Prof. Ronggang Ni, Qingdao University, China
Ronggang Ni was born in Daqing, China in 1987. He received the B.S., M.S. and Ph.D. degrees from Harbin Institute of Technology, Harbin, China, in 2010, 2012 and 2017, respectively, all in electrical engineering. From 2015 to 2016, he was a visiting scholar at Aalborg University, Denmark. In 2017, he was with the Shanghai STEP Electric Corporation, Shanghai, China. From 2018, he has been with Qingdao University, Qingdao, China, and is currently a full professor and the vice dean of the School of Electrical Engineering. Prof. Ni is a senior member of IEEE, the leader of Shandong Provincial Innovation Team on new energy transportation and electric drive, and the Chief Expert of Qingdao Expert Workstation on permanent magnet motor control. He served as session chair or technical committee at ICEMS, IPEMC, CIEEC, VPPC and ICPES, etc. He is also PI of 5 projects granted by NSFC and Shandong Province. Prof. Ni has authored more than 30 technical papers, and holds 11 patents. He delivered 6 tutorials or invited speeches on academic and industrial conferences. His research interests include electric machine topology, design and drive for electrified transportation and servo systems.
Speech Title: Position Sensorless Control of Permanent Magnet Synchronous Machine with Single Current Sampling
Abstract: In the realm of AC variable frequency drive systems, Permanent Magnet Synchronous Machines (PMSMs) are highly favored for their remarkable efficiency, high power density, and uncomplicated mechanical structure. Position sensorless control of PMSMs offers notable advantages in enhancing reliability and reducing system cost. However, the reliability of position sensorless control, particularly at low speeds, is impacted by the distortion of applied voltage and reconstruction error of phase current caused by the unmeasurable regions when using single DC current sampling.
This report presents the state-of-the-art of phase current reconstruction techniques using single DC current sensor along with position sensorless control. Additionally, it proposes the GINFORM (Generalized INdirect Flux detection by Online Reactance Measurement) method to minimize the negative impact of unmeasurable regions and enhance control reliability. Furthermore, a variable carrier frequency modulation strategy is introduced to improve the current loop bandwidth and dynamic performance.
The report provides experimental results from a 2.2kW PMSM platform to validate the effectiveness of the proposed GINFORM method under single current sampling. It also demonstrates the higher current loop bandwidth achieved with the variable carrier frequency modulation strategy compared to conventional methods. At the end, potential trends on PMSM control with fewer sensors are discussed.