| 摘要 |
PURPOSE:To improve speed-torque characteristic and efficiency considerably by performing control such that the phase difference between the current flowing through a winding and the voltage induced in the winding will be approximately zero at all times. CONSTITUTION:Clock signals CLK1, CLK2 for detecting the rotary position of a DC brushless motor and signals U, V, W for detecting the positions of a permanent magnet in U, V and W phases are inputted through a digital input section. A current phase delay detecting section 3 calculates SIGMAiu*sintheta and SIGMAiu*costheta for every clock timing based on these signals and U phase current iu, then the calculated values are integrated by electrical angle of 2pi and employed for calculation of delay angle psi between induced power (e) and winding current iu. PI control section 5 leads the winding application timing by lambda deg.so that the delay angle psi is zero. When lead angle control is carried out similarly for other phases, the power factor approaches to 1. |
