DEVICE FOR MEASURING GROUND CONNECTION RESISTANCE AND ONBOARD CHARGER FOR A VEHICLE PROVIDED WITH SUCH A DEVICE

• US 20150198644A1
• Filed: 06/06/2013
• Published: 07/16/2015
• Est. Priority Date: 06/20/2012
• Status: Active Grant

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Ripoll, Christophe, Konate, Christophe, Cuiller, Etienne
• Granted Patent: US 9,594,102 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/16 Connectors, e.g. plugs or sockets, specially adapted for charging electric vehicles
• CPC Class Codes: G01R 27/20 Measuring earth resistance; Measuring contact resistance, e.g. of earth connections, e.g. plates
• CPC Class Codes: G01R 27/205 Measuring contact resistance of connections, e.g. of earth connections
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A device for measuring resistance of a ground tap and a charger for an on-board vehicle including the device. The device includes a current source and an ammeter disposed on a first electrical branch, provided to link a phase of a power supply network with the ground of the installation; a second electrical branch provided to link a neutral wire of the power supply network with the ground of the installation, including a resistor across terminals of which is connected a voltmeter, and a first capacitor in series with the resistor; and a third electrical branch is provided for linking the neutral wire of the network with the ground of the installation, and including, on the third branch, in parallel with the first capacitor and with the first resistor, a second capacitor of higher value than the first capacitor.

Claims

1-10. -10. (canceled)

11. A device for measuring a ground resistance of an apparatus comprising:

a current source and an ammeter arranged on a first electrical branch, provided for connecting a phase of a power supply network with ground of the apparatus;

a second electrical branch provided for connecting a neutral wire of the power supply network with the ground of the apparatus, comprising a resistor at terminals of which a voltmeter is connected, and comprising a first capacitor in series with the resistor;

a third electrical branch provided for connecting the neutral wire of the network with the ground of the apparatus, and comprising on the third branch, in parallel with the first capacitor and the first resistor, a second capacitor of higher value than the first capacitor.

12. The device as claimed in claim 11, further comprising an inductor placed in series with the resistor and with the first capacitor, parallel to the second capacitor.

13. The device as claimed in claim 11, wherein the second capacitor is at least five times greater than the first capacitor, or at least ten times greater than the first capacitor.

14. The device as claimed in claim 11, wherein the second capacitor has a value between 10 and 100 nF, or between 20 and 300 nF.

15. The device as claimed in claim 12, wherein the inductor has a value between 1 and 10 mH.

16. A charger for a motor vehicle battery, comprising a device as claimed in claim 11.

17. The charger as claimed in claim 16, comprising a relay configured to connect the second electrical branch alternately to a first connecting terminal of the charger power supply, and a second connecting terminal of the charger power supply, distinct from the first terminal, including a second voltmeter connected between the ground connection terminal and the second terminal so that it can be disconnected by the relay, and including a third voltmeter connected between the ground connection terminal and the first terminal so that it can be disconnected by the relay.

18. The charger as claimed in claim 17, further comprising an electronic control unit configured, when the terminals are connected onto a power supply network, to switch the relay so that the second electrical branch is connected to that of the two terminals for which the voltage measured at the terminals of the second capacitor is lowest.

19. The charger as claimed in claim 18, wherein the electronic control unit is configured to prevent charging of a battery following an attempt to connect to a power supply network, if the voltage measured at the terminals of the resistor remains higher than a threshold voltage after activation of the relay.

20. The charger as claimed in claim 16, further comprising an electronic control unit configured to prevent charging of a battery if a ground resistance calculated from readings of the ammeter and the first voltmeter is greater than or equal to a threshold resistance.