Citation:
Jian-Xin Shen, He Hao, Meng-Jia Jin, Wei-Zhong Fei. Sensorless high-speed BLDC machine using hardware-RFO. COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, Vol. 31 Iss: 1, pp.182-190
Abstract:
High-speed permanent magnet (PM) brushless dc (BLDC) motor often needs a
continuous rotor position signal for dynamic phase-advancing control, whist such
kind of position signal cannot be directly obtained from the conventional Hall
effect sensors or via the traditional back-EMF-based sensorless control
strategy. Furthermore, during high-speed operation, the inverter free-wheeling
diodes may conduct for more than 30 elec-deg, obscuring the back-EMF zero-
crossings. Hence, the traditional back-EMF-based sensorless control strategy
becomes unworkable. To overcome these problems, a new sensorless control method
is proposed in this paper. It uses full hardware to observe the flux vector
which is excited by rotor magnets. Thus, it can provide the rotor position which
is the same as the phase angle of the observed flux vector. The proposed
sensorless control method is validated with a 2Kw, 85000rpm PM BLDC motor
system.
