Patent ID: 9680303
Date: 2017-06-13
CPC Classifications: H02J,Y02E

Claim:
1. A power storage system comprising a control means for controlling to charge and discharge a plurality of battery packs in parallel while connecting all of the plurality of battery packs in parallel to an external circuit, each of said battery packs of said plurality of battery packs being provided with a storage battery and further provided with a charge switch and a discharge switch which are connected in series to said storage battery, said control means including a bidirectional DC/DC converter which controls the charge and discharge of said battery packs of said plurality of battery packs, said control means further including a power storage system controller which controls said DC/DC converter and the charge switch and the discharge switch of each of said battery packs of said plurality of battery packs, wherein said control means is structured such as to charge so that differences of voltages of all of the plurality of battery packs are within a predetermined range, by making all of the plurality of battery packs in a chargeable state and carrying out pre-charge on the basis of application of electric power supply from said external circuit, and thereafter control to make all of the plurality of battery packs in a chargeable and dischargeable state in relation to said external circuit, wherein said control means is structured such as to start the charge by setting a rated charge current value per one battery pack to Iset and setting said rated charge current value Iset as an initial value of a charge current command value Iref(1), thereafter monitor the charge current of all of the plurality of battery packs after elapse of a predetermined time so as to subtract its maximum value Ibmax(1) from said charge current command value Iref(1), and add said rated charge current value Iset to result of subtraction Ierr (Iref(1)−Ibmax(1)) so as to set as a new charge current command value Iref(2) and carry out control of said pre-charge in such a manner as to carry on the charge.