The optimal control system for the compensation of the reactive power
in an energetic consumer assembly is presented, containing one or
more synchronous motors, connected to the same power bars in parallel,
including asynchronous motors and static converters. The compensation
of the reactive power absorbed from the system by the consumers
is possible, using a optimal control system that controls the reactive
power provided on the bars by the synchronous motors on condition
that the power losses in the created whole are zero. A limited functional
block diagram of the synchronous motor, which is the controlled
object completed with the control circuits of the exciting tension and
current is obtained having as set value the sum of all reactive currents
of the consumers from the power assembly. The optimization is obtained using the module criterion of Kessler