Provided is a method of calculating a resistance and a capacitance of an energy storage system, including a current application step of applying a predetermined current having a constant value to the energy storage system; a first voltage measurement step of measuring a voltage of the energy storage system while the predetermined current is applied to the energy storage system; a second voltage measurement step of measuring a voltage of the energy storage system after breaking the predetermined current applied to the energy storage system; and a step of calculating a resistance (R) and a capacitance (C) of the energy storage system based on the voltage of the energy storage system measured in the first voltage measurement step, the voltage of the energy storage system measured in the second voltage measurement step, and the predetermined current having the constant value.

Provided is a method of calculating a resistance and a capacitance of an energy storage system, including a current application step of applying a predetermined current having a constant value to the energy storage system; a first voltage measurement step of measuring a voltage of the energy storage system while the predetermined current is applied to the energy storage system; a second voltage measurement step of measuring a voltage of the energy storage system after breaking the predetermined current applied to the energy storage system; and a step of calculating a resistance (R) and a capacitance (C) of the energy storage system based on the voltage of the energy storage system measured in the first voltage measurement step, the voltage of the energy storage system measured in the second voltage measurement step, and the predetermined current having the constant value.

An energy storage system has at least one string of N modules, with each module including an energy storage device and a switching unit configured to for either serially connect the energy storage device into the string or to provide a short circuit. The energy storage system additionally includes a controller configured to perform (during on-load operation of the ESS) the steps of: changing the state of at least one switching unit of a module; measuring a current and a voltage at the energy storage device of the module, and determining characteristics of the energy storage device on a basis of at least a current through the string and change over time of the voltage measured before and after change of the state of the switching unit.

An energy storage system has at least one string of N modules, with each module including an energy storage device and a switching unit configured to for either serially connect the energy storage device into the string or to provide a short circuit. The energy storage system additionally includes a controller configured to perform (during on-load operation of the ESS) the steps of: changing the state of at least one switching unit of a module; measuring a current and a voltage at the energy storage device of the module, and determining characteristics of the energy storage device on a basis of at least a current through the string and change over time of the voltage measured before and after change of the state of the switching unit.

A diagnostic apparatus for a secondary battery includes a control device. The control device acquires an electricity storage amount that is the amount of electricity stored in the secondary battery, and V/K indicating the magnitude of change in OCV of the secondary battery with respect to temperature change of the secondary battery. The control device determines whether or not an SOC unevenness occurs in an electrode surface of the secondary battery by using the acquired electricity storage amount and V/K.

A diagnostic apparatus for a secondary battery includes a control device. The control device acquires an electricity storage amount that is the amount of electricity stored in the secondary battery, and V/K indicating the magnitude of change in OCV of the secondary battery with respect to temperature change of the secondary battery. The control device determines whether or not an SOC unevenness occurs in an electrode surface of the secondary battery by using the acquired electricity storage amount and V/K.

An apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure includes: a charging and discharging assembly for charging or discharging a battery module; a measurer for measuring a current of the battery module at every predetermined period during a cycle in which the battery module is charged or discharged; and a controller for receiving a measurement value for the current of the battery module from the measuring unit, estimating a state of charge (SOC) of the battery module during the cycle based on the received measurement value, calculating a change rate of the estimated SOC, and determining whether a defect occurs in the battery module based on a comparison result between the calculated change rate of the SOC and a preset reference change rate.

An apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure includes: a charging and discharging assembly for charging or discharging a battery module; a measurer for measuring a current of the battery module at every predetermined period during a cycle in which the battery module is charged or discharged; and a controller for receiving a measurement value for the current of the battery module from the measuring unit, estimating a state of charge (SOC) of the battery module during the cycle based on the received measurement value, calculating a change rate of the estimated SOC, and determining whether a defect occurs in the battery module based on a comparison result between the calculated change rate of the SOC and a preset reference change rate.

A battery management apparatus according to an embodiment of the present disclosure includes a voltage measurer for measuring a voltage of a battery module and output a measured voltage value; a current measurer for measuring a charging current of the battery module and output a measured current value; and a controller for receiving the measured voltage value and the measured current value, estimating a state of charge (SOC) of the battery module based on the measured voltage value and the measured current value, calculating an accumulated change rate by adding up a change rate of the estimated SOC per unit time, and detecting whether the battery module has a defect by comparing the calculated accumulated change rate with a reference change rate.

Embodiments of the present disclosure includes an apparatus for estimating the state of charge of a battery, comprising: a first coulomb counter (STCC) for sampling a first charge variation (ΔQ) on the battery in a time comprising a number of predetermined periods, by adding up a battery current Im in each of the predetermined periods; a compensator for calculating a second charge variation (ΔQ_comp) by compensating for the first charge variation (ΔQ); a second coulomb counter (CCE) for calculating a first predicted charge amount (Qe) by adding up the second charge variation (ΔQ_comp); and a state of charge estimator for estimating the state of charge of the battery on the basis of the first predicted charge amount (Qe). The technique increases the accuracy of a state of charge estimation by compensating for characteristics according to battery temperature and aging.