Sensor for a vehicle electrical system

Abstract

The invention relates to a sensor (S), in particular for an electrical network of an electrically driven vehicle, in particular an electric vehicle. The sensor according to the invention firstly comprises a measuring device (ME) for current measurement and / or voltage measurement in the electrical network, in particular with a low-resistance current-sense resistor for current measurement according to four-wire technology. Furthermore, the sensor (S) according to the invention comprises an integrated insulation monitoring device (ME, IQ, Rk, S3) for monitoring the electrical insulation of the high side and / or the low side of the electrical network. The sensor (S) according to the invention is characterized in that the insulation monitoring device (ME, IQ, Rk, S3) can be actively operated and applies measurement pulses into the electrical network for insulation monitoring.

Description

Technical Field

[0001] This invention relates to a sensor for an onboard electrical grid in electrically driven vehicles, particularly electric vehicles. Background Technology

[0002] In modern motor vehicles, especially in electrically driven motor vehicles, it is essential to measure the current in the onboard electrical network. For this purpose, the so-called four-wire technique, known for example from EP 0 605 800 A1, can be used. The current to be measured passes through a low-resistance current-sensing resistor (“shunt”), and the voltage drop across the low-resistance current-sensing resistor is measured, forming a measure of the current to be measured according to Ohm’s law. This measurement method based on the four-wire technique is used by current sensors known for example from EP 2 542 902 B1 and WO 2010 / 121841 A1.

[0003] Furthermore, insulation monitoring is required in vehicle electrical systems, as described, for example, in the technical standard DIN EN 61557-8. To this end, many semiconductor manufacturers offer chips that support passive insulation monitoring in addition to current measurement. However, active insulation monitoring is not possible using these known chips.

[0004] Therefore, different components are required for current measurement and active insulation monitoring in known vehicle-mounted electrical systems.

[0005] Finally, regarding the prior art, reference should also be made to DE 10 2014 204 870 A1, DE 10 2015 008 831 A1 and DE 10 2008 010 980 A1. DE 10 2014 204 870 A1 discloses an insulation monitoring system, but the difference between this document and the present invention lies particularly in the type of insulation monitoring and the type of coupling with the network. Summary of the Invention

[0006] Therefore, this invention is based on simplifying the tasks of current measurement and insulation monitoring in vehicle-mounted electrical networks.

[0007] This task is accomplished by the sensor according to the invention as described in the main claim.

[0008] This invention includes general technical teachings on integrating the technical functions of current measurement and active insulation monitoring into a single sensor, thereby reducing the amount of construction work required in vehicle electrical systems.

[0009] Therefore, according to the prior art, the sensor according to the present invention primarily includes a measuring device for current measurement and / or voltage measurement in an electric vehicle power grid.

[0010] In a preferred embodiment of the invention, as described above with respect to the prior art, the measuring device for current measurement operates according to a known four-wire technique and includes a low-resistance current sensing resistor (“shunt”).

[0011] However, the present invention is not limited to the four-wire measurement principle in terms of the operation of the measuring device for current measurement. Other measurement principles can also be used in the measuring device for current measurement. For example, the measuring device for current measurement can have a Hall sensor, as known for example from EP 2 511 714 A2. Furthermore, within the scope of the present invention, different measurement principles can also be applied to the measuring device for current measurement in order to achieve redundant current measurement. For example, the measuring device can have a low-resistance current sensing resistor and additionally a Hall sensor. This type of redundant current measurement is also described in EP 2 511 714 A2.

[0012] Furthermore, the sensor according to the invention, like the conventional chip described at the beginning, includes an integrated insulation monitoring device to monitor the electrical insulation of the vehicle electrical network on the high side and / or low side.

[0013] The sensor according to the invention is characterized in that the integrated insulation monitoring device operates actively and applies measurement pulses to the vehicle electrical network for insulation monitoring. Compared with the aforementioned chips with integrated insulation monitoring devices, the insulation monitoring device in the sensor according to the invention does not operate passively, or at least not entirely passively.

[0014] The advantage of integrating active insulation monitoring into sensors used for current and voltage measurements is that customers no longer need to apply high voltages to their battery management system (BMS), which significantly simplifies their hardware architecture, reduces testing workload during production, and saves costs.

