current I has reached the maximum current threshold Imax.The control module 66 then commands the switching module 32 in the blocked state at step SI 16. The voltage U across the device 10 again becomes equal to the limiting voltage Uiimi and the current I decreases.

[0066] The current I measured by sensor 52 decreases until it reaches the minimum current threshold Imin, corresponding to time D in [Fig. 2]. The cell control module 66 again performs step SI 14 and commands the switching module 32 to switch on. The voltage U returns to zero and the current I increases again.

[0067] In an unrepresented variant, at time D, the intensity I decreased until it became strictly below the minimum intensity threshold Imin.

[0068] The current intensity I is maintained between the minimum current threshold Imin and the maximum current threshold Imax as long as the tripping energy Ed is strictly less than the energy threshold Eth. When the tripping energy Ed becomes greater than or equal to the energy threshold Eth, which corresponds to time E in [Fig. 2], the electromechanical circuit breaker 4 trips. The processing module 62 performs step SI 18 following step S108. During step SI 18, the switching module 32 is controlled by the cell control module 66 in a blocked configuration, regardless of the current I measured by the sensor 52. Thus, the current is interrupted by both the electromechanical circuit breaker 4 and the device 10. The voltage U becomes equal to the limiting voltage Uiimi and the current I decreases until it becomes zero.When the current I becomes zero, the voltage U across the device 10 becomes equal to the nominal voltage of the network Us.

[0069] Advantageously, and as shown in [Fig.2], when the triggering energy Ed is greater than or equal to the energy threshold E* and the switching module 32 has been controlled in the locked configuration at step SI 18, a re-engagement sequence is implemented.

[0070] The reactivation sequence includes step S120, in which the processing module 62 waits until a minimum duration Dmin, calculated from the moment the control module 66 commands the switching module 32 to the blocked configuration in step S18, has elapsed. To this end, in step S328, the processing module 62 compares a duration T”, measured from time E, with the duration Dmin. When the duration Dmin has elapsed, that is, when the duration T”, is greater than or equal to Dmin, the control module 66 commands the switching module 32 to the on-mode configuration in step S122, corresponding to time F in [Fig. 2]. The processing module 62 compares a duration T, measured from the command of the switching module 32 to the on-mode configuration in step S122, with a test duration Dt in 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 commands the switching module 32 to the blocked configuration at step S128, corresponding to time G in [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 current I becomes zero following step S128, the disconnector control module 68 activates actuators 25 and 26, in order to switch disconnectors 23 and 24 to the open configuration. Device 10 is then in the tripped configuration.

[0072] As can be seen from the preceding explanations, the disconnectors 23 and 24 switch to 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 without any short circuit being detected, this means that the tripping of the electromechanical circuit breaker 4 has successfully isolated the short circuit. The cell control module 66 then maintains the communication module mutation 32 in passing configuration and device 10 resumes its normal operation and performs step S102 again.

[0074] Figure 4 represents an electrical installation 1, which differs from the installation electrical of [Fig.1] by its device 100, which replaces device 10. The elements of device 100 identical to those of device 10 or identified in [Fig.4] by the same reference signs are similar, at least functionally, to those of device 10 and are not described in detail.

[0075] The device 100 is a hybrid circuit breaker and includes a mechanical switch 112, also known as a bypass switch or fast mechanical switch, also called FMS (Fast Mechanical Switch). 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. 4], 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.

[0076] 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.

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

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

[0079] In the example of [Fig. 5], the switching module 132 is similar, at least Functionally, it relates to the switching module 32 and as such includes two transistors 134 and 135 are connected in anti-series, two diodes 136 and 137 are connected in anti-parallel to transistors 134 and 135 respectively, and a limiting element 139 has a limiting voltage Uiimn. The transistors 144 and 145 and the diodes 146 and 147 of the switching module 142 are similar, at least functionally, to the transistors 134 and 135 and the diodes 136 and 137 of the switching module 132. In particular, 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 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 Ulimll-

[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 distinct steps. 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 individually, or summed together. The list of the resulting steps is shown in the table below. For N=2 switching modules, three distinct steps P1, P2, P3 are obtained, with 3 = 22-1. Here, P1 is the step with the lowest value, equal to Uiimn, which is, for example, 0.5Us; P2 is greater than P1 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 includes a control unit 160, which differs from the control unit 60 in that it further includes a mechanical switch control module 164.

