Device for protecting and electrically commutating a part of electronic equipment with control of the states of the commutating device

Description

[0001] The invention relates to electronic equipment which is capable of supplying current to at least one controlled (or piloted) load, and more precisely to the protection and switching devices which equip some of this electronic equipment.

[0002] In certain areas, such as vehicles (possibly automotive), certain electronic equipment, which supplies current, in a controlled manner, to at least one controlled (or piloted) load, must protect itself against abnormal currents induced by this load or by its electrical connection lines.

[0003] Here, "abnormal current" means an overload current or a short-circuit current (clear or impedant) or a current resulting from improper use or failure of a controlled (or piloted) load or from the use of an unsuitable load.

[0004] This protection can, for example, be achieved by means of a protection and switching device installed on the power output of the electronic equipment.

[0005] Such a protection and switching device generally comprises switching means which are capable of being placed in a first state in which they allow the supply of current to the associated controlled load or in a second state in which they prohibit the supply of current to the associated controlled load, depending on the command they receive.

[0006] These switching means generally comprise at least one "intelligent" power electronic component (sometimes called "Smart-Power") which, unfortunately, does not have a very long service life when placed in abnormal operating conditions, i.e. when subjected to electrical overloads for relatively long periods. This results mainly from the fact that a fatigue phenomenon, induced by long overloads, gradually appears in these intelligent power electronic components, and ends up rendering them inoperative, which then prevents the controlled load from performing its function(s) even when the cause of the overload has disappeared.

[0007] In order to prevent the intelligent power electronic component from becoming inoperative too quickly, it is possible to add an integrated diagnostic function designed to temporarily place it in its second state (non-conducting) as soon as an overload is detected. The return to the first state (conducting) can then be done either automatically upon receipt of an external command or after a predefined delay, or following external manual intervention (by the user or a technician in an after-sales service). This certainly extends the life of the protection and switching device, but each time the intelligent power electronic component is placed in its second state (non-conducting), the controlled load can no longer perform its function(s), even in the absence of an overload.

[0008] Document EP 2 230 134 describes a device for controlling a switching component by activating a wired control signal, the device comprises a block receiving as inputs the wired control signal and an authorization signal. The block is arranged to produce as output a validated control signal which is activated when the wired control signal is activated if the authorization signal is activated, and which is kept activated after activation as long as the wired control signal is activated.

[0009] The invention therefore aims in particular to improve the situation.

[0010] For this purpose, it proposes a protection and switching device according to claim 1.

[0011] In this way, the objectives of safety and availability of the function of the electronic equipment can be reconciled when the cause of the overload has disappeared, even after a very long period of operation under overload conditions.

[0012] The protection and switching device according to the invention may include other characteristics which may be taken separately or in combination, and in particular: its control means may be capable of generating a command capable of placing, in a lasting but automatically reversible manner, the switching means in the second state in the event of confirmation of an abnormal current, and of generating a command capable of returning the switching means to the first state in the event of receipt of a first predefined signal external to the electronic equipment; as a variant, its control means may be capable of generating a command capable of placing, in a lasting but automatically reversible manner, the switching means in the second state when the determined value is greater than a second threshold strictly lower than the first threshold, and of generating a command capable of returning the switching means to the first state in the event of receipt of a first predefined signal external to the electronic equipment;➢ its control means may be capable of generating a command capable of returning the switching means to the first state once only in the absence of reception of the first signal but in the event of reception of a second predefined signal external to the electronic equipment; ➢ its control means may be capable of generating a command capable of placing, in a lasting but reversible manner in a non-automatic manner, the switching means in the second state when the determined value is greater than a third threshold between the first and second thresholds, and of generating a command capable of returning the switching means to the first state in the event of reception of a third predefined signal external to the electronic equipment;➢ its control means may be capable of recording an anomaly when alert signals are continuously generated by the switching means for a first selected duration, then, in the event of recording an anomaly, of generating a command capable of temporarily placing the switching means in the second state for a second selected duration, and of generating a new command capable of returning the switching means to the first state at the end of the second duration; its control means may be capable of recording an anomaly when the alert signals are continuously generated by the switching means for a first selected duration which follows a predefined buffer duration during which the switching means already generate alert signals. ;

[0013] The invention also proposes electronic equipment, suitable for supplying current to at least one controlled load, and comprising a protection and switching device of the type presented above.

