FIELD: electric engineering. SUBSTANCE: device provides prohibition of turning synchronous motors on in opposite phase when in-phase turning-on is desired, when first section of buses losses power supply or unsafe deviation angles of controlled voltage are detected. Device also provides automatic excitation of synchronous motors which are connected to first section of buses and focused excitation of motors from second bus section. When second bus section losses power supply or unsafe deviation angles of controlled voltage are detected then automatic shut-down of synchronous motors connected to second bus section is provided. Then excitation of motors that are connected to first bus section is focused. Three AND gates, OR gate and prohibition unit are introduced to accomplish the goal of invention. EFFECT: increased functional capabilities. 3 cl, 2 dwg
