System and method for high-precision synchronous acquisition of single current of parallel power battery packs

Abstract

The invention discloses a high-precision synchronous acquisition system and method for parallel-connected power battery unit current, comprising: a current acquisition module, a voltage modulation module and a control unit all arranged in the current acquisition channel; the current acquisition module acquires the battery cells of the parallel-connected battery pack The current of the body, and convert the current signal into a single-ended voltage signal, and then convert the single-ended voltage signal into a differential signal; the voltage modulation module performs voltage follow on the differential signal output by the current acquisition module and modulates the differential signal to meet the analog-to-digital conversion The signal required by the input, the modulated signal is transmitted to the control unit through analog-to-digital conversion; the control unit sends the synchronization signal to multiple current acquisition channels at the same time, and controls the synchronous acquisition of the battery cell current of multiple current acquisition channels. The application improves the stability of the measurement data of the Hall current sensor through the circuit design.

Description

technical field [0001] The invention relates to the technical field of battery pack monomer current acquisition, in particular to a system and method for high-precision synchronous acquisition of parallel power battery pack monomer current. Background technique [0002] Batteries are not only the energy source of electric vehicles, but also the core of new energy storage links. When the battery is in use, it must be combined in series and parallel to form a battery pack to meet the voltage and current requirements. [0003] During the research, the inventor found that the existing battery management system (BMS) rarely has a battery management system for parallel battery packs, and there are many problems in the detection method of the single current of the parallel power battery packs. In fact, due to the inconsistency of the battery cells, there are obvious differences in their internal resistance, etc., so that the currents of the parallel cells are different when they a...

AI Technical Summary

Problems solved by technology

For the current detection method using resistors combined with operational amplifiers, its advantages are low cost, high precision, and small size, but it has the disadvantages of large temperature drift, difficult selection of precision resistors, and no isolation effect; for the detection method using current transformers, Often, the large current on the primary side is converted proportionally and sent to instruments or relays, which is not suitable for direct detection of small currents.

The detection method using the Hall current sensor is mostly used for small current detection, and the input (current) and output (voltage) satisfy a linear relationship. This method has a simple structure, but is susceptible to external interference. Asynchronous, poor detection stability of Hall current sensor

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