Life Assessment of Electric Arc Furnace Transformers

Implementing the concept of a “smart furnace transformer” should stipulate its information support throughout its life cycle. This requires improving techniques for estimating the transformer’s health and forecasting its remaining useful life (RUL). A brief review of the problem being solved has shown that the known RUL estimation techniques include processing the results of measuring the facility state parameters using various mathematical methods. Data processing techniques (deep learning, SOLA, etc.) are used, but there is no information on their application in online monitoring systems. Herewith, fast (shock) changes in the resource caused by the failures and subsequent recoveries of the facility’s health have not been considered. This reduces the RUL forecasting accuracy for the repairable equipment, including transformers. It is especially relevant to consider the impact of sudden state changes when it comes to furnace transformers due to a cumulative wear effect determined by their frequent connections to the grid (up to 100 times a day). The proposed approach is based on calculating the RUL by analytical dependencies, considering the failures and recoveries of the facility state. For the first time, an engineering RUL forecasting technique has been developed, based on the online diagnostic monitoring data results provided in the form of time series. The equipment’s relative failure tolerance index, calculated with analytical dependencies, has first been used in RUL forecasting. As a generalized indicator, a relative failure tolerance index considering the facility’s state change dynamics has been proposed. The application of the RUL forecasting technique based on the results of dissolved gas analysis of a ladle furnace unit’s transformer is demonstrated. The changes in the transformer state during the operation period from 2014 to 2022 have been studied. The RUL was calculated in the intensive aging interval; the winding dismantling results were demonstrated, which confirmed developing destructive processes in the insulation. The key practical result of the study is reducing accidents and increasing the service life of the arc and ladle furnace transformers. The techno-economic effect aims to ensure process continuity and increase the metallurgical enterprise’s output (we cannot quantify this effect since it depends on the performance of a particular enterprise). It is recommended to use the technique to forecast the RUL of repairable facilities equipped with online monitoring systems.

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“…Refs. [59][60][61] provide an overview of known systems for the online monitoring of the furnace transformer's health. Ref.…”

Section: Online Monitoring Of the Furnace Transformer Healthmentioning

confidence: 99%

“…Ref. [60] proposes a test procedure to identify incipient faults and determine the general state of transformers. A model has also been implemented to assess the insulation wear degree, residual resource, and the possibility of reusing a furnace transformer.…”

Section: Online Monitoring Of the Furnace Transformer Healthmentioning

confidence: 99%

Method for Forecasting the Remaining Useful Life of a Furnace Transformer Based on Online Monitoring Data

et al. 2023

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“…Many works explain in detail how to perform and the expected results of the most well-known factory and field tests: resistance measurements, ration tests, polarity and phase relation, load and no-load losses, dielectric tests, thermal analysis, vibration analysis, dissolved gas analysis, partial discharge analysis, frequency response analysis, etc. [43,[105][106][107][108][109][110][111][112][113][114][115][116][117]. The same tests are currently applied to both power and furnace transformers.…”

Section: Eaf and Lf Transformersmentioning

confidence: 99%

Survey on the electric arc furnace and ladle furnace electric system

Maia

Onofri

2022

Ironmaking & Steelmaking

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This paper presents a multidisciplinary review of electric arc furnace (EAF) and ladle furnace (LF) power plants in use for steel production. The EAF and LF systems comprise of critical electrical equipment that is prone to fail. Depending on the fault condition, a complete shutdown can emerge and consequently cause production loss. This paper presents, in view of an electrical system, each equipment that is needed in order to correctly operate an EAF and an LF. The state of art of each equipment is presented in this review, together with some discussion of the possible problems and solutions that can emerge in this kind of installation, including its impact on the steel production.

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