Motor controller for sewing machines used in RMG sector: An efficiency improvement technique

A scheme has been developed to reduce the no-load losses of the industrial sewing machine motors used in Ready Made Garments (RMG) industries. The switching arrangement of the machine is such that the supply voltage of the motor is partially dropped across a reactive device which is a capacitor connected in series with the motor while the motor is running at no-load. This reduced voltage to the motor reduces the no-load loss significantly. During load condition the switching mechanism of the motor replaces the reactive component by a wire connection and allows full power to the load. The validity of this mechanism is verified by simulation programs and results are tabulated with proper comparison. It is evident that the use of this motor controller reduces no-load loss of the sewing machines substantially and under load condition the controller improves efficiency of the machines. As the loading increase, the efficiency of the machine also increases.