Does the placement of the power filter capacitors on the BMS control board far from the power chip weaken EMC performance?

Placing power filter capacitors too far from the power chip will severely weaken their EMC performance. The main function of decoupling capacitors is to provide local charge to the chip and filter high-frequency noise; their effectiveness is highly dependent on loop inductance. If capacitors are far from the chip, parasitic inductance from the connection traces will reduce their high-frequency filtering performance, causing high-frequency noise generated by the chip to remain unfiltered and propagate through the power network, worsening conducted and radiated EMI. Design guidelines require that each power pin should have a 0.1μF or smaller MLCC capacitor placed within 1-2mm of it. Large-capacity energy storage capacitors can be placed slightly further away, but still within the same power area. This is a fundamental practice for ensuring power integrity and good EMC.