Patent ID: 11933854
Assignee: NUVOTON TECHNOLOGY CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC B  G  H  Y | IPC B  G  H

Claim 19:
20. A battery management system comprising:
a battery management circuit that manages a secondary battery and includes: a reference signal generator that generates a first reference frequency signal and a second reference frequency signal, the second reference frequency signal having a phase different from a phase of the first reference frequency signal; an alternating current superimposer that superimposes an alternating current on the secondary battery, the alternating current having a frequency component of the first reference frequency signal; a voltage measurer that measures a voltage of the secondary battery by performing sampling using a frequency higher than a frequency of the first reference frequency signal; a current measurer that measures a current of the secondary battery by performing sampling using a frequency higher than the frequency of the first reference frequency signal; and a converter that converts each of results of measurements by the voltage measurer and the current measurer into a real part component and an imaginary part component of each of a complex voltage and a complex current, by multiplying the result of the measurement by the first reference frequency signal and the second reference frequency signal; and
an integration controller that specifies the frequency of the first reference frequency signal to the battery management circuit,
wherein the voltage measurer and the current measurer measure a voltage and a current of the secondary battery repeatedly, the battery management circuit transmits the real part component and the imaginary part component of each of the complex voltage and the complex current to the integration controller, and
the integration controller calculates a complex impedance of the frequency specified, from the real part component and the imaginary part component of each of the complex voltage and the complex current transmitted, and estimates a temperature of the secondary battery at a time of measurement, from the complex impedance calculated, a previously converted complex impedance, and information indicating a temperature of the secondary battery.