Detachable battery module, and method and apparatus for the charge equalization of a battery string using same

Abstract

Provided are a detachable battery module and a charge equalization method and apparatus for a battery string. According to the exemplary embodiments of the present invention, the charge equalization apparatus are modularized by being divided into the master unit and the slave unit, such that the charge equalization apparatus may be expanded and contracted independent of the number of batteries, the circuits are separated for each module, such that the circuits may be easily implemented, and when the circuits are damaged, only the damaged module is replaced, such that the effective countermeasure may be performed.

1 .- 17 . (canceled) 
     
     
         18 . A detachable battery module, comprising:
 at least one battery cell;   a switch block unit which switches the battery cell;   a module switch unit which selects the switch block; and   a battery monitoring unit which monitors the battery cell and measures a cell potential to transmit cell potential information.   
     
     
         19 . The detachable battery module of  claim 18 , wherein the battery monitoring unit and the switch block unit are configured of a single integrated circuit. 
     
     
         20 . The detachable battery module of  claim 18 , wherein the switch block unit or the module switch unit is configured of at least any one of a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), and a relay. 
     
     
         21 . The detachable battery module of  claim 19 , wherein the switch block unit or the module switch unit is configured of at least any one of a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), and a relay. 
     
     
         22 . A charge equalization apparatus for a battery string, comprising:
 at least one detachable battery module of  claim 18 ;   a control unit which receives cell potential information from the detachable battery module to compare the cell potential information with a prestored reference value so as to determine whether the charge of the battery cell is equalized; and   an equalization converter which performs the charge equalization by charging or discharging the battery cell for a predetermined operation time depending on whether the control unit performs the charge equalization.   
     
     
         23 . The charge equalization apparatus of  claim 22 , wherein the control unit and the equalization converter are a master module and the detachable battery module is a slave module which is removed from the mater module. 
     
     
         24 . The charge equalization apparatus of  claim 22 , wherein the reference value is any one of a state of charge (SOC) of the battery cell, a user's designated voltage, a battery pack or average voltage, and the user's designated voltage and a state of health (SOH) increased and decreased in the battery pack or average voltage. 
     
     
         25 . The charge equalization apparatus of  claim 22 , wherein the control unit determines whether the charge is equalized by comparing the cell potential information with
 an average value of the battery cells of all of the removable battery modules,   an average value of all the battery cells in one of the removable battery modules, or   a preset value.   
     
     
         26 . The charge equalization apparatus of  claim 22 , wherein the battery monitoring unit controls the detachable battery module and
 the module switch unit shares equalization converters for each detachable battery module or insulates between the detachable battery modules.   
     
     
         27 . The charge equalization apparatus of  claim 22 , wherein the equalization converter is configured of a chargeable/dischargeable DC/DC converter or an insulating transformer and the switch block unit or the module switch unit is configured of at least any one of a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), and a relay. 
     
     
         28 . The charge equalization apparatus of  claim 22 , wherein when the corresponding battery cell is undercharged or overcharged over other battery cells, the control unit moves a total energy of the battery cell to the corresponding battery cell, and
 when only the corresponding battery cell is undercharged or overcharged, energy of an external power supply moves to the undercharged battery cell or the energy of the overcharged battery cell moves to the energy of the external power supply.   
     
     
         29 . The charge equalization apparatus of  claim 22 , wherein
 the predetermined operation time is defined by comparing a programmed and prestored value with   a value calculated by mathematical modeling depending on a charging or discharging current amount of the equalization unit and a energy storage capacity of the corresponding battery cell,   a prestored value, or   the user's desired value obtained by measuring a cell voltage, a stage of charge (SOC), or a state of health (SOH) after an charge equalization operation is periodically performed on the corresponding battery cell for a predetermined time.   
     
     
         30 . A charge equalization method for a battery string using a detachable battery module, comprising:
 measuring a potential for at least one battery cell included in at least one detachable battery module by monitoring the battery cell;   transmitting information on the measured potential of the battery cell;   preparing a charge equalization cell list about overcharged or undercharged battery cells by comparing the transmitted cell potential information with a prestored reference value;   connecting battery modules including the corresponding battery cell depending on the charge equalization list; and   performing the charge equalization on the corresponding battery cell for a predetermined period by an equalization converter.   
     
     
         31 . The charge equalization method of  claim 30 , wherein the performing the charge equalization on the corresponding battery cell includes:
 determining whether the charge of the corresponding battery cell is equalized; and   re-measuring the cell potential of the corresponding battery cell when the charge equalization is completed, as a result of whether the charge is equalized.   
     
     
         32 . The charge equalization method of  claim 30 , wherein the reference value is any one of a state of charge (SOC) of the battery cell, a user's designated voltage, a battery pack or average voltage, and the user's designated voltage and a state of health (SOH) increased and decreased in the battery pack or average voltage. 
     
     
         33 . The charge equalization method of  claim 30 , wherein it is determined whether the charge of the corresponding battery cell is equalized, by comparing an average value of the battery cells of all of the detachable battery modules with the reference value,
 comparing an average value of all the battery cells in one of the detachable battery modules with the reference value, or   comparing a preset value with the reference value.   
     
     
         34 . The charge equalization method of  claim 33 , further comprising:
 when the corresponding battery cell is undercharged or overcharged over other battery cells, moving total energy of the battery cell to the corresponding battery cell, and   when only the corresponding battery cell is undercharged or overcharged, moving energy of an external power supply to the undercharged battery cell or moving the energy of the overcharged battery cell to the energy of the external power supply.   
     
     
         35 . The charge equalization method of  claim 30 , wherein the predetermined operation time is defined by comparing a programmed and prestored value (reference value) with
 a value calculated by mathematical modeling depending on a charging or discharging current amount of the equalization unit and a energy storage capacity of the corresponding battery cell,   a prestored value, or   the user's desired value obtained by measuring a cell voltage, a stage of charge (SOC), or a state of health (SOH) after an charge equalization operation is periodically performed on the corresponding battery cell for a predetermined time.