Analysis of Inverter Circulating Current and Magnetic Potential for Flux-Weakening Drive of BLDCM

The permanent magnet brushless DC motor (BLDCM) is typically controlled using the six-step commutation method, and flux-weakening method employed to enable operate at speeds higher than base speed. Currently, it considered that weak magnetic angle range 0-pi/3, while for deep weakening pi/3-pi/2. In field-weakening control, a forward shift of point results in circulating current flowing three-phase bridge inverter stator winding motor. This paper analyses principle formed by inverter. Through potential analysis Simulink simulation, concluded control generates windings. inverter’s affects motor’s potential, causing towards rotating direction rotor. When within 0-pi/6 electrical angle, phase remains below pi/6. configuration weakens field provides driving effect. However, when falls pi/6-pi/3, exceeds pi/6, resulting braking. During braking effect, reverse torque generated, leading decrease efficiency. Therefore, should be between 0-pi/6.