BATTERY MANAGEMENT SYSTEM AND DRIVING METHOD THEREOF
First Claim
1. A battery management system (BMS) for a hybrid vehicle that includes an engine control unit, a motor generator controlled by the engine control unit, and a battery in which a plurality of battery cells are grouped into a plurality of battery packs, comprising:
- a sensor that senses temperature, current, and open circuit voltage (OCV) of the battery at a present key-on time point; and
a main control unit (MCU) that calculates a key-off time period, the key-off time period being an amount of time that the battery has been in a key-off state from a key-off time point to a time point at which the present key-on state begins, that calculates a difference between temperatures of the battery respectively detected at the key-on time point and the key-off time point by receiving data of the temperature of the battery, that detects an OCV error range corresponding to an SOC error range at the key-off time point, and that infers an initial SOC of the battery by using the OCV and the OCV error range.
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Accused Products
Abstract
A battery management system (BMS) manages a battery for a hybrid vehicle including an engine control unit and a motor generator controlled by the engine control unit and connected to a battery including at least one battery pack, each pack including a plurality of battery cells. The BMS includes a sensor and an MCU unit. The sensor detects temperature, current, and open circuit voltage (OCV) of the battery. The MCU receives the detected temperature, current, and OCV, calculates a key-off time period which is a period between a time point when a battery key-on state ends and a time point when a subsequent battery key-on state begins, calculates an OCV error range corresponding to an SOC error range detected at the key-off time point, and infers an initial SOC of the battery.
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Citations
19 Claims
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1. A battery management system (BMS) for a hybrid vehicle that includes an engine control unit, a motor generator controlled by the engine control unit, and a battery in which a plurality of battery cells are grouped into a plurality of battery packs, comprising:
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a sensor that senses temperature, current, and open circuit voltage (OCV) of the battery at a present key-on time point; and a main control unit (MCU) that calculates a key-off time period, the key-off time period being an amount of time that the battery has been in a key-off state from a key-off time point to a time point at which the present key-on state begins, that calculates a difference between temperatures of the battery respectively detected at the key-on time point and the key-off time point by receiving data of the temperature of the battery, that detects an OCV error range corresponding to an SOC error range at the key-off time point, and that infers an initial SOC of the battery by using the OCV and the OCV error range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 18, 19)
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9. A method of determining an initial state of charge (SOC) of a battery of a hybrid vehicle at a key-on time point following a key-off time period, the key-off time period beginning with a key-off time point and ending with the key-on time point, the method comprising:
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comparing the key-off time period with a reference time period, wherein if the key-off time period is less than the reference time period, the initial SOC is determined to be the SOC at the key-off time point, and if the key-off time period is not less than the reference time period, determining whether an open circuit voltage (OCV) detected at the key-on time point is a voltage within an OCV error range corresponding to an SOC error range detected at the key-off time point, wherein, if the OCV detected at the key-on time point is not a voltage within an OCV error range corresponding to an SOC error range detected at the key-off time point, the initial SOC is determined according to the OCV and temperature of the battery at the key-on time point from a table that relates SOCs to OCVs based on temperature, and if the OCV detected at the key-on time point is a voltage within the OCV error range corresponding to an SOC error range detected at the key-off time point, determining whether an absolute value of a difference between temperatures of the battery detected at the key-on time point and the key-off time point is greater than a reference temperature value, wherein if the difference between temperatures detected at the key-on time point and the key-off time point is greater than the reference temperature, the initial SOC is determined according to the OCV and temperature at the key-on time point from a table that relates SOCs to OCVs based on temperature and wherein, if the difference between temperatures detected at the key-on time point and the key-off time point is not greater than the reference temperature, the initial SOC is determined to be the SOC at the key-off time point. - View Dependent Claims (10, 11)
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12. A driving method of a battery management system (BMS) for a hybrid vehicle including an engine control unit and a motor generator controlled by the engine control unit and connected to a battery including a plurality of battery cells grouped into a plurality of battery packs, comprising:
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comparing a key-off time period with a reference time period; determining whether an open circuit voltage (OCV) detected at the key-on time point is a voltage within an OCV error range corresponding to an SOC error range detected at the key-off time point; comparing a difference between temperatures of the battery detected at the key-on time point and the key-off time point with a reference temperature value; and determining an initial state of charge (SOC) as the result of the comparing of the key-off time period with the reference time period, determining whether the OCV detected at the key-on time point is a voltage within the OCV error range corresponding to an SOC error range detected at the key-off time point and comparing a difference between temperatures detected at the key-on time point and the key-off time point with the reference temperature value. - View Dependent Claims (13, 14, 15, 16, 17)
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Specification