DE102021213719B3 - Conduction device for conducting electric current and propulsion system for propelling a vehicle - Google Patents

Abstract

Conducting device (140) for conducting electrical current. The line device (140) comprises at least one high-voltage line (150), which has a conductor unit (200) for conducting electrical current, an insulating layer (205) for insulating the conductor unit (200), a shielding layer (210) for electromagnetic shielding of the conductor unit ( 200) and a jacket layer (215) to protect the high-voltage cable (150) from external influences. In addition, the line device (140) comprises at least one sensor unit (160) arranged on the casing layer (215) for sensing a casing temperature (TM) of the casing layer (215), the sensor unit (160) being designed to record the sensed casing temperature (TM) provide representative temperature signal (165).

Description

The present invention relates to a line device for conducting electric current, a drive system for driving a vehicle, and a method for detecting a temperature of a high-voltage line.

High-voltage cables, which can also be referred to as HV cables, can be used, among other things, in electric drive systems, for example to drive a vehicle.

Various types are mentioned in the prior art. So is in the DE 10 2018 006 425 A1 describes a temperature limitation system for high-voltage applications with a high-voltage line that has a line core, a line shield and insulation.

WO 2021 / 083 565 A1 discloses a method and a device for monitoring the temperature of a power transmission line from an energy source to an energy sink, comprising an electrical line that extends from a line start to a line end, with a sensor line being provided parallel to the course of the electrical line, and between the line and the Sensor path a thermal coupling is provided so that a local temperature change on the line causes a temperature change on the sensor path. Out of WO 2019 / 161 849 A1 discloses a method for determining an operating state of electrical equipment, with measurement of time-dependent current measurement values for a current amplitude of an electrical current flow in a switching element of electrical equipment.

In the article "Thermal assessment of power cables and impacts on cable current rating: An: overview" by Diana Enescu, Pietro Colella and Angela Russo in Energies 2020, vol. 13 no. 20, p. 5319, various models and methods for modeling are described of the temperature distribution in cables.

CN 2 11 740 434 U discloses a wireless three-dimensional temperature measurement sensor for a power cable connection.

In "Research on On-line Temperature Monitoring System of Power Cable" by Dawei Cheng, Congxu Zhao, Miao Yu in 2017 2 ^nd International Conference on Materials Science, Machinery and Energy Engineering (MSMEE 2017), Atlantis Press 2017, S391-394 discloses a power cable temperature monitoring system.

Against this background, the present invention provides an improved line device for conducting electric current, an improved drive system for driving a vehicle and an improved method for detecting a temperature of a high-voltage line according to the main claims. Advantageous configurations result from the dependent claims and the following description.

The line device presented here offers the advantage that the line temperature of high-voltage line systems can be recorded and also predicted. As a result, materials can be protected and the service life of the elements used can be extended.

A conduction device for conducting electric current is presented. The line device comprises at least one high-voltage line, which has a conductor unit for conducting electric current, an insulation layer for insulating the conductor unit, a shielding layer for electromagnetic shielding of the conductor unit and a jacket layer for protecting the high-voltage line from external influences. In addition, the line device comprises at least one sensor unit arranged on the casing layer for sensing a casing temperature of the casing layer, the sensor unit being designed to provide a temperature signal representing the sensed casing temperature.

For example, the high-voltage line can be a line for conducting electrical current within a drive system, for example for driving a vehicle. For this purpose, the high-voltage line includes one or more conductor units, which can be made of copper, for example. The insulation layer, the shielding layer and the jacket layer can be arranged in layers around this conductor unit in order to enclose the conductor units. For example, the insulation layer can be arranged between the conductor unit and the shielding layer. The shielding layer, which can be formed, for example, with a copper foil or a wire mesh, can in turn be arranged between the insulation layer and the jacket layer, with the latter being formed, for example, from a flexible and fluid-tight material, for example PVC, around the entire high-voltage line to protect in operation. During such operation, i.e. while the conductor unit is being used to conduct electrical current, it can heat up due to the flow of current. Since the heat in HV lines spreads radially in all spatial directions over time (∂x/∂t+ ∂y/∂t + ∂z/∂t), the temperature in the layers encasing the conductor unit can also increase as a result. At the cladding layer presented here Line device, the current temperature can be detected by the sensor unit, which can also be referred to as a sensor chip or safety cabling temperature sensor nodes. The sensed temperature value is made available to a suitable evaluation device, for example, using the temperature signal. This has the advantage that the thermal condition of the high-voltage cable can be recorded directly on the high-voltage cable. The temperature signal can, for example, provide the temperature signal at predetermined time intervals during operation of the line device, as a result of which a temperature change, for example a temperature increase, can advantageously be monitored. Accordingly, overheating of the line can advantageously be predicted and prevented, as a result of which the service life of both the high-voltage line and, for example, the drive system in which the high-voltage line is used can be extended.

