The invention discloses a multi-level pulse compensation type active EMI (Electro-Magnetic Interference) filter suitable for a multi-
noise source
switching power supply and a control method of the multi-level pulse compensation type active EMI filter. The invention provides a multi-level pulse compensation scheme based on switch behavior modeling, aiming at the problem of common-mode
noise of adjacent rising edges and falling edges generated by a high-frequency switch in a multi-
noise-source
switching power supply. The
time sequence delay and the edge slope of the compensation
signal are calculated by analyzing the dv / dt characteristics in the switching-on and switching-off processes of the switching device, and accurate matching and offset with a noise source in phase and amplitude are achieved. Compensation
control logic is realized by sharing a main control
chip with a power circuit, and an additional controller and a high-precision sampling
system are not needed; the self-
adaptive tracking of the compensation amplitude is realized through the
voltage following circuit; a multi-level compensation
signal is output through the totem-pole circuit and injected into a common-mode path, and effective suppression of
electromagnetic interference is achieved. The converter has the advantages of small size, low cost, simplicity and convenience in installation, high stability and the like, and is suitable for various multi-noise-source power
electronic systems including a dual-active bridge converter, a phase-shifted full-bridge converter and an
interleaving Buck converter.