DE102021115840A1 - Determining a state of degradation of a power supply path of an on-board power supply - Google Patents

Abstract

An onboard power supply system (1) for a vehicle (C) has an electrical power supply path (SVP), at least one measuring device (12, 13) for measuring voltage values (U (12), U (13)) at at least one end of the power supply path (SVP ) and an evaluation device (10) which is communicatively connected to the at least one measuring device (12, 13) and is set up to determine a count value (n [U (12)], n [U (13)]) which indicates how often the voltage values (U(12), U(13)) reach or fall below a specified limit value (Ug(12), Ug(13)) within a specified period of time, the evaluation device (10) also being set up for this, then , if the counter value (n [U (12)], n [U (13)]) reaches at least a predetermined counter threshold value (n_th [U (12)]; n_th [U (13)]), an associated degradation state of the power supply path ( SVP) to determine. A vehicle (C) has an electrical system (1). A method (S1-S5) is used to determine a degradation state of a power supply path (SVP) of an on-board power supply system (1) of a vehicle (C).

Description

The invention relates to an on-board power supply system for a vehicle, having an electrical power supply path, at least one measuring device for measuring voltage values at at least one end of the power supply path and an evaluation device communicatively connected to the at least one measuring device. The invention also relates to a vehicle with such a power supply system. The invention also relates to a method for determining a degradation state of a power supply path of an on-board power supply system of a vehicle, in which voltage values are measured at at least one end of the power supply path. The invention is particularly advantageously applicable to electric vehicles.

Anomalous degradation can occur along a power supply path of a vehicle due to environmental influences that prevail during driving and/or due to errors in production, e.g. due to friction effects, etc., which degrade their electrical conductivity and, in the worst case, lead to a path interruption. In order to ensure the availability of a power supply, in particular for safety-relevant functional components of the vehicle, their power supply is often provided via two redundant power supply paths.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide an improved possibility of ensuring a supply of electrically operated functional components of a vehicle.

This object is solved according to the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

• - einen elektrischen Stromversorgungspfad,
• - mindestens eine Messvorrichtung zum Messen von Spannungswerten an zumindest einem Ende des Stromversorgungspfads und
• - eine mit der mindestens einen Messvorrichtung kommunikativ verbundene Auswerteeinrichtung, die dazu eingerichtet ist, einen Zählwert (auch als „Counter“ bezeichenbar) zu bestimmen, der angibt, wie oft die Spannungswerte innerhalb eines vorgegebenen (Beobachtungs- oder Überwachungs-) Zeitraums einen vorgegebenen Grenzwert erreichen oder unterschreiten,

wobei

• - die Auswerteeinrichtung ferner dazu eingerichtet ist, dann, wenn der Zählwert einen vorgegebenen Schwellwert (im Folgenden als „Zählerschwellwert“ bezeichnet) erreicht, einen zugehörigen Degradationszustand des Stromversorgungspfads festzustellen.

The object is achieved by an on-board power supply system for a vehicle

• - an electrical power supply path,
• - at least one measuring device for measuring voltage values at at least one end of the power supply path and
• - an evaluation device that is communicatively connected to the at least one measuring device and is set up to determine a count value (also referred to as a "counter") that indicates how often the voltage values within a specified (observation or monitoring) period exceed a specified limit value reach or fall below

in which

• - the evaluation device is also set up to determine an associated degradation state of the power supply path when the counter value reaches a predetermined threshold value (hereinafter referred to as “counter threshold value”).

This on-board power supply provides the advantage of providing predictive diagnostics to monitor the health of power supply paths before their performance noticeably deteriorates or even fails. This means that previous redundant protection concepts can be supported or even replaced. In the present case, particular use is made of the fact that a current flow through a power supply path is typically accompanied by characteristic voltage dips (caused, for example, by inductive and capacitive effects in the power supply network). It has now been shown that a statement about the state of health or degradation of the power supply path can be derived from the voltage dips. An abnormal degradation state can be detected particularly reliably with the help of the voltage dip count value or "counter". The comparison of the counter value with a predetermined counter threshold value also enables the degradation state of the power supply path to be determined in a manner that is particularly easy to implement.

