Method and apparatus for controlling output of pressure setting signal to automatically control steam bypass control system, and method and apparatus for automatically controlling steam bypass control system by using the pressure setting signal

An apparatus for automatically controlling a steam bypass control system, the apparatus comprising:

• a pressure setting signal output unit for outputting a pressure setting signal according to a cold leg temperature of a reactor coolant;
• a first logic value output unit for outputting a first logic value that is changed according to reactor power;
• a second logic value output unit for outputting a second logic value that is changed according to a temperature difference between an average temperature of the reactor coolant and a reference temperature;
• a NAND gate circuit unit for outputting an inverse logic value according to the first and second logic values output from the first and second logic value output units;
• a first output control unit for controlling whether to output the pressure setting signal according to the inverse logic value of the NAND gate circuit unit;
• and
• a turbine bypass valve control unit for controlling whether to open or close a turbine bypass valve by using a deviation signal calculated between a measured main steam header pressure signal and a summed pressure signal obtained by summing a main steam header pressure setting signal according to a steam flow and a pressurizer pressure bias signal according to a pressurizer pressure with the pressure setting signal.

A method of controlling an output of a pressure setting signal to automatically control a steam bypass control system, the method comprising:

• individually outputting a first logic value that is changed according to an increase or decrease in reactor power and a second logic value that is changed according to a temperature difference between an average temperature of a reactor coolant and a reference temperature;
• outputting an inverse logic value according to the first and second logic values;
• and
• outputting a pressure setting signal according to a cold leg temperature of the reactor coolant to a turbine bypass valve control unit for emitting excess steam of a reactor, according to the inverse logic value.

A method of automatically controlling a steam bypass control system, the method comprising:

• individually outputting a first logic value that is changed according to an increase or decrease in reactor power and a second logic value that is changed according to a temperature difference between an average temperature of a reactor coolant and a reference temperature;
• outputting an inverse logic value according to the first and second logic values;
• outputting a pressure setting signal according to a cold leg temperature of the reactor coolant to a turbine bypass valve control unit for emitting excess steam from a reactor, according to the inverse logic value;
• and
• controlling whether to open or close a turbine bypass valve by using a deviation signal calculated between a measured main steam header pressure signal and a summed pressure signal obtained by summing a main steam header pressure setting signal according to a steam flow, a pressurizer pressure bias signal according to a pressurizer pressure, and the pressure setting signal.