Method and system for checking breaking capability of electronic fuse

Abstract

The invention relates to a method for checking the circuit breaking capability of an electronic safety device (1a), which is arranged between a voltage source (2) and an electrical consumer (3a), in which a voltage (Ua) at the consumer is monitored, the electronic safety device is switched off, and whether the voltage at the consumer falls to a threshold voltage within a defined time is checked. The invention also relates to a system (100) for checking the breaking capability of an electronic fuse, comprising: a voltage source (2); an electrical consumer (3a); an electronic safety device (1a) to be checked, which is arranged between the voltage source and the electrical appliance; a voltage measuring device (4a) provided for measuring a voltage at the consumer; and a test unit (5), which is designed to monitor the voltage at the consumer by means of the voltage measuring device, to switch the electronic safety device to be non-conductive, and to check whether the voltage at the consumer falls to a threshold voltage within a specified time.

Description

Technical Field

[0001] The present invention relates to a method and a system for checking the breaking capacity of an electronic fuse device disposed between a voltage source and an electrical appliance. Background Technology

[0002] Since it is possible for electronic fuses—for example, due to a failure of the semiconductor switch typically installed in the electronic fuse—to remain on even under overcurrent conditions, it is advantageous to periodically check whether the electronic fuse can be disconnected (i.e. switched to non-conducting) when using electronic fuses.

[0003] However, when electronic fuses are used in conjunction with so-called always-on appliances (such as some critical control devices or sensors in motor vehicles), it is not permissible to interrupt the power supply to said appliance by checking the breaking capability of the electronic fuse.

[0004] In this context, a method for checking the breaking capability of an electronic fuse is known from DE102021214971A1, wherein the electronic fuse includes a MOSFET, and wherein it is checked whether the drain-source voltage of the MOSFET increases when the gate-source voltage of the MOSFET decreases.

[0005] According to DE102021214975A1, a system for checking the breaking capacity of an electronic fuse is also known, wherein the electronic fuse to be checked is connected in parallel with a second electronic fuse, and wherein, in order to check the breaking capacity, the second electronic fuse is switched to conduction and the electronic fuse to be checked is switched to non-conduction. Summary of the Invention

[0006] The objective of this invention is to enable simple checking of the circuit-breaking capability of electronic fuses, preferably without interrupting the power supply to connected electrical appliances.

[0007] According to the present invention, the task is accomplished by a method for checking the breaking capacity of an electronic fuse device having the features of claim 1 and by a system for checking the breaking capacity of an electronic fuse device having the features of claim 4.

[0008] The circuit-breaking capability of an electronic fuse, which is installed between a voltage source and an electrical appliance (preferably a normally open appliance) for the purpose of protecting the appliance, is checked by the method according to the invention. Here, circuit-breaking capability is understood as the ability to reliably disconnect the electrical connection between the voltage source and the appliance in the event of a critical event, such as an overcurrent.

[0009] In the method according to the invention, in order to check the breaking capacity of the electronic fuse, the voltage (specifically, the electrical voltage) at the appliance is monitored by means of a suitable voltage measuring device. It is preferable to measure the voltage at the appliance at a high frequency (i.e., with particularly short time intervals). It is also conceivable that, in order to monitor the voltage at the appliance, the voltage at the interface of the electronic fuse on the appliance side is monitored.

[0010] In the method according to the invention, to check the circuit-breaking capability of the electronic fuse, the electronic fuse is switched to non-conducting mode while monitoring the voltage at the appliance, and it is checked whether the voltage at the appliance drops to a threshold voltage within a specified time. Here, the threshold voltage can be determined as an absolute value, or it can be determined relative to the voltage at the appliance at the moment of switching to non-conducting mode, or as a voltage difference relative to the supply voltage. If the voltage at the appliance drops to the threshold voltage within the specified time, the electronic fuse has circuit-breaking capability. If the voltage does not drop to the threshold voltage within the specified time, the electronic fuse does not have circuit-breaking capability.

[0011] Therefore, the method according to the present invention enables a simple check of the breaking capability of electronic fuses.

[0012] Preferably, if the voltage at the appliance drops to a threshold voltage or if the maximum test time has been reached since the electronic fuse was switched off, the electronic fuse is switched back on to avoid power interruption to the appliance. Here, the threshold voltage is preferably determined to be high enough to enable operation of the connected appliance. This allows for the inspection of electronic fuses used to protect so-called normally-on appliances using the method according to the invention.

[0013] Preferably, if the electronic fuse has been switched back to conduction due to reaching the maximum test time, i.e., if the voltage at the appliance has not dropped to the threshold voltage within a specified time, a new check according to the invention is performed. This involves re-monitoring the voltage at the appliance, switching the electronic fuse back to non-conduction, and re-checking whether the voltage at the appliance has dropped to the threshold voltage within the specified time. Preferably, multiple re-checks are performed. This eliminates temporary obstructions to the breaking capacity of the electronic fuse and thus reliably identifies permanent faults.

