CURRENT DISTRIBUTOR AND PROTECTION SYSTEM FOR A VEHICLE

Abstract

The invention relates to a current distributor (3) for a vehicle, having an input (E) and a plurality of load channels (LK1, LK2, LKn) which connect the input (E) to a connected load (L1, L2, Ln) via a safety fuse (F1, F2, Fn) and a line (W1, W2, Wn) in each case, and to a protection system (1) for a vehicle having such a current distributor (3). In this case, a standby channel (EK1) connects the input (E) to the connected loads (L1, L2, Ln) via an electronic fuse (EF1), wherein an evaluation and control unit (10) checks the safety fuses (F1, F2, Fn) for functionality and switches on a semiconductor switch (T) of the electronic fuse (EF1) and forms a redundant current path between the input (E) and the connected loads (L1, L2, Ln) via the standby channel (EK1) if at least one of the safety fuses (F1, F2, Fn) is identified as having been tripped.

Claims

1. A current distributor (3, 3A) for a vehicle, the current distributor (3, 3A) comprising: an input (E); and a plurality of load channels (LK1, LK2, LK3, LKn) each configured to connect the input (E) to a connected load (L1, L2, L3, Ln) via a safety fuse (F1, F2, F3, Fn) and a line (W1, W2, W3, Wn), wherein a standby channel (EK1) connects the input (E) to the connected loads (L1, L2, L3, Ln) via an electronic fuse (EF1), and wherein an evaluation and control unit (10) monitors the safety fuses (F1, F2, F3, Fn) for functionality and switches a semiconductor switch (T) of the electronic fuse (EF1) to a conducting state and forms a redundant current path between the input (E) and the connected loads (L1, L2, L3, Ln) via the standby channel (EK1) when at least one of the safety fuses (F1, F2, F3, Fn) is identified as having been tripped.

2. The current distributor as claimed in claim 1, wherein the evaluation and control unit (10) monitors the current flow (iT) in the standby channel (EK1) for an overcurrent fault, wherein the evaluation and control unit (10) evaluates the at least one tripped fuse (F1, F2, F3, Fn) as having been tripped when an overcurrent fault is present.

3. The current distributor as claimed in claim 2, wherein the evaluation and control unit (10) leaves the semiconductor switch (T) in the conducting state and maintains the redundant current path through the standby channel (EK1) when the tripped fuse (F1, F2, F3, Fn) is evaluated as defective.

4. The current distributor as claimed in claim 1, wherein one standby channel (EK1) is provided for each of the load channels (LK1, LK2, LK3, LKn).

5. The current distributor as claimed in claim 1, wherein the evaluation and control unit (10) determines and compares a first voltage (Uref) before and a second voltage (UB1, UB2, UB3, UBn) after the respective safety fuse (F1, F2, F3, Fn).

6. The current distributor as claimed in claim 5, wherein the evaluation and control circuit (10) identifies a tripped safety fuse (F1, F2, F3, Fn) when the first voltage (Uref) differs from the second voltage (UB1, UB2, UB3, UBn).

7. A protection system (1, 1A) for a vehicle, the system including a voltage source (5) configured to provide an on-board power supply voltage (UG) via a main line (A), and a current distributor (3, 3A) configured to apply the on-board power supply voltage to a plurality of connected loads (L1, L2, L3, Ln), wherein the current distributor (3, 3A) is embodied as claimed in claim 1.

8. The protection system as claimed in claim 7, wherein at least one protection function (7) switches the evaluation and control unit (10) cyclically in which the evaluation and control unit (10) monitors the safety fuses (F1, F2, F3, Fn) and the electronic safety fuse (EF1) of the current distributor (3, 3A) for functionality.

9. The protection system as claimed in claim 8, wherein the evaluation and control unit (10), after monitoring the safety fuses (F1, F2, F3, Fn), switches the semiconductor switch (T) into a conducting state and detects and evaluates a corresponding current flow (iT) in the standby channel (EK1) when all the safety fuses (F1, F2, F3, Fn) are evaluated as functional, wherein a detected current flow (iT) in the standby channel (EK1) represents a fault-free semiconductor switch (T).

10. The protection system as claimed in claim 8, characterized in that the evaluation and control unit (10) signals a defective safety fuse (F1, F2, F3, Fn) or a defective semiconductor switch (T) to the at least one protection function (7), wherein when at least one safety fuse (F1, F2, F3, Fn) is evaluated as defective, the safety function (7) switches the evaluation and control circuit (10) into an operating mode in which the evaluation and control unit (10) monitors the current flow (iT) in the standby channel (EK1) and either maintains the redundant current path through the standby channel (EK1) or disconnects the redundant current path in response to an overcurrent fault.

