Modular regulator circuit, for a modular electrical storage cell battery, having a number of modules dependent on the number of modules of the battery

• US 5,648,713 A
• Filed: 06/01/1995
• Issued: 07/15/1997
• Est. Priority Date: 07/04/1994
• Status: Expired due to Term

• Current Assignee: SAFT SA (Totalenergies Se)
• Original Assignee: SAFT SA (Totalenergies Se)
• Inventors: Mangez, Jean Claude
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/456,303
• Time in Patent Office: 775 Days
• Field of Search: 320/2, 320/6, 320/7, 320/15, 320/17, 320/18, 320/30, 320/14
• US Class Current: 320/103
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits

Abstract

A regulator circuit for a battery of electrical storage cells, and in particular a battery whose voltage is a function of state of charge and which is constituted by "n" identical modules connected in series. The circuit comprises "n-1" regulation modules each associated with two series-connected modules of the battery, each regulation module includes means for bringing the voltage across the terminals of each of the two series-connected battery modules with which it is associated to a common value by diverting current taken from across the terminals of the module which provides the greater voltage across its terminals, end until said greater voltage has been reduced to the value present across the terminals of the module providing the smaller voltage.

Claims

1. A regulator circuit for a battery of electrical storage cells, and in particular for a battery whose voltage is a function of its state of charge and which is constituted by "n" identical modules ("n" being an integer) connected in series between end terminals of the battery, the circuit comprising "n-1" regulation modules each respectively associated with two series-connected modules of the battery, each regulation module including regulator means for bringing the voltage across the terminals of each of the two series-connected battery modules with which it is associated to a common value by diverting current taken from the terminals of that one of the modules which provides the greater voltage until said greater voltage is reduced to the same value as the voltage present across the terminals of the module that has the smaller voltage.

2. A regulator circuit according to claim 1, also comprising charging current limitation means for limiting the charging current delivered to the battery, said means operating above a determined maximum current threshold for the current diverted by a regulation module from one or other of the two series-connected modules of the battery with which the regulation module is associated, each regulation module having means for determining when said threshold has been crossed, and means for applying corresponding control to the charging current limitation means.

3. A regulator circuit according to claim 1, comprising regulator means incorporated in each regulation module, comprising a circuit built around an operational amplifier and resistors for preparing the voltages present across the terminals of the two series-connected battery modules with which the regulation module is associated, and switching means controlled in mutual phase opposition depending on the polarity of the voltage present at the output from a comparator circuit so as to connect a balancing resistor across the terminals of that one of the two series-connected battery modules having the larger voltage across its terminals.

4. A regulator circuit according to claim 1, including charging current limitation means constituted by a circuit comprising at least one current-limiting transistor which is coupled between a terminal of the battery that is provided for connection to a load and a charger terminal of the battery provided for connection to a charger, said charger terminal being of the same polarity as said terminal, wherein the circuit is controlled via two intermediate transistors that are controlled in phase opposition, said intermediate transistors being oppositely switched on depending on the polarity of a voltage present at an output of an operational amplifier of a comparator circuit when said voltage provides current beyond a maximum current threshold for current flowing through one of balancing resistors, and wherein each of the intermediate transistors is associated with at least one additional transistor enabling said each intermediate transistor to act separately on the current-limiting transistor.

5. A regulator circuit according to claim 1, providing continuous balancing between modules of a battery during at least one of charging, discharging and rest.