Gas turbine engine/load compressor power plants

A single shaft gas turbine engine power plant comprising:

• a power head;
• a load compressor driven by said power head;
• variable inlet guide vanes for controlling the flow of air through the load compressor;
• and an inlet guide vane actuator for adjusting the position of the guide vanes;
• said power head being an air breathing gas turbine engine comprising a radial compressor;
• a combustor for heating, and thereby adding energy to, the air discharged from the engine compressor;
• and a radial gas turbine driven by hot gases flowing thereto from said combustor and drive-connected to said engine and load compressors;
• and said power plant also having means for controlling the flow of air through said load compressor by adjusting the position of said variable inlet guide vanes, said control means comprising means for generating a first guide vane position correction signal indicative of the difference between measured turbine exhaust gas temperature and a turbine exhaust gas setpoint temperature, a first controller for converting said first position correction signal to a first control signal for actuating the variable inlet guide vane actuator, means for generating a second guide vane position correction signal indicative of the difference between the pressure ratio across the load compressor and a setpoint pressure ratio, a second controller for converting said second position correction signal to a second control signal for actuating the variable inlet guide vane actuator, and means for selecting the smaller of the first and second control signals for transmission to the variable inlet guide vane actuator.