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

[0087] 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 all the electric current flowing through 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, at the step S304.

[0090] In the example of [Fig. 6], a short circuit is detected when the current I is strictly greater than the fault current 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 switches the mechanical switch 112 to the open position, via the mechanical switch control module 164, during step S306. The opening of the mechanical switch 112 corresponds to time J in [Fig. 6]. Furthermore, if a short circuit is detected, the processing module 62 begins calculating the tripping energy Ed received by the electromechanical circuit breaker 4. Indeed, since the fault threshold Icc is 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 starts calculating the triggering energy Ed as soon as the intensity I exceeds the minimum intensity threshold Imin, which corresponds to the instant Jo on the [Fig.6], and before the short circuit is detected, i.e. before step S304.

[0094] 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. 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. Thus, 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, breakdown may occur at the switch terminals. mechanical 112, that is to say a reappearance of an electric arc between contacts of the mechanical switch 112, while the latter is in 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 exceeds one or more levels P1, P2, P3. In the example described here, P1 is the smallest level. Thus, the dielectric strength of the mechanical switch 12 becomes greater than or equal to level P1, while being less than levels P2 and P3. P1 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 PI plateau is equal to a first waiting threshold Tb.

[0097] The processing unit 62 compares a waiting time T' to 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 PL bearing Advantageously, the cell control module 166 controls the switching module 132 in blocked configuration at step S310, which corresponds to time K on the [Fig.6], and the other switching modules, here the switching module 142, in passing configuration. Transistors 134 and 135 are blocked and do not conduct current, which then flows through the voltage limiting element 139 and the switching module 142. The voltage U across device 100, and therefore across mechanical switch 112, is then equal to the limiting voltage. The current flowing through the voltage limiting element 139 limits an increase in current I caused by the short circuit, and the PI plateau is also called the limiting plateau.Steps S308 and S310 allow the increase in current I to be limited as early as possible, by applying a voltage equal to the PI plateau, 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 plateau P2. Preferably, the time 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 plateau 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 at 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 step S318 in which it compares the current I to the minimum current threshold Imin. If the current I is strictly greater than the minimum current threshold Imin, the processing module 62 compares the current I to the maximum current threshold Imax in step S320. If the current I is strictly less than the maximum current 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 current I is greater than the maximum current threshold Imax. The control module 66 then commands the switching module 142 to the blocked configuration and the switching module 132 to the on 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 plateau Pe, and controls the switching modules whose limiting voltages do not form the clipping plateau Pe in the on-state configuration. Transistors 146 and 147 are blocked and do not conduct current, which then flows through the voltage limiting element 149 and the switching module 132. The voltage U across the device 100, and therefore across the mechanical switch 112, is then equal to the plateau P2, equal to the limiting voltage Uiimi2, in other words, to the clipping plateau Pe. The processing module 62 performs step S316 again, and an iterative operation is implemented.

[0103] If the trigger energy Ed is strictly less than the energy threshold Eth, as is the case between times L and P in [Fig. 6], the processing module 62 performs step S318, in which it compares the intensity I to the minimum intensity threshold Imin. If the intensity I is strictly greater than the minimum intensity threshold Imin, as is the case between times L and M in [Fig. 6], the processing module 62 compares the intensity I to 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. An iterative operation is then implemented. Steps S316, S318, and S320 are respectively similar to steps S108, S10, and S12 of the first embodiment.