11. The current distributor as claimed in claim 1, wherein the evaluation and control unit (10) monitors the current flow (iT) in the standby channel (EK1) for an overcurrent fault, wherein the evaluation and control unit (10) evaluates the at least one tripped fuse (F1, F2, F3, Fn) as defective when no overflow fault is present.

12. The current distributor as claimed in claim 2, wherein the evaluation and control unit (10) switches the semiconductor switch (T) to a blocking state and disconnects the redundant current path through the standby channel (EK1) when the tripped safety fuse (F1, F2, F3, Fn) is evaluated as having been triggered.

13. The protection system as claimed in claim 8, wherein at least one protection function (7) switches the evaluation and control unit (10), in response to the presence of at least one specified criterion into a test mode which monitors the safety fuses (F1, F2, F3, Fn) and the electronic safety fuse (EF1) of the current distributor (3, 3A) for functionality.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 shows a schematic block diagram of an exemplary embodiment of a protection system according to the invention for a vehicle having an exemplary embodiment of a current distributor according to the invention with n load channels.

[0020] FIG. 2 shows a schematic block diagram of an exemplary embodiment of a protection system according to the invention for a vehicle having an exemplary embodiment of a current distributor according to the invention with three load channels.

DETAILED DESCRIPTION

[0021] As can be seen from FIGS. 1 and 2 the exemplary embodiments illustrated of protection system 1, 1A according to the invention for a vehicle each comprise a voltage source 5, which provides an on-board power supply voltage UG via a main line A, and a current distributor 3, 3A which applies the on-board power supply voltage UG to a plurality of connected loads L1, L2, L3, Ln.

[0022] As can also be seen from FIGS. 1 and 2, the illustrated examples of a current distributor 3, 3A according to the invention for a vehicle each comprise an input E and a plurality of load channels LK1, LK2, LK3, LKn, which connect the input E to a connected load L1, L2, L3, Ln via a safety fuse F1, F2, F3, Fn and a line W1, W2, W3, Wn in each case. In this case a standby channel EK1 connects the input E to the connected loads L1, L2, L3, Ln via an electronic fuse EF1. An evaluation and control unit 10 monitors the safety fuses F1, F2, F3, Fn for functionality and switches a semiconductor switch T of the electronic fuse EF1 to the conducting state and forms a redundant current path between the input E and the connected loads L1, L2, L3, Ln via the standby channel EK1 if at least one of the safety fuses F1, F2, F3, Fn is identified as having been tripped.

[0023] As is also apparent from FIGS. 1 and 2, at least one protection function 7 switches the evaluation and control unit 10 cyclically and/or upon the presence of at least one specified criterion, into a test mode in which the evaluation and control unit 10 monitors the safety fuses F1, F2, F3, Fn and the electronic safety fuse EF1 of the current distributor 3, 3A for functionality. If all of the safety fuses F1, F2, F3, Fn are evaluated as functional, in the exemplary embodiments shown the evaluation and control unit 10 switches the semiconductor switch T to a conducting state after monitoring the safety fuses F1, F2, F3, Fn and detects and evaluates a corresponding current flow iT in the standby channel EK1. In this case a current flow iT detected in the standby channel EK1 represents a fault-free semiconductor switch T. In addition, the evaluation and control unit 10 signals a defective safety fuse F1, F2, F3, Fn and/or a defective semiconductor switch T to the at least one protection function 7. In the event of at least one safety fuse F1, F2, F3, Fn being evaluated as defective, the protection function 7 switches the evaluation and control circuit 10 into an operating mode in which the evaluation and control unit 10 monitors the flow of current iT in the standby channel EK1 and either maintains the redundant current path through the standby channel EK1 or in the case of an overcurrent, disconnects it.

[0024] As is also apparent from FIGS. 1 and 2, the standby channel EK1 branches at the input node El and is routed via the electronic fuse EF1, which comprises the semiconductor switch T and a current measuring unit 20, to output nodes Al, A2, A3, An on the lines W1, W2, W3, Wn of the individual load channels LK1, LK2, LK3, LKn. As a result, the standby channel EK1 is able to bypass each of the safety fuses F1, F2, F3, Fn in the different load channels LK1, LK2, LK3, LKn, which branch at an input node E3.