Suitable limit values can be determined, for example, experimentally or by simulation(s). The at least one counter threshold value can also be established, for example, experimentally or by simulation(s).

The vehicle can be a conventional motor vehicle or an at least partially electrically powered vehicle such as a hybrid vehicle or an all-electrically powered vehicle. In one development, the vehicle is a vehicle set up for autonomous driving.

In one development, the first end of the power supply path is connected to a functional component of the on-board power supply system in the form of a power distributor and/or the second end of the power supply path is connected to a functional component of the on-board power supply system in the form of an electrical consumer. The electrical load causes a current to flow and can be, for example, an electrically operated steering system, an electrically operated brake, an electrically operated suspension system, an electrically operated actuator, an electrically operated heating element, etc.

In one development, the power supply path includes at least one electrical connection system. This is particularly advantageous for connectors because connectors in particular are particularly susceptible to abnormal degradation phenomena such as fretting, etc., due to the requirement for a detachable connection. The power supply path can then in particular include the line (eg a cable) and the associated plug or plug-in connections. However, the connection system is not limited to this and can also be a screwed connection, for example.

In one development, the first end and/or the second end of the power supply path has an electronic fuse, in which the respective measuring device is integrated. This has the advantage that the voltage on the electronic fuse (also known as "E-Fuse") can be measured without additional measurement effort, since a voltage measurement function is already provided on electronic fuses due to the component. The electronic fuse can be integrated into a connection to the power supply path of a component connected to the power supply path.

The evaluation device can be an independent evaluation unit or functionally integrated into an already existing data processing device, e.g. in an on-board computer. In this case in particular, the evaluation device is a component of the on-board power supply system or of the vehicle that has the on-board power supply system, e.g. the on-board computer. However, the evaluation device can also be located outside of the vehicle and can be wirelessly communicatively coupled to the voltage measuring devices, for example via a network. In this case, the evaluation device can be a correspondingly programmed network server or a cloud computer (so-called “backend”), for example. The on-board electrical system including the evaluation device can then also be referred to as an on-board electrical system or the like.

In one development, how often the voltage values within the specified period reach or fall below a specified limit value can include adding all voltage values in the (observation or monitoring) period that reach or fall below the limit value. This corresponds, in particular, to an incrementing of the counter value with each newly added such voltage value.

In another development, how often the voltage values within the specified period reach or fall below a specified limit value can include counting once for the counter value each voltage dip in which at least one voltage value reaches or falls below the limit value in the period, for example a peak-shaped voltage dip. If the voltage dip includes several voltage values that reach or fall below the limit value, these are only counted together once. For example, two consecutive voltage dips can be distinguished from one another by the fact that there is a certain voltage rise between them. This corresponds, in particular, to an incrementing of the counter value with each newly added such voltage dip.

If a voltage value or voltage dip falls outside of the time period, the counter value can be reduced or decremented accordingly.

The at least one counter threshold value n_th is a natural number and can be defined arbitrarily, e.g. to n_th = 1, 2, 3, 4, ... etc. The higher the counter threshold value, the less critical the associated counter tends to be Stress Limit Associated Degradation State. However, if the counter threshold value is set to n_th = 1, for example, this means that reaching or falling below the associated voltage limit value provides a reliable indication of a specific degradation state. Such a limit value can also be referred to as a critical undervoltage mark and in particular can be seen as an indication of an abnormally degraded power supply path.

In principle, the comparison of the counter value with the counter threshold value can be implemented in any way. In this way, the counter value can be incremented starting with the value 0 and monitored when its content corresponds to the counter threshold value. Alternatively, the count may be decremented starting at the counter threshold and monitored when its contents equal zero. If one of these two methods is specifically described below, the other method is also meant.

In a further development, the evaluation device checks exactly how often the voltage values reach or fall below a specified limit value. In a further development, the evaluation device checks how often the voltage values reach or fall below a number of predetermined limit values, ie how often a first limit value is reached or fallen below, how often in the same period of time a second, particularly lower limit value is reached or fallen below, etc. The latter advantageously enables a determination of the presence of different degradation states, eg “slightly degraded”, “severely degraded”, and thus also a graded reaction thereto.

