Controllable switch

Abstract

Controllable switch (IC) comprising between two terminals (BO1, BO2): - a first branch (B1) comprising a first module (E1) comprising a switch controllable for closing and opening, and a second module (E2) connected in series with the first module, the second module being capable of limiting the current in the first branch or storing energy, - a second branch (B2) comprising a third module (E3) comprising a switch controllable for opening and closing, capable of interrupting the current flowing in the second branch and maintaining the voltage between the two terminals of the switch when it is in the open state, - a control module (E5) capable of controlling the first and third modules. Figure for the abstract: figure 1

Description

Title of the invention: Controllable switch Technical field

[0001] The present invention relates to a controllable power switch used in particular in aeronautical applications, or in other varied technical fields such as for example: automotive, defense, medical, nuclear.

[0002] The controllable switch according to the invention is an electrical distribution component which can be used in particular in HVDC distribution. State of the prior art

[0003] The electrification of aircraft is a major trend, as is the increase in installed electrical power. As a result, electrical distribution system architectures are evolving. Originally 28V DC, the main network voltage has gradually increased to 115V three-phase AC at fixed frequency, then to variable frequency.

[0004] One of the objectives is the elimination of hydraulic networks for reasons of ease of maintenance and reduction of on-board mass (wiring, generator and other equipment). The increase in voltage levels in current aircraft (230V AC, + / -135V DC) for local networks follows this same trend. New 540V DC networks and up to 800V DC are now appearing in new electrical distribution or propulsion architectures.

[0005] Whatever the electrical distribution architectures envisaged, they systematically use distribution components allowing:

[0006] - the distribution of electrical energy to the aircraft loads,

[0007] - the protection of the lines which carry electrical energy to these loads.

[0008] These distribution components can for example be contactors, circuit breaker contactors or SSPC cards (from English: Solid State Power Controller) depending on the applications and the powers concerned.

[0009] Contactors and circuit breaker contactors are both electromechanical components consisting of electromagnetic components (control coils generating a magnetic field) and mechanical parts (structural parts and moving parts ensuring electrical contact between the connection points of the contactor input and the output). The circuit breaker contactor has an overcurrent protection function, called I2t, acting according to the energy / thermal selection principle, which controls the opening of the contactor in the event that the value of the current Funde integral Ji2.dt exceeds a predefined threshold.

[0010] A contactor consists of an assembly of an electric motor (close to the electromagnet), moving and fixed parts to ensure the passage of current and electronics that control the electric motor. The reaction time is quite slow (several tens of milliseconds). The breaking capacity is higher than with an SSPC card. The contactor as well as the circuit breaker contactor can incorporate simple to moderately complex control electronics that do not allow as many communication capabilities, configuration and protection functions as an SSPC card.

[0011] SSPC cards use semiconductors of the JFET, MOSFET, IGBT, Bipolar or Thyristor type, etc. which act as power switches. The technologies used can be of multiple natures (Si, SiC, GaN, etc.).

[0012] The switching element of an SSPC card is made up of power semiconductors. The control of the switching element is fast and adjustable according to the required need. The breaking capacity is moderate. An SSPC card can incorporate protection, communication, control and intelligent configuration functions because it integrates a significant portion of electronics.

[0013] Furthermore, an electrical system comprises various distribution devices, some of which are located close to the sources, and others are further away from the latter, close to the loads. The distribution devices close to the sources are called primary and must allow the distribution of high currents (for example, beyond fifty amperes). The distribution devices close to the loads are called secondary and switch weaker currents (for example, less than fifteen amperes).

[0014] Selectivity is essential in the management of the electrical system. A fault occurring on a distribution line must be interrupted by the nearest electrical distribution device. The cut-off is generally made at the level of the secondary distribution devices. It occurs at the level of the primary distribution if the fault occurred nearby, on a load or primary distribution bar, or if the secondary distribution device failed to interrupt the fault close to a load.

