Does the harmonic current at the power port of the BMS control board comply with the Class A limit of GB/T17625.1-2022?

Excessive harmonic current at the power supply port is primarily due to insufficient performance of the PFC circuit in the front-end AC-DC power supply or charger, leading to distortion of the input current waveform. Meeting Class A limits hinges on employing a high-efficiency active PFC circuit to improve the power factor and smooth the current. This is supplemented by an input filtering network, such as using a CMC series high-current common-mode inductor to suppress switching noise, and paired with X2 safety capacitors and differential-mode inductors to filter specific harmonics. During design, it is essential to ensure the PFC circuit operates stably across the entire load range and to evaluate the saturation current of the filtering components, thereby controlling harmonic current at its source and ensuring compliance with standard limits.