System of Batteries and Method of Controlling this System

Abstract

A system of electric batteries includes a plurality of batteries (HVB.sub.1, HVB.sub.2, HVB.sub.3) connected to each other by two polarities. Each battery has at least two relays (RN, RP, RA) for the connecting of poles of the battery to the two polarities. The system includes a secondary power supply to provide an activation energy to the relays. The system includes means of supervision to control the relays (RN, RP, RA) in a staggered manner so that each activation of a relay follows a previous activation by at least a predetermined time period (DT).

Claims

1.-9. (canceled)

10. A system of electric batteries comprising: a plurality of batteries connected to each other by two polarities, each battery comprising a first relay and a second relay for direct connection respectively of a first pole of the battery to a first one of the polarities and a second pole to a second one of the polarities; a third relay connecting the second pole to the second polarity across a preload resistance; a secondary power supply to provide an activation energy to the relays; means of supervision arranged to control the relays in a staggered manner so that each activation of a relay follows a previous activation by at least a predetermined time period as a function of characteristics of the relays so that a power supply current of the relay is about the same as a maintenance current level after a preceding activation command and expiration of the time period, wherein the batteries are connected in parallel, and the third relay is activated first for connection of each battery.

11. The system according to claim 10, wherein the means of supervision comprises a secondary supervisor associated with each battery and a main supervisor connected to each secondary supervisor, wherein each secondary supervisor receives a connection order from the main supervisor and controls the successive staggered activation of the relays of the corresponding battery, and wherein the main supervisor provides successive staggered connection orders such that a second order is given after a first order and after the relays controlled by the secondary supervisor having received the first order have been activated.

12. The system according to claim 11, wherein the secondary supervisor controls, in order, the third relay, the first relay and then the second relay.

13. The system according to claim 12, wherein the secondary supervisors send state information indicating that the relays are closed or not.

14. The system according to claim 10, wherein the means of supervision comprises a central supervisor to command each relay individually.

15. The system according to claim 14, wherein the central supervisor is programmed to command, in an initialization phase, the third and then the first relay of one of the batteries and then to verify whether, for another battery whose initialization phase has been triggered, a voltage difference between the second pole and the second polarity is less than a predetermined threshold, in which case the supervisor controls an establishment phase in which the second relay of the other battery is actuated.

16. The system according to claim 15, wherein during the initialization phase, times for commanding of the third and the first relay are spaced apart by a delay time.

17. The system according to claim 15, wherein an establishment phase includes commanding of deactivation of the third relay.

18. A method for control of a system of electric batteries, the system comprising a plurality of batteries connected to each other by two polarities, each battery comprising a first relay and a second relay for direct connection respectively of a first pole of the battery to a first one of the polarities and a second pole to a second one of the polarities, and a third relay connecting the second pole to the second polarity across a preload resistance, the system further comprising a secondary power supply to provide an activation energy to the relays, the relays being controlled in a staggered manner so that each activation of a relay follows a previous activation by at least a predetermined time period as a function of the characteristics of the relays so that a power supply current of the relay is about the same as a maintenance current level after the preceding activation command and expiration of the time period, and the batteries are connected in parallel, the method comprising first activating the third relay for the connection of each battery.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The invention will be better understood and other features and advantages will appear from the perusal of the following description, making reference to the enclosed drawings, in which:

[0028] FIG. 1 shows schematically a battery and its supervisor according to the prior art;

[0029] FIG. 2 is a time diagram of the control of the battery of FIG. 1;

[0030] FIG. 3 shows schematically a battery system according to a first embodiment of the invention;

[0031] FIG. 4 shows schematically a battery system according to a second embodiment of the invention;

[0032] FIG. 5 is a time diagram explaining the operation of the system of FIG. 4.