[0015] Therefore, a primary distribution member must be designed to allow the fault current to pass for a time greater than that required for a secondary distribution member to interrupt the fault current.

[0016] Electrical distribution architectures using SSPC cards in HVDC zones are envisaged, due to the functionalities offered by this type of component.

[0017] An SSPC HVDC card, although having the capacity to quickly open the electrical circuit in the event of a fault, is not always able to allow a very energetic current wave to pass. This is why the ratio between the current value generating an immediate opening and the nominal current value is generally of the order of 1.5 to 2. This is due to the heat dissipation and the limit operating temperature of the power components that make up the SSPC board. However, in the case of a fault appearing on a high voltage bus, the ratio between the fault current value and the nominal current value can easily exceed 10 or even 20.

[0018] The switching device of an SSPC HVDC card is also not able to dissipate a very large amount of energy when it opens. This dissipated energy may correspond to the energy stored in a source, in the wiring or in certain loads. Indeed, semiconductor components have a very limited breaking capacity compared to that of electromechanical switching devices. This breaking capacity constraint is illustrated by a limit pair "series inductance value on the line and maximum switched current", to be taken into consideration by the architect carrying out the definition of the electrical distribution.

[0019] The aim of this invention is therefore to propose a solution which makes it possible to overcome these difficulties. Statement of the invention

[0020] The invention aims to solve the problems of the prior art by providing a controllable switch comprising between two terminals:

[0021] - a first branch comprising a first module comprising a switch controllable for closing and opening, and a second module connected in series with the first module, the second module being capable of limiting the current in the first branch or of storing energy,

[0022] - a second branch comprising a third module comprising a switch controllable for opening and closing, capable of interrupting the current flowing in the second branch and of maintaining the voltage between the two terminals of the switch when it is in the open state,

[0023] - a control module capable of controlling the first and third modules.

[0024] The controllable power switch combines two switching branches, thus enabling optimization of the performance in nominal operation, through the first branch, and also in fault conditions of a source or a load, during switching, thanks to the second branch designed to improve the breaking capacity of the power switch in the event of a fault.

[0025] According to a preferred characteristic, the controllable switch comprises a measuring module capable of measuring the physical quantities of the first, second and third modules and of supplying the measured physical quantities to the control module.

[0026] According to a preferred characteristic, the third module of the second branch has a resistance in the on state lower than the resistance of the first and second modules of the first branch.

[0027] According to a preferred characteristic, the third module comprises at least one MOSFET type power transistor.

[0028] According to a preferred characteristic, the third module comprises at least one power transistor of the SiC MOSFET type.

[0029] According to alternative preferred features:

[0030] - the first module integrates the second module and includes a switch of type IGBT driven to present a high impedance to limit the current flowing through it in the event of a fault.

[0031] - the first module comprises a controlled switch and the second module has a dissipative element.

[0032] - the first module comprises a controlled switch and the second module includes a passive circuit capable of storing and dissipating energy from an energy source.

[0033] The invention also relates to a method for controlling a controllable switch as previously presented, characterized in that it comprises steps of:

[0034] - monitoring the current flowing through the controllable switch while it is farm,

[0035] - test to determine if the current through the controllable switch IC exceeds a predefined limit value,

[0036] - command to open the third module when the test result is positive,

[0037] - command to open the first module.

[0038] The invention also relates to a method for controlling a controllable switch as previously presented, characterized in that it comprises steps of:

[0039] - monitoring of the current flowing through the controllable switch while it is farm,

[0040] - test to determine if the current through the controllable switch IC exceeds a predefined limit value,

[0041] - command to open the third module when the test result is positive,

[0042] - command to close the third module,

[0043] - command to open the first module,

[0044] - command to open the third module.

[0045] The invention also relates to a method for controlling a controllable switch as previously presented, characterized in that it comprises steps of:

[0046] - monitoring the current flowing through the controllable switch while it is farm,

[0047] - test to determine if the current flowing through the controllable switch exceeds a predefined limit value,

[0048] - command to close the first module when the test result is positive,

[0049] - command to open the third module,

[0050] - test to determine if the current flowing through the first module reaches a value in lower than a predefined limit value,

[0051] - command to open the first module when the test result is positive.

