Abstract: The invention provides a liquid treatment apparatus such as a reverse osmosis apparatus wherein a portion of an inlet liquid permeates through a filter or a membrane e.g. to provide freshwater from saltwater. The apparatus comprises a pump which provides the necessary pressure of the liquid to drive the permeation process, and a recovery unit which transfers pressure of a residue quid to the inlet liquid. The pump and the recovery unit are driven at synchronous and variable speed to control the output and thereby e.g. to adjust for fouling of the filter or membrane. The invention further provides methods of controlling the synchronous speed, e.g. based on a pressure or based on the consumption of the produced liquid.

Abstract: A method for controlling an electric motor (such as a synchronous reluctance electric motor) is suggested, in which the torque angle in the d-q-reference frame is at least in part and/or at least at times varied depending on at least one working condition of the electric motor.

Abstract: A method (29) for controlling a synchronous reluctance electric motor (2) is suggested, wherein the electric voltage (7) that is applied to the synchronous reluctance electric motor (2) is controlled, and wherein the control of said electric voltage (7) is based on the electric current (14) in the d-q-reference frame (25, 26).

Abstract: The invention provides a liquid treatment apparatus such as a reverse osmosis apparatus wherein a portion of an inlet liquid permeates through a filter or a membrane e.g. to provide freshwater from saltwater. The apparatus comprises a pump which provides the necessary pressure of the liquid to drive the permeation process, and a recovery unit which transfers pressure of a residue quid to the inlet liquid. The pump and the recovery unit are driven at synchronous and variable speed to control the output and thereby e.g. to adjust for fouling of the filter or membrane. The invention further provides methods of controlling the synchronous speed, e.g. based on a pressure or based on the consumption of the produced liquid.

Abstract: The invention provides a liquid treatment apparatus such as a reverse osmosis apparatus wherein a portion of an inlet liquid permeates through a filter or a membrane e.g. to provide freshwater from saltwater. The apparatus comprises a pump which provides the necessary pressure of the liquid to drive the permeation process, and a recovery unit which transfers pressure of a residue quid to the inlet liquid. The pump and the recovery unit are driven at synchronous and variable speed to control the output and thereby e.g. to adjust for fouling of the filter or membrane. The invention further provides methods of controlling the synchronous speed, e.g. based on a pressure or based on the consumption of the produced liquid.

Abstract: A method (29) for controlling a synchronous reluctance electric motor (2) is suggested, wherein the electric voltage (7) that is applied to the synchronous reluctance electric motor (2) is controlled, and wherein the control of said electric voltage (7) is based on the electric current (14) in the d-q-reference frame (25, 26).

Abstract: A method for controlling an electric motor (such as a synchronous reluctance electric motor) is suggested, in which the torque angle in the d-q-reference frame is at least in part and/or at least at times varied depending on at least one working condition of the electric motor.

Abstract: A wind turbine control system is provided. The control system includes a first and a second control unit which are coupled to each other over a first network. The first control unit is configured as a critical control unit, comprising a first set of functions comprising critical control functions for the operation of a wind turbine, and the second control unit is configured as a secondary control unit, comprising a second set of functions comprising non-critical control functions and data management functions.

Abstract: The invention provides a liquid treatment apparatus such as a reverse osmosis apparatus wherein a portion of an inlet liquid permeates through a filter or a membrane e.g. to provide freshwater from saltwater. The apparatus comprises a pump which provides the necessary pressure of the liquid to drive the permeation process, and a recovery unit which transfers pressure of a residue quid to the inlet liquid. The pump and the recovery unit are driven at synchronous and variable speed to control the output and thereby e.g. to adjust for fouling of the filter or membrane. The invention further provides methods of controlling the synchronous speed, e.g. based on a pressure or based on the consumption of the produced liquid.

Abstract: A wind turbine control system is provided. The control system includes a first and a second control unit which are coupled to each other over a first network. The first control unit is configured as a critical control unit, comprising a first set of functions comprising critical control functions for the operation of a wind turbine, and the second control unit is configured as a secondary control unit, comprising a second set of functions comprising non-critical control functions and data management functions.