FLOATING BATTERY CHARGING NETWORK

• US 3,703,675 A
• Filed: 02/17/1971
• Issued: 11/21/1972
• Est. Priority Date: 02/25/1970
• Status: Expired due to Term

• Current Assignee: Andre A.L. Alric, Francis J. Higounenq, Gilbert R.A. Porte, Joseph M.H. Glotin, Serge P. Boussin
• Original Assignee: Andre A.L. Alric, Francis J. Higounenq, Gilbert R.A. Porte, Joseph M.H. Glotin, Serge P. Boussin
• Inventors: Alric, Andre A. L., Porte, Gilbert R. A., Glotin, Joseph M. H., Higounenq, Francis J., Boussin, Serge P.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/116,175
• Time in Patent Office: 643 Days
• Field of Search: 320/22-24,31-33,37,38,39,40,5,8-11 307/48,66 318/443 244/77R
• US Class Current: 320/159
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y10S 320/14 Battery acts as buffer

Abstract

Method and apparatus for charging storage batteries and discharging same into a network through a contactor controlled by comparing network voltage with a reference voltage and battery off-load voltage with a reference voltage and a clock to cut off charging after a predetermined time to limit battery charge to 95% of its rated capacity.

Claims

1. In a method of using a buffer battery in a d.c. distribution network having a charging current source which normally covers the network current requirements and which can also charge the battery, comprising the steps of cutting the battery into the network through a contactor depending at least upon a predetermined network voltage drop below the normal battery voltage or upon a drop of the battery off-load voltage below a reference voltage, and in the event of the latter event, charging for a predetermined period of time and at the end of the predetermined period of time, comparing the actual charging current with a reference current, proceeding with the charging when the charging current is above said reference current, and stopping the charging when the charging current is below said reference current.

2. A method according to claim 1, wherein the predetermined period is short enough to ensure that the charging energy is always insufficient to reach the limited state of battery charge, and the charging current is assessed at least at the end of the first charging period and, if the current thus measured is relatively small, the first charging period is prolonged until the charging current has dropped to a first predetermined lower level, whereas if the charging current at the end of the first charging period is relatively high, a further predetermined charging time is given whereafter the current is re-assessed.

3. A method according to claim 2, wherein the current measured at the end of a charging period following the first charging period is compared with another threshold, and if the current thus measured is below such other threshold charging is stopped, but if the measured current is above such other threshold charging continues until the charging current has dropped to another lower level greater than the first level.

4. A method according to claim 3, wherein the sum of the charging periods is limited to a predetermined value.

5. A method according to claim 1, wherein the contactor is systematically closed on the network whenever the same is connected to any safety device, including an aircraft automatic pilot at landing.

6. A method according to claim 1, wherein the contactor remains closed and a predetermined time period is restarted after any voltage drop initiating contactor closure.

7. A method according to claim 1, when the charging current continues to increase during a predetermined time in a charging sequence, a warning is triggered.

8. A method according to claim 1, wherein the charging procedure begins at each cutting-in of the battery.

9. A circuit arrangement comprising a storage battery system a contactor connected to said battery system, a network for charging and loading the battery connected to said contactor, at least one OR gate connected to send a contactor-closing signal to said contactor, a first comparator circuit for comparing the network voltage with a reference voltage connected to said OR gate, a second comparator circuit for comparing the battery off-load voltage with a reference voltage also connected to said OR gate, a detector of current flow connected to detect the charging current flow between the network and the battery, and an electronic clock connected to said detector to be started by said detector and to send a contactor-closing signal to said contactor.

10. A circuit arrangement according to claim 9, wherein a circuit arrangement for comparing the load current with a current threshold actuated after a predetermined period of time by a signal from saId clock, the last-mentioned circuit arrangement comprising two branches, one of which is operative if the load current is below the threshold and initiates, upon the current dropping below a first level, a signal opening said contactor, the second branch being operative if the load current is above the threshold and leaving said contactor closed for a second period determined by said electronic clock.

11. A circuit arrangement according to claim 10, wherein a comparator circuit for comparing the charging current with a threshold current level associated with said second branch of said two-branch circuit arrangement, said comparator circuit transmitting an opening signal to said contactor when the charging current drops below the threshold during the second charging period, said comparator circuit maintaining the contactor-closing signal if the current is still above the threshold at the end of the second charging period, the contactor-opening signal being transmitted when the current drops below another lower level higher than the first level.