The specified period of time can, for example, be the period of time that has elapsed since the vehicle was switched on, the start of a journey, etc., the duration of which can therefore also be variable. The period can also be adjusted depending on the service life time, a defined driving situation (e.g. a parking maneuver) or the previous error history. The predetermined period of time can even include the entire service life of the vehicle. However, the specified period can also be a running time window, e.g. the last 100 ms, 1 s, 10 s, 1 min, 10 min, etc.

In one development, the degradation state can be determined by measuring or evaluating the voltage values at only one end of the power supply path or at only one of the components connected to the power supply path, which can be implemented particularly easily and inexpensively.

• - eine erste Messvorrichtung zum Messen von ersten Spannungswerten an einem ersten Ende des Stromversorgungspfads und
• - eine zweite Messvorrichtung zum Messen von Spannungswerten an einem zweiten Ende des Stromversorgungspfads

umfasst, die Auswerteeinrichtung dazu eingerichtet ist,

• - einen ersten Zählwert zu bestimmen, der angibt, wie oft die ersten Spannungswerte innerhalb des vorgegebenen Zeitraums einen vorgegebenen ersten Grenzwert erreichen oder unterschreiten und
• - einen zweiten Zählwert zu bestimmen, der angibt, wie oft die zweiten Spannungswerte innerhalb des vorgegebenen Zeitraum einen vorgegebenen zweiten Grenzwert erreichen oder unterschreiten,

und die Auswerteeinrichtung ferner dazu eingerichtet ist, dann, wenn der erste Zählwert einen vorgegebenen ersten Zählerschwellwert erreicht und/oder der zweite Zählwert einen vorgegebenen zweiten Zählerschwellwert erreicht, einen zugehörigen, insbesondere anomalen, Degradationszustand des Stromversorgungspfads festzustellen. Es ergibt sich der Vorteil, dass ein Effekt der beiden Komponenten auf die Spannungseinbrüche kompensiert wird und daher die Spannungseinbrüche den Degradationszustand des Stromversorgungspfads als solchem zuverlässiger abbilden.However, the degradation state can also be determined by measuring or evaluating the voltage values at both ends of the power supply path or at both components connected to the power supply path. In one configuration, the at least one measuring device

• - a first measuring device for measuring first voltage values at a first end of the power supply path and
• - a second measuring device for measuring voltage values at a second end of the power supply path

includes, the evaluation device is set up to

• - to determine a first counter value, which indicates how often the first voltage values within the predetermined period of time reach or fall below a predetermined first limit value and
• - to determine a second counter value, which indicates how often the second voltage values within the predetermined period of time reach or fall below a predetermined second limit value,

and the evaluation device is also set up to determine an associated, in particular abnormal, degradation state of the power supply path when the first counter value reaches a predetermined first counter threshold value and/or the second counter value reaches a predetermined second counter threshold value. This results in the advantage that an effect of the two components on the voltage dips is compensated for and the voltage dips therefore map the degradation state of the power supply path as such more reliably.

In one development, the first counter threshold value n_th1 and the second counter threshold value n_th2 are the same, ie n_th=n_th1=n_th2 applies. A specific degradation state of the power supply path is thus determined when both the first counter threshold value is reached n_th times and the second counter threshold value is reached n_th times.

In one configuration, the first counter threshold value and the second counter threshold value are different. This advantageously enables a particularly reliable detection of existing degradation phenomena. In addition, the extent or degree of degradation can be better estimated and a more detailed statement can be made regarding a probability of failure or the time of failure. This configuration also allows smaller degradation phenomena to be detected earlier.

In a further development, the limit value (i.e. the only limit value or the first and/or the second limit value) is a limit value which can be variably adapted to at least one environmental parameter and/or an aging of the power supply path. This achieves the advantage that environmental effects that influence the ohmic resistance of the power supply path but are not based on abnormal degradation are also taken into account, which in turn significantly reduces the probability of erroneous determinations or false alarms. The fact that the limit value is a variably adaptable limit value can also be expressed in such a way that the limit value is a limit value that is dependent on at least one environmental parameter.

