TECHNICAL FIELD

The present application claims priority to Korean Patent Application No. 10-2018-0122131 filed on Oct. 12, 2018 in the Republic of Korea, the disclosures of which are incorporated herein by reference.

The present disclosure relates to a battery management apparatus and method, and more particularly, to a battery management apparatus and method for balancing voltages of cell assemblies when a battery pack is electrically connected to another battery pack in parallel.

BACKGROUND ART

Recently, due to the depletion of fossil energy and environmental pollution, there is a growing interest in electrical products that may be driven using electrical energy without using fossil energy.

Accordingly, the development and demand for technology of mobile devices, electric vehicles, hybrid electric vehicles, power storage devices and uninterruptible power supplies increase. For this reason, the demand for secondary batteries as energy sources is rapidly increasing, and the types of demand are also diversifying. Thus, many researches on secondary batteries have been conducted to meet various demands.

Meanwhile, in order to drive an electric vehicle or a hybrid electric vehicle, an electric motor requiring a high power must be operated. In addition, a power storage device that powers a building or certain area must provide enough power to meet the demanded power. In order to provide high output or large capacity power, a plurality of cell assemblies, each having unit cell assemblies, are connected in series or in parallel to form a battery pack, thereby supplying a desired output or power.

Further, a plurality of battery packs are connected in parallel and used for a high-performance electric vehicle that requires high capacity. At this time, when the battery packs are connected in parallel, if a voltage difference occurs between the voltages of the battery packs, a high current flows between the battery packs without outputting the voltage to a final output terminal. For this reason, when a voltage difference occurs between the voltages of the battery packs, the battery packs may be overdischarged and the high current may cause damage to electrical components included in each of the battery packs.

DISCLOSURE

Technical Problem

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery management apparatus and method, which determines whether balancing is required when a battery pack is electrically connected to another battery pack in parallel, and performs balancing by using a balancing resistor if it is determined that balancing is required.

These and other objects and advantages of the present disclosure may be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure may be realized by the means shown in the appended claims and combinations thereof.

Technical Solution

Various embodiments of the present disclosure to accomplish the above object are as follows. A battery management apparatus according to the present disclosure may comprise: a sensing unit detachably mounted to a battery system and configured to measure a voltage of a cell assembly included in a battery pack, which is electrically connected to another battery pack in parallel, when being mounted to the battery system; a balancing circuit having a balancing resistor connected to a charging and discharging path of the cell assembly in parallel and a balancing switch for electrically connecting or disconnecting the cell assembly and the balancing resistor; and a processor operably coupled to the sensing unit and the balancing circuit.

Preferably, when it is detected that the battery pack is electrically connected to another battery pack in parallel, the processor may determine whether balancing is required between the voltage of the cell assembly and a voltage of a cell assembly included in the another battery pack, and, when it is determined that the balancing is required, the processor may calculate a balancing current of an operation state of each of the balancing switch and a balancing switch included in the another battery pack by using balancing circuit data, compare each of the calculated balancing currents with a reference balancing current, and control the operation state of the balancing switch based on the comparison result.

Preferably, when it is detected that the battery pack is electrically connected to another battery pack in parallel, the processor may send a connection completion signal and a voltage request signal for requesting the voltage of the cell assembly included in the another battery pack to the another battery pack.

Preferably, the processor may compare a voltage difference between the voltage of the cell assembly and the voltage of the cell assembly included in the another battery pack with a reference voltage difference, and determine that the balancing is required when the voltage difference is greater than the reference voltage difference.

Preferably, the processor may calculate the balancing current of the operation state of each of the balancing switch and the balancing switch included in the another battery pack by using balancing circuit data that includes at least one of the voltage of the cell assembly, the voltage of the cell assembly included in the another battery pack, a resistance of the balancing resistor and a resistance of a balancing resistor included in the another battery pack.

Preferably, the processor may control the balancing switch to any one of the operation states of the balancing switch and the balancing switch included in the another battery pack, which correspond to a balancing current smaller than the reference balancing current among the calculated balancing currents.

Preferably, when it is determined that the balancing is required, the processor may calculate a balancing time of the operation state of each of the balancing switch and the balancing switch included in the another battery pack by using balancing circuit data, compare each of the calculated balancing times with a reference balancing time, and control the operation state of the balancing switch based on the comparison result.

Preferably, the processor may calculate the balancing time of the operation state of each of the balancing switch and the balancing switch included in the another battery pack by using balancing circuit data that includes at least one of the voltage of the cell assembly, the voltage of the cell assembly included in the another battery pack, a resistance of the balancing resistor and a resistance of a balancing resistor included in the another battery pack.

Preferably, the processor may control the balancing switch to any one of the operation states of the balancing switch and the balancing switch included in the another battery pack, which correspond to a balancing time smaller than the reference balancing time among the calculated balancing times.

A battery pack according to the present disclosure may comprise the battery management apparatus.

A battery management method according to the present disclosure may use a battery management apparatus including: a sensing unit detachably mounted to a battery system and configured to measure a voltage of a cell assembly included in a battery pack, which is electrically connected to another battery pack in parallel, when being mounted to the battery system; a balancing circuit having a balancing resistor connected to a charging and discharging path of the cell assembly in parallel and a balancing switch for electrically connecting or disconnecting the cell assembly and the balancing resistor; and a processor operably coupled to the sensing unit and the balancing circuit.

The battery management method may comprise: by the processor, detecting whether the battery pack is electrically connected to the another battery pack in parallel; by the processor, determining whether balancing is required between the voltage of the cell assembly and a voltage of a cell assembly included in the another battery pack; when it is determined that the balancing is required, by the processor, calculating a balancing current of an operation state of each of the balancing switch and a balancing switch included in the another battery pack by using balancing circuit data; and by the processor, comparing each of the calculated balancing currents with a reference balancing current and controlling the operation state of the balancing switch based on the comparison result.

Advantageous Effects

According to at least one of embodiments of the present disclosure, when a battery pack is electrically connected to another battery pack in parallel, it is determined whether balancing is required, and then, if it is determined that balancing is required, balancing is performed by using a balancing resistor. Thus, it is possible to protect the battery packs and circuits in the battery packs from a high current that flows due to parallel connection of battery packs with different voltages.

The effects of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