12. A circuit arrangement according to claim 9, wherein said contactor is electromagnetic and the contacts of two relays are disposed in series in the contactor coil circuit, the first relay being a relay whose normally open contact receives the closing signal, while the second relay is a normally closed relay receiving the opening signal.

13. A circuit arrangement according to claim 12, wherein the circuit portion comprising the two relay contacts is shunted by the normally open contact of a third relay whose winding receives a permanent closure signal from the contactor.

14. A circuit arrangement according to claim 10, wherein said detector of current flow direction between said network and said battery system and the means for estimating the current level in the connection between said network and said battery system take the form of a Hall detector whose magnetic field winding is in series in such connection, the semiconductor of said detector being flowed through by a constant current.

15. A circuit arrangement according to claim 14, wherein said detector output voltage is applied in parallel to a number of bistables which have different characteristics and which change their state at predetermined values of the output voltage.

16. A circuit arrangement according to claim 14, wherein said detector output voltage is applied to a differentiating module which outputs a signal when the output voltage is increasing, the latter signal being applied to a delay relay, one of whose contacts initiates a warning when the voltage continues to rise for a predetermined time.

17. A circuit arrangement according to claim 9, which comprises a three-position operation selector having a main '"'"''"'"''"'"''"'"'supply off'"'"''"'"''"'"''"'"' position, a position giving a merely the transmission of an energizing signal for the third relay, and a normal operation position in which the entire circuit arrangement is energized and a starting signal is given.

18. A circuit arrangement according to claim 17, wherein the selector in the normal operation position also energizes a timer which outputs a signal for a short time after starting.

19. A circuit arrangement according to claim 9 wherein a first OR-gate receives the output signal of two AND-gates, the first AND-gate receiving at least the contactor starting signal and the brief timer signal, the second AND-gate receiving the starting signal, a signal output by the contactor when open and a signal from the second comparator circuit, the OR-gate output being connected to the input of a second OR-gate also receiving the signal of the first comparator circuit directly, and the contactor-closing signal is taken from the output of the second OR-gate, such output being looped to the OR-gate input by way of a third AND-gate which also receives a signal from the contactor when the same is closed, thus forming a closure-signal store.

20. A circuit arrangement according to claim 9, wherein a bistable which outputs a signal when the current flow is from the battery system to the network in the discharging direction outputs a stop and zero resetting signal to said electronic clock.

21. A circuit arrangement according to claim wherein said electronic clock is started by the signal of a bistable detecting the beginning of the flow of current in the charging direction;

and such clock outputs a signal after a first charging period to one input of an AND-gate whose other input receives the starting signal, the output of the last-mentioned AND-gate being connected to the input of two other AND-gates connected one each to the two outputs of a bistable, the latter outputs being alternately operative above and below a current threshold, the output of each of the latter AND-gates being connected to the input of one of the two OR-gates of a pair, the output of such OR-gates determining the transmission of a contactor-opening signal, the outputs of each of the last-mentioned OR-gates being looped to their respective inputs each by way of another AND-gate whose input also receives the signal transmitted by a bistable when the current flow is in the charging direction.

22. A circuit arrangement according to claim 23 wherein the output signal of the OR-gate or OR-gate pair receiving from the threshold bistable the signal corresponding to a current level below the threshold goes to an output AND-gate which also receives from a bistable the signal transmitted when the current reaches a first lower level, the last-mentioned AND-gate then delivering an opening signal to the contactor, and the output signal of the other OR-gate of the OR-gate pair goes in parallel to a pair of output AND-gates, one of which also receives a signal for a second charging period from the electronic clock while the other receives a signal beyond the second charging period, the latter AND-gate pair receiving from two bistables, each adapted to output a signal when the current drops to a lower level, the one a signal for a current level at least equal to the threshold and the second a signal for a lower level, these two AND-gates each outputting a contactor-opening signal.

23. A circuit arrangement according to claim 22, wherein the signals of the three output AND-gates go to the input of at least one OR-gate whose output supplying the contactor-opening signal is looped to its input by an AND-gate also receiving the inversion of the contactor-closing signal.

24. A circuit arrangement according to claim 9, wherein said second comparator circuit is brought into operation by the contactor-closing signal, and said electronic clock is rendered inoperative and zero reset by the latter signal.

25. A circuit arrangement according to claim 12, wherein the wiper of the contactor in normal position connects to the battery system circuit a parallel arrangement comprising an indicating lamp and a potentiometer from which the closed-contactor signal is taken.

26. A circuit arrangement according to claim 25 wherein the manual selector comprises an auxiliary contact in series in the parallel circuit arrangement comprising the indicating lamp and the potentiometer.