[0014] The invention also proposes a vehicle, possibly of the automobile type, and comprising at least one piece of electronic equipment of the type presented above.

[0015] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which: there figure 1 schematically and functionally illustrates electronic equipment connected to a power supply means and comprising an exemplary embodiment of a protection and switching device according to the invention, and the figure 2 schematically illustrates in a diagram an example of the temporal evolution of the state in which the switching means of a protection and switching device according to the invention are placed in the presence of abnormal currents and filtering of the alert signals intended to determine the anomalies which can be counted.

[0016] The invention aims in particular to propose a protection and switching device DP intended to equip electronic equipment EE capable of supplying current to at least one controlled load CC.

[0017] In the following, it is considered, by way of non-limiting example, that the electronic equipment EE is a computer performing at least one function when it is supplied with current. But the invention is not limited to this type of electronic equipment. It relates in fact to any type of electronic equipment which must supply current to at least one controlled (or piloted) load while protecting itself against abnormal currents induced by this load or its electrical connection lines.

[0018] It is recalled that here, "abnormal current" means an overload current or a short-circuit current (clear or impedance) or a current resulting from improper use or failure of a DC controlled (or piloted) load or from the use of an unsuitable load.

[0019] Furthermore, it is considered in the following, by way of non-limiting example, that the electronic equipment EE is part of a vehicle, possibly of the automobile type (such as for example a car). But the invention is not limited to this application. Indeed, electronic equipment EE can be external to a system or can be part of any system having power supply means, and in particular a vehicle (land, sea (or river), or air), a household appliance, a consumer or professional electronic device, a building, or an installation, possibly of the industrial type.

[0020] We have schematically represented on the figure 1 an example of electronic equipment EE connected to a controlled (or piloted) DC load and comprising an example of an embodiment of a protection and switching device DP according to the invention.

[0021] The controlled (or piloted) load DC is supplied with current by the electronic equipment EE via the protection and switching device DP which is installed on its power output. This is, for example, an electric motor, or an internal or external lighting device of a vehicle, or any other electrical load or actuator.

[0022] It should be noted that the EE electronic equipment could supply several (at least two) DC controlled (or piloted) loads.

[0023] As illustrated without limitation on the figure 1 , a DP protection and switching device, according to the invention, comprises at least MCN switching means and MCT control means.

[0024] The switching means MCN are in particular capable of being placed in a first (conducting) state e1 in which they allow the current supply to the controlled load CC or in a second (non-conducting) state e2 in which they prohibit the current supply to the controlled load CC, depending on a command c0 that they receive. When the electronic equipment EE is part of a system (here a vehicle), its protection and switching device DP receives this last command c0 from the system, for example via an on-board communication network. It will be noted that this command c0 can be provided by a user of the system or by another electronic equipment (or component) forming part of the system. Furthermore, this command c0 can be analog or digital.

[0025] These MCN switching means are also capable of delivering an alert signal sa in the event of detection of an abnormal current induced by the controlled load CC.

[0026] For example, the MCN switching means may generally comprise at least one "intelligent" power electronic component, programmed to deliver an alert signal sa each time it detects an abnormal current induced by the DC controlled load.

[0027] The MCT control means are capable of determining a value vp of a parameter, which is representative of a loss of reliability of the MCN switching means induced by abnormal currents, as a function of the alert signals sa delivered, and of generating a command c1 which is capable of definitively placing the MCN switching means in the second (non-conducting) state e2 when this determined value vp is greater than a first threshold s1.

[0028] In the following, the c1 command is called, for example, "final inhibition command". It can be analog or digital.

[0029] Each time the MCN switching means are subjected to an abnormal current for a relatively long period, they are subject to a kind of "stress" which fatigues them and therefore induces a loss of reliability. The MCT control means therefore allow the MCN switching means to operate normally as long as they consider that the latter (MCN) remain sufficiently reliable to continue operating normally without risk of failure, that is to say as long as the determined value vp is lower than the first threshold s1.

