Power converter apparatus provided with low-pass filter circuit for reducing switching frequency components

A power converter apparatus comprising:

• at least one switching circuit configured to generate an alternating current (AC) voltage by switching a direct current (DC) voltage at a predetermined switching frequency (fSW);
• and
• a filter circuit configured to convert the AC voltage from the switching circuit into a DC voltage by low-pass filtering the AC voltage, and outputs the DC voltage to a load, the filter circuit being connected to be inserted between the switching circuit and the load,
• wherein the filter circuit comprises:
• a first bypass capacitor having a first impedance, the first bypass capacitor being configured to bypass first switching noise of a first frequency component of the AC voltage from the switching circuit, and recirculate the first switching noise to the switching circuit, the first frequency component being determined by the first impedance;
• a second bypass capacitor having a second impedance, the second bypass capacitor being configured to bypass second switching noise of a second frequency component of the AC voltage from the switching circuit, and recirculate the second switching noise to the switching circuit, the second frequency component being determined by the second impedance and lower than the first frequency component of the AC voltage from the switching circuit;
• and
• at least one inductor inserted between the first bypass capacitor and the second bypass capacitor,
• wherein an inductance (L) of the inductor is set so that a resonance frequency (fr) of the filter circuit is lower than multiple times the switching frequency (fSW) by insertion of the inductor, thereby suppressing an over-current flowing through the first and second bypass capacitors, and reducing the switching noise flowing to the load.