Control device for the charging of at least one battery

• US 5,739,673 A
• Filed: 02/27/1997
• Issued: 04/14/1998
• Est. Priority Date: 02/27/1996
• Status: Expired due to Term

• Current Assignee: SGS-Thomson Microelectronics (STMicroelectronics NV)
• Original Assignee: SGS-Thomson Microelectronics (STMicroelectronics NV)
• Inventors: Le Van Suu, Maurice
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Law, Patrick B.
• Application Number:
  US08/807,823
• Time in Patent Office: 411 Days
• Field of Search: 320/2, 320/22, 320/27, 320/30, 320/31, 320/48, 320/49, 320/32, 320/39, 320/35
• US Class Current: 320/139
• CPC Class Codes: B60L 2260/48 by fuzzy logic
• CPC Class Codes: H02J 7/00041 in response to measured battery parameters, e.g. voltage, current or temperature profile
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters

Abstract

A battery-charger uses a fuzzy logic microprocessor. The use of fuzzy logic makes it easier to take account of the diversity of the types of batteries to be charged and to control the state of the batteries charged while, at the same time, producing a battery at very low cost, whereas these functions are normally carried out by far bigger microprocessors. The invention can be applied especially to the charging of batteries assembled to constitute powerful energy sources, that are used especially for automobile haulage, large-scale consumer articles, professional and industrial equipment or computer equipment.

Claims

1. A device for controlling the charging of at least one battery, the device comprising:

a microprocessor;

a memory coupled to the microprocessor;

a set of voltage divider bridges for measuring the charging conditions of the at least one battery; and

a circuit for controlling the charging of the at least one battery, wherein the memory includes stored therein;

a set of membership functions associated with signals measured on the set of voltage divider bridges, the set of membership functions forming correspondence values quantified by coefficients of values of these signals, wherein each membership function has a qualification that designates the membership function;

a set of rules setting up correspondence values between the qualifications of the membership functions and further setting up command signals to be applied to the circuit for controlling the charging of the at least one battery;

a program that organizes results of the rules to produce the command signals;

a rotating memory to store several successive states of one of the charging conditions of the at least one battery;

wherein the set of rules includes at least one rule that takes account of the successive states to set up a correspondence with signals to be applied to one of the circuit for controlling the charging of the at least one battery and the set of voltage divider bridges for measuring the charging conditions of the at least one battery.

2. The device according to claim 1, further comprising:

a counter circuit having n cascade-connected flip-flop circuits to receive 2 n successive measurement signals from the set of voltage divider circuits and take the average thereof.

3. The device according to claim 2, further comprising:

a circuit for changing the number of flip-flop circuits of the counter that are cascade-connected.

4. The device according to claim 1, further comprising:

a converter for converting an analog signal into a converted digital signal;

a circuit for determining, from the converted digital signal, a digital signal corresponding to a period proportional to the time the at least one battery is to be charged; and

a clock and a counter to prompt the charging of the at least one battery during a certain period of time referenced, as a function of the converted digital signal, with respect to a synchronization signal.

5. The device according to claim 1, further comprising:

a circuit for detecting the passage through zero of a voltage supply signal for charging the at least one battery.

6. The device according to claim 1, further comprising:

a circuit for measuring the temperature of the battery, the circuit including a resistor having one of a negative and positive temperature coefficient.

7. The device according to claim 1, wherein the set of voltage dividers includes a divider bridge connected to the terminals of the circuit for controlling the charging of the at least one battery, wherein the divider bridge measures a voltage signal corresponding to the voltage of the at least one battery.

8. The device according to claim 7, further comprising:

a foot resistor coupled to the at least one battery, for measuring a voltage signal which, along with the voltage signal corresponding to the voltage of the at least one battery, represents one of the presence and absence of the efficient working condition of the at least one battery.

9. The device according to claim 1, wherein the program manages the charging of the battery with charging cycles, each cycle comprising a stabilization phase, a measurement phase and a charging phase;

and

the memory includes area for the storage, from one cycle to another, of the values of certain charging conditions of the at least one battery, so that the values of certain charging conditions can be compared to one another.

10. The device according to claim 1, further comprising:

an interface circuit that operates by carrier current; and

a master circuit coupled to the interface circuit.

11. The device according to claim 1 in combination with a plurality of like devices for controlling the charging of at least one battery.