[0030] This first threshold s1 can, for example, be predefined based on overload reliability information from the intelligent power electronic component.

[0031] For example, the control means MCT may be capable of generating a command c2 which is capable of placing, in a durable but reversible manner automatically, the switching means MCN in the second (non-conducting) state e2 in the event of confirmation of an abnormal current (or fault), as illustrated in the figure 2 ). Alternatively, the control means MCT may be capable of generating a command c2 which is capable of placing, in a lasting but automatically reversible manner, the switching means MCN in the second (non-conducting) state e2 when the determined value vp is greater than a second threshold s2 strictly lower than the first threshold s1. In these cases, the control means MCT are capable of generating a command c3 which is capable of placing the switching means MCN in the first state e1 in the event of receipt of a first predefined signal ps external to the electronic equipment EE.

[0032] In the following, the command c2 is called, for example, "re-triggerable inhibition command". It can be analog or digital. Similarly, the first signal ps can be analog or digital.

[0033] For example, the first signal ps can be transmitted by the system (here a vehicle) after an event has occurred within it, such as for example a standby or a wake-up of the electronic equipment EE, or the reception of a new command c0, or the switching off or on of the vehicle's ignition. It is important to note that this first signal ps does not result from a specific operation dedicated to re-engagement on the part of a user of the vehicle or a technician in an after-sales service (re-engagement is in fact automatic).

[0034] It will be noted that the control means MCT may also be capable of generating a command c3 which is capable of returning the switching means MCN to the first state e1 once only in the absence of reception of the first signal ps but in the event of reception of a second predefined signal ds external to the electronic equipment EE.

[0035] In the following, the command c3 is called, for example, "single disinhibition command". It can be analog or digital. Similarly, the second signal ps can be analog or digital.

[0036] It will be understood that in the presence of this latter option, if the abnormal current persists or returns after sending the single disinhibition command c3 (and therefore replacing the MCN switching means in the first state e1), the MCT control means again generate a re-triggerable inhibition command c2 which places the MCN switching means in the second state e2 (pending reception of a first signal ps).

[0037] On the other hand, if the abnormal current has disappeared after sending the single disinhibition command c3 (and therefore after replacing the MCN switching means in the first state e1), the MCT control means leave the latter (MCN) in their first state e1 (in which they are available to supply the switched load CC).

[0038] For example, the second ds signal can be transmitted by the system (here a vehicle) after the driver has switched on or switched on the ignition (without necessarily starting the vehicle) or has reactivated a command (for example: request to switch off, then switch on the headlights again).

[0039] It will also be noted that the control means MCT may also be capable of generating a command c4 which is capable of placing, in a lasting but reversible manner in a non-automatic manner, the switching means MCN in the second state e2 when the determined value vp is greater than a third threshold s3 between the first s1 and second s2 thresholds (i.e. s2 < s3 < s1). In this case, the control means MCT are capable of generating a command c5 which is capable of placing the switching means MCN in the first state e1 in the event of receipt of a third predefined signal ts external to the electronic equipment EE, after the third threshold s3 has been exceeded and before the first threshold s1 has been reached. It is possible to envisage using several third thresholds s3 associated with the command c4.

[0040] In the following, the command c4 is called, for example, "resettable inhibition command". It can be analog or digital. Similarly, the command c5 can be analog or digital. Likewise, the third signal ts can be analog or digital.

[0041] For example, the third signal ts may be transmitted by the system (here a vehicle) after a vehicle user or an after-sales service technician has performed a specific operation dedicated to resetting and therefore not automatic. Such a specific operation may, for example, consist of disconnecting the vehicle battery, or providing a specific sequence of commands, or actuating a dedicated control member, or even a particular intervention in an after-sales service.

[0042] It will be understood that in the presence of this last option, if the overload persists or returns after sending the reset command c5 (and therefore replacing the MCN switching means in the first state e1), the MCT control means again generate a resettable inhibition command c4 which places the MCN switching means in the second state e2 (pending reception of a new third signal ts). This procedure is then repeated as long as the first threshold s1 has not been reached.

