A speed sensorless vector control for brushless DC motor using binary observer

In this paper, a binary observer with continuous inertial coordinate-operator feedback is proposed to alleviate the chattering phenomenon and enhance the estimation performance in the speed sensorless vector control of brushless DC motors. Binary control consists of a primary loop regulator and an auxiliary loop regulator which smoothly regulates the gain of the primary loop regulator. Substituting a continuous switching input for a discontinuous one, the binary observer has a good estimation performance under the existence of delays and an implementation switching frequency limitation.