VOLTAGE MEASURING DEVICE AND METHOD

Abstract

A measuring device is detachably connected between the vehicle traction voltage system and the high voltage appliance. The measuring device includes a first and second terminal configured to receive a first and second probe of a voltage measuring instrument, a first and second resistor arranged to connect each terminal, upon the measuring device being attached to the vehicle voltage traction system, to a first and second traction voltage conductor of the traction voltage system extending through the measuring device. The measuring device, upon the measuring device being attached to the vehicle voltage traction system, connects to a Hazardous Voltage Interlock Loop of the vehicle extending through the measuring device so that the HVIL is broken when the measuring device is detached from the traction voltage system, thereby inactivating the traction voltage system.

Claims

1. A measuring device for enabling measuring of traction voltage being supplied by a traction voltage system to a high voltage appliance in a vehicle with the traction voltage system in operation, the measuring device being configured to be detachably connected between the vehicle traction voltage system and the high voltage appliance, the measuring device comprising: a first and second terminal configured to receive a first and second probe of a voltage measuring instrument, and a first and second resistor arranged to connect each terminal, upon the measuring device being attached to the vehicle voltage traction system, to a first and second traction voltage conductor of the traction voltage system extending through the measuring device, wherein the measuring device is configured to, upon the measuring device being attached to the vehicle voltage traction system, connect to a Hazardous Voltage Interlock Loop (HVIL) of the vehicle extending through the measuring device so that the HVIL is broken when the measuring device is detached from the traction voltage system, thereby inactivating the traction voltage system.

2. The measuring device according to claim 1 wherein the measuring device is adapted to be attached to a cable comprising the traction voltage conductors.

3. The measuring device according to claim 1 wherein the measuring device is adapted to be attached to a cable comprising both the traction voltage conductors and low voltage conductors of the HVIL.

4. The measuring device according to claim 1, the measuring device being arranged to be connected to a first connector connecting to a first cable and the traction voltage system in one end and to a second connector connecting to a second cable and the high voltage appliance in another end.

5. The measuring device according to claim 4, the measuring device being arranged to be connect in series between the traction voltage and the high voltage appliance.

6. The measuring device according to claim 1, the first and second resistor having a resistance value in the range of 200-400 k.

7. The measuring device according to claim 4 wherein the connectors of the measuring device are bayonet mounts

8. A method for measuring of traction voltage being supplied by a traction voltage system to a high voltage appliance in a vehicle, the method comprising the steps of: turning off the traction voltage system connecting a measuring device in accordance with claim 1 to a first and second traction voltage conductor of the traction voltage system connecting the measuring device to a Hazardous Voltage Interlock Loop, HVIL, of the vehicle turning on the traction voltage system, and connecting a first and second probe of a voltage measuring instrument to the terminals of the measuring device to measure the voltage in the traction voltage system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Aspects and embodiments are now described, by way of example, with reference to the accompanying drawings, in which:

[0036] FIG. 1 schematically illustrates parts of a traction voltage system of a vehicle

[0037] FIG. 2 schematically illustrates parts of a traction voltage system of a vehicle with a measuring device attached

[0038] FIG. 3 shows a flowchart illustrating a method for measuring of traction voltage in a vehicle.

DETAILED DESCRIPTION

[0039] The aspects of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the invention are shown.

[0040] These aspects may, however, be embodied in many different forms and should not be construed as limiting; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and to fully convey the scope of all aspects of invention to those skilled in the art. Like numbers refer to like elements throughout the description.

[0041] FIG. 1 shows a part of a traction voltage system 1o of a vehicle. The traction voltage system 1o is a high voltage system. The traction voltage system 1o is powered by a high voltage power source (not shown). The high voltage power source could for example comprise one or more batteries, one or more fuel cells or one or more generators.

[0042] The traction voltage system 1o comprises a traction junction box 20 for distribution of traction voltage to a number of high voltage appliances 22. The high voltage appliances could for example be converters or compressors. The traction junction box 20 is in turn connected to the high voltage power source.

[0043] The system further comprises traction voltage conductors 12a-12d. The first conductor, comprising conductors 12a and 12c, could for example have positive polarity. The second conductor, comprising conductors 12b and 12d, could for example have negative polarity. The traction voltage conductors could for example be comprised in a high voltage cable 24a, 24b. The traction voltage conductors 12a-d are used to conduct voltage from the junction box 20 to the consumers 22.

[0044] A connecting device 16 is disposed between the junction box 20 and the consumer 22. The connecting device 16 is in FIG. 1 depicted as a connector 16 of the traction voltage system. The connector 16 of the traction voltage system 10 comprises a first part 16a and a second part 16b which can be disconnected to allow for connection of additional components to the traction voltage system 10.