12. The combination according to claim 11, further comprising:

a master logic circuit, wherein each device further comprises;

an interface for communication with the master logic circuit; and

circuitry for modifying one of the set of membership functions and the set of rules as a function of signals received from the master logic circuit.

13. A device for controlling the charging of at least one battery, the device comprising:

a microprocessor;

a memory coupled to the microprocessor;

a set of voltage divider bridges for measuring the charging conditions of the at least one battery; and

a circuit for controlling the charging of the at least one battery, wherein the memory includes stored therein;

a set of membership functions associated with signals measured on the set of voltage divider bridges, the set of membership functions forming correspondence values quantified by coefficients of values of these signals, wherein each membership function has a qualification that designates the membership function;

a set of rules setting up correspondence values between the qualifications of the membership functions and further setting up command signals to be applied to the circuit for controlling the charging of the at least one battery; and

a program that organizes results of the rules to produce the command signals.

a counter circuit having n cascade-connected flip-flop circuits to receive 2 n successive measurement signals from the set of voltage divider circuits and take the average thereof.

14. A method of charging a battery, comprising the steps of:

measuring a plurality of signals that respectively relate to a plurality of charging conditions of the battery;

establishing a set of membership functions that assign a qualification to each measured signal, the qualification being quantified by coefficient determined by the membership function;

establishing a set of rules that generate commands based on the quantified qualification assigned by the set of membership functions; and

organizing the rules to generate a battery charging command.

15. The method according to claim 14, further comprising the step of storing successive states of one of said plurality of charging conditions.

16. The method according to claim 15, wherein one of said rules generates a command based on the successive states.

17. The method according to claim 16, further comprising the step of averaging the successive states.

18. The method according to claim 17, further comprising the step of managing the charging of the battery, the battery having a plurality of charging cycles, each cycle including a stabilization phase, a measurement phase and a charging phase.

19. The method according to claim 18, further comprising the step of storing charging conditions from the plurality of charging cycles.

20. The method according to claim 14, further comprising the step of managing the charging of the battery, the battery having a plurality of charging cycles, each cycle including a stabilization phase, a measurement phase and a charging phase.

21. The method according to claim 20, further comprising the step of storing charging conditions from the plurality of charging cycles.

22. A system for charging at least one battery, the system comprising:

a supply coupled to the at least one battery for charging the battery;

a circuit for coupling the supply to the at least one battery;

means for measuring a plurality of signals that respectively relate to a plurality of charging conditions of the at least one battery;

a microprocessor coupled to the circuit for controlling the circuit to couple the supply to the at least one battery; and

a memory comprising;

a set of membership functions that assign a qualification to each measured signal, the qualification being quantified by coefficient determined by the membership function;

establishing a set of rules that generate commands based on the quantified qualification assigned by the set of membership functions; and

organizing the rules to generate a battery charging command.

23. The system according to claim 22, wherein said means for measuring includes a plurality of voltage dividers.

24. The system according to claim 22, wherein the means for measuring includes a resistor having one of a positive and negative temperature coefficient for measuring the temperature of the at least one battery.

25. The system according to claim 24, wherein the means for measuring includes a voltage divider for measuring a voltage corresponding to a voltage of the battery.

26. The system according to claim 25, further comprising a multiplexor coupled to the means for measuring that receives the plurality of signals.

27. The system according to claim 26, further comprising a comparator for receiving a signal corresponding to the temperature measured by the resistor, and compares the signal corresponding to the temperature to a reference.

28. The system according to claim 27, further comprising a counter for counting to a digital value corresponding to the voltage of the at least one battery measured by the voltage divider, wherein when the digital value is reached by the counter, the microprocessor controls the circuit to couple the supply to the at least one battery.

29. The system according to claim 22, wherein the means for measuring includes a voltage divider for measuring a voltage corresponding to a voltage of the battery.

30. The system according to claim 22, wherein the means for measuring includes a voltage divider for measuring a voltage corresponding to a voltage of the battery.

31. The system according to claim 30, further comprising a counter for counting to a digital value corresponding to the voltage of the at least one battery measured by the voltage divider, wherein when the digital value is reached by the counter, the microprocessor controls the circuit to couple the supply to the at least one battery.

32. The system according to claim 22, wherein the at least one battery includes a plurality of batteries and the system further comprises:

a master logic circuit,

a plurality interfaces respectively associated with the plurality of batteries, each interface for communication with the master logic circuit.

33. The system according to claim 32, further comprising circuitry for modifying one of the set of membership functions and the set of rules as a function of signals received from the master logic circuit.