Abstract: The current invention is a computer implemented method of evaluating relative efficiency of equipment by constructing a mathematical model of the operation of the equipment, calculating a distance between an actual operating point and the mathematically obtained optimal operating point of the equipment, and processing the distances to identify efficiency changes of the equipment.

Abstract: A system and method of surge limit control for turbo compressors including a turbo compressor having an inlet and an outlet, an anti-surge valve, a variable speed drive to operate the compressor, a rotational speed transmitter, an inlet temperature transmitter, an inlet pressure transmitter, an outlet pressure transmitter and/or guide vanes, and a controller, the controller including a PID control module wherein the computer uses information from the transmitters to continuously calculate a pressure ratio of the compressor at the compressor's current operational speed and compare it to the compressor's calculated pressure ratio at surge limit conditions. A computer generates a control signal for determining when to open the anti-surge valve if the pressure ratio of the compressor at the compressor's current operational speed guide vanes are within a user defined safety margin to the calculated pressure ratio at surge limit conditions.

Abstract: A method for controlling a system includes determining the lag in data from a variable signal. The data is arranged in matrices with one column for each variable signal. The columns are shifted to produce a plurality of different shifted matrices, each shifted matrix having a given value for the lag in data for each variable signal. A variable signal estimator processes each shifted matrix to output a variable signal function defining each variable signal in terms of its mathematical dependencies on all of the variable signals. A criterial function processes each variable signal function to provide an optimal lag value for each variable signal. A point calculation algorithm processes each shifted matrix to produce a point for each column. A lag estimator processes each point and optimal lag value to output a lag function defining each lag in terms of its mathematical dependency on all of the variable signals.