[0043] It will be noted that in the presence of the two previous options allowing the MCT control means to generate a single disinhibition command c3 or a resettable inhibition command c4, it may happen that after the generation of a single disinhibition command c3 the abnormal current is still present. In this case, either the value vp has exceeded the first threshold s1 and therefore the MCT control means generate a definitive inhibition command c1 suitable for definitively placing the MCN switching means in the second state e2, or the value vp is now between the third threshold s3 and the first threshold s1 and therefore the MCT control means generate a resettable inhibition command c4 which is suitable for placing, in a lasting but reversible manner in a non-automatic manner, the MCN switching means in the second state e2.

[0044] In order to determine the vp value, several methods can be implemented. One of these methods is described below as an illustrative example.

[0045] For example, the MCT control means may be capable of recording an anomaly when the alert signals sa delivered verify at least one criterion, and of determining the parameter value vp based at least on the number of anomalies recorded.

[0046] Several accounting methods can be implemented. One of these methods is described below as a non-limiting example with reference, in part, to the figure 2 which illustrates an example of the temporal evolution of the state in which the MCN switching means of the DP protection and switching device are placed in the presence of abnormal currents and filtering of the alert signals intended to determine the anomalies which can be counted.

[0047] For example, the MCT control means may be capable of counting an anomaly when alert signals sa are generated continuously by the MCN switching means for a first chosen duration Δt1. In other words, the MCT control means filter the alert signals sa and validate (or count) an anomaly when the MCN switching means generate alert signals sa continuously for a first chosen duration Δt1. It will be understood that the generation of the alert signals sa continuously for the first duration Δt1 constitutes a criterion.

[0048] In the event of an anomaly being recorded, the MCT control means generate a command c5 which is suitable for temporarily placing the MCN switching means in the second state e2 for a second chosen duration Δt2, and generate a new command c6 suitable for placing the MCN switching means in the first state e1 at the end of the second duration Δt2.

[0049] The first duration Δt1 is chosen according to the components that constitute the MCT control means. It is representative of the minimum duration during which the MCT control means must be subjected to an abnormal current for this to statistically induce fatigue (or stress). For example, this first duration Δt1 can be between 10 ms and 300 ms.

[0050] The temporary placement of the MCN switching means in the second state e2 during the second duration Δt2 is intended, on the one hand, to allow time for the CC controlled load to no longer induce abnormal current, and, on the other hand, to allow the MCN switching means to recover from the fatigue (or stress) suffered.

[0051] The second duration Δt2 can be chosen according to the MA power supply means and / or the components that constitute the MCT control means. For example, this second duration Δt2 can be between 500 ms and 1000 ms.

[0052] The c6 command can be analog or digital.

[0053] It will be understood, as illustrated, that at the end of the second duration Δt2 if one of the thresholds s1 to s3 has not been reached, the control means MCT generate a command which places the switching means MCN in the first (passing) state e1. Then, if the abnormal current persists or has returned at the end of this second duration Δt2, the control means MCT recommence their observation (or filtering) of any alert signals sa delivered by the switching means MCN. Consequently, if alert signals sa are again delivered continuously by the switching means MCN for a new first duration Δt1, the control means MCT will again count an anomaly, and therefore will generate a new command c5 suitable for temporarily placing the switching means MCN again in the second state e2 for a new second duration Δt2. And so on until one of the thresholds s1 to s3 has been reached.

[0054] For example and as illustrated without limitation on the figure 2 , the MCT control means may be capable of recording an anomaly when alert signals sa are generated continuously by the MCN switching means for a first duration Δt1 which follows a predefined buffer duration Δt3 during which the MCN switching means already generate alert signals sa.

[0055] This buffer (or exclusion) duration Δt3 is a duration during which we consider that each alert signal sa is not “reliable”, that is to say suitable for being taken into account.