[0014] The system according to the invention for checking the circuit-breaking capability of electronic fuses includes a voltage source and an electrical appliance, the electrical appliance being supplied with electrical energy required for its normal operation by the voltage source. Preferably, the electrical appliance is a so-called normally-on appliance, i.e., an appliance whose power supply should not be interrupted.

[0015] The system according to the invention for checking the breaking capacity of an electronic fuse also includes the electronic fuse to be checked. Here, the electronic fuse is disposed between the voltage source and the appliance to protect the appliance; that is, it is electrically connected to the voltage source on the input side and electrically connected to the appliance on the output side. The electronic fuse includes one or more semiconductor switches, such as so-called MOSFETs or so-called IGBTs, which can be switched between an on state and an off state in a known manner via a control input.

[0016] The system according to the invention for checking the breaking capacity of an electronic fuse further includes a voltage measuring device, which is configured in a known manner to directly or indirectly measure the voltage at the appliance, for example by measuring the voltage at the interface on the appliance side of the electronic fuse. Here, the voltage measuring device is preferably configured to measure the voltage at the appliance at a high frequency (i.e., at particularly short time intervals).

[0017] The system according to the invention for checking the breaking capacity of an electronic fuse further includes a test unit configured to implement the method according to the invention for checking the breaking capacity of the electronic fuse. Therefore, the test unit is specifically configured to: monitor the voltage at the appliance by means of a voltage measuring device, switch the electronic fuse to non-conducting mode, and check whether the voltage at the appliance drops to a threshold voltage within a specified time.

[0018] Therefore, for the reasons described above with respect to the method according to the invention, the system according to the invention makes it possible to simply check the breaking capability of electronic fuses.

[0019] Preferably, the test unit is further configured to provide a fault signal to the superior control unit in the event of a negative output during the test, i.e., if the voltage at the appliance does not drop to a threshold voltage within a specified time. Preferably, the test unit includes a communication interface constructed in a known manner for communicating with the superior control unit.

[0020] In a preferred embodiment, the system according to the invention is configured to inspect a plurality of electronic fuses. In this case, the system according to the invention includes: at least one additional electrical appliance; at least one additional electronic fuse disposed between a voltage source and one of the at least one additional electrical appliance; and at least one additional voltage measuring device configured to measure the voltage at one of the at least one additional electrical appliance. In this case, the test unit is further configured to: monitor the voltage at the at least one additional electrical appliance by means of the at least one additional voltage measuring device, switch the at least one additional electronic fuse to non-conducting mode, and check whether the voltage at the at least one additional electrical appliance drops to a threshold voltage within a predetermined time. Preferably, the test unit is further configured to: provide a separate fault signal to a higher-level control unit for each of the electronic fuses, or provide a fault signal to the higher-level control unit including a description of each of the electronic fuses.

[0021] Advantageously, this invention is applied to vehicles, particularly automobiles. Advantageously, vehicles equipped with the above-described system are also suitable for solving the tasks outlined above. The system serves to protect the vehicle's own onboard network. Attached Figure Description

[0022] The following is based on the attached document. Figure 1 Description of embodiments of the present invention, Figure 1 A schematic diagram of a system for checking the breaking capacity of an electronic fuse device according to the present invention is shown. Detailed Implementation

[0023] Figure 1 A system 100 according to the invention is shown for checking the circuit-breaking capability of (for example, three) electronic safety devices 1a-1c.

[0024] System 100 includes a voltage source 2, which is configured in a known manner to provide a supply voltage Uv.

[0025] System 100 also includes three electrical appliances 3a-3c, which are electrically connected to voltage source 2 respectively.

[0026] The system 100 also includes three electronic safety devices 1a-1c, wherein the first electronic safety device 1a is disposed between the voltage source 2 and the first electrical appliance 3a to protect the first electrical appliance 3a, the second electronic safety device 1b is disposed between the voltage source 2 and the second electrical appliance 3b to protect the second electrical appliance 3b, and the third electronic safety device 1c is disposed between the voltage source 2 and the third electrical appliance 3c to protect the third electrical appliance 3c.

[0027] The system 100 also includes four voltage measuring devices 4a-4d, wherein the first voltage measuring device 4a is configured to measure the voltage Ua at the first electrical appliance 3a, the second voltage measuring device 4b is configured to measure the voltage Ub at the second electrical appliance 3b, the third voltage measuring device 4c is configured to measure the voltage Uc at the third electrical appliance 3c, and the fourth voltage measuring device 4d is configured to measure the supply voltage Uv.

[0028] System 100 also includes a test unit 5, which provides the measurement values ​​of the four voltage measuring devices 4a-4d to the test unit, and the test unit is configured to perform the method according to the invention to check the breaking capacity of the three electronic fuses 1a-1c.

