Qian Li

Title: Innovations of Qian Li in Power Factor Correction

Introduction

Qian Li is an accomplished inventor based in Blacksburg, VA (US). He has made significant contributions to the field of electrical engineering, particularly in power factor correction technologies. His innovative approach has led to the development of a patented technology that enhances efficiency in power systems.

Latest Patents

Qian Li holds a patent titled "Adaptive on-time control for power factor correction stage light load efficiency." This invention improves the light load efficiency of a power factor correction circuit through adaptive on-time control. It allows for the selection between continuous conduction mode and discontinuous conduction mode. The discontinuous conduction mode increases the time between switching pulses, which controls the connection of a cyclically varying voltage to a filter/inductor. This method delivers a desired DC voltage and significantly reduces the switching frequency at light loads, where switching frequency-related losses dominate efficiency. The control mode for switching is preferably selected for each switching pulse within a half cycle of the cyclically varying input voltage. Additionally, a multi-phase embodiment allows for the cancellation of EMI noise at harmonics of the switching frequency, while adaptive change of phase angle enables the cancellation of dominant higher-order harmonics as the switching frequency is reduced.

Career Highlights

Qian Li is associated with Virginia Tech Intellectual Properties, Inc., where he continues to innovate and develop new technologies. His work has been instrumental in advancing the efficiency of power systems, making a notable impact in the field.

Collaborations

He has collaborated with esteemed colleagues such as Fred C. Lee and Ming Xu, contributing to various projects and research initiatives that further enhance his work in power factor correction.

Conclusion

Qian Li's innovative contributions to power factor correction technology demonstrate his commitment to improving electrical engineering practices. His patented work not only enhances efficiency but also addresses critical challenges in power systems.