[0015] Another advantage of integrating the active insulation monitoring device into the sensor for current and voltage measurement according to the invention is the saving of many components. For example, known sensors for current and voltage measurement contain many components that are also required by separate insulation monitoring devices (e.g., voltage measurement input, A / D converter, microcomputer, electrical insulation, communication interface). If the active insulation monitoring device is integrated into the sensor, these components of the current sensor can be shared by the active insulation monitoring device, so that these components are no longer needed.

[0016] This specification describes the use of sensors according to the invention in automotive electrical networks. However, sensors according to the invention can also be used in stationary battery applications. Therefore, the specific terminology of automotive electrical networks used in the context of this invention can be replaced by more general terms for electrical networks. However, for ease of understanding, the specific terminology of automotive electrical networks is used throughout this specification.

[0017] In the context of active insulation monitoring, the required coupling of the measurement pulse to the vehicle electrical network necessitates coupling the insulation monitoring device to the vehicle electrical network. Preferably, as will be described in detail, this coupling of the insulation monitoring device for applying the measurement pulse is not performed on the high side (positive terminal of the battery) or the low side (negative terminal of the battery) of the vehicle electrical network, but rather at the chassis grounding point of the vehicle.

[0018] In one variant of the invention, resistive coupling between the insulation monitoring device and the vehicle electrical network is provided, whereby the measuring pulse is a DC measuring pulse (DC: direct current). In another variant of the invention, capacitive coupling between the insulation monitoring device and the vehicle electrical network is provided, wherein the measuring pulse is an AC measuring pulse (AC: alternating current). In a third variant of the invention, resistive coupling between the insulation monitoring device and the vehicle electrical network is also provided, but the measuring pulse is an AC measuring pulse.

[0019] In the context of this invention, the term "high side" (as briefly described above) preferably means that the vehicle electrical network can be connected to the positive terminal of the battery at the high side. Conversely, the term "low side" in the context of this invention preferably means that the vehicle electrical network can be connected to the negative terminal of the battery at the low side. This differs from so-called chassis grounding, which is formed by the vehicle and its chassis.

[0020] Active insulation monitoring devices are now preferably designed to determine the leakage capacitance between the low side and / or high side of the vehicle electrical network and the chassis ground.

[0021] The active insulation monitoring device can also adapt the frequency of the measurement pulse coupled to the vehicle electrical network based on the determined leakage capacitance. For example, an active insulation monitoring device using a multi-frequency method is known from EP 2 717 063 A1, and the content of that patent application regarding the frequency adaptation of the measurement pulse is applicable to this specification.

[0022] As briefly mentioned above, the measuring device for the sensor used for current measurement preferably operates according to, for example, the four-wire technique described in EP 0605 800 A1. Therefore, the sensor preferably has two current connections to feed the vehicle electrical grid current to be measured into or out of the sensor. The measuring device then measures the vehicle electrical grid current, for example, according to the four-wire technique.

[0023] Active insulation monitoring requires voltage measurements to be taken at different measurement points within the vehicle's electrical grid.

[0024] Therefore, the sensor according to the invention first has a first voltage measurement terminal to measure the voltage at a first measurement point in the on-board electrical network located on the high side behind the switchable high-side contactor. It should be noted here that the terms "front" and "rear" refer to the battery's perspective; that is, from the battery's perspective, the first measurement point is located behind the switchable high-side contactor. Therefore, the first measurement point is located on the high side of the on-board electrical network, preferably between the high-side contactor and the load (e.g., the inverter). Furthermore, it should be noted that the high-side contactor is preferably arranged in the main path, wherein a secondary path extends in parallel with the main path, the secondary path being used to limit current during the connection process, and the secondary path including a disconnect switch and a resistor ("pre-charge resistor"). Then, the first measurement point for active insulation monitoring is preferably located in the main path.

[0025] Furthermore, the sensor according to the invention has a second voltage measurement terminal for measuring the voltage at a second measurement point located on the low side of the vehicle electrical network behind the switchable low-side contactor. The second measurement point for active insulation monitoring is located on the low side of the vehicle electrical network, i.e., preferably between the low-side contactor and the load (e.g., the inverter).