[0029] Test unit 5 is specifically configured to: monitor the voltage Ua-Uc at each electrical appliance 3a-3c by means of voltage measuring devices 4a-4c, switch the three electronic fuses 1a-1c to non-conducting respectively, and check whether the voltage Ua-Uc at the three electrical appliances 3a-3c has dropped to a determined threshold voltage respectively.

[0030] Here, the threshold voltage can be stored in the test unit 5 as an absolute voltage value, or it can be determined by the test unit 5 based on the voltage difference (Spannungsdeltawert) stored in the test unit 5 and the measured supply voltage Uv.

[0031] In addition, the same threshold voltage can be specified for all three appliances 3a-3c, or separate threshold voltages can be specified for the three appliances 3a-3c.

[0032] The test unit 5 is also configured to switch the electronic fuse 1a-1c back to conduct if the voltage Ua-Uc at the corresponding electrical appliances 3a-3c drops to the corresponding threshold voltage, or if the maximum test time has been reached since the corresponding electronic fuse 1a-1c switched to non-conducting, in order to avoid interruption of power supply to the electrical appliances 3a-3c.

[0033] Test unit 5 is also configured to, if one of the electronic fuses 1a-1c has been switched to conduction again due to reaching the maximum test time, then: re-monitor the voltage Ua-Uc at the corresponding electrical appliance 3a-3c, re-switch the corresponding electronic fuse 1a-1c to non-conduction, and re-check whether the voltage Ua-Uc at the corresponding electrical appliance 3a-3c drops to the threshold voltage within the specified time.

[0034] Here, the test unit 5 is configured to perform a predetermined number of re-checks. Then, if, in all checks, the voltage Ua-Uc at the corresponding appliances 3a-3c fails to drop to the threshold voltage within a predetermined time, a fault signal F is provided to the superior control unit 101. The fault signal F indicates which of the three appliances 3a-3c failed to drop to the threshold voltage within a predetermined time, i.e., which of the three electronic fuses 1a-1c is faulty.

[0035] List of reference numerals

[0036] 100 System for checking the breaking capacity of electronic fuses

[0037] 1a-1c Electronic safety device

[0038] 2 voltage sources

[0039] 3a-3c electrical appliances

[0040] 4a-4d Voltage Measuring Device

[0041] 5 test units

[0042] 101 Upper-level control unit

[0043] F fault signal

[0044] Ua-Uc is the voltage at the appliance.

[0045] Uv power supply voltage

Claims

1. A method for checking the breaking capacity of an electronic fuse (1a), said electronic fuse being disposed between a voltage source (2) and an electrical appliance (3a), wherein: Monitor the voltage (Ua) at the appliance (3a). Switch the electronic fuse (1a) to non-conductive, and Check whether the voltage (Ua) at the appliance (3a) drops to the threshold voltage within a specified time.

2. The method according to claim 1, wherein, If the voltage (Ua) at the appliance (3a) drops to the threshold voltage or if the maximum test time is reached since the electronic fuse (1a) was switched to non-conductive, the electronic fuse (1a) is switched to conductive again.

3. The method according to claim 2, wherein, If the electronic safety device (1a) has been switched back on due to reaching the maximum test time, then: Re-monitor the voltage (Ua) at the appliance (3a). Switch the electronic fuse (1a) back to non-conductive, and Recheck whether the voltage (Ua) at the appliance (3a) drops to the threshold voltage within the specified time.

4. A system (100) for checking the breaking capacity of an electronic fuse (1a), said system comprising: Voltage source (2); Electrical appliances (3a); The electronic fuse device (1a) to be inspected is located between the voltage source (2) and the electrical appliance (3a); Voltage measuring device (4a), the voltage measuring device being configured to measure the voltage (Ua) at the appliance (3a); and Test unit (5), the test unit is configured to: - The voltage (Ua) at the appliance (3a) is monitored by means of a voltage measuring device (4a). - Switch the electronic fuse (1a) to non-conductive, and - Check whether the voltage (Ua) at the appliance (3a) drops to the threshold voltage within the specified time.

5. The system (100) according to claim 4, wherein, The test unit (5) is also configured to provide a fault signal (F) to the upper-level control unit (101) if the voltage (Ua) at the appliance (3a) does not drop to the threshold voltage within a specified time.

6. The system (100) according to claim 4 or 5, further comprising: At least one other electrical appliance (3b, 3c); At least one additional electronic safety device (1b, 1c) is disposed between the voltage source (2) and one of the at least one additional electrical appliances (3b, 3c); and At least one additional voltage measuring device (4b, 4c) is configured to measure the voltage (Ub, Uc) at one of the at least one additional electrical appliances (3b, 3c). The test unit (5) is further configured to: The voltage (Ub, Uc) at the at least one additional electrical appliance (3b, 3c) is monitored by means of the at least one additional voltage measuring device (4b, 4c). Switch the at least one additional electronic safety device (1b, 1c) to non-conductive, and Check whether the voltage (Ub, Uc) at the at least one other electrical appliance (3b, 3c) drops to the threshold voltage within a specified time.

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