Control strategy of electrolytic capacitor-less permanent magnet synchronous motor drive based on regulation of inverter power

Electrolytic capacitor-less permanent magnet synchronous motor drive has the advantages of long life and high power density. In order to improve the input power factor and reduce the harmonics of the grid current in the electrolytic capacitor-less motor drive system, a novel control method based on the regulation of the inverter power is proposed in this paper. On the basis of the establishment of the relationship between the grid current and the inverter power, a proportional-resonant controller is designed to regulate the inverter power, the output of which is regarded as the reference of the q-axis current. Meanwhile, the generation of d-axis flux-weakening current is synchronous with the phase of the grid voltage. The effectiveness of the proposed method is demonstrated by the experiment results on an air conditioner.