STATE OF CHARGE CALCULATION DEVICE, STATE OF CHARGE CALCULATION METHOD AND POWER SUPPLY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a state of charge calculation device capable of calculating a state of charge with high accuracy and in a short time.SOLUTION: The state of charge calculation device comprises: a clock unit 52 measuring, defining a starting point when a storage battery 100 composed of one or more storage battery cells 10 transitions from charge operation to stop operation, a first time point t1 before resolution of diffusion polarization caused by charging and a predetermined time point t21 after the first time point t1; a voltage holding unit 53 holding a first voltage value V1 detected from the storage battery 100 at the first time point t1; an open circuit voltage estimation unit 54 estimating an open circuit voltage Voc of the storage battery 100 on the basis of voltage variation characteristics (V1/V21) of the first voltage value V1 and a voltage value V21 detected from the storage battery 100 at the predetermined time point t21 after the first time point t1; and a state of charge calculation unit 55 calculating the state of charge from the open circuit voltage Voc estimated by the open circuit voltage estimation unit 54.