Lithium battery box and accurate temperature control method

Abstract

The invention relates to the related field of new energy lithium battery energy storage, in particular to a lithium battery box and an accurate temperature control method.The lithium battery box comprises a battery box body, a vent hole cover plate, a steering engine and vent holes. The heat of the battery with relatively high heating is dissipated by accurately adjusting the opening and closing and the opening angle of the specific vent holes; the opening and closing angles of the ventilation holes are automatically controlled by collecting battery temperature information, and the battery temperature is controlled within a reasonable range through an automatic control algorithm; a multiplexer is adopted to control multiple paths of ventilation holes, so that IO resources of a BMS microcontroller are saved; a plurality of judgment strategies are adopted, a temperature threshold value is not singly depended on, a temperature matrix, a variance matrix and a differential matrix are established, and the battery heating condition is judged in advance in combination with a battery SOC-OCV curve.

Description

Technical field [0001] The present invention relates to a new energy lithium battery energy storage related field, specifically a lithium battery box and a precise temperature control method. Background [0002] With the national policy tilt on the new energy industry, lithium batteries and BMS systems have been widely used in many fields. The national standard of the energy storage industry requires that the maximum temperature difference between the cells in the battery pack shall not be higher than 5 °C. Most existing battery packs only open the air hole in the cabinet, use a fan to dissipate heat, and cannot accurately control the temperature of the battery for a specific location. [0003] 1. Most existing packs only open the air hole in the box, using a fan to extract air or passive heat dissipation. This method has an average heat dissipation, which can only dissipate heat for the entire pack as a whole, and cannot focus on heat dissipation for single cells with higher tem...

AI Technical Summary

Problems solved by technology

This method dissipates heat more evenly, and can only dissipate heat for the entire pack as a whole, and cannot focus on dissipating heat for single cells with higher temperatures

Since the national standard has clear requirements on the temperature difference of the battery cells in the pack, the existing solutions rely too much on the early air duct design and cannot cope with special situations such as a sudden rise in the temperature of the single battery cells.

[0004] 2. For energy storage schemes with large currents, the heat generated in the pack is often large

If the problem of temperature difference is not solved, it will inevitably lead to further increase in the internal resistance of the battery with more heat, forming a vicious circle

[0005] 3. Since the heating of the battery is random, it is necessary to set up multiple additional adjustable cooling holes, and the opening and closing angle of the cooling holes should be determined by the automatic control of the heat generated by the battery. Unstable air volume, frequent opening and closing of ventilation holes, resulting in fluctuating battery temperature and affecting the thermal environment inside the pack

[0007] 5. The temperature perception of the BMS system is only a response to real-time data. It cannot predict the cooling strategy in advance according to the data processing situation, and cannot dynamically provide an appropriate temperature control strategy for the whole pack.

[0008] 6. Data such as temperature, voltage, current, and SOC are only isolated to the BMS system, and cannot be coordinated with each other, relying on their changing trends to influence each other

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