[0026] Furthermore, the sensor preferably has a third voltage measurement terminal for measuring voltage at a third measurement point on the high side of the vehicle electrical network located between the battery and the high-side contactor. Preferably, the vehicle electrical network has a fuse on the high side. Then, the third measurement point for active insulation monitoring is located on the high side, preferably between the battery and the fuse.

[0027] Voltage measurements at these three points within the vehicle's electrical network enable active insulation monitoring, allowing the derivation of leakage capacitance and leakage resistance between the low-side and / or high-side and chassis grounding from the voltage measurements. The calculation of leakage capacitance or leakage resistance is largely derived from known methods used for active insulation monitoring, such as EP 0 654 673B1, EP 2 256 506 B1, and DE 10 2018117 296B4. Therefore, a detailed description of the calculation of leakage resistance or leakage capacitance is not necessary here.

[0028] In a preferred embodiment of the invention, the sensor has a controllable, high-voltage-resistant first disconnect switch at a first voltage measurement terminal on the high side. The first disconnect switch optionally enables measurement sensing at the first voltage measurement terminal or disconnection of the first voltage measurement terminal.

[0029] Furthermore, the sensor according to the invention preferably includes a controllable, high-voltage resistant second disconnect switch at the second voltage measurement terminal, wherein the second disconnect switch optionally enables measurement interrogation or disconnection of the second voltage measurement terminal at the second voltage measurement terminal.

[0030] As mentioned above, as part of active insulation monitoring, the measurement pulses are coupled to the vehicle's electrical grid. Therefore, in a preferred embodiment, the sensor according to the invention has a coupling output terminal to enable coupling of the sensor to the vehicle's chassis ground; the coupling output terminal of the sensor is preferably high impedance.

[0031] In order to generate a measurement pulse for active insulation monitoring, the sensor in the preferred embodiment has a pulse voltage source that is capable of generating a measurement pulse during active insulation monitoring and outputting the measurement pulse at the coupling output terminal of the sensor.

[0032] Optionally, the sensor may have a controllable, high-voltage resistant third disconnect switch at the sensor's coupling output terminal, wherein the third disconnect switch may optionally couple the pulse voltage source to the chassis ground or isolate the pulse voltage source from the chassis ground.

[0033] Furthermore, in a preferred embodiment, the sensor includes a calculation unit for calculating at least one resistance value and one capacitance value within the active insulation monitoring range. Methods for calculating leakage resistance and / or leakage capacitance are described in the aforementioned patent applications EP 0 654 673 B1, EP 2256 506 B1, and DE 10 2018 117 296 B4, therefore, the calculation need not be described in detail here.

[0034] For example, the calculation unit can calculate the following quantities based on the voltage measurement value and the measurement pulse from the pulse voltage source:

[0035] • The first leakage resistance between the high side of the on-board electrical network in front of the high-side contactor and the vehicle's chassis ground.

[0036] • The first leakage capacitance between the high side of the on-board electrical network in front of the high-side contactor and the vehicle chassis ground.

[0037] • The second leakage resistance between the low side of the on-board electrical network in front of the low-side contactor and the vehicle's chassis ground.

[0038] • The second leakage capacitance between the low side of the on-board electrical network in front of the low-side contactor and the vehicle's chassis ground.

[0039] • The third leakage resistance between the high side of the vehicle electrical network behind the high-side contactor and the vehicle's chassis ground.

[0040] • The third leakage capacitance between the high side of the vehicle electrical network behind the high-side contactor and the vehicle chassis ground.

[0041] • The fourth leakage resistance between the low side of the on-board electrical network behind the low-side contactor and the vehicle's chassis ground.

[0042] • The fourth leakage capacitance between the low side of the on-board electrical network behind the low-side contactor and the vehicle's chassis ground.

[0043] Therefore, within the scope of this invention, the leakage resistance and leakage capacitance relative to the chassis ground can preferably be determined in both the DC group and the DC link, and respectively for the high side and low side of the vehicle electrical network.

