Charge equalization apparatus for a battery string
Provided are a charge equalization 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. A charge equalization apparatus for a battery string, comprising:
two or more detachable battery modules, each of the two or more detachable battery modules comprising: two or more battery cells; a switch block unit configured to switch the two or more battery cells; a module switch unit configured to separate all electrical connections for each of the two or more detachable battery modules from each other and to select the switch block unit; and a battery monitoring unit configured to monitor the two or more battery cells and measure a cell potential of each of the two or more battery cells to transmit information on the cell potential;
a control unit configured to receive the information from the battery monitoring unit, compare the information with a prestored reference value to determine whether charges of the two or more battery cells are equalized, and transmit a control signal to the battery monitoring unit; and
a single equalization converter configured to perform a charge equalization by charging or discharging the two or more battery cells,
wherein the module switch units of the two or more detachable battery modules are connected in parallel and are configured to share the equalization converter,
wherein the battery monitoring unit is a battery stack monitor directly connected to each of the two or more battery cells and is connected via communication with the control unit to receive the control signal from the control unit and controls operations of the switch block unit and the module switch unit according to the control signal,
wherein the module switch unit is a relay, and
wherein the control unit and the single equalization converter form a single master module; and each of the two or more detachable battery modules form a slave module and is configured to be independently attachable to and detachable from the single master module.
2. The charge equalization apparatus of claim 1 , wherein when the slave module is attached to the single master module, the battery monitoring unit is configured to be connected independently to the control unit.
3. The charge equalization apparatus of claim 1 , wherein the battery monitoring unit and the switch block unit are configured of a single integrated circuit.
4. The charge equalization apparatus of claim 1 , wherein the switch block unit selected at least from a group consisting of a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), and a relay.
5. The charge equalization apparatus of claim 1 , wherein the equalization converter is configured of a chargeable/dischargeable DC/DC converter or an insulating transformer.