Research on Control Method of Brushless DC Motor Based on Continuous Three-Phase Current

Abstract

Abstract. With regard to non-conduction phase and non-commutation current pulsation in brushless DC motor for aviation in conventional two-two conduction based drive mode which are not only to restrict range of speed regulation of motor but also lead to larger torque pulsation, a continuous three-phase current based drive mode is presented to solve limit value of current to minimize copper loss in three phase winding by taking motor torque equation and counter potential equation as restrictive condition. The method is to divide motor rotor position into 12 sectors and then allocate the limit value to three phase current based on the sector. According to the principle that the sum of currents from three phases of star winding is equal to zero, it is advisable to adopt two phase current close loop control to achieve continuous output of three phase current to suppress commutation torque pulsation, improve motor power density and expand range of speed regulation. The mentioned continuous three phase current based drive method has its feasibility and efficiency verified by Matlab simulation.