[0044] By combining the insulation monitoring results with the voltage measurements at three measurement points, a statement can be made regarding the insulation level within the HV battery or the powertrain of an electric motor vehicle, as well as a statement regarding the polarity (HV-Pos or HV-Neg) of the insulation fault on the DC link side. In addition to measuring the insulation on the DC group side (when the main contactor is open, and when the switch in the secondary path in parallel with the high-side contactor is open, and when the disconnect switch in the measurement path for the first and second measurement points is open), the insulation monitoring device also determines the polarity of the insulation fault with respect to HV-Pos / HV-Neg, and the individual value of the leakage resistance from the HV group side to chassis ground, based on the measured voltage at the third measurement point. If the main contactor is now closed, the insulation value for the entire vehicle will be determined as the parallel value of HV-Pack and HV-Link, taking into account the measured voltage at the third measurement point, the polarity of the insulation fault with respect to HV-Pos / HV-Neg, and the individual value of the leakage resistance, thereby also allowing the calculation of the leakage resistance downstream of the contactor relative to chassis ground.

[0045] As mentioned above, the three voltage measurement terminals are used for active insulation monitoring. However, the sensor may also have other voltage measurement terminals for measuring the voltage in the vehicle electrical network at other measurement points.

[0046] For example, a fourth voltage measurement terminal can be provided to measure the voltage in the vehicle electrical network at a fourth measurement point located on the high side of the vehicle electrical network in front of the switchable high-side contactor. In a preferred embodiment, the fourth measurement point is located behind the fuse and on the high side in front of the branch leading to the main path and the secondary path for current limiting.

[0047] Furthermore, a fifth voltage measurement terminal can be provided to measure the voltage at a fifth measurement point located in the aforementioned secondary path, which extends in parallel with a switchable high-side contactor on the high side of the vehicle electrical network. This secondary path in parallel with the switchable high-side contactor is known in the prior art and enables a soft-close process when the high-side contactor is closed. For this purpose, the switch in the secondary path closes first, where a resistor (“pre-charge resistor”) limits the current. Only then does the high-side contactor close.

[0048] Furthermore, the sensor may have a sixth voltage measurement terminal to measure the voltage at a sixth measurement point on the low side of the on-board electrical network located in front of the switchable low-side contactor. The sixth measurement point is preferably located on the low side between the fuse and the low-side contactor.

[0049] These three additional voltage measurement terminals can also be used for purposes other than active insulation monitoring.

[0050] Furthermore, it should be noted that the integration of the sensor for current / voltage measurement and the active insulation monitoring device can be accomplished in a common integrated circuit (“chip”). However, it is also possible that the two components (the sensor for current / voltage measurement and the active insulation monitoring device) are arranged only on a common printed circuit board or only in a common housing.

[0051] Furthermore, it should be mentioned that the present invention claims protection not only for the aforementioned sensor according to the invention as a single component, but also for a battery management system (BMS) for an onboard electrical network of an electric vehicle having such a sensor according to the invention. The battery management system further includes a measurement path between the voltage measurement terminal of the sensor and the associated measurement point. Additionally, the battery management system includes a coupling path between the coupled output terminal of the sensor and the vehicle's chassis ground.

[0052] Furthermore, it should be mentioned that the present invention also claims protection for the complete on-board electrical network of a vehicle including such a battery management system having sensors according to the present invention. The on-board electrical network may also include, for example, the following other components:

[0053] • A battery for supplying power to an onboard electrical grid, wherein the battery is preferably rechargeable.

[0054] • The discharge circuit between the high and low sides of the vehicle electrical network behind the high-side contactor and the low-side contactor.

[0055] Inverter.

[0056] Finally, the present invention also claims protection for vehicles (e.g., electric vehicles) having such an onboard electrical network, the onboard electrical network being equipped with a battery management system having sensors according to the present invention. Attached Figure Description

[0057] Figure 1 A circuit diagram of an onboard electrical network for an electrically driven motor vehicle according to the present invention is shown. Detailed Implementation

[0058] As is known in the art, the on-board electrical network connects the DC group of an electrically driven motor vehicle to the DC link. The DC group is connected to the DC link via two switchable contactors RHV+ and RHV-, respectively, on the high side and low side.

