Stator element

a technology of stator element and stator, which is applied in the direction of dynamo-electric machines, electrical equipment, magnetic circuit shapes/forms/construction, etc., can solve the problems of reducing the efficiency of the generator, large amounts of excessive heat, and eddy current loss, so as to reduce the electrical conductivity

Inactive Publication Date: 2011-12-15
SIEMENS AG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0010]The inventive stator element, which may favourably be in the shape of a complete ring-shaped stator or a stator segment adapted to built a ring-shaped stator, is provided with a better cooling performance as the heat exchange capability is significantly increased. In other words, an improved heat exchange is established between the yoke and the cooling means, that is the cooling medium conducting excess heat off the yoke resulting in a better cooling performance of the cooling means and the inventive stator element.
[0015]Thereby, it is possible that the cooling channel and / or the cooling cavity is integrally built inside the yoke. Accordingly, the yoke may completely encompass the cooling channel and / or the cooling cavity as they are an integrally built part of the yoke giving rise to a large area of heat exchange from the yoke to the cooling channel and / or cooling cavity and hence, an improved cooling behaviour of the stator element.
[0020]It is of advantage, when the cooling channel and / or the cooling cavity extends in a meander-like shape. Meander-like shapes allow a most-possible long path of the cooling channel and / or the cooling cavity through the yoke giving rise to further increased heat exchange or cooling properties respectively of the stator element respectively. Both, that is cooling channels and / or cooling cavities may be arranged in a meander-like manner, whereby additionally separate connecting elements in particular regarding the meander-like shaped cooling cavities may be useful in the turns of the meander. Generally, the inventive stator element has the possibility to create specifically shaped or designed cooling paths which would not be feasible or at least difficult to obtain with conventional cooling pipes or the like.

Problems solved by technology

Thereby, large amounts of excessive heat occur due to the induction of current within the stator.
Eddy currents generate magnetic fields opposing the original magnetic field and thus, resulting in a so called eddy current loss.
In large scale wind turbines, eddy current losses may reach a significant level, the efficiency of the generator is usually decreased.
Yet, these methods do not provide sufficient cooling of the stator of an electrical machine like a generator for instance, particularly in times of high-performance.

Method used

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first embodiment

[0032]FIG. 1 shows a principle cut view of an inventive stator element 1 according to the invention. The stator element 1 is in the shape of a segment of a circle and thus, represents a stator segment adapted to built a ring-shaped stator when connected to further respective stator elements 1. Likewise, the stator element 1 could be a complete ring-shaped stator (cf. FIG. 2). The stator element 1 is part of an electric machine for generating power such as a generator used in a large scale wind turbine for instance. The stator element 1 has a yoke 2 built of several laminated steel plates 3. Stator tooth 4 radially protrude from the yoke 2 for accommodating stator windings (not shown) in known manner.

[0033]The stator element 1 comprises a cooling means in the shape of several cooling channels 5 integrally built inside the yoke 2, whereby a plated metal layer 6 completely surrounds each of the cooling channels 5 so as to provide a lining of the cooling channels 5 assuring that no cool...

second embodiment

[0039]FIG. 2 shows a principle cut view of an inventive stator element 1 according to the invention. The essential difference to the embodiment according to FIG. 1 concerns the cooling means, which are not built as cooling channels as depicted in FIG. 1 but as cooling cavities 10 disposed in direct contact to the back side of the yoke 2. Thus, the plated metal layer 6 is only disposed in the contact region of the cooling cavities 10 with the yoke 2. In other words, this embodiment comprises partly plating of the cooling cavities 10 or the yoke 2 respectively so as to ensure a leak-proof lining of the cooling cavities 10 in their contact areas with the yoke 2. That is, a plated metal layer 6 is disposed in the region of the upper areas of the cooling cavities 10 with respect to FIG. 2. Still, maximal thermal exchange between the yoke 2 and the cooling cavities 10 is provided giving rise to a maximal removal of excess heat from the yoke 2. This embodiment represents an alternative to ...

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Abstract

A stator element having a yoke is provided. The stator has several laminated metal plates and a number of tooth radially protruding from one side of the yoke. The stator also has a cooling unit providing a path for the flow of a cooling medium along the yoke. The yoke is at least partially provided with a plated metal layer in the region contacted by the cooling unit.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority of European application No. 10165725 filed Jun. 11, 2010, which is incorporated by reference herein in its entirety.FIELD OF THE INVENTION[0002]The invention relates to a stator element having a yoke comprising several laminated metal plates and a number of tooth radially protruding from one side of the yoke and a cooling means providing a path for the flow of a cooling medium along the yoke.BACKGROUND OF THE INVENTION[0003]Electric machines for power generation such as used in wind turbines for instance comprise a stator and a rotor, the latter being rotatable relative to the stator. During the operation of the electric machine, that is a generator for instance, magnetic fields originating from permanent magnets or wound poles attached to the rotor induce electrical currents into the stator cores and coils in order to generate electrical power. Thereby, large amounts of excessive heat occur due to the ind...

Claims

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Application Information

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IPC IPC(8): H02K1/20
CPCH02K1/20Y02E10/725H02K9/22H02K9/19Y02E10/72H02K9/227H02K9/197
InventorPEDERSEN, CARSTEN KIHOLM
OwnerSIEMENS AG