[0052] The methods have advantages similar to those previously presented.

[0053] In a particular embodiment, the steps of the method according to the invention are implemented by computer program instructions.

[0054] Consequently, the invention also relates to a computer program comprising instructions adapted to the implementation of the steps of a method as described above.

[0055] The invention also relates to an information medium readable by a computer, and comprising computer program instructions adapted to the implementation of the steps of a method as described above. Brief description of the drawings

[0056] Other characteristics and advantages will appear on reading the following description of a preferred embodiment given by way of non-limiting example, described with reference to the figures in which:

[0057] [Fig.l] illustrates a controllable switch according to one embodiment of the invention.

[0058] [Fig.2] illustrates the operation upon closing of the controllable switch according to an embodiment of the invention.

[0059] [Fig.3] illustrates the operation upon opening of the controllable switch according to one embodiment of the invention.

[0060] [Fig.4] illustrates a timing diagram of the current and the controls of the elements of the controllable switch according to the invention, in load fault mode, according to a first mode of operation.

[0061] [Fig.5] illustrates a method of controlling the controllable switch, corresponding to the first mode of operation.

[0062] [Fig.6] illustrates a timing diagram of the current and the controls of the elements of the controllable switch according to the invention, in load fault mode, according to a second operating mode.

[0063] [Fig.7] illustrates a method of controlling the controllable switch, corresponding to the second mode of operation.

[0064] [Fig.8] illustrates a branch of a controllable switch according to an embodiment of the invention.

[0065] [Fig.9] illustrates a timing diagram of currents and voltages in elements of the controllable switch, and commands of the elements of the switch com- commandable, according to the embodiment of the invention of the preceding figure.

[0066] [Fig. 10] illustrates a method of controlling the controllable switch, corresponding to the embodiment of the invention of the previous figure.

[0067] Identical, similar or equivalent parts of the different figures bear the same numerical references so as to facilitate the transition from one figure to another.

[0068] The different parts represented in the figures are not necessarily on a uniform scale, in order to make the figures more readable.

[0069] The different possibilities (variants and embodiments) must be understood as not being mutually exclusive and can be combined with each other.

[0070] Detailed description of particular embodiments

[0071] According to a preferred embodiment shown in [Fig.l], an embodiment of a controllable switch IC according to the invention comprises two terminals BO1 and BO2 between which two branches B1 and B2 are connected in parallel.

[0072] In use, a power source is connected upstream of the controllable switch IC and a load is connected downstream of the controllable switch IC. The power source and the load are not shown.

[0073] The first branch B1 comprises a first module El comprising a first switch controllable for closing and opening. The first module El makes it possible to control the establishment of the current in the first branch B1 and is capable of maintaining the voltage across the terminals of the controllable switch when the latter is in the open state. The first module El has a low resistance in the on state (lower than the third module described below) and a high impedance in the open state.

[0074] The first branch B1 comprises a second module E2 connected in series with the first module EL. The second module E2 has the function of limiting the current in the first branch B1. The second module E2 has a high resistance in the on state, compared to the first and third modules. The second module E2 may be a controlled or uncontrolled member. To simplify the description, the second module E2 is considered in the following as being uncontrolled.

[0075] According to a first embodiment, the second module E2 is integrated into the first module EL. In this case, the first module El performs both the functions of the modules El and E2 presented previously, that is to say that it makes it possible to control the establishment of the current in the first branch B1, that it is capable of maintaining the voltage across the terminals of the controllable switch when the latter is in the open state and that it limits the current in the first branch B1. An example of a first module El which performs all these functions comprises an IGBT type switch, in particular a single IGBT type switch, controlled so as to have a high impedance to limit the current passing through it in the event of a fault.