According to one specific embodiment, the line device can have an evaluation device that can be designed to determine an internal temperature of the high-voltage line using the temperature signal. The evaluation device can be, for example, an electronic control unit (ECU) or a central processing unit, for example of the vehicle, which can be designed to, on the basis of a predetermined thermal model with regard to the radial heat propagation within the high-voltage line and the detected outside temperature on the jacket of the high-voltage cable to determine the current temperature of the inner layers of the high-voltage cable. A corresponding model can, for example, be created in advance using series of measurements and/or calculated using parameters of the high-voltage line, such as materials and dimensions. This has the advantage that the current temperature and thus the thermal load on the conductor unit can be continuously determined based on the temperature measured on the sheath of the high-voltage cable.

An evaluation device can be an electrical device that processes electrical signals, for example sensor signals, and outputs control signals as a function thereof. The evaluation device can have one or more suitable interfaces, which can be designed in terms of hardware and/or software. In the case of a hardware design, the interfaces can be part of an integrated circuit, for example, in which the functions of the device are implemented. The interfaces can also be separate integrated circuits or at least partially consist of discrete components. In the case of a software design, the interfaces can be software modules which are present, for example, on a microcontroller alongside other software modules.

The evaluation device can be designed to determine, as the internal temperature, an insulation temperature of the insulation layer and additionally or alternatively a shielding temperature of the shielding layer and additionally or alternatively a conductor temperature of the conductor unit. For example, the evaluation device can be designed to determine the current thermal states of the individual layers of the HV line, for example using a thermal equivalent circuit diagram and additionally or alternatively differential equations of the thermal model. This has the advantage that, in addition to the overall temperature of the high-voltage cable, a current temperature value of the elements and materials processed in the high-voltage cable can also be optimally determined. This avoids excessive loads and optimizes the overall service life of the high-voltage cable.

According to a further embodiment, the evaluation device can be designed to provide a regulating signal for regulating a current flow in the high-voltage line using the internal temperature. If the high-voltage line is arranged on the input side or on the output side of an inverter, such a regulating signal can be provided to the inverter, for example, in order to regulate a function of the inverter in such a way that the current flow through the high-voltage line is regulated. In this case, for example, the current flow can be reduced when the temperature of the high-voltage line is increased, as a result of which the temperature can advantageously also be reduced and an overloading of the high-voltage line can thereby be avoided.

According to a further embodiment, the evaluation device can be designed to determine the internal temperature using at least one stored parameter of the high-voltage line. For example, parameters such as the geometry of the high-voltage line, the materials used and, additionally or alternatively, the routing of the line can be stored in the evaluation device. Using such parameters, the internal temperature of the high-voltage line can advantageously be optimally determined. For example, a corresponding parameter is used in a model for determining the internal temperature based on the measured jacket temperature.

In addition, the evaluation device can be designed to a temperature value of the sensed jacket temperature and additionally or alternatively to compare a specific internal temperature with a stored reference value. For example, such a comparison value can be a temperature value of the optimal operating temperature and additionally or alternatively a temperature value of the recommended maximum temperature of the high-voltage line. Such a stored comparison value can be compared with the currently determined temperature value by the evaluation device and a desired state can thereby be compared with an actual state. In other words, line parameters can be stored in the evaluation unit and the temperatures of the individual cabling layers can be calculated recursively on the basis of a thermal model using the recorded temperature on the surface. Advantageously, a malfunction or overheating of the high-voltage line can be detected or directly avoided as a result.

