High-frequency Voltages for Accurate Estimation of Rotor Position in Position Sensorless Brushless DC Motor, Journal of the Japan Society of Applied Electromagnetics and Mechanics (JSAEM) Vol.19, No.3, pp.544-549,2011
Abstract: It is necessary to estimate the initial rotor position in high accuracy when the sensorless control is applied to brushless DC motors. First, this paper explains the estimation method of initial rotor position by impressing two kinds of high-frequency voltage. Next, this paper clarifies the influence of the amplitude and frequency of high-frequency voltage on the estimation accuracy and obtains the optimal values. The brushless DC motor with a load of approximately same inertia as that of the motor can start smoothly by using four optimal values of high-frequency voltage.