[0076] For this, we use the fact that the impedance presented by a semi-component Insulated gate driver such as an IGBT can be controlled by the voltage value applied between the gate and emitter of the component. Above a threshold voltage value Vge_th applied between the gate and emitter of the component (th for threshold), the component allows a current to pass between emitter and collector. The higher the voltage value, while remaining below a maximum value leading to degradation of the component, the lower the voltage drop, and therefore the impedance presented by the component to the passage of current.

[0077] The control of the IGBT type switch involves the application of a control voltage value Vge, for example in the range of 12V to 15V, in nominal operating mode. The applied value depends on the desired current distribution between branch B1 and branch B2. In current limiting mode, and depending on the desired current value, the applied voltage value Vge will be lower, for example between 7V and 10V. For the opening of 1TGBT, a voltage value Vge below the threshold voltage Vge_th is applied between the gate and emitter of the component.

[0078] According to another embodiment, the first module E1 comprises a controlled switch and the second module E2 comprises a dissipative element, for example a resistor with very high dissipation power.

[0079] According to yet another embodiment, branch B1 is designed to operate an energy transfer to a capacitive reserve, instead of dissipating the energy. The operating mode is preferably non-resonant, so as not to generate too high a voltage at the terminals of branches B1 and B2 which would risk damaging component E3.

[0080] An example according to this embodiment is shown in [Fig.8], which illustrates the branch B1, in the case of a monodirectional current assembly and use with a continuous source.

[0081] Branch Bl comprises the first module El, comprising an IGBT and a diode DI.

[0082] Branch B1 includes the second module E2, in series with the first module EL

[0083] The second module E2 is a passive circuit comprising an inductance L1, a capacitor C2 and a resistor RI connected in series between terminals of the second module E2.

[0084] The second module E2 also includes a resistor R2 connected in parallel with the resistor RI and the capacitor C2.

[0085] The second module E2 also comprises a capacitor Cl connected in series with a transil diode Ul, these two components being connected in parallel with the resistor RI and the capacitor C2.

[0086] The second module E2 finally includes a resistor R3 connected in parallel with the capacitor Cl.

[0087] The operation of this embodiment will be explained below.

[0088] According to another embodiment, the second module E2 is integrated into the first module El. In this case, the first module El performs both the functions of the modules El and E2 presented previously. In other words, the branch B1 comprises only one controllable switch El having the capacity to limit the current, by desaturation, for example. In this embodiment, the switch El can be an IGBT for example.

[0089] In all cases, the first branch B1 achieves a limitation of the current passing through it, either thanks to the second module E2 when it is actually present, or thanks to the first module El, when the latter integrates the module E2 and performs both the functions of the module El and of the module E2.

[0090] The second branch B2 comprises a third module E3 comprising a switch controllable for opening and closing, capable of interrupting the current flowing in the second branch and of maintaining the voltage between the two terminals of the switch when it is in the open state.

[0091] The third module E3 has a resistance in the on state which is much lower than the resistance of the modules El and E2 of the first branch Bl.

[0092] The third module E3 is therefore crossed by the majority of a nominal current passing through the controllable switch IC, except in the event of a fault.

[0093] The third module E3 can advantageously comprise one or more controllable power switches of the MOSFET type or of the silicon carbide MOSFET type, known as SiC MOSFET, so as to obtain a very low on-state resistance.

[0094] The controllable switch IC comprises a module E4 which comprises measurement sensors making it possible to measure the physical quantities necessary for controlling the modules El to E3.

[0095] The measuring sensors make it possible to measure currents and voltages useful for controlling the switch. They are conventional in themselves and are not described in detail.

[0096] The controllable switch IC comprises a control module E5 connected to the modules El to E4 and capable of controlling the first and third modules El and E3, on the basis of the values ​​measured by the module E4.

[0097] The operation upon closing of the controllable switch IC according to an embodiment of the invention is now described with reference to [Fig.2]. The controllable switch IC according to this embodiment has the capacity to limit the current flowing through it.

