Slow speed control system with linear voltage drive for brushless DC motor

The authors consider a stable slow-speed drive and high-precision positioning mechanism, applying a linear voltage drive to the brushless DC motor. To compare the performance of the linear voltage drive and switch drive, the brushless DC motor and two driving circuits have been modeled, and computer simulations have been performed by using MATRIXx. The validity of the slow-speed brushless DC motor control system was also proved by experiment. According to the experimental results, a rotational speed fluctuation can be obtained within 1%, where the rotational speed is 2 rad/sec and the given load is 0.3 N-m. It was verified that the performance of the positioning mechanism is sufficiently precise by testing the response to a step load