[0104] As can be seen in [Fig. 6], at time M, the triggering energy Ed is strictly less than the energy threshold Eth and the intensity I has decreased until it becomes equal to the minimum current threshold Imin. Thus, following step S318, a step S322 is performed, during which the control module 66 controls the switching module 142 in the forward-biased configuration and, advantageously, the switching module 132 in the reverse-biased configuration. The voltage U across the device 10 becomes equal to the PI plateau, in other words, the limiting plateau, and the current I increases, until it reaches the maximum current threshold Imax, corresponding to time N in [Fig. 6].

[0105] The processing module 62 then performs steps S316, S318, and S320, and determines that the current I is greater than or equal to the maximum current threshold Imax. The control module 66 then commands 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 commands the switching module 142 in the blocked configuration, where the limiting voltage Uiim2i of the limiting element 149 forms the clipping plateau Pe, and commands the switching module 132 in the on configuration, where the limiting voltage Uiimn of the limiting element 139 does not form the clipping plateau Pe. The voltage U across the device 10 again becomes equal to the limiting voltage Uiimi2, that is, to the clipping plateau Pe, and the current I decreases.

[0106] The current intensity I is maintained between the minimum current threshold Imin and the maximum current threshold Imax as long as the tripping energy Ed is strictly less than the energy threshold Eth. Thus, controlling the switching module 132 in a blocked configuration at step S322 limits the increase in current I and reduces the number of commands for 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 time P in [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 step P3, and each switching module 132, 142 is controlled by the cell control module 66 in a blocked configuration, regardless of the current 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 plateau P3 and the current I decreases until it becomes zero, at an instant Po which follows the instant P. When the current I has become zero at the instant Po, the voltage U across 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 at step S326 accelerates the reduction of the current I, compared to a variant where only the switching modules whose limiting voltages form the clipping bearing Pe, here the switching module 142, are used.

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

[0111] The reactivation sequence includes step S328, in which the processing module 62 waits until the minimum duration Dmin, calculated from the command of the switching modules 132 and 142 in the blocked configuration, which takes place in step S326, has elapsed. To this end, in step S328, the processing module 62 compares a duration T”, measured from time P, with the duration Dmin. When the duration Dmin has elapsed, i.e., when the duration T”, is greater than or equal to Dmin, the cell control module 66 commands all the switching modules 132, 142 in the on configuration in step S330, corresponding to time Q in [Fig. 2]. The processing module 62 determines in 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 command of the switching modules 132 and 142 in on configuration at time Q, to 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 at step S334 by comparing the current I to the fault current Le. If the processing module 62 determines that the current I is strictly greater than the fault current 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 commands the switching module 32 to the blocked configuration at step S336. The voltage U across the device is then equal to the P3 step until the current I becomes zero. The voltage U then becomes equal to the nominal network voltage Us.

[0112] Advantageously, when the current I becomes zero following step S336, the disconnector control module 68 activates actuators 25 and 26, in order to switch disconnectors 23 and 24 to the open configuration. Device 10 is then in the tripped 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 time T is greater than or equal to the test time Dt, in other words, if the test time Dt has elapsed without any short circuit being detected, this means that the tripping of the electromechanical circuit breaker 4 has successfully isolated the short circuit. This is shown in [Fig. 6], between times Q and R, between which the current I remains below the fault threshold Le. The cell control module 66 then maintains the switching modules 132 and 142 in the passing configuration and the mechanical switch control module 164 controls the mechanical switch 112 in the closed configuration at step S338. The device 10 then resumes its normal operation and performs step S302 again.

[0114] Particularly advantageously, when the processing module 62 calculates the tripping energy Ed, if the current I becomes substantially less than the minimum current Imin, for example equal to 90% of the minimum current threshold Imin before the switching modules 132 and 142 are controlled in blocked configuration at step S326, then the processing module 62 cancels the calculation of the tripping energy Ed, or reduces the tripping energy Ed.