[0059] The vehicle's electrical grid is powered by a rechargeable battery (BAT). The positive terminal (+) of the battery BAT is connected to the high side of the electrical grid, while the negative terminal (-) is connected to the low side. Thus, the low side of the electrical grid forms the battery ground, represented by the symbols GND, VMGND1, and VMGMD2. However, this must be connected to the chassis ground (GND). Chassis To distinguish them, the chassis ground GND Chassis It is not typically connected to the vehicle's electrical grid.

[0060] In the vehicle-mounted electrical network, fuses F+ and F- are located on the high and low sides of the DC group, respectively, as is known from the prior art.

[0061] Furthermore, it should be mentioned that the secondary path is connected in parallel with the switchable contactor RHV+ located on the high side of the vehicle electrical network. This secondary path includes a resistor PRES (“pre-charge resistor”) and a disconnect switch PR. Before energizing both contactors RHV+ and RHV-, the disconnect switch PR is closed first, allowing a small current to begin flowing through the secondary path. The RHV+ contactor is only closed at this point. This stepwise closure of the disconnect switch PR and the contactor RHV+ prevents a sudden increase in current in the vehicle electrical network during the energizing process.

[0062] Buffer capacitor C DC-Link It is connected in the DC link between the high side and the low side.

[0063] In addition, the discharge circuit Rx is connected in the DC link between the high side and the low side, which is shown only schematically here.

[0064] Finally, the vehicle's electrical grid supplies power to the inverter INV, which is only shown schematically here.

[0065] In vehicle electrical systems, there is now a sensor S according to the present invention, which has two functions. On the one hand, sensor S enables the measurement of vehicle electrical system current I according to four-wire technology. On the other hand, sensor S also enables active insulation monitoring, and these two functions will be described below.

[0066] For current measurement, sensor S has two current connectors A1 and A2, used to introduce the vehicle grid current I to be measured into sensor S and to discharge it from sensor S, respectively. Measuring device ME then measures the vehicle grid current I in sensor S, wherein the measuring device can operate, for example, according to the four-wire technique known from EP 0 605 800A1.

[0067] In addition, sensor S has three voltage measurement terminals M1, M2 and M3 for active insulation monitoring, which measure the voltage in the vehicle power grid at three measurement points 1, 2 and 3, respectively.

[0068] For active insulation monitoring, sensor S also has a pulse voltage source IQ, which outputs a measurement pulse at the coupling output terminal AK via coupling resistor Rk and controllable switch S3. The coupling output terminal AK is connected to the chassis ground GND. Chassis Then, the measuring device ME can calculate the following leakage resistance or leakage capacitance based on the voltage measurements at measuring points 1, 2, and 3:

[0069] • The high side of the vehicle electrical network before the high-side contactor RHV+ is connected to the vehicle chassis ground GND. CHASSIS The first leakage resistance Rf1 between them.

[0070] • The high side of the vehicle electrical network before the high-side contactor RHV+ is connected to the vehicle chassis ground GND. CHASSIS The first leakage capacitor Cy1 between them.

[0071] • The low side of the on-board electrical network in front of the low-side contactor RHV- is connected to the vehicle chassis ground GND. CHASSIS The second leakage resistance Rf2 between them.

[0072] • The low side of the on-board electrical network in front of the low-side contactor RHV- is connected to the vehicle chassis ground GND. CHASSIS The second leakage capacitor Cy2 between them.

[0073] • The high side of the vehicle electrical network after the high-side contactor RHV+ is connected to the vehicle chassis ground GND. CHASSIS The third leakage resistance Rf3 between them.

[0074] • The high side of the vehicle electrical network behind the high-side contactor RHV- is connected to the vehicle chassis ground GND. CHASSIS The third leakage capacitor Cy3 between them.

[0075] • The low side of the vehicle electrical network behind the low-side contactor RHV- is connected to the vehicle chassis ground GND. CHASSIS The fourth leakage resistance Rf4 between them.

[0076] • The low side of the vehicle electrical network behind the low-side contactor RHV- is connected to the vehicle chassis ground GND. CHASSIS The fourth leakage capacitor Cy4.

[0077] The calculations for leakage resistances Rf1, Rf2, Rf3, Rf4 and leakage capacitances Cy1, Cy2, Cy3, Cy4 can be performed in a conventional manner, as explained, for example, in EP 0 654 673 B1, EP 2 256 506 B1 and DE10 2018 117 296B4.

