A New Adaptive Motor Bus Transfer Approach

The induction or synchronous motor can temporarily produce voltage such as a generator after disconnection from the power system. Subsequently, voltage and frequency differences between the motor terminal and the power system are gradually increased. In such conditions, the mechanical damages to motor may be occurred during motor reconnection when the synchronizing conditions are not complied. To overcome this problem,several methods have been proposed in the literature to reconnect a motor to the power system based on the bus transfer approach. In this paper, several bus transfer methods such as parallel transfer, fast transfer, delayed transfer, residual voltage transfer, and in-phase transfer are investigated based on simulation of an industrial system. Afterwards, a novel adaptive bus transfer technique is proposed to minimize the imposed thermal and mechanical stresses on the electrical motor.