System for controlling a turbine

A system for controlling a turbine, comprising:

• a closed loop turbine control fuel governor comprising a plurality of Variable Coefficient Proportional Integrative Derivative (VCPID) control loops operating in parallel with one another to regulate fuel flow to the turbine, each VCPID control loop being associated with a respective turbine parameter and one or more external parameters,
• an external pressure transducer for sensing a well pressure generated by a pump attached to a petroleum well and driven by the turbine, the well pressure comprising an external parameter of the one or more external parameters,
• wherein each VCPID control loop incorporates feedback from the parallel operating VCPID control loops to feed an integral term of a current VCPID control loop in the following manner:
• a previous derivative gain and a previous proportional gain are summed and subtracted from a selected output for the turbine to yield a first result term, and the first result term is input to an integral gain portion of the current VCPID control loop,
• wherein each VCPID control loop includes a VCPID output that is fed to a minimum select function,
• wherein the minimum select function selects a fuel command based on the VCPID output, the fuel command being a command that requires a least amount of fuel to not exceed a setpoint to the parallel VCPID control loops,
• wherein the closed loop turbine control fuel governor provides the least amount of fuel to the turbine to regulate the fuel flow to the turbine.