[0056] In the example of the figure 2 , just before a time t0 the control means MCT receive a command c0 requesting the placement of the switching means MCN in their first state e1. At this time t0 the control means MCT execute this request and begin to observe the alert signals sa delivered. It is considered here that an alert signal sa is actually delivered at time t0 and therefore the control means MCT trigger at time t0 a time delay of a buffer duration Δt3. Here, at the expiration of the buffer duration Δt3 (time t1), an alert signal sa is still delivered. Consequently, the control means MCT trigger at time t1 another time delay of a first duration Δt1. Here, at the end of the first duration Δt1 (time t2) the MCT control means note with their filtering function that an alert signal sa is still delivered, but that none of the thresholds s1 to s3 have been reached.Consequently, they record (or validate) an anomaly, and at time t2 the MCT control means generate a command c5 suitable for temporarily placing the MCN switching means in the second state e2 for a second duration Δt2. Then, at the end of the second duration Δt2 (time t3), the MCT control means generate a command c6 suitable for placing the MCN switching means in the first state e1.

[0057] It is then considered that at time t3 an alert signal sa is actually delivered and therefore the control means MCT trigger at this time t3 a new time delay of a buffer duration Δt3. Here, at the expiry of this new buffer duration Δt3 (time t4), an alert signal sa is still delivered. Consequently, the control means MCT trigger at time t4 another time delay of a first duration Δt1. Here, at the expiry of the new first duration Δt1 (time t5) the control means MCT note with their filtering function that an alert signal sa is still delivered, but that none of the thresholds s1 to s3 has been reached. Consequently, they count (or validate) an anomaly, and generate at time t5 a new command c5 suitable for temporarily placing the switching means MCN in the second state e2 for a new second duration Δt2.Then, at the end of this new second duration Δt2 (not shown), the control means MCT can generate a command c6 suitable for returning the switching means MCN to the first state e1, and so on.

[0058] It is then considered that at time t6 the switching means MCN have been returned to the first state e1 and that an alert signal sa is actually delivered. Consequently, the control means MCT trigger at this time t6 a new time delay of a buffer duration Δt3. Here, at the expiry of this new buffer duration Δt3 (time t7), an alert signal sa is still delivered. Consequently, the control means MCT trigger at time t7 another time delay of a first duration Δt1. Here, at the expiry of the new first duration Δt1 (time t8) the control means MCT note with their filtering function that an alert signal sa is still delivered, but that one of the thresholds, for example s2, has been reached.Consequently, they record (or validate) an anomaly, and generate at time t8 a re-triggerable inhibition command c2 suitable for placing, in a lasting but reversible manner automatically, the switching means MCN in the second state e2. Then, the control means MCT wait to receive a new command c0 (intended to replace the switching means MCN in the first state e1) or a first signal ps (intended to replace the switching means MCN in the first state e1).

[0059] It should be noted that the protection and switching device DP may, if necessary, inform the electronic equipment EE of the inhibition status of the power supply (available / temporarily inhibited / permanently inhibited) as well as possibly of a level of availability of the switching means MCN. This level may, for example, be a percentage (100% corresponding to a new state of the switching means MCN and 0% corresponding to a definitive stoppage of operation of the switching means MCN (characterized by a definitive inhibition)).

[0060] As illustrated without limitation on the figure 1 , the MCT control means can be possibly arranged in three parts: a first part P1 dedicated to observing the alert signals sa delivered by the switching means MCN in order to determine each alert signal sa that can be counted, a second part P2 responsible for filtering the alert signals sa in order to determine anomalies to be counted (or validated), and for incrementing the value vp by one unit each time an anomaly has been determined in order to determine when this value vp exceeds one of the thresholds s1 to s3, and a third part P3 receiving each external command c0 and each signal ps, ds or ts, and responsible for generating the different commands intended to control the placement of the switching means MCN in their first e1 or second e2 state.

[0061] Furthermore, these MCT control means can be implemented in the form of software modules (or computer or "software"), or a combination of electronic circuits (or "hardware") and software modules.

