Substitution of the Universal Motor drives with electrolytic capacitorless PMSM drives in home appliances

The Universal Motors (UM) have been used for a long time in variety of small and cheap drives, mainly in home appliances and hand tools. Their main features are cheapness, robustness and simplicity of the control, which make them still attractive. However during last twenty years they are replacing with drives of other types, mainly with induction and Permanent Magnet Synchronous Motor (PMSM) drives, which are more efficient and have better performance. This paper presents new generation of the motor drives for home appliances - electrolytic capacitorless PMSM drive, where electrolytic capacitor in the DC-link of the inverter is substituted with a small film one. The main purpose of them is to substitute UM, which are still used. Proposed drives have simple control system, decreased size, increased reliability and cost less than the conventional PMSM drives. Elimination of the electrolytic capacitor increases total device reliability, saves space, and improves spectrum of the input current, so Power Factor Corrector (PFC) used to satisfy existing standards on harmonic current emission can be omitted, which decreases size and cost of the appliances.