A NEW CONTRIBUTION INTO CURRENT CALCULATON METHOD FOR SALIENT POLE SYNCHRONOUS GENERATOR DAMPER BARS AT NO-LOAD CONDITION
Main Article Content
Abstract
The prediction of the induced current in damper windings with high accuracy are the key parameters in design process and pole shoe temperature rise estimation. This paper describes a new contribution in combined FEM -State Space method to calculate damper bar current of no load salient pole synchronous generator.
In the first stage of the method, damper bar parameters have been calculated including inductances and flux linkages with the magnetostatic FEM calculation. These parameters are calculated in some rotor positions within one stator slot pitch, considering the machine rotational periodicity. Nonlinear interpolation used between calculated parameters is the contribution of this paper to decreasing simulation time and improving the accuracy of the results.
subsequently due to obtained inductances and flux linkages, differential equations have been driven and solved. This paper claims that simulation time reduced 50 percent in comparison to original combined method. To evaluate the effectiveness of the suggested method, it has been applied to a small 4 poles, 9 KVA salient pole generator as well as a large 32 poles, 250 MVA generator. Comparing the obtained results of described method and the results of transient FEM confirms the validity of the proposed method.
In the first stage of the method, damper bar parameters have been calculated including inductances and flux linkages with the magnetostatic FEM calculation. These parameters are calculated in some rotor positions within one stator slot pitch, considering the machine rotational periodicity. Nonlinear interpolation used between calculated parameters is the contribution of this paper to decreasing simulation time and improving the accuracy of the results.
subsequently due to obtained inductances and flux linkages, differential equations have been driven and solved. This paper claims that simulation time reduced 50 percent in comparison to original combined method. To evaluate the effectiveness of the suggested method, it has been applied to a small 4 poles, 9 KVA salient pole generator as well as a large 32 poles, 250 MVA generator. Comparing the obtained results of described method and the results of transient FEM confirms the validity of the proposed method.