Battery internal resistance measuring and calculating method and circuit of battery pack management system

A technology of battery management system and battery pack management, which is applied in the direction of measuring resistance/reactance/impedance, measuring electricity, measuring devices, etc., and can solve the problems of increasing the number of devices and cost

CN104698383AActive Publication Date: 2015-06-10DONGGUAN POWERWISE TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2015-06-10

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Abstract

The invention discloses a battery internal resistance measuring and calculating method and circuit of a battery pack management system. The method includes: respectively using a first cycle and a second cycle to collect and cache the voltage of the single battery in a battery pack and the currents of a battery stack cathode; addressing and selecting the cached voltage to fine a first voltage point V1 and a second voltage point V2, and saving the first voltage point V1 and the second voltage point V2; addressing and selecting the cached currents to find a first current point I1 and a second current point I2, and saving the first current point I1 and the second current point I2; calculating the internal resistance R of the single battery according to the following relation: R=(V2-V1) / (I2-I1). By the arrangement, the method has the advantages that adding of a battery internal resistance exciting bank or measuring device is not needed, current and voltage detecting are not limited to discharge conditions, current detecting and voltage detecting are separated and asynchronous, the sample space of battery internal resistance measuring is increased, and internal resistance measuring is simplified, the real-time variation condition of battery internal resistance can be monitored conveniently, equipment can be reduced, and cost is lowered.
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Description

technical field

[0001] The invention relates to the field of energy storage power station and electric vehicle control, in particular to a method and circuit for measuring and calculating the battery internal resistance of a battery pack management system. Background technique

[0002] Internal resistance is an important technical indicator to measure battery performance. When the battery is in different power states, its internal resistance is different; when the battery is in different service life, its internal resistance is also different. Whether the battery is about to fail, the capacity is insufficient, or the charge and discharge are improper, it can be reflected in the change of its internal resistance. Therefore, detecting internal resistance has become a popular way to judge whether a battery is good or bad.

[0003] The existing method for detecting the internal resistance of the battery in the battery pack uses a separate device to discharge the battery, which...

Examples

Embodiment Construction

[0022] figure 1 It is a schematic diagram of the battery internal resistance measuring and calculating circuit of the battery pack management system according to the embodiment of the present invention. Such as figure 1 As shown, the battery internal resistance measurement circuit of the battery pack management system in this embodiment includes: a battery stack 10 , a central controller 16 of an energy storage system, and at least two battery management systems 13 and 14 . Wherein, the battery stack 10 includes at least two or more sets of energy storage battery groups 11 and 12 connected in series.

[0023] The battery management systems 13, 14 are in one-to-one correspondence with the battery packs 11, 12, and the first period T 1 The voltage of a single battery in the battery pack 11 or the battery pack 12 is collected in real time. The energy storage system central control 16 takes the second period T 2 The current of the negative electrode of the battery stack 10 is ...