[0045] In alternative embodiments, the junction box 20 and the consumer 22 could each comprise a connector. In this case, a cable having a connector at each end is used to connect the junction box 20 and the consumer 22. For example, the junction box 20 and the consumer 22 could comprise a male connector, while the cable could comprise a female connector at each end.

[0046] The traction voltage system 10 in FIG. 1 further comprises a High Voltage Interlock Loop (HVIL) 18. The HVIL 18 is in the example embodiment of FIG. 1 comprises HVIL conductors 14a-d integrated in the same cables 24a, 24b as the traction voltage conductors 12a-d but could also be disposed as separate parts. The HVIL 18 comprises a low voltage loop which monitors the parts of the traction voltage system.

[0047] FIG. 2 shows the same part of the traction voltage system 10 as FIG. 1, but with a measuring device 30 in accordance with an embodiment of the present disclosure installed. The measuring device 30 is illustrated as a high voltage breakout box.

[0048] The measuring device 30 comprises a pair of terminals 32a, 32b. The terminals 32a, 32b allow for connection of a couple of probes of a voltage measuring instrument to the measuring device 30. The measuring instrument could be a voltmeter or a multimeter.

[0049] The measuring device 30 further comprises a pair of resistors 34a, 34b. The resistors 34a, 34b are disposed between the traction voltage conductors 12a-d and the terminals 32a, 32b. The resistors could have a resistance of 200-400 k, for example 300 k.

[0050] The measuring device 30 shown in FIG. 2 further comprises connectors 36a, 36b for connection of the measuring device to the traction voltage conductors 12a-d. The connectors 36a, 36b of the measuring device are configured to be connected to the traction voltage system 10 via the connectors 16a, 16b of the traction voltage system.

[0051] The measuring device 30 shown in FIG. 2 further comprises traction voltage conductors 12e, 12f. The measuring device is in FIG. 2 connected to the traction voltage system 1o by connecting the traction voltage conductors 12a-12d of the vehicle to the traction voltage conductors 12e-12f of the measuring device.

[0052] The connectors 36a, 36b of the measuring device could for example comprise bayonet mounts. The bayonet mounts could be connected to corresponding connectors 16a, 16b the cable 24a, 24b enclosing the traction voltage conductors 12a-d. The connectors 36a, 36b of the measuring device could alternatively be quick connectors.

[0053] In the alternative embodiment where the junction box 20 and the consumer 22 each comprises a quick connector connected by a cable, the measuring device 30 could be attached by removing the cable at one end and providing an additional cable for connecting the other side of the measuring device 30. Alternatively, the existing cable could be removed entirely before attaching the measuring device using a pair of separate cables compatible with the measuring device 30.

[0054] The connectors 36a, 36b of the measuring device 30 shown in FIG. 2 further connects to the HVIL of the vehicle. This is in FIG. 2 performed by connecting the HVIL conductors 14a-14d of the vehicle to HVIL conductors 14e, 14f of the measuring device. Thus, the series coupling of the measuring device 30 between the connectors 16a, 16b closes the HVIL.

[0055] Advantageously, the provision of the resistors 34a, 34b between the conductors 12e, 12f of the traction voltage system and the measuring probes 32a, 32b, the user is protected from being exposed to harmful current of the traction voltage system. This allows for measurement to be conducted while the vehicle is operating, without the risk of harming the technician.

[0056] Further advantageous, any detachment of the measuring device 30 from the connectors 16a, 16b would break the HVIL which would activate a mechanism (not shown) for closing down the traction voltage system.

[0057] FIG. 3 shows a flowchart illustrating a method for measuring of traction voltage in a vehicle. In a first step S101, the traction voltage of the vehicle is turned off. This could for example be done using a switch or any other feature provided in the vehicle for turning off the high voltage system.

[0058] In a further step S102, the measuring device is connected to the traction voltage system

[0059] In a further step S103, the measuring device is connected to the HVIL

[0060] In a further step S104, the high voltage system is turned on

[0061] In embodiments where the conductors of the traction voltage system and the conductors of the HVIL are comprised within the same cable, steps S102 and S103 are conducted simultaneously.

[0062] In a further step S105, a voltage measuring instrument is connected to the measuring device to measure the traction voltage

[0063] The method thus allows for measuring of traction voltage while the system is turned on.

[0064] The aspects of the present disclosure have mainly been described above with reference to a few embodiments and examples thereof. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.

[0065] Thus, while various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.