Design requirement
1、 Design requirements for lithium battery of emergency X-ray machine:
According to the product specifications and customer requirements, the intelligent high current lithium battery matching the host is designed to integrate the functions of high specification safety performance, good charge and discharge performance, high current working capacity and outstanding cycle life into the solution.
2、 Design scheme of lithium battery for emergency X-ray machine:
1) Protection board (PCM): the protection circuit is designed according to the chemical characteristics of lithium iron phosphate battery and the working characteristics of X-ray machine. In addition to overcharge, over discharge, overcurrent and short circuit protection functions, the protection board design also fully considers the problems of high-power heat dissipation and the balance of the whole battery.
2) Protection circuit: imported IC and MOS tubes are used to conduct online real-time monitoring of overcharge, over discharge, overcurrent, short circuit and other functions of the cell. Make the cell work in a safe, stable and efficient range.
3) Overcurrent fuse: mainly designed for secondary protection. Since the battery pack adopts high-power cells with relatively large capacity, although the battery management system has overcurrent and short-circuit protection, the protection function will fail if there is an abnormality, and a very large current will be generated in the case of output short circuit, resulting in danger. Therefore, an overcurrent fuse is added in the scheme. In case of abnormal short circuit, the fuse will disconnect the circuit, And unrecoverable, so as to achieve the purpose of abnormal protection.
4) Cell: large26650 / 3.2v/3000mah lithium iron phosphate cell is adopted. The maximum charging rate of the cell is 1c and the maximum discharge rate is 2C. The cell itself has multiple safety protection functions. The built-in battery management system can effectively avoid battery safety problems.
5) Parameters of the whole battery: 38.4v/39ah (usually nominal 36V / 39ah), normal working current 35A, maximum working current 60A and instantaneous starting current 100A.
6) Battery pack: resistive equalization is adopted between the cells of the battery pack, which can make up for the capacity reduction caused by the difference of single cells in the process of use and prolong the service life of the battery to the greatest extent.
7) The battery pack adopts plastic support to isolate and fix the battery cell, which is more conducive to the heat dissipation and safe use of the battery.
