Method for regulating the rotational speed of a compressor as a function of the available gas flow of a source and regulation thereby applied

A controller for controlling a speed of a compressor as a function of an available flow of gas originating from a source, comprising:

• an input for a signal that is representative of an inlet pressure at an inlet of the compressor;
• an input for a signal that is representative of the speed of the compressor;
• a desired value to be set for the inlet pressure, and,
• wherein the controller is configured to control the speed of the compressor by reducing the speed when the inlet pressure is less than the set desired value of the inlet pressure, or by increasing the speed when the inlet pressure is greater than the set desired value of the inlet pressure until the inlet pressure is equal to the set desired value,
• wherein the controller further comprises:
• a memory in which a characteristic data of the compressor are stored or can be stored that relate to an efficiency and/or a specific energy requirement of the compressor, which is a ratio of a power supplied to the compressor to a compressed gas flow supplied, as a function of the speed and the inlet pressure;
• and,
• wherein the controller is further configured to calculate an adjusted desired value of the inlet pressure to adjust the set desired value, the adjusted desired value corresponding to a maximum of an efficiency of the compressor or to a minimum of a specific energy requirement after the control of the speed at the adjusted desired value of the inlet pressure.