摘要
基于某电动汽车350MHz处的辐射发射超标问题,介绍了针对窄带干扰板级常用的几种优化措施。通过对芯片外围所用的电容、磁珠进行选型,降低了350MHz发射强度,并采用交叠层电容拼接方法在ADUM5401隔离芯片两侧地之间构建等效电容,350MHz干扰幅值明显降低;最后对优化后的电池管理系统部件及电池包系统进行了优化效果验证。结果表明,超标频段发射强度明显降低,符合GB14023-2011的限值要求。
Based on the case that 350 MHz emission of an electric vehicle outside of the limits of standard, several optimization measures for narrow band interference were discussed. Firstly, the capacitors and magnetic beads used in the peripheral circuit of ADUM5401 were optimized to reduce the EMI intensity of 350 MHz. Secondly, an equivalent capacitor was constructed between the two sides of the ADUM5401 isolation ground by using the overlapping plan stitching capacitor technology, which can effectively inhibit the emission. Finally, the optimized BMS and battery pack system were tested and the test results show that the emission intensity of 350 MHz decreased obviously and meets the limit requirement of GB 14203-2011.