According to the invention, the sensor unit is designed to wirelessly transmit the temperature signal. In addition, the sensor unit is designed to transmit the temperature signal by wire, for example using wire lines, by means of polymer fibers (POF) or alternatively by means of an optical waveguide (LWL). The type of signal transmission can advantageously be optimized for the overall system in which the high-voltage line is used.

According to the invention, the line device comprises a further sensor unit for sensing the jacket temperature, wherein the further sensor unit can be arranged on the jacket layer and designed to provide a further temperature signal representing the jacket temperature sensed. For example, the further sensor unit can be designed in the same way as the sensor unit, which is why the sensor unit and the further sensor unit can also be referred to as a sensor chip set. If one of the two sensors were to come loose on its own, for example due to vibration or a technical defect, then the other sensor could advantageously continue to be active.

In addition, the sensor unit and the further sensor unit can be arranged at opposite ends of the high-voltage line. According to the invention, the sensor unit and the additional sensor unit are arranged on opposite sides of the high-voltage line in relation to a cross section of the high-voltage line.

The points at which the line is connected to other electrical elements, for example to a battery, an inverter or a drive, can be referred to as the end of the high-voltage line. The sensor units can be arranged, for example, at one end close to the battery and one close to the inverter, in order to advantageously sense the temperature of the high-voltage line at points close to the device. In addition or as an alternative, the sensor unit and the further sensor unit can be arranged on opposite sides of the high-voltage line, that is to say at radially opposite points on the casing layer. This has the advantage that the heat of the high-voltage line can be recorded in the X-direction and Y-direction and additionally or alternatively in the Z-direction. This can advantageously result in a redundant safety system.

According to a further embodiment, the at least one high-voltage line can be designed as a direct current conductor. For example, the conductor device can include a plurality of high-voltage lines, wherein, for example, two of these high-voltage lines can be embodied as DC conductors. This has the advantage that, for example, a connection between a battery and an inverter can be monitored.

According to a further embodiment, the at least one high-voltage line can be designed as an AC conductor. For example, the conductor device can include a plurality of high-voltage lines, in which case, for example, three of these high-voltage lines can be designed as AC conductors. This has the advantage that, for example, a connection between an inverter and an electric drive can be monitored.

In addition, a drive system for driving a vehicle is presented, the drive system having an inverter and a variant of the previously presented line device. The line device is designed to connect the inverter to a battery and additionally or alternatively to an electric drive using at least one high-voltage line. The use of a variant of the previously presented line device within the drive system has the advantage that optimal temperature monitoring is enabled both on the AC side and on the DC side, which means that the service life of the overall system can be optimized. Optionally, the battery and/or the electric drive can be part of the drive system.

In addition, a method for detecting a temperature of a high-voltage line is presented, the method having a step of sensing a jacket temperature of a jacket layer of the high-voltage line. In addition, the method includes a step of providing a temperature signal representing the jacket temperature and a step of determining an internal temperature the high-voltage line using the temperature signal.

• 1 ein Blockschaltbild eines Fahrzeugs gemäß einem Ausführungsbeispiel;
• 2 eine schematische Querschnittsdarstellung einer Leitungsvorrichtung gemäß einem Ausführungsbeispiel;
• 3 eine schematische Seitenansicht einer Leitungsvorrichtung gemäß einem Ausführungsbeispiel;
• 4 ein Diagramm einer Wärmeentwicklung in einer Leitungsvorrichtung gemäß einem Ausführungsbeispiel; und
• 5 ein Ablaufdiagramm eines Verfahrens zum Erfassen einer Temperatur einer Hochvoltleitung gemäß einem Ausführungsbeispiel.

The invention is explained in more detail by way of example with reference to the attached drawings. Show it:

• 1 a block diagram of a vehicle according to an embodiment;
• 2 a schematic cross-sectional view of a line device according to an embodiment;
• 3 a schematic side view of a line device according to an embodiment;
• 4 a diagram of a heat development in a line device according to an embodiment; and
• 5 a flowchart of a method for detecting a temperature of a high-voltage line according to an embodiment.

In the following description of preferred exemplary embodiments of the present invention, the same or similar reference symbols are used for the elements which are shown in the various figures and have a similar effect, with a repeated description of these elements being dispensed with.

