Methods for diagnosing and monitoring the state of electrical devices in power substations based on detecting and measuring the level of partial discharges in equipment isolation are considered, the analysis of design diagrams of systems diagnosing the state of electrical devices in power stations under load is considered, the physical processes in insulation of electrical devices in power stations are considered — the mechanism and causes of partial discharges and their effect on the isolation and technical condition of data devices.
The article considers the impact of hardness and the number of solid-phase inclusions, as well as the properties of steels with ferritic, austenitic and martensitic matrices with heterophase cementitious structures on wear resistance. It is demonstrated that to ensure high wear resistance and impact toughness, solid phase particles in the structure of a heterophase metal material must be isolated from each other by sections of a relatively viscous matrix. Such structures can be obtained on the surface of a part or tool by surfacing, chemical-thermal treatment, and other methods. The results of calculations of the hardness of steel with different content of the carbide phase in its structure and the specific strain energy absorbed by the cementitious layer from the relative content of carbides in the ferritic, austenitic and martensitic matrices are presented. The contribution of carbide particles to determining the level of wear resistance of a two-phase material with different amounts of them in steels with different matrices is evaluated.
The article describes a methodology for professional support of an electric drive for continuous use of the mode of long- and short-term starts. The results of relevant experimental studies are presented and the sequence of engineering monitoring procedures is proposed in order to increase the durability of the equipment.
The article describes technologies for producing compacted graphite iron, its advantages over similar materials, as well as the process of its introduction into domestic production.
The basic data about residual stresses are considered, and the classification of residual stresses that occur in the surface layer of parts is provided. At the moment, it is customary to divide residual stresses by the volume of balancing into macro-stresses, micro-stresses and submicron stresses, and by the sign — compressive and tensile. The main causes of residual stresses are analyzed, and the factors influencing their occurrence are identified. There are three main causes of residual stresses: uneven plastic deformations in the cutting zone, as a result of the force of the tool on the workpiece, high temperatures accompanying the cutting process, and structural and phase transformations occurring on the surface of the workpiece.
The article deals with the problems of formation of a crust on the surface of the starting mixture and overgrowing of the nozzle channel when the jet is completely blocked. Ways to solve problems are described and the process of designing additional equipment is described.
To ensure the smooth operation of power cable lines, it is necessary to carefully analyze the type of faults and their location. This article discusses the most common types of faults and the main causes of cable damage. A case study of cable faults in urban networks shows that insulation degradation is the main cause, especially as cables have a lifespan of 35 years. Therefore, to prevent failures and reduce threats, it is necessary to strengthen the surveillance of cabling systems and use cables with higher reliability and functionality, such as XLPE cables.