[0078] In addition, the sensor S has multiple disconnect switches S1, S2, and S3, which are high voltage resistant and allow the voltage measurement terminals M1, M2, and M3 and the coupling output terminal AK to be disconnected respectively.

[0079] Finally, sensor S has three additional voltage measurement terminals M4, M5, and M6, which allows voltage measurements to be performed at three additional measurement points 4, 5, and 6 within the vehicle electrical network. However, voltage measurements at measurement points M4, M5, and M6 are optional and unrelated to active insulation monitoring.

[0080] This invention is not limited to the preferred embodiments described above. Instead, numerous variations and modifications are possible, which also utilize the spirit of the invention and thus fall within its scope of protection. In particular, the invention also claims protection over the subject matter and features of dependent claims independently of the cited claims, and especially claims protection over the subject matter and features of dependent claims even when they lack the features of the main claim. Therefore, the invention encompasses various inventive aspects that are protected independently of each other.

[0081] List of reference numerals

[0082] 1. The first measuring point located on the high side of the vehicle electrical network behind the switchable contactor RHV+.

[0083] 2. The second measuring point is located on the lower side of the on-board electrical network behind the switchable contactor RHV-.

[0084] 3. The third measuring point located on the high side of the on-board electrical grid in front of the switchable contactor RHV+.

[0085] 4. The fourth measuring point located on the high side of the on-board electrical grid in front of the switchable contactor RHV+.

[0086] 5. The fifth measurement point located on the high side of the on-board electrical network in the secondary path connected in parallel with the switchable contactor RHV+.

[0087] 6. The sixth measuring point located on the lower side of the on-board electrical network in front of the switchable contactor.

[0088] A1 is a current connector used to introduce onboard electrical current into the sensor.

[0089] A2 is a current connector used to drain the current from the sensor in the vehicle's electrical grid system.

[0090] AK sensor coupling output terminal

[0091] BAT batteries

[0092] C DC-LINK Buffer capacitor

[0093] Cy1 Switchable Contactor: High Side of Vehicle Electrical Network in Front of the Onboard Power Grid and Chassis Ground (GND) Chassis leakage capacitance between

[0094] Cy2 switchable contactor connects the low side of the vehicle electrical grid in front of the chassis ground GND. Chassis leakage capacitance between

[0095] Cy3 switchable contactor connects the high side of the vehicle electrical network to the chassis ground (GND). Chassis leakage capacitance between

[0096] Cy4 switchable contactor connects the low side of the vehicle electrical network behind the chassis ground (GND). Chassis leakage capacitance between

[0097] F- Fuse on the low side of the vehicle's electrical network

[0098] F+ Fuse on the high side of the vehicle electrical network

[0099] GND Battery Ground

[0100] GND Chassis Chassis grounding

[0101] I. Onboard electrical grid current

[0102] INV Inverter

[0103] IQ pulse voltage source

[0104] Voltage measurement terminals of M1-M6 sensors

[0105] ME sensor measurement device

[0106] + Positive terminal of battery BAT

[0107] - The negative terminal of battery BAT

[0108] The switch in the secondary path of PR connected in parallel with the switchable contactor RHV+

[0109] The resistor in the secondary path of PRES connected in parallel with the switchable contactor RHV+.

[0110] RHV - Switchable contactor on the low side of the vehicle-mounted electrical network

[0111] RHV+ Switchable contactor on the high side of the vehicle-mounted electrical grid

[0112] Rk coupling resistor

[0113] Rx discharge circuit

[0114] Ry1 is connected to the chassis ground GND on the high side of the on-board electrical network in front of the switchable contactor. Chassis leakage resistance between

[0115] Ry2 is connected to the chassis ground GND on the low side of the on-board electrical network in front of the switchable contactor. Chassis leakage resistance between

[0116] Ry3 is connected to the chassis ground GND on the high side of the on-board electrical network behind the switchable contactor. Chassis leakage resistance between

[0117] Ry4 is connected to the chassis ground GND on the low side of the on-board electrical network behind the switchable contactor. Chassis leakage resistance between

