Analysis Of Turbine Generator Research Articles

Transient Characteristic Analysis of Turbine Generator Based on Separated Partial Finite Element Model

This article presents an effective modeling method for electric machines to reduce the computational cost of finite element (FE) analysis coupled with circuit equations. In this method, center and end regions of the machines are separately modeled. The center of the machines is partially modeled considering their periodic structure. As a result, the total number of elements can be decreased. Moreover, the computational accuracy is kept unchanged by introducing two correction coefficients which adjust the total amount of magnetic flux across the coils. The proposed method is applied to the steady-state characteristic analysis of a turbine generator. It is shown that the proposed method can reduce the computational time to about one-third in comparison with the conventional FE model, while the computational results almost coincide with the measurements. Then, the proposed method is also applied to a time-consuming eddy current analysis of the turbine generator for estimating its transient characteristics. It is shown that the estimated transient constants of the turbine generator are in good agreement with the measured results.

Finite-element analysis of turbine generator using homogenization method taking account of magnetic anisotropy

PurposeThis paper aims to propose a homogenization method considering magnetic anisotropy for a magnetic field analysis of a turbine generator. To verify the validity of the proposed method, the effects of magnetic anisotropy and a space factor on a no-load saturation curve and no-load iron loss of the turbine generator are discussed.Design/methodology/approachThe proposed method was derived from the combination of the homogenization of microscopic fields in a laminated iron core with the modelling of two-dimensional magnetic properties based on free energy. To verify the validity, the proposed method was applied to a finite-element analysis of a simple ring core model. Finally, a no-load saturation curve and iron loss of the turbine generator was investigated by using the proposed method.FindingsThe computational accuracy of the homogenization method considering magnetic anisotropy is almost the same as that of the detailed modelling of the laminated structure in the magnetic field analysis of the laminated iron core. Furthermore, it is clarified that magnetic anisotropy does not have a large influence on the no-load saturation curve of the turbine generator because of the large air gap. On the other hand, the space factor affects the shape of the no-load saturation curve.Originality/valueThis paper verifies the validity of the homogenization method considering magnetic anisotropy method and elucidates the effects of magnetic anisotropy and a space factor on no-load characteristics of the turbine generator.

Acoustic analysis of turbine generator to predict overall noise using statistical energy analysis methodology

In the growing regions across the globe, products are being differentiated not only by their performance but also on characteristics like noise, aesthetics, ergonomics, etc. Noise norms are getting more and more stringent and customers are looking for quieter products. Engineers and technicians now face the challenge of developing effective products for lower noise emissions in addition to enhanced performance. As generators are a major noise source in a power plant, it is essential to contain generator noise well within the limit to meet statutory requirements. The major contributors to generator noise include cooling fan, rotor jet, electromagnetic excitation, and vibrations. These sources should be configured properly for reducing the overall noise. Therefore, it is essential to establish a robust process to predict the generator noise accurately. This paper describes the process for predicting generator noise by using Statistical Energy Analysis methodology. Correlation of the predictions with test data is also discussed.

The Inlet Pipe Design and Analysis of Fuze Turbine Generator

The structure and aerodynamic performance of inlet pipe which is the key component of turbine generator have direct and significant influences on the input characteristic and safety reliability of fuze turbine generator. A kind of inlet pipe structure was designed by applying the variable cross section pipe and simulated based on the inlet pipe type and application analysis of turbine generator. The results showed that the air flow pressure which the turbine generator obtained from the ballistic can be controlled in a certain range by adjusting the relative structure parameters of inlet pipe to guarantee the stable output characteristics of generator, which can completely meet the technical requirements of fuze.

Assessment of Insulation Condition in Gas Turbine Generator Stator Windings

The results of off-line and on-line diagnostic tests performed on the stator winding of an air-cooled gas turbine(G/T) generator are reported in this paper. Off-line diagnostic tests included measurements of the ac current, dissipation factor(tan), and partial discharge(PD). Six epoxy-mica capacitors were installed in the three phases of G/T generator for performing on-line diagnostic testing with the turbine generator analyzer(TGA). The TGA showed that the normalized quantity number(NQN) and the PD magnitude() were high in phase A of the stator winding. Internal discharges were generated in phases B and C, and slot discharge occurred in phase A. According to the trend analyses of the NQN and values available for insulation condition assessment for G/T generator stator windings, it was concluded that phases B and C were in good condition, whereas phase A has been significantly deteriorated.

Using improved self-organizing map for partial discharge diagnosis of large turbogenerators

Partial discharge (PD) classification is a powerful way to predict insulation problems of the windings of rotating machinery. While online PD tests have been carried out for over 40 years, effective diagnostic methods are still under development. In this paper, a practical diagnostic method is proposed based on an improved self-organizing map (SOM) with improved clustering indications. Three feature extraction methods are employed for the SOM implementation, including Weibull analysis, statistical operators, and fractal parameters. Experimental PD data of industrial model bars are used to validate the efficiency of using SOM for PD classification. The method is applied to investigate the turbine generator analyzer (TGA) data obtained from a power plant of British Nuclear Fuels Ltd. Diagnostic results are included to demonstrate that the relationship between the new PD measurement and historical data can be visualized and more confidential diagnostic information can be provided, especially when small-size database, new class of data, and doubtful measurements are involved in a practical environment.

Analysis of turbine generator steady‐state reactances for load conditions

Analysis of turbine generator steady‐state reactances for load conditions

Application of partial discharge testing to motor and generator stator winding maintenance

Deterioration of stator winding insulation continues to be one of the predominant causes of large motor and generator failures. Over the past several years, practical methods have been developed for measuring the partial discharge activity in the high voltage insulation of stator windings, since partial discharges are a symptom of most of the insulation failure mechanisms in motors and generators rated 4 kV or more. The turbine generator analyzer (TGA) test has now been specifically developed to enable industrial plant staff to reliably perform a partial discharge test on operating motors and turbine generators. This paper presents several case studies of the use of these new partial discharge test technologies on rotating machines. Test results show that machines with deteriorated windings have a partial discharge activity at least 30 times higher than good windings. The availability of these test methods enables plant staff to economically and reliably plan stator winding maintenance, avoid unexpected failures and often extend the time between major maintenance outages.