DEVICE OF PROTECTION AGAINST LOSS OF POWER AT SUBSTATIONS WITH FREQUENCY-CONTROLLED SYNCHRONOUS MOTORS Russian patent published in 2012 - IPC H02H7/08 H02J9/06 

FIELD: electricity.

SUBSTANCE: device is composed of the following components: a unit of power direction control, a start-up unit of minimum frequency, a logical unit, the first timer, the first actuating unit, the first unit to monitor connection of a synchronous motor, the second actuating unit, the second unit to control connection of a synchronous motor, the third actuating unit, the second timer and the fourth actuating unit. The first actuating unit is an output of the first stage of protection against power loss and acts to disconnect an input breaker of a switchgear bus section with voltage of 6 (10) kV that lost power. The second and third actuating units act at disconnection of the first and second synchronous motors, if they are connected to the bus section directly, without a frequency converter. The fourth actuating unit is an output of the second stage of protection and acts at disconnection of all synchronous motors at a bus section that lost power.

EFFECT: higher reliability and resistance of process systems as a result of faster protection action and reduced idle time of process units.

1 dwg