Method for estimating parameter of equivalent circuit model for battery, and battery management system
AssigneeLG Chem, Ltd.
InventorHyoung Jun Ahn
Life of this patent
Estimating the term…
Abstract
Disclosed is a method and a battery management system for estimating the parameters of an equivalent circuit model for a battery. The equivalent circuit model includes a first resistor, a second resistor connected in series to the first resistor and a capacitor connected in parallel to the second resistor. The method according to an embodiment of the present disclosure individually estimates the resistance of the first resistor and the resistance of the second resistor based on a first number of terminal voltages and a first number of currents measured in a sequential order at each time step in a sliding time window having a predefined size, and stores data indicating the estimated results in the memory.
Claims11
A method for estimating parameters of an equivalent circuit model for a battery, the equivalent circuit model including a first resistor, a second resistor connected in series to the first resistor, and a capacitor connected in parallel to the second resistor, the method being performed by a battery management system in a battery pack, the method comprising:
- reading, from a memory, measurement data indicating a first number of terminal voltages and a first number of currents, measured in a sequential order at each time step in a sliding time window having a predefined size;
- calculating a voltage variation of a current time step based on a terminal voltage measured at the current time step and a terminal voltage measured at a previous time step included in the first number of terminal voltages;
- calculating a current variation of the current time step based on a current measured at the current time step and a current measured at the previous time step included in the first number of currents;
- estimating a resistance of the first resistor at the current time step based on a resistance of the first resistor estimated at the previous time step, the voltage variation, and the current variation;
- generating:
- a measured voltage vector based on the first number of terminal voltages;
- and
- a measured current vector based on the first number of currents;
- estimating a resistance of the second resistor at the current time step based on:
- the measured voltage vector;
- the measured current vector;
- the resistance of the first resistor estimated at the current time step;
- and
- a resistance of the second resistor estimated at the previous time step;
- and
- adjusting a duty cycle of a switching signal outputted to a switch in the battery pack based on one or more of:
- a predicted terminal voltage that is predicted using the estimated resistance of the first resistor and the estimated resistance of the second resistor;
- and
- an estimated state of charge (SOC) of the battery that is estimated at the current time step using the estimated resistance of the first resistor and the estimated resistance of the second resistor.
A battery management system for estimating parameters of an equivalent circuit model for a battery, the equivalent circuit model including a first resistor, a second resistor connected in series to the first resistor, and a capacitor connected in parallel to the second resistor, the battery management system comprising:
- a sensing unit configured to measure a terminal voltage and a current of the battery at each time step;
- and
- a control unit operably coupled to the sensing unit, the control unit being configured to:
- record the terminal voltage and the current measured by the sensing unit at each time step in a memory;
- read, from the memory, measurement data indicating a first number of terminal voltages and a first number of currents, measured in a sequential order at each time step in a sliding time window having a predefined size;
- calculate a voltage variation of a current time step based on a terminal voltage measured at the current time step and a terminal voltage measured at a previous time step included in the first number of terminal voltages;
- calculate a current variation of a current time step based on a current measured at the current time step and a current measured at the previous time step included in the first number of currents;
- estimate a resistance of the first resistor at the current time step based on a resistance of the first resistor estimated at the previous time step, the voltage variation, and the current variation;
- generate a measured voltage vector based on the first number of terminal voltages and a measured current vector based on the first number of currents;
- and
- estimate a resistance of the second resistor at the current time step based on:
- the measured voltage vector;
- the measured current vector;
- the resistance of the first resistor estimated at the current time step;
- and
- a resistance of the second resistor estimated at the previous time step.
Dependencies are inferred from the claim text.