ELECTRIC DRIVE Russian patent published in 2000 - IPC

FIELD: servo control systems. SUBSTANCE: electric drive has a current transmitter made in the form of a subtracter, whose first input is coupled to the measuring windings, and the second one - to the output of the frequency converter, and the output forms the current transmitter output. The common node of the star- connected power windings of the motor is connected to the midpoint of the frequency converter power supply and coupled, for example via an inverter to the subtractor input. The inverter output, via the respective resistor, is connected to the second input of the subtracter. The common node of the star-connected measuring winding is connected to the power supply earthing terminal. Besides, at the output the current transmitter is provided with an integrator. EFFECT: simplified drive circuit and enhanced efficiency due to the absence of shunts and power loss, respectively. 4 cl, 1 dwg