Mitigation of rotating stall in turbine exhaust section using flow control vanes

A system, comprising:

• a controller configured to control a plurality of flow control vanes along a flow path through a turbine section and a turbine exhaust section, wherein the turbine section comprises one or more turbine stages, each stage of the one or more turbine stages has a plurality of turbine blades downstream from a plurality of turbine vanes, and the turbine exhaust section is coupled to the turbine section, wherein the controller is configured to:
• control the plurality of flow control vanes to move to an extended position in a first operating condition susceptible to a rotating stall condition in the turbine section;
• and
• control the plurality of flow control vanes to move to a retracted position in a second operating condition not susceptible to the rotating stall condition in the turbine section.

A method, comprising:

• controlling a plurality of flow control vanes along a flow path through a turbine section and a turbine exhaust section, wherein the turbine section comprises one or more turbine stages, each stage of the one or more turbine stages has a plurality of turbine blades downstream from a plurality of turbine vanes, and the turbine exhaust section is coupled to the turbine section, wherein controlling comprises:
• controlling the plurality of flow control vanes to move to an extended position in a first operating condition susceptible to a rotating stall condition in the turbine section;
• and
• controlling the plurality of flow control vanes to move to a retracted position in a second operating condition not susceptible to the rotating stall condition in the turbine section.