In one development, the at least one environmental parameter includes a temperature of the power supply path and/or humidity in the area of the power supply path, and the limit value is therefore dependent on this.

Taking the temperature of the power supply path into account is particularly advantageous because its ohmic resistance and thus also the voltage drop across it depend noticeably on the temperature. Thus, in turn, the advantage is achieved that the probability of error detection or non-detection of abnormal degradation is noticeably reduced. The temperature can, for example, be measured via a temperature sensor, estimated from a temperature in the engine compartment of the vehicle and/or from an ambient temperature of the vehicle.

It is also possible to estimate the temperature of the power supply path via a current strength of a current flowing through it or by considering a current history through the power supply path, e.g. on the basis of empirical values stored, for example, in a table or characteristic curve, or by model-based estimates. Typically, the higher the current, the higher the temperature of the power supply path. Consequently, the limit value can also be a limit value that is dependent on the current strength of the current flowing through the power supply path.

Humidity can also affect the ohmic resistance of the power supply path through leakage currents: the higher the humidity, the more the resistance typically drops. The humidity can be, for example, air humidity in the environment of the vehicle.

In one development, the limit value is a limit value that is dependent on (permissible) aging of the power supply path. This has the advantage of being able to distinguish between permissible aging of the power line and "abnormal" degradation, e.g. due to signs of wear, component, assembly and/or material defects, etc. This is advantageous because the effect of permissible aging is typically known to a manufacturer of the vehicle and can be remedied, for example, through normal maintenance and therefore generally does not lead to a failure of the power supply path during driving operation. The abnormal degradation, on the other hand, cannot be predicted when designing the on-board energy supply system and is therefore particularly critical, since it can lead to an unforeseen failure of the power supply path. The fact that the limit value is a limit value that is dependent on a permissible aging of the power line can, for example, be implemented in such a way that it changes, e.g. is increased, with increasing age or the service life of the vehicle or the power line.

In a further development, the variable limit values with their influencing parameters are stored and can be called up in tables or as two-dimensional or multi-dimensional characteristic curves. However, they can also be provided as functions dependent on their influencing parameters.

The object is also achieved by a vehicle that has an on-board power supply system as described above. The vehicle can be designed analogously to the on-board power supply system and vice versa, and has the same advantages.

In one configuration, the vehicle is set up to trigger at least one action after a specific, in particular abnormal, degradation state has been detected. A further development thereof is that the at least one action is at least one action from the group: outputting a message to a driver, a service station (e.g. a workshop) and/or a manufacturer of the vehicle; Targeted shutdown of the path affected by degradation to prevent a thermal event; Saving a message in the error memory includes.

• - an zumindest einem Ende des Stromversorgungspfads Spannungswerte gemessen wird,
• - ein Zählwert bestimmt wird, der angibt, wie oft die Spannungswerte innerhalb eines vorgegebenen Zeitraums einen vorgegebenen Grenzwert erreichen oder unterschreiten und
• - dann, wenn der Zählwert einen vorgegebenen Zählerschwellwert erreicht oder überschreitet, ein zugehöriger Degradationszustand des Stromversorgungspfads festgestellt wird.

The object is also achieved by a method for determining a specific, in particular abnormal, state of degradation of a power supply path of an on-board power supply system of a vehicle, in which

• - voltage values are measured at at least one end of the power supply path,
• - a counter value is determined, which indicates how often the voltage values within a predetermined period of time reach or fall below a predetermined limit value and
• - If the counter value reaches or exceeds a predetermined counter threshold value, an associated degradation state of the power supply path is determined.

The method can be designed analogously to the on-board power supply system and the vehicle, and vice versa, and has the same advantages.