[0118] S sensor

[0119] S1-S3 Controllable Disconnect Switches

[0120] VMGND1 Battery Ground

[0121] VMGND2 Battery Ground

Claims

1. A sensor (S) for an electrical network having a high side for connecting to a positive (+) terminal of a battery (BAT), a low side for connecting to a negative (-) terminal of the battery (BAT), and a chassis ground (GND). CHASSIS The sensor includes: a) A measuring device (ME) for measuring current and / or voltage in the electrical network, and b) An integrated insulation monitoring device (ME, IQ, Rk, S3) for monitoring the electrical insulation of the high-side and / or low-side of the electrical network. Its features are, c) The insulation monitoring devices (ME, IQ, Rk, S3) are capable of actively operating and applying measurement pulses to the electrical network for insulation monitoring, and are capacitively or resistively coupled to the electrical network. d) Active insulation monitoring devices (ME, IQ, Rk, S3) determine the low side and / or high side of the electrical network to the chassis ground (GND) of the electrical network. CHASSIS The leakage capacitance between (Cy1, Cy2, Cy3, Cy4), and e) The active insulation monitoring device (ME, IQ, Rk, S3) adapts the frequency of the measurement pulse according to the determined leakage capacitance (Cy1, Cy2, Cy3, Cy4).

2. The sensor (S) according to claim 1, characterized in that, The sensor (S) also includes: a) A first current connector (A1) for introducing the network current (I) of the electrical network into the sensor (S). b) A second current connector (A2) for discharging the network current (I) of the electrical network from the sensor (S). c) wherein the measuring device (ME) measures the network current (I).

3. The sensor (S) according to any one of the preceding claims, characterized in that, The sensor (S) also includes: a) A first voltage measurement terminal (M1) is used to measure the voltage at a first measurement point (1) on the high side of the electrical network, following the switchable high-side contactor (RHV+) on the high side of the electrical network. b) A second voltage measurement terminal (M2) for measuring voltage at a second measurement point (2) on the low side of the electrical network, following the switchable low-side contactor (RHV-) on the low side of the electrical network, and c) A third voltage measurement terminal (M3) is used to measure the voltage at a third measurement point (3) on the high side of the electrical network between the battery (BAT) and the high-side contactor (RHV+) on the high side of the electrical network.

4. The sensor (S) according to claim 3, characterized in that, The sensor (S) also includes: a) A controllable, high-voltage resistant first disconnect switch (S1) located at the first voltage measuring terminal (M1), the first disconnect switch (S1) being capable of selectively sensing or disconnecting the first voltage measuring terminal (M1) at the first voltage measuring terminal (M1), and / or b) A controllable, high-voltage resistant second disconnect switch (S2) located at the second voltage measurement terminal (M2), the second disconnect switch (S2) being able to optionally perform measurement inquiry or disconnect the second voltage measurement terminal (M2) at the second voltage measurement terminal (M2).

5. The sensor (S) according to claim 3, characterized in that, The sensor (S) also includes: a) Coupled output terminal (AK), which is used to couple the sensor (S) to the chassis ground (GND). CHASSIS ), b) A pulse voltage source (IQ) for active insulation monitoring, said pulse voltage source (IQ) being capable of generating a measurement pulse during active insulation monitoring and outputting said measurement pulse at said coupling output (AK). c) A controllable, high-voltage resistant third disconnect switch (S3) located at the coupling output terminal (AK) of the sensor (S), the third disconnect switch (S3) optionally coupling the pulse voltage source (IQ) to the electrical network or isolating the pulse voltage source (IQ) from the electrical network.

6. The sensor (S) according to claim 5, characterized in that, The sensor (S) also includes: A calculation unit is used to calculate at least one resistance value (Rf1, Rf2, Rf3, Rf4) and / or one capacitance value (Cy1, Cy2, Cy3, Cy4) within the range of insulation monitoring.