DETAILED DESCRIPTION

[0033] A system of electric batteries according to a first embodiment of the invention is shown in FIG. 3. The system comprises a plurality of batteries HVB.sub.1, HVB.sub.2, HVB.sub.3, connected to each other by two polarities, each battery conforming to the battery described in the prior art and in connection with FIGS. 1 and 2. Thus, the battery comprises three relays for connecting poles of the battery to the two polarities. The system comprises a secondary power supply 2 common to all the batteries HVB.sub.1, HVB.sub.2, HVB.sub.3 in order to provide an activation energy to the relays. Each battery is controlled by a secondary supervisor SHVB.sub.1, SHVB.sub.2, SHVB.sub.3, while a main supervisor SP is connected to each of the secondary supervisors SHVB.sub.1, SHVB.sub.2, SHVB.sub.3. The main supervisor SP and the secondary supervisors SHVB.sub.1, SHVB.sub.2, SHVB.sub.3 form means of supervision I. Each secondary supervisor SHVB.sub.1, SHVB.sub.2, SHVB.sub.3 is able to receive a connection order C.sub.F1, C.sub.F2, C.sub.F3 from the main supervisor SP. Based on the reception of this connection order C.sub.F1, C.sub.F2, C.sub.F3, the secondary supervisor SHVB.sub.1, SHVB.sub.2, SHVB.sub.3 carries out the initialization phase and the establishment phase in the same way as in the prior art. Thus, the secondary supervisor SHVB.sub.1, SHVB.sub.2, SHVB.sub.3 controls the successive staggered activation of the relays of the corresponding battery HVB.sub.1, HVB.sub.2, HVB.sub.3.

[0034] The main supervisor SP, for its part, provides successive staggered connection orders C.sub.F1, C.sub.F2, C.sub.F3 so as to ensure that all the relays controlled by the secondary supervisor SHVB.sub.1 having received a first order C.sub.F1 have been activated before delivering a second order C.sub.F2 to the next secondary supervisor SHVB.sub.2. For this, the secondary supervisors SHVB.sub.1, SHVB.sub.2, SHVB.sub.3 send state information E.sub.H, E.sub.F2, E.sub.F3 to the main supervisor SP indicating that the phases of initialization and establishment have been completed, and the main supervisor SP sends the next connection order C.sub.F1, C.sub.F2, C.sub.F3 after the predetermined time period. Thus, each activation of a relay follows a previous activation by at least the predetermined time period.

[0035] According to a second embodiment, shown in FIG. 3, the system of batteries differs from the system according to the first embodiment in that the means of supervision I′ comprise a central supervisor SC able to command each relay individually. As in the prior art, the battery HVB.sub.1, HVB.sub.2, HVB.sub.3 comprises a first relay RN and a second relay RP for direct connection respectively of a first pole (−) of the battery to a first one of the polarities and a second pole (+) to a second one of the polarities, and furthermore a third relay RA connecting the second pole (+) to the second polarity across a preload resistance R.sub.prec.

[0036] Thus, the central supervisor SC is able to send activation commands C.sub.RA1, C.sub.RP1, C.sub.RN1 for each relay RN, RP, RA of a first one of the batteries HVB.sub.1, activation commands C.sub.RA2, C.sub.RP2, C.sub.RN2 for each relay of a second one of the batteries HVB.sub.2, activation commands C.sub.RA3, C.sub.RP3, C.sub.RN3 for each relay of a third one of the batteries HVB.sub.3, and so on. The central supervisor SC is able to receive states of the relays E.sub.RA1, E.sub.RP1, E.sub.RN1 for each relay of the first battery HVB.sub.1, states of the relays E.sub.RA2, E.sub.RP2, E.sub.RN2 for each relay of the second battery HVB.sub.2, states of the relays E.sub.RA3, E.sub.RP3, E.sub.RNS for each relay of the third battery HVB.sub.3, and so on.

[0037] For each battery HVB.sub.i, referenced by an index i between I and n, n being the total number of batteries HVB of the system, the central supervisor SC is programmed to command successively in an initialization phase the third RA and then the first relay RN of the battery with index i, with a time staggering of at least one delay time DT, as shown by the first two curves C.sub.RA1 and C.sub.RN1 of the diagram in FIG. 5. Next, the central supervisor SC verifies, for a battery of index k between I and n, whether the initialization phase I has already been performed and whether the voltage difference between the second pole (+) and the second polarity V.sub.HVB−V.sub.HVN is less than a predetermined threshold. In this case, the supervisor controls an establishment phase in which the second relay RP of the battery of index k is actuated and then the third relay RA is deactivated, as shown for example by the first and the third curve C.sub.RA1 and C.sub.RP1 of the diagram in FIG. 5. If no battery is in this case, the supervisor commands the initialization phase for the battery of index i+1 with a time staggering of at least the delay time DT between the command of the first relay RN of the battery with index i and the command of the third relay RA of the battery with index i+1, as shown for example by the fourth curve C.sub.RA2 of the diagram.

[0038] For each activation or deactivation of one of the relays RN, RP, RA, the central supervisor SC monitors the state of the commanded relay, for example, the state E.sub.RA1 for a command C.sub.RA1. If the state does not correspond to the command after a certain time period, the supervisor assumes that the battery is out of service and disconnects it from the system by deactivating all its relays. If the state corresponds to the command, and the delay time DT has expired, the next command is authorized.