• 1 zeigt eine vereinfachte Skizze eines Bordnetzes eines Fahrzeugs;
• 2 zeigt einen Ausschnitt aus der Skizze aus 1;
• 3 zeigt einen Verlauf von an einem Ende eines Stromversorgungspfads des Bordnetzes aus 1 aufgenommenen Spannungswerten für einen nicht degradierten Stromversorgungspfad;
• 4 zeigt einen Verlauf von an einem Ende eines Stromversorgungspfads des Bordnetzes aus 1 aufgenommenen Spannungswerten für einen degradierten Stromversorgungspfad;
• 5 zeigt zwei zeitgleich aufgenommene Verläufe von an beiden Enden eines Stromversorgungspfads des Bordnetzes aus 1 aufgenommenen Spannungswerten für einen degradierten Stromversorgungspfad; und
• 6 zeigt einen möglichen Ablauf des Verfahrens für die in 5 beschriebene Messsituation.

The characteristics, features and advantages of this invention described above, and the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawings.

• 1 shows a simplified sketch of a vehicle electrical system;
• 2 shows a section of the sketch 1 ;
• 3 shows a course from at one end of a power supply path of the vehicle electrical system 1 sampled voltage values for a non-degraded power supply path;
• 4 shows a course of at one end of a power supply path of the vehicle electrical system out 1 recorded voltage values for a degraded power supply path;
• 5 shows two simultaneously recorded curves from both ends of a power supply path of the vehicle electrical system 1 sampled voltage values for a degraded power supply path; and
• 6 shows a possible procedure for the in 5 described measurement situation.

1 shows a simplified sketch of an on-board power supply system 1 of a vehicle C. The on-board power supply system 1 has, purely by way of example, a generator 2 (e.g. an alternator) and a battery 3, the negative poles of which are connected via screwed power lines Ls to a body 4 of the vehicle C, which serves as a reference potential.

A positive pole of the battery 3 is connected via a further screwed power line Ls to a first power distributor 5, which is connected to a second power distributor 6 via yet another screwed power line Ls. Additional components of the vehicle electrical system 1 can also be connected to the first power distributor 5 (not illustrated). The second power distributor 6 is also connected to a positive pole of the generator 2 via another power line Ls that is screwed on and is plugged into a consumer 7 via a cable 8 . Consumer 7 is connected to body 4 via a power line Lst. The load 7 can be, for example, an electrically powered steering system 7a.

In the present case, there is a power supply path SVP between the second power distributor 6 and the consumer 7, which includes the cable 8, a first electrical plug connection St1 of the cable 8 to the second power distributor 6 and a second electrical plug connection St2 of the cable 8 to the second power distributor 6 .

The power supply path SVP and thus the consumer 7 are protected by an electronic fuse 12 integrated into the second power distributor 6, by means of which the voltage U (12) applied thereto and/or the current flowing through it and thus also through the power supply path SVP can be measured . A voltage measuring device and advantageously also a current measuring device are thus functionally integrated in the electronic fuse 12 . At the other end of the power supply path SVP, there is a voltage measuring device 13 in or on the load 7, at which a voltage U (13) can be measured and which, in a further development, can also be designed as an electronic fuse. The voltages U(12) and U(13) are advantageously measured at the same measuring rate.

Other lines or branches of the second power distributor 6 can also be secured with respective electronic fuses (not shown).

The voltage measuring devices 12, 13, etc. are connected to data lines 9, via which the electrical voltages and/or currents measured by them or their measured values can be transmitted to an evaluation device, here in the form of an on-board computer 10, for example.

2 shows a section of the second power distributor 6 of the vehicle electrical system 1. The electronic fuse 12 is connected via a line path 14 to a plug-in connection element 15 of the first plug-in connection St1 and a plug-in connection counter-element 16 of the first plug-in connection St1 plugged in with the cable 8. The plug-in connection element 15 can be integrated, for example, in a housing of the second power distributor.

The second power distributor 6 also has an output to the first power distributor 5 and at least one other power supply output, as indicated here to a consumer 11 .

Returning again to 1 In principle, voltages can also be measured on any other power supply paths of the vehicle electrical system 1 . For example, the generator 2, the battery 3, the first power distributor 5, etc. can also be provided with respective voltage measuring devices (not shown), which are also connected to data lines 9, via which the electrical voltages and possibly currents measured on these components can be measured the on-board computer 10 can be transmitted.

