Parameter estimation device, parameter estimation method, and computer program

A parameter estimation system configured to estimate a parameter of an equivalent circuit model of a secondary battery, the parameter estimation system comprising:

• a voltage sensor configured to output a voltage signal indicating a voltage of the secondary battery;
• a current sensor configured to output a current signal indicating a charge/discharge current of the secondary battery;
• a voltage acquisition unit configured to acquire the voltage signal in a time-series manner;
• a current acquisition unit configured to acquire the current signal in a time-series manner;
• a storage unit configured to store therein the charge/discharge current indicated by the current signal;
• a first calculation unit configured to receive the current signal and to calculate a difference between the charge/discharge current indicated by the received current signal and the charge/discharge current stored in the storage unit;
• an estimation unit configured to receive the voltage signal and the current signal and to estimate the parameter on the basis of the voltage indicated by the voltage signal and the charge/discharge current indicated by the current signal;
• and
• a prohibition unit configured to record, in a memory, prohibition data so as to prohibit the estimation of the parameter performed by the estimation unit when an absolute value of the charge/discharge current is smaller than a first threshold, wherein
• the prohibition unit is further configured to
• record the prohibition data in the memory when (i) the absolute value of the charge/discharge current is not smaller than the first threshold and (ii) the difference calculated by the first calculation unit is smaller than a second threshold, and
• not record the prohibition data in the memory when (i) the absolute value of the charge/discharge current is not smaller than the first threshold and (ii) the difference calculated by the first calculation unit is not smaller than the second threshold.