[0098] [Fig.2] represents states S0 to S2 of the controllable switch IC and the transitions from one state to the next.

[0099] To simplify the figure, modules E1 and E3 are represented by switches perfect having an open position in the rest state.

[0100] The initial state S0 is the rest state, in which the switches E1 and E3 are open. The second module E2 is conducting. The controllable switch IC is open.

[0101] When the closing of the controllable switch IC is requested by the control module E5, the following closing sequence is carried out.

[0102] The module E5 controls the closing of the switch El, which allows the transition from state S0 to state SL. The switch El then establishes the current in the branch Bl, since the second module E2 is already conducting. Because the switch El is controlled upon closing, the voltage across its terminals and the time of application of the constraint are also controlled.

[0103] Closing the switch El makes it possible to limit the value of the current on closing, due to the presence of the second module E2, in particular if the switch El establishes a short-circuit current between the power source connected upstream of the controllable switch IC and the load connected downstream of the controllable switch IC.

[0104] In state SI, switch El is closed, the second module E2 is on and switch E3 is open.

[0105] Module E5 controls the closing of switch E3, which allows the transition from state SI to state S2. Switch E3 establishes the current in branch B2. Because switch E3 is controlled upon closing, the voltage across its terminals and the time of application of the constraint are also controlled. Switch E3 closes at zero current and at very low voltage, since the voltage taken across the terminals of the controllable switch IC, therefore of modules El and E2, is only a few volts at most.

[0106] Closing switch E3 causes almost all of the current from controllable switch IC to flow into branch B2, because the total series resistance of all modules El and E2 is much greater than that of switch E3.

[0107] In state S2, switch El is closed, the second module E2 is on and switch E3 is closed. Controllable switch IC is closed.

[0108] The operation upon opening of the controllable switch IC according to an embodiment of the invention is now described with reference to [Fig.3].

[0109] [Fig.3] represents the states S0 to S2 and the transitions from one state to the next of the controllable switch IC.

[0110] As in the previous figure, modules E1 and E3 are represented by perfect switches having an open position in the rest state.

[0111] The initial state is state S2, in which the switches E1 and E3 are closed. The second module E2 is on. The controllable switch IC is closed.

[0112] When the opening of the controllable switch IC is requested by the control module E5, the following opening sequence is carried out.

[0113] The module E5 controls the opening of the switch E3 which allows the transition from state S2 to state SL. The opening of the switch E3 is done under a moderate voltage, because the modules El and E2 allow the current to flow in the controllable switch IC.

[0114] In state SI, switch E1 is closed, the second module E2 is conducting and switch E3 is open. All of the current flows through branch B1.

[0115] The module E5 controls the opening of the switch El, which allows the transition from state SI to state S0. Once the switches El and E3 are open, isolation is ensured between the upstream and downstream parts of the controllable switch IC.

[0116] [Fig.4] represents a first mode of control of the controllable switch IC in the event of a fault. The upper part of [Fig.4] represents a timing diagram of the current flowing through the controllable switch IC and the lower part of [Fig.4] represents the controls of the modules El and E3 of the controllable switch IC.

[0117] Initially, the controllable switch IC is closed, that is to say that the modules E1 and E3 are closed. We consider a phase PI between times t0 and t1 in which a current flows through the controllable switch IC and is consumed by the load. The phase PI is an operating phase of the controllable switch IC at nominal current.

[0118] It is assumed that a short-circuit type fault appears at time t1. When the fault appears, the current increases rapidly during a phase P2. The current slope is defined by the characteristics of the energy source and the connecting cables between the source and the fault location. Phase P2 is a phase of rising current during the short circuit.

[0119] Almost all of the current passing through the controllable switch IC passes through branch B2, therefore through the third module E3, as explained above.

[0120] As soon as the fault current reaches a predefined limit value at a time t2, the module E5 commands the opening of the third module E3. There is no discontinuity in the current which passes successively from branch B2 to branch BL. During a phase P3, the second module E2 limits the current passing through it to a value determined by construction or by adjustment according to the technology adopted. Phase P3 is a current limitation phase during the short circuit.

