A novel regenerative braking method of BLDCM for Wheeled Mobile Robot

This paper proposes a novel regenerative braking method of Brushless DC Motor (BLDCM) for Wheeled Mobile Robot (WMR). The drive servo system is converted into a parallel-connected boost circuit to brake and store power without changing any hardware device, and the chopping frequency of the stator phase current is twice as high as the traditional methods with same switch frequency, so the swing range of stator phase current is reduced evidently, at the same time, it minifies the pulse of braking torque, and the performance of regenerative braking is improved greatly. In addition, the relation of the stator phase voltage, the duty ratio of switch and the boosted voltage is discussed detailedly, and the explanation of this method is presented in theory. In order to verify the concept, a simulation and an experiment prototype of a BLDCM for WMR were built. Under the same conditions that motor speed is 250 rad/s, gear ratio is 36:1, and the braking torque is 0.1 Nm, the stator phase current waveform acquired by utilizing the regenerative braking method proposed in this paper is contrasted with the one acquired by utilizing the traditional method, the results proved that the novel method has high performance as well as simplicity and reliability, and provides an excellent solution for BLDCM to brake.