A hybrid power generation system for generating electrical power comprises a compressor for producing a compressed oxidant and a recuperator in flow communication with the compressor. The hybrid power generation system further comprises a fuel cell assembly comprising a plurality of fuel cells in flow communication with the recuperator to provide the compressed oxidant for the fuel cell assembly. The hybrid power generation system further comprises a tail gas burner in flow communication with the fuel cell assembly. A control system is used for controlling the amount of cathode exhaust stream introduced in the tail gas burner for stable combustion and reduction of fuel and carbon monoxide emission. The hot compressed gas from the tail gas burner is introduced to a turbine, where the hot compressed gas is expanded, thereby producing electrical power and an expanded gas.