1 10 shows a block diagram of a vehicle 100 according to an exemplary embodiment. In this exemplary embodiment, vehicle 100 is designed as an electric vehicle and includes a drive system 105 for driving vehicle 100. Drive system 105 includes, by way of example only, a battery interface 110 to a battery 115, an inverter 120, a drive interface 125 to an electric drive 130, and a line device 140. Optionally, the battery 115 and/or the electric drive 130 are included in the drive system 105.

In one exemplary embodiment, line device 140 includes, merely by way of example, AC cabling 145 for connecting inverter 120 to drive interface 125, with AC cabling 145 having a high-voltage line 150 and, by way of example, a second high-voltage line 152 and a third high-voltage line 153, each of which is AC conductors are formed. Additionally or alternatively, the line device 140 in one embodiment includes a DC cabling 155 with, for example, a fourth high-voltage line 156 and a fifth high-voltage line 157 for connecting the battery interface 110 to the inverter 120, wherein in this embodiment the fourth and fifth high-voltage lines 156, 157 as DC conductors are formed.

At least one, some or all of the high-voltage lines 150, 152, 153, 156, 157 have at least one sensor unit 160 for sensing a jacket temperature of the respective high-voltage lines 150, 152, 153, 156, 157. For a better overview, only the sensor unit 160 on the high-voltage line 150 is shown in the representation shown here. Sensor unit 160 is ring-shaped, purely by way of example, and is fastened around high-voltage line 150, which is embodied as a cable, for example. Alternatively, the sensor unit 160 is attached to the high-voltage line 150 in a different manner in a non-positive, positive or material manner.

Sensor unit 160 is designed to provide a temperature signal 165 representing the sensed jacket temperature. In this exemplary embodiment, the temperature signal 165 can be provided to an evaluation device 170 of the conductor device 140 , the evaluation device 170 being designed only by way of example to determine an internal temperature of the high-voltage line 150 using the temperature signal 165 . For example, evaluation device 170 is designed to determine the internal temperature of high-voltage line 150 using a time profile of the temperature values displayed by temperature signal 165 on the jacket of high-voltage line 150 and a model of high-voltage line 150 . Furthermore, the evaluation device 170 is optionally designed to provide a regulation signal 175 for regulating a current flow in the high-voltage line 150 using a value of the internal temperature. For example, the regulation signal 175 is used by a controller of the inverter 120 to regulate a magnitude of the alternating current provided to the electric drive 130 . As a result, for example, an amperage of the current flowing through high-voltage line 150 can be reduced when the internal temperature of high-voltage line 150 is too high in order to ensure safe operation of drive system 105 over the long term.

2 14 shows a schematic cross-sectional illustration of a conduction device 140 according to an embodiment. The conduit device 140 shown here corresponds or is similar to the conduit device described in the previous figure.

The line device 140 comprises at least the high-voltage line 150, a conductor unit 200, also referred to as a core, for conducting electrical current, an insulating layer 205 for insulating the conductor unit 200, a shielding layer 210 for electromagnetically shielding the conductor unit 200, and a jacket layer 215 for protecting the high-voltage line 150 against external influences. According to known high-voltage lines surrounds the Insulation layer 205, the conductor unit 200 ring-shaped, the shielding layer 210, the insulation layer 205 ring-shaped and the jacket layer 215, the shielding layer 210 ring-shaped. In addition, a sensor unit 160 is arranged on the jacket layer 215 of the high-voltage line 150 and is designed to sense a jacket temperature of the jacket layer 215 . In this case, the sensor unit 160 is designed to provide a temperature signal 165 representing the sensed jacket temperature.

In one exemplary embodiment, line device 140 has a second high-voltage line 152 and optionally a third high-voltage line 153, which are designed in the same way as high-voltage line 150 and, merely by way of example, have a second sensor unit 230 for sensing a second jacket temperature of second high-voltage line 152 and a third sensor unit 235 for sensing a have the third jacket temperature of the third high-voltage line 153 . In this case, the sensor unit 160, the second sensor unit 230 and the third sensor unit 235 are designed, merely by way of example, to wirelessly transmit the temperature signal representing the jacket temperature of the respective high-voltage lines 150, 152, 153.

