Abstract
This paper proposed a novel rectification method for a high-level ac voltage convert to a low-level dc voltage, in which the Permanent Magnet Synchronous Motor (PMSM) Matlab/Simulink model in generation mode has been established in order to analyze the energy characteristics of PMSM operating in scooters at full drive speed. From the simulation results, the terminal voltage and line current in load-side have a wide convert rate when the internal resistance of battery is a great value. In design, the gate driver signals can be generated, referring to the virtual hall signals, to chop the different back Electromotive Force (back-EMF). Then, the ac voltages of back-EMF can be rectified to the dc voltage by Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) at the same time. Finally, the proposed method has been implemented in scooters idling stop system successfully, and a safe low level dc voltage always can be obtained to charge battery immediately (in general 12V) no matter what a variable speed in scooters.