Statistical analysis of turbo generator sets failure causes

Abstract

Failure diagnostics and general decrease of accident rate at power plants is a major task of energy generation industry, and solution of it provides reliable energy supply country wide and technological progress in mechanical engineering. Along with some other crucial means, the task could be solved by means of teaching the maintenance staff based on accidents that have already occurred. That is no secret that everywhere in the world due to indecision or misinterpretation a huge number of accidents have happened merely because the personnel were not aware of similar cases at other power plants. Nevertheless with the development of computational technologies and mathematical algorithms the role of personnel in some cases has been reduced to observation and action in critical situation, while the rest is performed by machines: various types of diagnostics and prediction of failure systems based on artificial neural networks are widely applied and developed. However, in order to train these systems, it is absolutely required to know the reasons that could lead to and consequences that could follow some deterioration in turbo generator sets performance. The aim of the present paper is to give statistical analysis of turbo generator sets failure reasons based on open source data presented by Russian and foreign researchers and analysts in the field. The statistical data could be used to perform classification and ranking of failure reasons in terms of frequency of occurrence, possibility to identify or detect, etc. and the paper also gives brief listing of possible ways of detection or identification of failure modes and possible consequences for the main units of a turbo generator.

Failures of Electrical Machines - Review

“…As it is shown in Fig. 2, the distribution of the failures across these subsystems is quite uniform, but still the stator contains the most failures [6]. The Allianz insurance company's data has been revealed in report [5] and it states that the majority of failure causes are related to the design and materials and operation of the generator itself, the aging with other causes is the minority here.…”

“…Since the turbo and hydro generators are such complex technical devices which are commonly designed for long lifespan and specific requirements [5], there is a problem to find a significant number of similarly oriented studies on the failure origin, faulted component and failure rates. However, for turbo generators the reference [6] presents a percentage of failures related to subsystems of turbo generators. As it is shown in Fig.…”

“…Maintenance interval may affect the failure rate significantly as it is shown in [12], [13]: 12 month or less (1.24 % and 4.03 %) and 24 months or more (8.81 % and 14.29 %). Maintenance in levels of safety checks, limited inspections and major overhauls are recommended to distinguish, as each maintenance level has different time requirements and capabilities to identify and detect failures [6].…”

Optimization Model of Vibrodiagnostic Maintenance of Turbogenerators

“…The main criteria for the turbogenerator operation are high reliability, many starts, and flexible work [3]. Today, turbogenerators have increasing requirements for operational safety [4,5]. This represents the basis for planning and implementing quality and necessary maintenance technology procedures practically.…”

Synchronous machine performance under geomagnetic disturbances

“…Together with power transformers, they differ from other power system equipment in terms of cost (up to US $20 million) and replacement period (up to 12-18 months). According to statistics, because bearings and sealings are crucial parts of the stator-rotor system, about 55% of synchronous machine failures are within the statorrotor system [18]. Compared with other aspects of reliable synchronous machines operation [19][20][21][22], the problem of the impact of GMDs on synchronous machines is less studied.…”