| The high performance speed control of REPM BLDC motor with wide range speed between zero and no-load speed is researched. A strategy controlling winding commutation directly to control motor is proposed with respect to the principle of machine. Rotator position and assess commutation signal controls Commutation in less than 3 speed ratio simultaneity. PI control algorithm can adjust phase differentia between rotator positions and assess commutation signal to make them same. 60°electric angle on-crest used in traditional 120°trapezoid BLDCM can make the BLDCM operation in condition of PMSM in ratio of 3~30. The frequency of voltage and phases are determined by rated speed. It can make the power angle invariable on 60°by closed loop control. As operating in super low speed of ratio above to 30, it also adopts the overlap of 3-phase trapezoid voltage when super lower speed and it adopts open loop to make the power angle close to 0° while increasing the value of voltage during allowable circuit.When the system operation in several models, hysteretic switch between two speed points can prevent speed fluctuation. Difference operation model is used in difference speed, which can prolong speed band and increase security and stability. The result of experiment shows that it can control the motor with a wider and high performance, and the control is effective to the performance of the system.It also makes some research on the field-weakening control of REPM BLDC motor and the control of generator, and the strategy is expatiated particular. A scheme is proposed too.
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