[0062] The DP protection and switching device supports three types of requirements: a safety requirement through the definitive inhibition of the power supply to the electronic equipment EE as soon as it is considered that the switching means MCN are no longer sufficiently reliable, an availability requirement allowing the electronic equipment EE to continue to carry out its mission in the presence of an abnormal current, thanks to the avoidance of an untimely shutdown of the power supply to the electronic equipment EE as long as the abnormal current has not been confirmed, for example by accounting, an availability requirement allowing the electronic equipment EE to be automatically re-enabled after a re-enabled inhibition of its switching means MCN intended to increase their operating time in the presence of an abnormal current.

[0063] The invention therefore makes it possible to reconcile the objectives of safety (risk of failure of the electronic equipment) and availability of the function of the electronic equipment when the cause of the abnormal current has disappeared, even after a very long period of operation in the presence of an abnormal current. Furthermore, the invention does not induce a significant increase in the cost of the electronic equipment because the protection and switching device can be arranged in the form of software modules installed in the electronic equipment. Furthermore, the invention does not require specific intervention, for example in an after-sales service, after the disappearance of the abnormal current, as long as the value of the parameter representative of a loss of reliability of the switching means remains below the first threshold s1 or the possible third threshold s3.

Claims

1. Protection and switching device (PD) for electronic equipment (EE) capable of supplying current to at least one controlled load (DC), said device (PD) comprising switching means (MCN) suitable for being placed in one of the first and second states, in which they respectively allow and prohibit the supply of current to said controlled load (DC), in accordance with a control, characterised in that the said switching means (MCN) are capable of delivering an alert signal in the event of the detection of an abnormal current induced by said controlled load (DC), and in that it also includes control means (MCT) capable of determining a value of a parameter, representative of a loss of reliability of said switching means (MCN) induced by abnormal currents, on the basis of said alert signals delivered, and to generate a command suitable for definitively placing said switching means (MCN) in said second state when said determined value is greater than a first threshold, and wherein said means of control (MCT) are suitable for counting an anomaly when said warning signals issued verify at least one specific criterion, and for determining said value of the parameter according to at least the number of anomalies recorded.

2. Device according to claim 1, characterized in that said means of control (MCT) are capable of generating a control capable of placing said switching means (MCN) in the said second state in the event of confirmation of an abnormal current, and of generating a control capable of replacing said switching means (MCN) in said first state in the event of reception of a first predefined signal external to said equipment Electronic (EE).

3. Device according to claim 1, characterized in that said control means (MCT) are capable of generating a control capable of placing, in a durable but reversible manner automatically, said switching means (MCN) in said second state when said determined value is greater than a second threshold strictly below said first threshold, and of generating a control suitable for placing said switching means (MCN) back in said first state in the event of reception of a first predefined signal external to the said electronic equipment (EE).

4. Device according to one of claims 2 and 3, characterized in that said control means (MCT) are capable of generating a command suitable for replacing said switching means (MCN) in said first state only once in the absence of reception of said first signal but in the event of reception of a second predefined signal external to said electronic equipment (EE).

5. Device according to one of claims 3 and 4, characterized in that said control means (MCT) are capable of generating a control capable of placing, in a durable but reversible manner in a non-automatic manner, the said switching means (MCN) in said second state when said determined value is greater than a third threshold between said first and second thresholds, and to generate a command suitable for returning said switching means (MCN) to said first state in the event of reception of a third predefined signal external to said electronic equipment (EE).

6. Device according to one of the preceding claims, characterized in that said control means (MCT) are capable of accounting for an anomaly when warning signals are generated continuously by said switching means (MCN) during a first chosen duration, then, in the event of accounting for an anomaly, generating a command suitable for temporarily placing said switching means (MCN) in said second state for a second chosen duration, and to generate a new command suitable for replacing said switching means (MCN) in said first state at the expiration of said second duration.

7. A device according to claim 6, characterized in that said control means (MCT) are capable of accounting for an anomaly when said warning signals are continuously generated by said switching means (MCN) during said first selected duration following a predefined buffer time during which said switching means (MCN) already generate warning signals.

8. Electronic equipment (EE) suitable for supplying current to at least one controlled load (CC), characterised in that it comprises a protection and switching device (DP) according to one of the preceding claims.

9. A vehicle, characterised in that it comprises at least one piece of electronic equipment (EE) according to claim 8.