Control device and control method for a fuel gas supply system

A control device configured to control a fuel gas supply system which includes a compressor which compresses fuel gas and supplies the compressed fuel gas to a load apparatus, inflow amount regulating means for regulating an amount of the fuel gas which flows into the compressor, and an anti-surge valve for returning the fuel gas discharged from the compressor to an inlet side of the compressor,

• wherein the control device comprises:
• a main pressure control unit configured to control the inflow amount regulating means and the anti-surge valve on the basis of a feedforward control value which is generated on the basis of a load of the load apparatus and a predetermined conversion process, and a feedback control value which is generated on the basis of a deviation between a set value of a discharge pressure of the compressor and a measured value of the discharge pressure of the compressor;
• and
• an emergency pressure control unit configured to calculate a bias-added control value by adding a predefined bias value to an anti-surge valve control value which is calculated on the basis of at least one of the feedforward control value and the feedback control value and controls the anti-surge valve, and switches the anti-surge valve control value to the bias-added control value on the basis of occurrence of load variation of a predetermined value or more to control the anti-surge valve;
• wherein the emergency pressure control unit is configured to set the bias-added control value to the predefined bias value when the feedforward control value is a value of a closed state of the anti-surge valve, and provide control such that the bias-added control value becomes smaller as the feedforward control value becomes larger when the feedforward control value is a value of an open state of the anti-surge valve.