Abstract: A method for obtaining an estimate for a process quantity of a turbomachine comprises measuring (301) first process quantities and calculating (302) an estimate for a second process quantity, for example mass flow, on the basis of the measured first process quantities and a reference table of interrelations between process quantities prevailing in reference inlet conditions corresponding to a pre-defined inlet fluid temperature, a pre-defined inlet fluid pressure, and pre-defined fluid properties at the inlet. The reference table and the measured first process quantities represent such a set of data values that the estimate is obtainable on the basis of different sub-sets of the data values. Hence, the estimation task is over-posed in the sense that there is more data than necessary for obtaining the estimate. In the calculation of the estimate, more weight is given to such a part of the data which has a smaller error contribution.

Abstract: An electric machine comprising a stator having a stator winding, a housing accommodating the stator, a rotor, and an air gap having a generally cylindrical configuration. A plurality of circumferentially distributed, radial, first cooling gas ducts are provided in a stator core. Jets of cooling gas are directed to regions of an end winding which are relatively distant from the stator core, in order to achieve impingement cooling thereof. Flows of cooling gas are directed to portions of the end winding which are between the impingement cooled regions of the end winding and the respective front face of the stator core.

Abstract: A method for obtaining an estimate for a process quantity of a turbomachine comprises measuring (301) first process quantities and calculating (302) an estimate for a second process quantity, for example mass flow, on the basis of the measured first process quantities and a reference table of interrelations between process quantities prevailing in reference inlet conditions corresponding to a pre-defined inlet fluid temperature, a pre-defined inlet fluid pressure, and pre-defined fluid properties at the inlet. The reference table and the measured first process quantities represent such a set of data values that the estimate is obtainable on the basis of different sub-sets of the data values. Hence, the estimation task is over-posed in the sense that there is more data than necessary for obtaining the estimate. In the calculation of the estimate, more weight is given to such a part of the data which has a smaller error contribution.

Abstract: A rotor structure of a permanent magnet electrical machine and a method for manufacture of the rotor structure. The rotor structure has a shaft. An outer surface of the shaft is provided with a permanent magnet. A support collar encircles the permanent magnet. A protective piece is located between the outer surface of the shaft and an inner surface of the support collar and is arranged as an axial mechanical extension for the permanent magnet. The protective piece reduces local maximum values of forces forming between the support collar and the permanent magnet during rotation of the rotor.

Abstract: A stator assembly includes a stator core and at least one conductive bundle. The stator core has a first end, a second end, and a plurality of slots extending from the first end to the second end. The conductive bundle includes a plurality of individually insulated conductive wires. At least one portion of the at least one conductive bundle extends from the first end to the second end of one slot of the plurality of slots. The at least one portion is twisted by a predetermined amount within the one slot to minimize a circulatory current along the plurality of individual insulated conductive wires in the at least one portion.

Abstract: An electric machine comprising a stator having a stator winding, a housing accommodating the stator, a rotor, and an air gap having a generally cylindrical configuration. A plurality of circumferentially distributed, radial, first cooling gas ducts are provided in a stator core. Jets of cooling gas are directed to regions of an end winding which are relatively distant from the stator core, in order to achieve impingement cooling thereof. Flows of cooling gas are directed to portions of the end winding which are between the impingement cooled regions of the end winding and the respective front face of the stator core.

Abstract: The invention is a compensator for minimizing circulatory current losses generated in a winding of an electric machine, the compensator comprising a frame part made of a magnetically conductive material and a winding formed in the frame part, the winding comprising at least one conductor having at least two sub-conductors; and at least one opening in said frame part. Said at least two sub-conductors extend through said at least one opening in such a way that the total current flowing through the opening is substantially zero, when a substantially equal current is led to the sub-conductors; and that at least two different sub-conductors are placed to extend through at least one opening. There is also disclosed an electric machine, the compensator being used in connection with the stator of the electric machine; and a method for forming a compensator to be used for minimizing circulatory current losses generated in a winding of an electric machine.

Abstract: A stator assembly includes a stator core and at least one conductive bundle. The stator core has a first end, a second end, and a plurality of slots extending from the first end to the second end. The conductive bundle includes a plurality of individually insulated conductive wires. At least one portion of the at least one conductive bundle extends from the first end to the second end of one slot of the plurality of slots. The at least one portion is twisted by a predetermined amount within the one slot to minimize a circulatory current along the plurality of individual insulated conductive wires in the at least one portion.

Abstract: The invention is a compensator for minimizing circulatory current losses generated in a winding of an electric machine, the compensator comprising a frame part made of a magnetically conductive material and a winding formed in the frame part, the winding comprising at least one conductor having at least two sub-conductors; and at least one opening in said frame part. Said at least two sub-conductors extend through said at least one opening in such a way that the total current flowing through the opening is substantially zero, when a substantially equal current is led to the sub-conductors; and that at least two different sub-conductors are placed to extend through at least one opening. There is also disclosed an electric machine, the compensator being used in connection with the stator of the electric machine; and a method for forming a compensator to be used for minimizing circulatory current losses generated in a winding of an electric machine.

Abstract: A method for determining the position of the rotor (5) of an electric machine in the radial direction (X, Y) and in the axial direction (Z) applies a cogged ring (2), through which the shaft (5a) of the rotor (5) is placed. The shaft (5a) is provided with an auxiliary ring (6) placed substantially at the cogged ring (2). The cogged ring is provided with at least three sets of cogs, wherein the cogs of the first set (3a1, 3a2 . . . , 3a8) are used to measure the movement of the shaft (5a) in the radial direction (X, Y), the cogs of the second (3b1, 3b2, 3b3, 3b4) and third (3c1, 3c2, 3c3, 3c4) sets are used to measure the movement of the shaft (5a) in the axial direction (Z), and that the cogs of the second (3b1, 3b2, 3b3, 3b4) and third (3c1, 3c2, 3c3, 3c4) sets are placed, in the axial direction (Z), at least partly in a different location in relation to each other.

Abstract: A method for determining the position of the rotor (5) of an electric machine in the radial direction (X, Y) and in the axial direction (Z) applies a cogged ring (2), through which the shaft (5a) of the rotor (5) is placed. The shaft (5a) is provided with an auxiliary ring (6) placed substantially at the cogged ring (2). The cogged ring is provided with at least three sets of cogs, wherein the cogs of the first set (3a1, 3a2 . . . , 3a8) are used to measure the movement of the shaft (5a) in the radial direction (X, Y), the cogs of the second (3b1, 3b2, 3b3, 3b4) and third (3c1, 3c2, 3c3, 3c4) sets are used to measure the movement of the shaft (5a) in the axial direction (Z), and that the cogs of the second (3b1, 3b2, 3b3, 3b4) and third (3c1, 3c2, 3c3, 3c4) sets are placed, in the axial direction (Z), at least partly in a different location in relation to each other.