[0025] As is also apparent from FIGS. 1 and 2, the evaluation and control unit 10 monitors the flow of current iT in the standby channel EK1 for an overcurrent fault. The evaluation and control unit 10 evaluates the at least one tripped safety fuse F1, F2, F3, Fn as having been tripped if an overcurrent fault has occurred. Alternatively, the evaluation and control unit 10 evaluates the at least one tripped safety fuse F1, F2, F3, Fn as being defective if an overcurrent fault has not occurred. The evaluation and control unit 10 leaves the semiconductor switch T in the conducting state and maintains the redundant current path through the standby channel EK1 if the triggered safety fuse F1, F2, F3, Fn is evaluated as defective. Alternatively, the evaluation and control unit 10 switches the semiconductor switch T into the blocking state and disconnects the redundant current path through the standby channel EK1 if the tripped safety fuse F1, F2, F3, Fn is evaluated as having been tripped.

[0026] In order to monitor the safety fuses F1, F2, F3, Fn, the evaluation and control unit 10 determines a first voltage Uref before and a second voltage UB1, UB2, UB3, UBn after the respective fuse F1, F2, F3, Fn and compares these with each other. In this process the first voltage Uref is tapped off at an input node E2. The evaluation and control circuit 10 detects a tripped safety fuse F1, F2, F3, Fn if the first voltage Uref differs from the second voltage UB1, UB2, UB3, UBn.

[0027] As can be seen from FIG. 2, in the illustrated exemplary embodiment, a standby channel EK1 is provided for a specifiable number of three load channels LK1, LK2, LK3. In addition to the activation by the at least one protection function 7, the evaluation and control unit 10 in the illustrated exemplary embodiment switches into the test mode if the first voltage Uref exceeds a specified threshold value Umin. As is also apparent from FIG. 2, the evaluation and control unit 10 comprises a comparison unit 14, which compares the second voltages UB1, UB2, UB3 and the threshold value Umin with the first voltage Uref, and an evaluation circuit 12 which evaluates the comparison processes and outputs the evaluation result via a data channel DAT to the at least one protection function 7. In addition, the evaluation and control unit 10 or the evaluation circuit 12 can receive control commands from the at least one protection function 7 via the data channel DAT. In addition, the evaluation circuit 12 can switch the semiconductor switch T into a conducting or a blocking state via an output driver 16. As is also apparent from FIG. 2, a source terminal S of the semiconductor switch T is connected to the input node El, a gate terminal G of the semiconductor switch T is connected to the output driver 16 and a drain terminal D of the semiconductor switch T is connected to the current measuring unit 20. The current measuring unit 20 comprises a current meter M, the output of which is connected to the evaluation circuit 12. In addition, the current measuring unit 20 comprises three diodes D1, D2, D3. A first diode D1 connects the standby channel EK1 to a first output node Al of a first line W1 of a first load channel LK1, a second diode D2 connects the standby channel EK1 to a second output node A2 of a second line W2 of a second load channel LK2, and a third diode D3 connects the standby channel EK1 to a third output node A3 of a third wire W3 of a third load channel LK3.

[0028] Embodiments of the present invention cyclically activate the test mode of the evaluation and control unit 10. As a result, the safety fuses F1, F2, F3, Fn are cyclically monitored and the state of the semiconductor switch T of the electronic fuse EF1 is also monitored. If a fault is present in at least one of the safety fuses F1, F2, F3, Fn (fuse is blown), the evaluation and control unit 10 switches into the operating mode. In addition, the evaluation and control unit 10 outputs a corresponding signal indicating which one of the safety fuses F1, F2, F3, Fn has failed to the at least one protection function 7 via the data channel 7 DAT.

[0029] If a fault has been found in the semiconductor switch T, the fault is also output to the at least one protection function 7. The at least one protection function 7 decides whether a subsequent working cycle is permissible or whether the vehicle must be stopped as soon as possible. Thus, the vehicle can be switched off, for example, until the replacement of the semiconductor switch T, since in the event of a defective safety fuse F1, F2, F3, Fn no alternative current path is now available any longer through the standby channel EK1 and semiconductor switch T.

[0030] In the operating mode the electronic fuse EF1 replaces the function of the at least one tripped fuse F1, F2, F3, Fn, carries the current to the electrical loads L1, L2, L3, Ln and the evaluation and control unit 10 monitors the current flow iT in the standby channel EK1. In the event of an impermissible current level or overtemperature, the evaluation and control unit 10 switches off the current flow iT in the standby channel EK1 via the semiconductor switch T. In addition, the evaluation and control unit 10 outputs a corresponding signal via the data channel DAT to the at least one protection function 7. The at least one protection function 7 specifies whether and how much longer the vehicle can continue to be operated as a result of the fault or faults. The semiconductor switch T is advantageously designed in such a way that it can carry the current of all load channels LK1, LK2, LK3, LKn for a certain period of time.

[0031] Embodiments of the invention can be used in intelligent current distributors, since they represent cost-effective variants of a hybrid current distributor which comprises safety fuses and electronic fuses, for a redundant power supply in the on-board power supply.