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BQ76940: 采集电压后,紧接着开启均衡后,单体电压采集异常,跳变非常夸张

Part Number: BQ76940


Dear TI:

    目前使用BQ76940。

仿真代码如下:

while(250ms)    ////循环采集电芯电压,250一次

{

    afe_bq769x0_adpt_cell_vol_data();    //采集单体电芯电压
    afe_bq769x0_adpt_cc_data();            //采集电流
    afe_bq769x0_adpt_temp_data();       //采集温度
    afe_bq769x0_balance_start();           //开启均衡

}

问题:

    发现当我没有加入“开启均衡”的代码时,采集的电压,电流和温度均正常。当加入最后一行“开启均衡”时,电压采集跳变夸张且无规律。

    请问,在采集电压后,立即判断开启或者关闭均衡,是有问题的吗?我这里的均衡接口,每250ms后,如果满足>=3800mv且响铃压差>=50mv,都会去打开电芯均衡,不会管上一次有没有开启过。

开启均衡后,异常图表如下“”

  • 您好,请参考下面内容。

    The cell measurement does not take place during balancing, but the voltage can take time to settle for cell measurements depending on the input filter component values (Rc and Cc). An example waveform can be found in Figure 5 of this app note: http://www.ti.com/lit/an/slua775/slua775.pdf

    If filter settling is the issue, I do not think you can solve this without modifying the hardware. If the voltage variation is small, maybe you could turn off balancing when you are getting close to the OV voltage - one idea for software modification.