3 shows as a plot of a voltage U in V over a time t in s a profile of voltage values recorded at one end of the power supply path SVP, here purely by way of example the profile of the voltage values U (13) measured by the second measuring device 13 at the load 7. The curve shows several, here: four, pronounced voltage dips, which, however, do not reach an associated lower limit voltage U _g (13) in the time window shown. Therefore, the associated count value is n[U(13)]=0 and there is a healthy power supply path SVP.

4 shows one to 3 analog plot, in which the last of the voltage dips has now reached or fallen below the lower limit voltage U _g (13) in the time window shown, as shown by indicated by the dotted circle. Since a voltage drop is considered an "event" here, the associated counter value is n[U(13)] = 1, even if several consecutive voltage values U(13) of this voltage drop reach or fall below the lower limit voltage U _g (13). .

Depending on how the lower limit voltage U _g (13) is selected, a healthy power supply path SVP can still be present or not. For example, the lower limit voltage U _g (13) can be chosen so low that once it is reached or fallen below it can already be regarded as a reliable indication of an abnormally degraded power supply path, ie n_th=1 applies. Such a lower limit value U _g (13) can also be referred to as a critical undervoltage mark.

5 shows two side by side 3 and 4 analog plots of voltage values recorded at both ends of the power supply path SVP at the same time or in the same period of time, namely voltage values U(12) in the left part and voltage values U(13) in the right part. Purely by way of example, the beginning of both partial images has been set to t=0 s.

While the voltage values U (12) reach or fall below their associated limit value U _g (12) with three voltage dips (corresponding to n [U (12)] = 3), the voltage values U (13) reach or fall below their associated limit value U _g (13) with four voltage dips (corresponding to n [U (13)] = 4). Depending on the set threshold values n_th1 = n_th [U (12)] or n_th2 = n_th [U (13)], this can speak for or against an abnormally degraded power supply path, for example.

6 shows a possible procedure for the in 5 described measurement situation.

At the beginning of the method, in a step S1, the voltage values U(12) and U(13) are measured continuously or quasi-continuously with the same measuring rate as possible.

In a step S2, the respective curves of the voltage values U (12) and U (13) measured in step S1 are evaluated to determine whether voltage dips as an “event” reach or fall below the respective limit values U ₉ (12) or U _g (13).

If this is not the case (“N”), the process branches back to step S2.

If, on the other hand, this is the case (“Y”), in a step S3 the associated counter value n [(U(12)] or n [(U(13)]) is incremented by one for each newly added such voltage dip in the course of the voltage values U (12) a new voltage dip occurs, which reaches or falls below the limit value U _g (12) coming from above, the count value n [(U (12)] according to n [(U (12)] := n[(U(12)] + 1 incremented.

In addition, the counter value n [(U(12)]) is reduced by those voltage dips that have fallen outside of the specified time period.

This scheme is applied analogously to the course of the voltage values U(13).

In a step S4, it is checked whether the count value n [(U (12)] reaches the associated threshold value n_th [U (12)], and it is checked whether the count value n [(U (13)]] exceeds the associated threshold value n_th [U(13)] reached.

If both conditions are not met together ("N"), the process branches back to step S2.

However, if both conditions are met together ("Y"), this corresponds to a determination of a specific, e.g. abnormal, degradation state, and at least one action is then triggered in a step S5.

Of course, the present invention is not limited to the embodiment shown.

In step S4, at least one further condition can be logically ANDed or ORed with the condition specified there. For example, an abnormal degradation state can also be detected if only one of the two conditions is met, but the associated count value n[(U(12)] or n[(U(13)] is very high. This can also be used as a variant of a - basically always possible - graded limit value monitoring.

In general, "a", "an" etc. can be understood as a singular or a plural number, in particular in the sense of "at least one" or "one or more" etc., as long as this is not explicitly excluded, e.g. by the expression "exactly a" etc.

A numerical specification can also include exactly the specified number as well as a usual tolerance range, as long as this is not explicitly excluded.

