Protection from loss of power at the substation with frequency-controlled synchronous drive

摘要

A utility model may be utilized in the art relaying substations with a frequency-regulated electric motor. The technical result - an increase of reliability and stability of preservation processes with breaks power by controlling the braking process of the motor depending on the position of the check valve in the piping of the pump. The security device of the power losses in sub with variable-speed synchronous electric drive comprising: a direction control power block minimum frequency block minimum control voltage, the first timer, the first logical unit and second time relay, the third timer, the second logic unit and first execution unit, a logical OR unit, the fourth timer, a second execution unit, the pressure monitoring unit in the pipeline at the output of the differential pressure calculating unit, the control unit pressure Nia in the pipe at the inlet, a comparison unit, the third execution unit. The first execution unit is an output of the first stage of protection against loss of power and acts on the input voltage off switch 6 has lost power switchgear bus section (10) kV and quenching field synchronous motor. The second execution unit is an output of the second protection stage and acts on the tripping synchronous motors on the tire section, lost power. A third execution unit is an output from the protection tripping differential pressure and acts on the braking resistance. The apparatus is intended to improve the reliability and stability of preservation processes at intervals of power supply and is intended for installation in a switchgear cell transformer substations supply the large variable speed synchronous motor.