Abstract: An annular stator provided with axial stator slots and stator teeth formed between adjacent stator slots. Each stator slot receives a conductor of a stator winding. The stator is formed of stator sectors. Each stator sector includes two outermost stator teeth and intermediate stator teeth between the two outermost stator teeth. A width of the two outermost stator teeth is equal. Adjacent stator slots within each stator sector are distanced by a first slot pitch and adjacent stator slots belonging to different stator sectors are distanced by a second slot pitch. The first slot pitch is smaller than the second slot pitch.

Abstract: A method for controlling a synchronous double stator electric machine. A first stator and a first set of magnetic poles on a common rotor forms a first electric machine. A second stator and a second set of magnetic poles on the rotor forms a second electric machine. The first electric machine and the second electric machine is shifted mechanically by a predetermined angle. An electrical shift is produced to the control of at least the mechanically shifted electric machine with a respective frequency converter in order to at least partly compensate for the mechanical shift in the mechanically shifted electric machine.

Abstract: A rotor for an electrical machine including a plurality of pole sections with adjacent poles within each of the pole sections being distanced by a first uniform pole pitch. Adjacent poles belonging to different pole sections are distanced by a second (smaller) pole pitch at one end of each pole section, and by a third (larger) pole pitch at the other end of each pole section. Alternatively, a corresponding adjustment of coil pitches can be done in a stator of an electrical machine.

Abstract: A method is disclosed for manufacturing the winding coil of an electrical machine from flat wire. The coil can include coil sides fitted to a groove of an electrical machine and end sections which are left outside the groove and form a coil end. Flat wire can be used for winding a spool in which the coil rounds are in the same winding plane and in which there are two parallel straight coil sides on opposite sides. After this, the parallel straight coil sides can be bent towards each other essentially to the right angle in comparison to the winding plane.

Abstract: An electric machine includes a support frame, an outer rotor, a stator, and a dampening mechanism. The outer rotor and the stator are supported to the support frame, and the dampening mechanism is configured for dampening vibrations of the outer rotor. The outer rotor includes an annular end plate, and the dampening mechanism includes a first damper having a first constraint element and a first visco-elastic layer provided on a surface of the first constraint element. The first constraint element is connected to the annular end plate through the first visco-elastic layer.

Abstract: The disclosure relates to an electric machine with a permanent magnet rotor, where permanent magnets have been fitted on an outer surface of a cylindrical rotor, and relates to a permanent magnet. The permanent magnets forming the electric machine's rotor pole are shaped so that the electric machine's air gap is substantially constant in a middle of the pole, and the air gap increases in an essentially straightforward manner when moving towards the edge of the pole. The permanent magnet is of an even thickness in the middle, and becomes thinner towards the edges. This can result in a decrease in the torque ripple and cogging torque of an electric machine.

Abstract: A rotor for an electrical machine including a plurality of pole sections with adjacent poles within each of the pole sections being distanced by a first uniform pole pitch. Adjacent poles belonging to different pole sections are distanced by a second (smaller) pole pitch at one end of each pole section, and by a third (larger) pole pitch at the other end of each pole section. Alternatively, a corresponding adjustment of coil pitches can be done in a stator of an electrical machine.

Abstract: A method is disclosed for manufacturing the winding coil of an electrical machine from flat wire. The coil can include coil sides fitted to a groove of an electrical machine and end sections which are left outside the groove and form a coil end. Flat wire can be used for winding a spool in which the coil rounds are in the same winding plane and in which there are two parallel straight coil sides on opposite sides. After this, the parallel straight coil sides can be bent towards each other essentially to the right angle in comparison to the winding plane.