[0121] The opening of the first module El is then controlled by the module E5, at a time t3 which can be determined on the basis of an energy activation criterion (12) or on the passage of the current value below a predetermined threshold. This is followed by a phase P4 during which the first module El dissipates the energy and the current passing through the controllable switch IC decreases, until it becomes zero at a time t4 depending on the control mode of the first module El. Phase P4 is a phase of decrease in current when the controllable switch IC opens.

[0122] [Fig.5] represents a method for controlling the controllable switch IC, in the event of a fault, corresponding to [Fig.4]. The control method comprises steps 1 to 4 implemented in the control module E5.

[0123] Step 1 is a monitoring of the physical quantities of the controllable switch IC measured by the module E4, in particular the current which passes through the controllable switch IC while it is closed, that is to say that the modules E1 and E3 are closed.

[0124] The next step 2 is a test to determine whether the current through the controllable switch IC exceeds a predefined limit value.

[0125] When the test result is positive, step 2 is followed by step 3 in which the control module E5 commands the opening of the third module E3.

[0126] The next step 4 is a command to open the first module El by the control module E5.

[0127] [Fig.6] represents a second mode of control of the controllable switch IC in the event of a fault. The upper part of [Fig.6] represents a timing diagram of the current flowing through the controllable switch IC and the lower part of [Fig.4] represents the controls of the modules El and E3 of the controllable switch IC.

[0128] Initially, the controllable switch IC is closed, that is to say that the modules E1 and E3 are closed. We consider a phase PI' between times t0' and tl' in which a current flows through the controllable switch IC and is consumed by the load. The phase PI' is an operating phase of the controllable switch IC at nominal current.

[0129] It is assumed that a short-circuit type fault appears at time tl'. When the fault appears, the current increases rapidly during a phase P2'. The current slope is defined by the characteristics of the energy source and the connecting cables between the source and the fault location. Phase P2' is a phase of rising current during the short circuit.

[0130] Almost all of the current passing through the controllable switch IC passes through branch B2, therefore through the third module E3, as explained above.

[0131] As soon as the fault current reaches a predefined limit value at time t2', the module E5 commands the opening of the third module E3. There is no discontinuity in the current which passes successively from branch B2 to branch B1. During a phase P3', the second module E2 limits the current passing through it to a value determined by construction or by adjustment according to the technology adopted. Phase P3' is a current limitation phase during the short circuit.

[0132] It is assumed that the first module El has a breaking capacity but that it is limited. The closing of the third module E3 is then commanded by the module E5, at time t3', before reaching the physical limits of the second module E2.

[0133] This results in an increase in the current flowing through the controllable switch IC and the transfer of almost all of the current from branch B1 to branch B2, during a phase P4'. During this phase, the module E5 commands the opening of the first module El. Then at a time t4', the module E5 commands the opening of the third module E3. Phase P4' is a phase of current increase during the short circuit.

[0134] This is followed by a phase P5' during which the current flowing through the controllable switch IC decreases, until it becomes zero at a time t5' depending on the control mode of the third module E3. Phase P5' is a phase of decrease in the current when the controllable switch IC opens.

[0135] [Fig.7] represents a method for controlling the controllable switch IC, in the event of a fault, corresponding to [Fig.6]. The control method comprises steps 1' to 6' implemented in the control module E5.

[0136] Step 1' is a monitoring of the physical quantities of the controllable switch IC measured by the module E4, in particular the current which passes through the controllable switch IC while it is closed, that is to say that the modules E1 and E3 are closed.

[0137] The next step 2' is a test to determine whether the current flowing through the controllable switch IC exceeds a predefined limit value.

[0138] When the test result is positive, step 2' is followed by step 3' at which module E5 commands the opening of the third module E3.

[0139] The next step 4' is a command to close the third module E3 by the module E5.

