Inverter-fed motor drive with emi suppression

摘要

This invention provides cost-effective suppressing conducted radio-noise emissions from industrial inverter-motor drives whose EMI performance is able to meet the CISPR or FCC limits on conducted emissions. The invention includes some small size L,C filtering elements built inside the inverter, e.g., two grounding capacitance connected from both side of DC link to grounding heat sink of devices, a line capacitance across a DC link, three line capacitances across phase leads in AC input side of the diode rectifier, a zero sequence inductance both in each phase input and in each phase output lead of the inverter. Optionally, an extra secondary winding of the zero sequence inductor is connected to main circuit of inverter via a L, R, C network.