METHOD OF MONITORING THE CAPACITIVE FILTER OF A BATTERY CHARGER

• US 20140217980A1
• Filed: 09/10/2012
• Published: 08/07/2014
• Est. Priority Date: 09/13/2011
• Status: Active Grant

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Malrieu, Julien
• Granted Patent: US 9,764,654 B2
• Time in Patent Office: Days
• US Class Current: 320/109
• CPC Class Codes: B60L 2240/529 Current
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: G01R 31/3644 Constructional arrangements
• CPC Class Codes: G01R 31/64 Testing of capacitors
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 8/04686 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 1/126 using passive filters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• 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 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

A device for charging a battery, or a battery of an electric traction automotive vehicle, based on a three-phase or single-phase power supply network, including a filtering stage including a capacitive assembly and configured to be connected to the power supply network. The device includes a mechanism to monitor capacitive assembly and to detect a deviation in value of the capacitance of at least one capacitor of the capacitive assembly on the basis of voltages and currents measured across the input terminals of the filtering stage.

Claims

1-13. -13. (canceled)

14. A device for charging a battery, or a battery of a motor vehicle with electric traction, from a three-phase or single-phase power supply network, the device comprising:

a filtering stage comprising a capacitive assembly and configured to be connected to the power supply network; and

means for monitoring the capacitive assembly and for detecting a deviation in capacitance value of at least one capacitor of the capacitive assembly from voltages and currents measured at an input of the filtering stage.

15. The device as claimed in claim 14, further comprising a buck stage connected to the filtering stage, and a boost stage configured to be connected to the battery and coupled to the buck stage.

16. The device as claimed in claim 14, wherein the monitoring means comprises:

means for determining characteristic values of the measured voltages and currents;

means for computing at least one parameter representative of the capacitive assembly from the voltage and current characteristic values;

means for determining a state of the at least one capacitor of the capacitive assembly from the representative parameter; and

processing means for delivering a control signal and/or a warning signal to alert a user to degradation of the capacitive assembly.

17. The device as claimed in claim 16, wherein the characteristic values are rms values.

18. The device as claimed in claim 16, wherein the control signal can limit battery charge performance levels.

19. The device as claimed in claim 16, wherein the means for determining the state of the capacitors comprises at least one computation module configured to compute a difference between the representative parameter and a capacitive constant, and at least one comparison module configured to compare the computed difference with a variation threshold.

20. The device as claimed in claim 14, wherein the monitoring means comprises activation means for activating the monitoring means when the device is connected to the power supply network and before a start of charging of the battery, the representative parameter being proportional, when the monitoring means is activated before the start of the charging of the battery, to the ratio between rms current value of a first phase and the product of frequency with a value of the rms voltage between the first phase and another phase.

21. The device as claimed in claim 15, wherein the monitoring means comprises on-charge activation means for activating the monitoring means when the battery is on charge on a single-phase power supply network, the representative parameter corresponding, when the monitoring means is activated after a start of a charge on a single-phase power supply network, to the ratio between the difference between twice the square of rms value of the power supply current and the square of the rms value of the current at the input of the buck stage and the product of rms voltage at terminals of the power supply network and frequency of the power supply network.

22. A motor vehicle with traction that is at least partially electrical, comprising:

an electrical machine coupled to drive wheels and an inverter stage configured to power the electrical machine from a battery; and

a device for charging the battery as claimed in claim 14.

23. A method for controlling a device for charging a battery, or a battery of a motor vehicle with electric traction, from a three-phase or single-phase power supply network, the method comprising:

filtering at least one input voltage from the power supply network using a filtering stage including a capacitive assembly;

measuring a power supply current at an input of the filtering stage;

measuring a power supply voltage at the input of the filtering stage; and

monitoring a state of capacitors of the capacitive assembly based on a variation of at least one parameter representative of the capacitive assembly from the voltages and currents measured at the inputs of the filtering stage.

24. The method as claimed in claim 23, further comprising:

determining rms values of the measured voltages and currents;

computing at least one parameter representative of the capacitive assembly from the rms voltage and current values;

determining a state of the capacitors of the capacitive assembly from the computed representative parameters; and

delivering a control signal to limit battery charge performance levels and a warning signal to alert a user to degradation of the capacitive assembly.

25. The method as claimed in claim 24, wherein the determining the state of the capacitors of the capacitive assembly includes at least one computation of an absolute value of the difference between a capacitive constant and the parameter representative of the capacitive assembly, and a comparison of the computed absolute value with a variation threshold.

26. The method as claimed in claim 23, wherein the representative parameter corresponds, when the monitoring is activated before a start of charging of the battery, to the ratio between the value of rms current of a first phase and the product of frequency with the value of the rms voltage between the first phase and another phase, and, when the monitoring is activated after a start of a charge on a single-phase network, to the ratio between the difference between twice the square of the rms value of the power supply current and the square of the rms value of the current at the input of a buck stage and the product of the rms voltage at the terminals of the power supply network and frequency of the power supply network.