[0140] The next step 5' is a command to open the first module El by the module E5.

[0141] The next step 6' is a command to open the third module E3 by the module E5.

[0142] [Fig.9] represents a control mode of the controllable switch IC shown in [Fig.8], in the event of a fault. [Fig.9] represents from top to bottom:

[0143] - a timing diagram of the current flowing through capacitor Cl and the voltage across capacitor Cl,

[0144] - a timing diagram of the current flowing through capacitor C2 and the voltage across capacitor C2,

[0145] - a timing diagram of the current flowing through the third module E3 and the voltage across the terminals of the third module E3,

[0146] - the controls of the modules El and E3 of the controllable switch IC.

[0147] In the initial state, modules E1 and E3 are open.

[0148] The closing of the controllable switch IC is requested by the control module E5, the following closing sequence is carried out.

[0149] Module E5 controls the closing of the third module E3 at a time t0”. The third module E3 establishes the current in branch B2. Because the third module E3 is controlled upon closing, the voltage across its terminals and the time of application of the constraint are also controlled. The voltage source then supplies the current required for the load supplied by switch E3.

[0150] It is assumed that a short-circuit type fault appears downstream of the third module E3 at time t1”. The current in the third module E3 increases rapidly. The current slope is defined by the characteristics of the energy source and the connecting cables between the source and the fault location. As soon as the fault current reaches a predefined limit value at time t2”, the module E5 commands the closing of the first module EL. The module E5 commands the opening of the third module E3 at time t3”, very shortly after time t2”.

[0151] Opening the third module E3 causes the current in branch B2 to decrease. Branch B1 causes the entire source current to flow.

[0152] The inductance L1 makes it possible to limit the slope of the current when the first EL module closes. It is useful in the case of using the controlled switch IC with a capacitive type source (little series inductance).

[0153] The current increases in the capacitor C2, being limited by the resistor RL The voltage across the capacitor C2 also increases. If a threshold voltage value imposed by the trigger voltage of the transil diode Ul is exceeded, the source current charges the capacitor CL The second module E2 stores the energy coming from the source.

[0154] The capacitance value of capacitor C2 is chosen in such a way that the growth of the current in branch B1 is rapid. The capacitance value of capacitor C2 must not be too large, otherwise the source current would continue to flow in branch B2. On the other hand, the capacitance value of capacitor C1 is significantly larger than the capacitance value of capacitor C2 and remains dimensioned by the permissible overvoltage and the estimate of the line inductance between source and controllable switch IC.

[0155] Once the energy of the line inductance is transferred to the capacitors C1 and C2, the current in the first module E1 is cancelled. When the current flowing through the first module E1 reaches a value lower than a predefined limit value, the module E5 commands the opening of the first module E1 at a time t4”. The energy stored in the capacitors C1 and C2 is dissipated in the resistors R3 and R2, respectively.

[0156] [Fig. 10] represents a method for controlling the controllable switch IC, in the event of a fault, corresponding to [Fig.9]. The control method comprises steps 1” to 6” implemented in the control module E5.

[0157] Step 1” is a monitoring of the physical quantities of the controllable switch IC measured by the module E4, in particular the current which passes through the controllable switch IC while it is closed, that is to say that the third module E3 is closed.

[0158] The next step 2” is a test to determine whether the current through the controllable switch IC exceeds a predefined limit value.

[0159] When the test result is positive, step 2” is followed by step 3” in which the control module E5 commands the closing of the first module EL

[0160] The next step 4” is a command to open the third module E3 by the control module E5.

[0161] The next step 5” is a test to determine whether the current flowing through the first module El reaches a value lower than a predefined limit value.

[0162] When the test result is positive, step 5” is followed by step 6” in which the control module E5 commands the opening of the first module EL

[0163] The advantages of the controllable switch IC according to the invention are as follows:

[0164] The third module E3 can be sized to the value of the nominal current of the controllable switch IC, but is not necessarily designed to interrupt all of the energy stored on the distribution line at the highest current point. This makes it possible to limit the number of components to be used, thus resulting in a proven cost saving if, for example, very expensive SiC MOSFET chips are used, or to select semiconductor chips by favoring resistance in the on state rather than resistance to high current and high voltage.