7. The sensor (S) according to claim 6, characterized in that, a) The calculation unit is capable of calculating the following variables based on the voltage measurement values ​​at at least one of the voltage measurement terminals (M1-M3) and the measurement pulse of the pulse voltage source (IQ): a1) The high side of the electrical network preceding the high-side contactor (RHV+) is connected to the chassis ground (GND). CHASSIS The first resistor (Rf1) between and / or a2) The high side of the electrical network preceding the high-side contactor (RHV+) is connected to the chassis ground (GND). CHASSIS The first capacitor (Cy1) between and / or b) The calculation unit is capable of calculating the following variables based on the voltage measurement values ​​at at least one of the voltage measurement terminals (M1-M3) and the measurement pulse of the pulse voltage source (IQ): b1) The low side of the electrical network in front of the low-side contactor (RHV-) is connected to the chassis ground (GND). CHASSIS The second resistor (Rf2) between and / or b2) The low side of the electrical network preceding the low-side contactor (RHV-) is connected to the chassis ground (GND). CHASSIS The second capacitor (Cy2) between ) and / or c) The calculation unit is capable of calculating the following variables based on the voltage measurement values ​​at at least one of the voltage measurement terminals (M1-M3) and the measurement pulse of the pulse voltage source (IQ): c1) The high side of the electrical network following the high-side contactor (RHV+) is connected to the chassis ground (GND). CHASSIS The third resistor (Rf3) between and / or c2) The high side of the electrical network following the high-side contactor (RHV+) is connected to the chassis ground (GND). CHASSIS The third capacitor (Cy3) between and / or d) The calculation unit is capable of calculating the following variables based on the voltage measurement values ​​at at least one of the voltage measurement terminals (M1-M3) and the measurement pulse of the pulse voltage source (IQ): d1) The low side of the electrical network following the low-side contactor (RHV-) is grounded to the chassis (GND). CHASSIS The fourth resistor (Rf4) between and / or d2) The low side of the electrical network following the low-side contactor (RHV-) is grounded to the chassis (GND). CHASSIS The fourth capacitor (Cy4) between ).

8. The sensor (S) according to any one of claims 5-7, characterized in that, The sensor (S) also includes: a) The fourth voltage measurement terminal (M4) is used to measure the voltage at the fourth measurement point (4) on the high side of the electrical network in front of the switchable high-side contactor (RHV+) on the high side of the electrical network. b) A fifth voltage measurement terminal (M5) for measuring voltage at a fifth measurement point (5) in a secondary path extending in parallel with the switchable high-side contactor (RHV+) on the high side of the electrical network, and / or c) The sixth voltage measurement terminal (M6) is used to measure the voltage at the sixth measurement point (6) on the low side of the electrical network in front of the switchable low-side contactor (RHV-) on the low side of the electrical network.

9. The sensor (S) according to any one of claims 1, 2, 4-7, characterized in that, a) The electrical network is the on-board electrical network of an electric vehicle; and / or b) The measuring device (ME) has a low-resistance current sensing resistor for current measurement according to the four-wire technique.

10. The sensor (S) according to claim 9, characterized in that, The electric vehicle in question is an electric car.

11. The sensor (S) according to claim 9, characterized in that, a) The coupling output terminal (AK) is used to couple the sensor (S) to the electric drive vehicle; and / or b) The coupled output terminal (AK) is high impedance.

12. A battery management system for an electrical network, comprising: a) The sensor (S) according to any one of claims 5-8 b) A first measurement path, which extends from the first voltage measurement terminal (M1) of the sensor (S) to the first measurement point (1) on the high side of the electrical network located behind the high-side contactor (RHV+). c) A second measurement path, which extends from the second voltage measurement terminal (M2) of the sensor (S) to the second measurement point (2) on the low side of the electrical network located behind the low-side contactor (RHV). d) A third measurement path, which runs from the third voltage measurement terminal (M3) of the sensor (S) to a third measurement point (3) on the high side of the electrical network located before the high-side contactor (RHV+), and e) The coupling output terminal (AK) of the sensor (S) is located at the ground of the chassis (GND). CHASSIS The coupling path between ).

13. An electrical network having a battery management system according to claim 12.

14. The electrical network according to claim 13, characterized in that, Electrical networks have the following other components: a) A battery (BAT) for powering the electrical network, the battery (BAT) being rechargeable, and / or b) The discharge circuit (Rx) between the high and low sides of the electrical network located after the high-side contactor (RHV+) and the low-side contactor (RHV-), and / or c) Inverters (INV) powered by the high and low sides of the electrical network.

15. A vehicle having an electrical network according to claim 13 or 14.

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