Economical Pathway of Adopting Single-Phase Induction Motors in Emerging DC Microgrids

A major practical challenge in adopting highly advantageous DC microgrids is related to the deployment or displacement of the low-cost small single-phase induction motors (SPIMs) in millions of home or industrial appliances. Power electronic inverters are generally required to generate AC voltages from the DC grids (e.g., 380VDC) to drive AC motors, creating a prohibitive cost barrier. This paper reviews various types of small SPIMs in the market today as well as the inverter topologies and control strategies used to drive them from a DC bus. Key enabling technologies, including low-cost monolithic inverter power ICs, Sensorless motor control, and peak current limiting control, are then identified to overcome such cost barrier while enhancing functionalities and performance, such as improved efficiency, better starting torque, reduced noise, and variable speed control. The objective is to explore technological pathways for transitioning from single-phase AC motors powered by AC grids today to single-phase AC motors powered by DC microgrids in the near future. Ultimately, the goal is to achieve lower-cost, higher-performance three-phase induction motors powered cost-effectively by DC microgrids.