[0165] The closing sequence of the controllable switch IC by the first module El first makes it possible to limit the value of the establishment current by the presence of a higher total impedance value in the branch B1 by all the modules El and E2. This constitutes the equivalent of a precharge function which limits the inrush current.

[0166] During the closing sequence of the controllable switch IC, the third module E3 is closed at zero current and at low voltage, since the voltage across all of the modules El and E2 is low compared to the voltage of the source.

Claims

Claims

1. Controllable switch (IC) comprising between two terminals (BO1, BO2): - a first branch (Bl) comprising a first module (El) comprising a switch controllable for closing and opening, and a second module (E2) connected in series with the first module, the second module being capable of limiting the current in the first branch or storing energy, - a second branch (B2) comprising a third module (E3) comprising a switch controllable for opening and closing, capable of interrupting the current flowing in the second branch and maintaining the voltage between the two terminals of the switch when it is in the open state, - a control module (E5) capable of controlling the first and third modules.

2. Controllable switch according to claim 1, comprising a measuring module (E4) capable of measuring the physical quantities of the first, second and third modules (El, E2, E3) and of supplying the measured physical quantities to the control module (E5).

3. Controllable switch according to claim 1 or 2, in which the third module (E3) of the second branch has a resistance in the on state lower than the resistance of the first and second modules of the first branch.

4. Controllable switch according to any one of claims 1 to 3, in which the third module (E3) comprises at least one MOSFET type power transistor.

5. Controllable switch according to any one of claims 1 to 3, in which the third module (E3) comprises at least one power transistor of the SiC MOSFET type.

6. Controllable switch according to any one of claims 1 to 5, in which the first module (El) integrates the second module (E2) and comprises an IGBT type switch controlled so as to have a high impedance to limit the current passing through it in the event of a fault.

7. Controllable switch according to any one of claims 1 to 5, in which, the second module being capable of limiting the current in the first branch, the first module (El) comprises a switch controlled and the second module (E2) has a dissipative element.

8. Controllable switch according to any one of claims 1 to 5, in which, the second module being capable of storing energy, the first module (El) comprises a controlled switch and the second module (E2) comprises a passive circuit capable of storing and dissipating energy coming from an energy source.

9. Method for controlling a controllable switch (IC) according to any one of claims 1 to 7, characterized in that it comprises steps of: - monitoring (1) the current flowing through the controllable switch while it is closed, - testing (2) to determine whether the current flowing through the controllable switch IC exceeds a predefined limit value, - command (3) to open the third module (3) when the test result is positive, - command (4) to open the first module (1).

10. Method for controlling a controllable switch (IC) according to any one of claims 1 to 7, characterized in that it comprises steps of: - monitoring (1') the current flowing through the controllable switch while it is closed, - testing (2') to determine whether the current flowing through the controllable switch IC exceeds a predefined limit value, - command (3') to open the third module (E3) when the test result is positive, - command (4') to close the third module (E3), - command (5') to open the first module (El), - command (6) to open the third module (E3).

11. Method for controlling a controllable switch (IC) according to claim 8, characterized in that it comprises steps of: - monitoring (1”) of the current flowing through the controllable switch while it is closed, - test (2”) to determine whether the current flowing through the controllable switch (IC) exceeds a predefined limit value, - command (3”) to close the first module (El) when the test result is positive, - command (4”) to open the third module (E3), - test (5”) to determine whether the current flowing through the first module (El) reaches a value lower than a predefined limit value, - command (6”) to open the first module (El) when the test result is positive.

12. A computer program comprising instructions for carrying out the steps of the method according to any one of claims 9 to 11 when said program is executed by a computer.

13. A computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to any one of claims 9 to 11.

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