Modeling of Gas Turbine Speed Governors Considering Air Pressure Dynamics of Combustion Chamber

In existing power system simulation software, varying regularities of air pressure in combustion chamber were not considered in primary frequency regulation (PFR) simulation using gas turbine speed governors system. This resulted in simulation error deviated from practice. Working characteristics of gas turbine in PFR were analyzed. It is found out that the bypass valve will in real-time adjust combustion chamber air-fuel ratio so that combustion stability of gas turbine was maintained, and the combustion chamber pressure and gas turbine poweroutput would be changed. A new simulation model of gas turbine speed governor was established, embodying air pressure dynamic effect of combustion chamber. The air pressure of combustion chamber was modified with gas turbine nozzle action, and then air-fuel ratio control process was carried on. Simulation and experiment results showed that the model can truly represent real frequency-governing properties of gas turbine governors.