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 method for controlling a speed of a compressor as a function of an available gas flow originating from a source, whereby the compressor is provided with a controller for controlling the speed, comprising the following steps:

• setting of a desired value for an inlet pressure at an inlet of the compressor;
• determining the inlet pressure at the inlet of the compressor;
• determining the speed of the compressor;
• controlling 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, and this until the inlet pressure is equal to the set desired value;
• wherein the method further comprises the following additional steps:
• storing a characteristic data of the compressor relating to an efficiency and/or a specific energy requirement onto a memory of the controller, whereby the specific energy requirement 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;
• adjusting the desired value of the inlet pressure, said 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.

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 a 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, and this 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 adjust the desired value of the inlet pressure, and wherein the desired value corresponds 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.