Method for calculating additional loss of steam-turbine generator stator winding

Abstract

The invention provides a method for calculating an additional loss of a steam-turbine generator stator winding. The method comprises the steps of establishing a generator stator straight-line segment temperature field entity model according to an actual structure and an actual size of an air-cooled steam-turbine generator; establishing a generator stator straight-line segment temperature field calculation model corresponding to the generator stator straight-line segment temperature field entity model; setting material and boundary conditions for the generator stator straight-line segment temperature field calculation model, carrying out finite element calculation of a three-dimensional steady-state flow-solid coupling temperature field by use of the generator stator straight-line segment temperature field calculation model to obtain the temperature field with correction calculation of winding loss; and acquiring a calculation expression of the additional loss of the steam-turbine generator stator winding. In the method, according to the situation that an inner strand wire of a coil bar extending into a ventilation duct is not affected by a transverse leakage magnetic flux, an expression among the loss of the steam-turbine generator stator winding with the radial ventilation duct, the number of ventilation ducts and width correction calculation is provided, and the generator stator straight-line segment temperature field can be obtained accurately.

Description

technical field [0001] The invention relates to the technical field of turbogenerators, in particular to a calculation method for additional losses of stator windings of turbogenerators. Background technique [0002] During the actual operation of large air-cooled turbogenerators, the design, manufacture and operation departments are particularly concerned about the temperature of the stator winding and iron core. Therefore, engineering and scientific circles have put forward a lot of research work on the theory and method of additional loss of air-cooled turbogenerator. For a long time, when calculating the stator temperature field of a turbogenerator, whether the calculation result of the loss value on the stator strands is accurate or not has been one of the most critical factors affecting the temperature rise of the motor temperature field. [0003] At present, the calculation of stator strand winding loss of large generator mainly includes two parts: basic copper loss ...

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Problems solved by technology

Moreover, the calculation of the additional loss of the windings of the large generator stator strands mainly uses the method of calculating the Field coefficient, but does not further consider the influence of the strands extending into the radial ventilation ditch

[0004] Since the width of the radial ventilation groove of the turbogenerator stator occupies a considerable proportion of the axial length of the stator core, especially the larger the capacity of the turbogenerator, in order to improve the ventilation and cooling effect, the number of radial ventilation grooves of the stator is usually increased accordingly. The total loss of the stator bar also changes, especially the bar extending into the ventilation ditch, because the influence of the additional eddy current loss caused by the transverse leakage flux does not need to be considered in the calculation, which will inevitably have a certain impact on the calculation result of the motor temperature field, resulting in the calculation The deviation of the temperature field of the turbogenerator is relatively large

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