Generalized Vector Control Strategy for Torque Angle Compensation of IPM-Type Brushless DC Motors

Based on the combination of the conventional rotor field-oriented control and the mechanical energy conversion theory, an optimal current torque angle compensation control strategy for interior permanent-magnet (IPM) brushless dc motors (BLDCMs) is proposed to eliminate the machine losses and suppress the commutation torque ripple simultaneously. First, with the proper assignment of the machine energy, the torque component of the stator current can be controlled directly so that the optimal motor current can be injected into the motor windings. Then, considering that some vectors related to the output torque of BLDCMs cannot be decoupled, the validity of the proposed strategy is proved and analyzed in detail. Moreover, the non-linear variation of the motor parameters during operation cannot be neglected; thus, some simplified pre-experiments are implemented to construct the complete curves of the parameters. Experimental results verify the feasibility of the proposed strategy.