In one embodiment, the temperature signal 165 of the sensor unit 160 and optionally corresponding temperature signals of the second sensor unit 230 and the third sensor unit 235 are transmitted to an evaluation device 170 of the conductor device 140 . By way of example, evaluation device 170 includes a calculation unit 237 that is designed to determine an internal temperature of high-voltage line 150 using temperature signal 165 . Merely as an example, the internal temperature in this exemplary embodiment can be determined as an insulation temperature T _{insulation_internal} of the insulation layer 205, or T _I for short, and a shielding temperature T _shield of the shielding layer 210, or Ts for short, and a conductor temperature T _conductor of the conductor unit 200, or T _L for short, since heat propagation within the high-voltage line 150 takes place radially from the conductor unit 200 to the cladding layer 215. The determined temperature values can be used, for example, to regulate a current flow, as described in the previous figure. In addition, the determined temperatures T _I , T _S , T _L can be adjusted in this exemplary embodiment using a thermal equivalent circuit diagram and differential equations of a thermal model, which are merely exemplary, which are stored in a memory unit 238 of the evaluation device 170 in this exemplary embodiment.

In another exemplary embodiment, the temperature signal 165 or the temperature signals can also be transmitted additionally or alternatively by means of an optical waveguide and additionally or alternatively by means of polymer fibers, and the evaluation device can be designed, for example, to only measure a temperature of the insulation layer or a temperature of the shielding layer or a temperature of the to determine the head unit.

In one exemplary embodiment, conductor device 140 also includes a further sensor unit 240 for sensing the jacket temperature of high-voltage line 150. Here, further sensor unit 240 is arranged on the jacket layer, for example, and is designed to provide a further temperature signal 245 representing the jacket temperature sensed. The sensor unit 160 and the further sensor unit 240 in the exemplary embodiment shown here are arranged on opposite sides of the high-voltage line 150 purely by way of example. This thermal sensor chip set is designed, for example, to record the temperatures on the outer HV cable jacket of each cable in the DC or AC circuit and to send the temperature values to a central processing unit, ie to the evaluation device 170 . Because heat spreads radially in HV lines (∂x/∂t+ ∂y/∂t + ∂z/∂t), it makes sense to measure temperature in two out of three dimensions. In one exemplary embodiment, the high-voltage lines 150, 152, 153 designed as individual lines are each equipped with two sensors for detecting the heat in the x-direction and y-direction or z-direction. This creates a redundant safety system. In other words, for example, sensor units 160, 240 on high-voltage line 150 are offset from one another in the z direction, i.e. offset in relation to a longitudinal extent of high-voltage line 150 and/or offset in the x or y direction, i.e. on different sides the high-voltage line 150.

3 shows a schematic side view of a conduit device 140 according to an embodiment. The line device 140 shown here corresponds to or is similar to the line device described in the previous figures and includes, by way of example, AC cabling 155 and DC cabling 145 A sensor unit 160 and a further sensor unit 240 are arranged on each of the high-voltage lines 150, 152, 153 of the DC cabling. In one exemplary embodiment, the sensor unit 160 and the further sensor unit 240 are arranged at opposite ends of the high-voltage lines 150, 152, 153, 156, 157.

4 shows a diagram 400 of heat development in a conduction device 140 according to an embodiment. The lei shown here ducting device 140 corresponds or is similar to the ducting device described in the previous figures. In the diagram 400 shown here, the jacket temperature T _jacket of the jacket layer 215 of the high-voltage line 150, T _M for short, is shown as an example, which can also be referred to as the surface temperature and can be detected by the sensor unit 160 and using the temperature signal 165, for example, to the evaluation device 170 is deployable. In this exemplary embodiment, evaluation device 170 is designed to determine the internal temperature using at least one stored parameter of high-voltage line 150 . The geometry and material data of the line are only stored as an example for this purpose. In this exemplary embodiment, a conductor temperature T _L of the conductor unit 200 and a shield temperature Ts of the shield layer 210 can be determined as the internal temperature of the high-voltage line 150 using these parameters and the temperature signal 165 . By way of example only, the evaluation device 170 is designed to compare the temperature values of the sensed jacket temperature T _M and the determined internal temperature with stored comparison values. By way of example, using a thermal equivalent circuit diagram, the following temperatures can be calculated recursively: conductor temperature T _L , insulation temperature of the insulation layer, shielding temperature Ts and the jacket temperature T _M . When a recorded maximum temperature of 127 degrees Celsius, for example, of the jacket temperature T _M is reached and thus a specific conductor temperature T _L of 127 degrees Celsius, for example, the current flow in the high-voltage line 150 can be regulated in this exemplary embodiment by means of the evaluation device 170 in order to reduce the temperature.