[0115] 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.

[0116] In an alternative not shown, the interrupt cell 118 comprises only one 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 at step S104. The cell control module 66 only controls the switching module 132 at step SI16 if the dielectric strength of the mechanical switch 112 is greater than or equal to the clipping capacity Pe.If the dielectric strength of the mechanical switch 112 is less than the clipping plateau Pe, the cell control module 66 waits until the dielectric strength of the mechanical switch 112 becomes greater than or equal to the clipping plateau Pe before performing step SI 16. If, during step S124, the test time Dt has elapsed without a short circuit being detected, the mechanical switch control module 164 commands the mechanical switch to 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, with an interruption cell connected in parallel with the mechanical switch.

[0118] The [Fig.8] 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.

[0119] 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.

[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 respectively to the input 218a and 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 non-interruptible electrical link 119a, 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 also non-interruptible.

[0121] 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.

[0122] 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.

[0123] 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. 8].

[0124] 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 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 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 required for their operation, thereby reducing the number of diodes needed compared to the interrupt cell 118.

[0126] 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.

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

[0128] 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

Demands

1. A 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 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 voltage 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 voltage limiting element (39; 139, 149; 239, 249) having a limiting voltage (U11, U11, U112, U111, U1122) OR the limiting voltages, alone and / or summed together, forming one or a plurality of distinct levels (P1, 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 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) 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, the process 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), as a function of the intensity (I) measured by the current sensor (52); characterized in that the process further comprises the following successive steps: has. when an electrical fault of the short-circuit type 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), control (S 114; S322) in the on-mode 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 threshold (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 current (I) measured by the sensor (52) reaches a maximum current threshold (Imax) and the tripping energy (Ed) calculated by the processing module (62) is strictly less than the energy threshold (Eth), control (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 threshold (Pe) by the cell control module (66); and c. when the tripping 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. A method according to claim 1, further comprising the following successive steps: a. command (S 122; S330) each switching module (32; 132, 142; 232, 242) in the on-mode configuration, while the trip energy (Ed) is greater than or equal to the energy threshold (Eth) and each switching module (32; 132, 142; 232, 242) was commanded in the off-mode configuration in step e); and b. each switching module (32; 132, 142; 232, 242) having been ordered in the on-mode configuration in step f), if a short circuit is detected while a time (T) counted from a time when each switching module (32; 132, 142; 232, 242) is ordered in the on-mode configuration in step g) is less than a test time (Dt), order (S 128; S336) each switching module (32; 132, 142; 232, 242) in the blocked configuration.

3. A 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), control in 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).

4. A method according to claims 2 and 3, further comprising the following step: a. controlling (S338) the mechanical switch (112) in confi- closed function 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 one of the preceding claims, in which the device comprises a plurality of switching modules (132, 142; 232, 242), connected to each other, step d) further comprising a control in forward 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 plateau (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 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 voltage 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 voltage limiting element (39; 139, 149; 239, 249) having a limiting voltage (Uiimi, Uiimi1, Unmi2, Unm21, Unm22X) or one or more limiting voltages (Uiimi; Uiimn, Uiimi2; Uiim2i, Ulim22), alone and / or summed together, forming one or a plurality of distinct stages (P1, P2, P3), each switching module (32; 132, 142; 232, 242) being configured to switch between a forward configuration, in which a current flowing between the source (3) and the electromechanical circuit breaker (4) flows through the or one of the semiconductor elements (34, 35; 134, 135, 144, 145; 234, 244), and a- blocked configuration, in which if 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 (Ed) 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 passing configuration and in the blocked configuration, the device (10; 100) being configured to implement the method of any one of the preceding claims.

7. 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 unidirectional in current 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 interrupt cell (218) comprises two rectification branches (220, 222), the input (218a) and output (218b) of the interrupt cell (218) forming respectively a midpoint of one of the rectification branches (220, 222), each rectification 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 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 plateau (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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