Abstract: An exemplary arrangement is disclosed for cooling an electrical machine having an external rotor rotating around its rotation axis and a stator having sheet packs, located inside the rotor at the end of an air gap. In the arrangement, a first part of a coolant flow is conducted from both ends of the stator through axial cooling channels into the stator sheet pack. A second part of the coolant flow is conducted from both ends of the stator into the air gap and from the air gap through at least one radial cooling channel into the stator sheet pack. Both parts of the coolant flow are conductable into at least one heat exchanger placed radially inside and at a distance from the stator sheet pack. At least one fan is placed radially inside the heat exchanger to send the first and the second part of the coolant flow to the ends of the stator.

Abstract: The disclosure relates to an electric machine with a permanent magnet rotor, where permanent magnets have been fitted on an outer surface of a cylindrical rotor, and relates to a permanent magnet. The permanent magnets forming the electric machine's rotor pole are shaped so that the electric machine's air gap is substantially constant in a middle of the pole, and the air gap increases in an essentially straightforward manner when moving towards the edge of the pole. The permanent magnet is of an even thickness in the middle, and becomes thinner towards the edges. This can result in a decrease in the torque ripple and cogging torque of an electric machine.

Abstract: An exemplary arrangement is disclosed for cooling an electrical machine having an external rotor rotating around its rotation axis and a stator having sheet packs, located inside the rotor at the end of an air gap. In the arrangement, a first part of a coolant flow is conducted from both ends of the stator through axial cooling channels into the stator sheet pack. A second part of the coolant flow is conducted from both ends of the stator into the air gap and from the air gap through at least one radial cooling channel into the stator sheet pack. Both parts of the coolant flow are conductable into at least one heat exchanger placed radially inside and at a distance from the stator sheet pack. At least one fan is placed radially inside the heat exchanger to send the first and the second part of the coolant flow to the ends of the stator.

Abstract: A generator of a wind turbine is at low power conditions operated as a motor by control of a frequency converter to feed electric power from an electric power transmission network to the generator for raising the speed of the wind rotor above a predetermined level for lubricating rotating parts of a drive train of the wind turbine.

Abstract: In an electrical machine cooling element according to the invention, the electrical machine (25) comprises a rotor and a stator (26). In the electrical machine (25), the outer surface (14) of the stator is divided into sections (22a-b) equal to the length (L) of the stator. The cooling element (1) comprises a minimum of two modules (2), each module (2) comprising adjacent pipes (3a-c) substantially parallel to the stator's longitudinal axis, the ends of the pipes being joined using connecting parts (4a-b). The cooling agent flows in opposing directions (Fd) in the adjacent pipes, and the width of the module (2) is equal to the width (Wu) of the outer surface section (22a-b) at most.

Abstract: A farm including a plurality of electric power generation units connected to a grid point of a power network. The power generation units are organized in a plurality of upstream branches. Each upstream branch is separable from an adjacent downstream branch by an interrupter.

Abstract: A device for controlling at a fault condition. An apparatus is connected by a connection line to a grid point of a transmission net in an electric power network. A voltage raising apparatus includes a first branch connected to the grid point including a switching element and a second branch including a current resisting means. The voltage raising apparatus includes a computer for signal processing of a sensed fault condition on the network and for affecting the operation of the switching element such that on a fault condition at least part of the current is diverted through the voltage raising apparatus and for evaluation of further actions.

Abstract: A device for controlling at a fault condition. An apparatus is connected by a connection line to a grid point of a transmission net in an electric power network. A voltage raising apparatus includes a first branch connected to the grid point including a switching element and a second branch including a current resisting means. The voltage raising apparatus includes a computer for signal processing of a sensed fault condition on the network and for affecting the operation of the switching element such that on a fault condition at least part of the current is diverted through the voltage raising apparatus and for evaluation of further actions.

Abstract: The present invention relates to a mount structure for supporting an electric motor comprising a rotor and a stator frame, such an electric motor being preferably a marine engine rotating a propeller, on a ground base, such as a hull of a ship. The mount structure comprises at least one vibration damping unit, which comprises a vibration damping rail, which is arranged to receive and damp the vibration of the electric motor and which is secured to the stator frame.