Theoretical provisions on operation and maintenance for determining the reliability of ship electric drives

Abstract

The results of the performed studies have confirmed that at present the most common type of drive of ship mechanisms is an electric drive. Electric drives are the main recipients of electric energy, including the ship energy. The number of electric motors installed on ships is, as a rule, hundreds of units. It is proposed, based on the classification developed earlier, to conventionally refer the majority of ship electric drives, despite their wide variety, to three main groups, differing in operating modes and operating conditions determined by their functional purpose: close to typical modes S1 and S6 — the first group; S2 — the second group; S3, S4, S5, S7, S8, the third group. The specific conditions and operating modes of ship electric drives, which differ significantly from land-based ones and are determined by higher climatic and mechanical loads, lead to a decrease in their reliability, the need for increased attention to maintenance and repairs of electric drives, their components and elements. The basic principles of the approach to working with statistical data necessary for calculating the reliability indicators of marine electric drives are formulated. To analyze the past record of operation and maintenance of ship electric drives, a method based on the collection and processing of statistical information in operational conditions was used, which is the most effective, allowing to take into account the complex impact on the reliability of electric drives of all operational factors that are difficult to reproduce during testing, and does not require the cost of creating test benches and performing tests. Judging by the number of failures, the regulated ship electric drives of approximate mode S2 (windlasses, capstans, etc.) and modes S3, S4, S5, S7 and S8 (hoist winches and cranes) are less reliable in comparison with others.