180-Degree Commutation System of Permanent Magnet Brushless DC Motor Drive Based on Speed and Current Control

To drive Brushless dc motor, each coil of conventional 120-degree commutation rotates only 120-degree with current to generate torque, and wait for next excitation in the other 60 degree without torque generated. However, each coil of 180-degree commutation works for the entire electrical period, which is expected to deliver more power. Analysis, modeling and simulation of 180-degree commutation have not been addressed in previous publications. In this paper, 180-degree commutation theory is analyzed. A 180-degree square-waveform inverter method is designed. A novel 180-degree commutation system is proposed with initial condition, speed and current control. Simulation results prove that the proposed 180-degree system works properly with greater maximum torque than conventional 120-degree system.