The method of calculating the most replicated IF circuit loaded on asynchronous ED is described. The analysis of various methods of vector control of the IF is carried out. Various IF topologies are considered, allowing to abandon filters, transformers and improve the quality of voltage. Examples of the implementation of marine and energy IF at a capacity from 200 kW to 1 MW are given.
Sliding is one of the main characteristics of asynchronous motors, in other words, the sliding of an asynchronous motor is the relative difference between the rotational speeds of the rotor and the magnetic flux generated by the stator windings of an alternating current motor. Sliding can be measured in relative units and as a percentage. It varies depending on the operating mode, the load on the shaft and the supply voltage. Given the importance of the above, this paper considers the details about the sliding of asynchronous motors and what it depends on and how it is determined in a completely simple way.
Inter-turn short circuits in the windings of power consumer transformers with a voltage of 6–10/0.4 kV are the most common cause of their failure. It is important to diagnose inter-turn closures in the initial stage of development, before involving a significant number of turns in an accident. A device is proposed that allows diagnosing the appearance of inter-turn circuits at an early stage of development, which will make it possible to avoid serious accidents.
The paper considers the issue of replacing silica gel in air-drying filters in measuring current and voltage transformers 35–110 kV without disconnecting electrical equipment. The process of replacing the sorbent in these devices is carried out under operating voltage by employees of the substation service without involving operational personnel. The introduction of this technique on electric grid enterprises of the energy system allows to reduce the costs of operating electrical equipment and production of operational switches, as well as to increase the reliability of the company.
The types of electric drives and their control systems are analyzed. Three stages of calculating the thrust characteristics of ships are considered: an approximate qualitative calculation, modeling of ships in open basins, and automatic design using CAD. The first stages are usually performed for new types of ships, and the last stage is refined using existing libraries of ship types and modes of their use. The impact of the military-industrial complex on the traction characteristics of ships is mainly manifested in increasing efficiency, maneuverability and adjusting additional and General resistance to the movement of the ship, which requires expanding the capabilities of CAD.
The article is devoted to the methodology of investigation, accounting and prevention of malfunctions of electric trains 81-740/741 "Rusich" operated on the ArbatskoPokrovskaya, Sokolnicheskaya and Butovskaya lines of the Moscow Metro. The real measures aimed at reducing the failures of electric trains are considered. The servi- ceable condition of the equipment of the wagons largely determines the safety of the movement of electric trains and compliance with the current schedule of work on the line.
The reliability of electrical equipment and the safety of its operation, as well as the level of electrical safety and fire safety in the organizations of the electric power industry are directly related to the state of insulation of electrical networks. The current problem of choosing methods and means of monitoring the state of insulation of electrical networks is highlighted. The methods and methods of insulation control of distribution electrical networks are analyzed.
The controller is the main part of automation in any equipment. A programmable logic controller is a microprocessor device designed to collect, process, transform, store information, generate control commands and operate in real time.
This article provides suggestions for organizing continuous monitoring of the technical condition of a power transformer without disconnecting them from the network. It is proved that the specified method has sufficient for practical use the accuracy of the results obtained, which depends on the accuracy provided by the measuring devices. It is substantiated that the use of the developed method for continuous monitoring of the state of a power transformer is expedient and effective. The example shows the possibility of detecting violations of the insulation condition of transformer windings at an early stage of their formation. Recommendations for using the developed method are givene.
The issues of developing methods for analyzing the synchrophasors of voltage and current transients in the power system based on transformations of the differential equation, the convolution integral and methods based on extended time-frequency representations are considered.