Reference List

1

power supply system

2

generator

3

battery

4

body

5

First power distributor

6

Second power distributor

7

electrical consumer

7a

Electrically powered steering

8th

Cable

9

data line

10

on-board computer

11

electrical consumer

12

Electronic fuse

13

tension measuring device

14

conduction path

15

connector element

16

mating mating element

C

vehicle

S1-S5

process steps

SVP

power path

St1

First electrical plug connection

St2

Second electrical connector

t

time

u

tension

U(12)

Voltage value measured on the electronic fuse 12

U(13)

Voltage value measured at the voltage measuring device 13

Ug(12)

Limit value for the voltage values U(12)

Ug(13)

Limit value for the voltage values U(13)

Claims (10)

Onboard power supply system (1) for a vehicle (C), having - an electrical power supply path (SVP), - at least one measuring device (12, 13) for measuring voltage values (U (12), U (13)) at at least one end of the power supply path (SVP) and - an evaluation device (10) which is communicatively connected to the at least one measuring device (12, 13) and is set up to determine a counter value (n [U (12)], n [U (13)]), which indicates how often the voltage values (U (12), U (13)) reach or fall below a specified limit value (U _g (12), U _g (13)) within a specified period of time, with - the evaluation device (10) also is set up for this purpose, if the counter value (n [U (12)], n [U (13)]) reaches at least a predetermined counter threshold value (n_th [U (12)]; n_th [U (13)]), a determine the associated degradation state of the power supply path (SVP). Power supply system (1) according to claim 1 , wherein the at least one measuring device (12) - a first measuring device (12) for measuring first voltage values (U (12)) at a first end of the power supply path (SVP) and - a second measuring device (13) for measuring voltage values (U (13)) at a second end of the power supply path (SVP), the evaluation device (10) is set up to - determine a first counter value (n [U (12)]), which indicates how often the first voltage values (U (12)) within the predetermined period of time reach or fall below a predetermined first limit value (U _g (12)) and - determine a second counter value (n [U (13)]) which indicates how often the second voltage values (U( 13)) reach or fall below a predetermined second limit value (U _g (13)) within the predetermined period of time, and the evaluation device (10) is also set up to do so when the first count value (n [U (12)]) exceeds a predetermined first counter threshold (n_th[U(12)]) reaches un d/or the second counter value (n [U (13)]) reaches a predetermined second counter threshold value (n_th [U (13)]) to determine an associated degradation state of the power supply path (SVP). Power supply system (1) according to claim 2 , where the first counter threshold (n_th[U(12)]) and the second counter threshold (n_th[U(13)]) are different. On-board energy supply system (1) according to one of the preceding claims, in which the limit value (U _g (12), U _g (13)) depends on a temperature of the power supply path (SVP). On-board energy supply system (1) according to one of the preceding claims, in which the limit value (U _g (12), U _g (13)) is dependent on humidity in the area of the power supply path (SVP). Power supply system (1) according to any one of the preceding claims, wherein the limit value (U _g (12), U _g (13)) of a current through a current flowing in the power supply path (SVP). On-board energy supply system (1) according to one of the preceding claims, in which the limit value (U _g (12), U _g (13)) is dependent on aging of the power supply path. Vehicle (C) having an on-board energy supply system (1) according to one of the preceding claims. Vehicle (C) after claim 8 , wherein the vehicle (C) is set up to trigger at least one action (S5) after detection of an abnormal degradation state (S4). Method (S1-S5) for determining a degradation state of a power supply path (SVP) of an on-board energy supply system (1) of a vehicle (C), in which - at at least one end of the power supply path (SVP) voltage values (U(12), U(13)) are measured (S1), - a counter value (n [U (12)], n [U (13)]) is determined (S3), which indicates how often the voltage values (U(12), (U(13) ) reach or fall below (S2) a specified limit value (U _g (12), U _g (13)) within a specified period of time and - if the counter value (n [U (12)], n [U (13)] ) reaches or exceeds a predetermined counter threshold value (n_th [U(12)]; n_th [U(13)]) (S4), a degradation state of the power supply path (SVP) is determined (S5).

Images