5 shows a flowchart of a method 500 for detecting a temperature of a high-voltage line according to an embodiment. The method 500 includes a step 505 of sensing a jacket temperature of a jacket layer of the high-voltage line. In addition, the method 500 includes a step 510 of providing a temperature signal representing the jacket temperature and a step 515 of determining an internal temperature of the high-voltage line using the temperature signal.

Reference List

100

vehicle

105

drive system

110

battery interface

115

battery

120

inverters

125

drive interface

130

drive

140

conduction device

145

DC wiring

150

high-voltage line

152

second high-voltage line

153

third high-voltage line

155

AC wiring

156

fourth high-voltage line

157

fifth high-voltage line

160

sensor unit

165

temperature signal

170

evaluation device

175

control signal

200

leader unit

205

isolation layer

210

shield layer

215

jacket layer

230

second sensor unit

235

third sensor unit

237

calculation unit

238

storage unit

240

additional sensor unit

245

another temperature signal

400

diagram

500

Method for detecting a temperature of a high-voltage line

505

step of sensing

510

step of providing

515

step of determining

x

x direction

y

y direction

e.g

z direction

ti

insulation temperature

tsp

conductor temperature

TS

screen temperature

TM

jacket temperature

Claims (10)

Conducting device (140) for conducting electric current, the conducting device (140) having the following features: at least one high-voltage line (150), which has a conductor unit (200) for conducting electric current, an insulation layer (205) for insulating the conductor unit (200), a shielding layer (210) for electromagnetic shielding of the conductor unit (200) and a jacket layer (215 ) for protecting the high-voltage line (150) from external influences; and at least one sensor unit (160) arranged on the casing layer (215) for sensing a casing temperature (T _M ) of the casing layer (215), _wherein the sensor unit (160) is designed to generate a temperature signal (165 ), wherein the sensor unit (160) is designed to transmit the temperature signal (165) wirelessly, with a further sensor unit (240) for sensing the jacket temperature (T _jacket ), wherein the further sensor unit (240) on the jacket layer (215 ) is arranged and designed to provide a further temperature signal (245) representing the sensed jacket temperature, the sensor unit and the further sensor unit being arranged on opposite sides of the high-voltage line with respect to a cross section of the high-voltage line. Line device (140) according to claim 1 , With an evaluation device (170) which is designed to use the temperature signal (165) to determine an internal temperature of the high-voltage line (150). Line device (140) according to claim 2 , wherein the evaluation device (170) is designed to measure an insulation temperature (T _I ) of the insulation layer (205) and/or a shielding temperature (Ts) of the shielding layer (210) and/or a conductor temperature (T _L ) of the conductor unit ( 200) to determine. Line device (140) according to any one of claims 2 or 3 , wherein the evaluation device (170) is designed to provide a regulating signal (175) for regulating a current flow in the high-voltage line (150) using the internal temperature. Line device (140) according to any one of claims 2 until 4 , wherein the evaluation device (170) is designed to determine the internal temperature using at least one stored parameter of the high-voltage line (150). Line device (140) according to any one of claims 2 until 5 , wherein the evaluation device (170) is designed to compare a temperature value of the sensed jacket temperature (T _M ) and/or the determined internal temperature with a stored comparison value. Conduit device (140) according to any one of the preceding claims, wherein the sensor unit (160) and the further sensor unit (160) are arranged at opposite ends. Line device (140) according to one of the preceding claims, wherein the at least one high-voltage line (150) is designed as a DC conductor. Line device (140) according to one of the preceding claims, wherein the at least one high-voltage line (150) is designed as an AC conductor. Drive system (105) for driving a vehicle (100), wherein the drive system (105) has an inverter (120) and a line device (140) according to any one of the preceding claims for connecting the inverter (120) to a battery (115) and/or or for connecting the inverter (120) to an electric drive (130).

Images