COMPENSATION OF ELASTIC VIBRATIONS OF INDUSTRIAL MECHANISMS

The method of compensation of elastic vibrations of electric drives of industrial positioning mechanisms, as well as methods for assessing the level of these vibrations are shown. It is proposed to choose the parameters of the electric motor and the mechanism optimal according to the criterion of minimum vibrations at the design stage of the displacement mechanisms. Positioning mechanisms of the "actuator" type with screw –nut transmission make it possible to implement this approach

PRELIMINARY ANALYSIS OF THE MODERNIZATION OF METAL-CUTTING MACHINES

The method of modernization and analysis of the choice of the electric motor are shown. It has been established that it is expedient to carry out modernization based on a feasibility study in several stages with the development and approval of technical documentation at each stage

Research of current distribution by phases in asynchronous electric motor with a combined winding

THE PURPOSE. The asynchronous electric motor with a squirrel cage rotor is widely used in the electric driven industry and agricultural machinery. One of the possible ways to improve its energy characteristics is to use a combined 12-zone stator winding instead of the standard 6-zone one. However, in a combined winding with a parallel connection of the «star» and «delta» phases, the phases may not be loaded equally. Therefore, the main purpose of the work under analysis is to study the distribution of currents between the phases of the «star» and «delta» in the asynchronous motor with a combined winding.METHODS. The study was performed on the AIR71V4 engine, rewound onto a combined winding, in which the real ratio of the active resistances of the «delta» and «star» turned out to be 7% less than the theoretical one. The tests were carried out in no-load and short-circuit mode when powered from a three-phase network, as well as in short-circuit mode when one of the line wires is broken.RESULTS. The work gives the values of the currents flowing through the phases of the combined winding. For the experimental sample, the deviation of the obtained currents from the theoretical values is determined. Equations of currents are obtained when one of the linear wires is broken. Schemes for switching on the main contacts of a thermal relay for a motor with a combined winding are proposed.CONCLUSION. The results of the study showed that in an asynchronous motor with a combined winding, in which the real ratio of the active resistances of the «delta» and «star» is less than the theoretical one, the current is not proportionally distributed over the phases. The most preferred circuit for switching on a thermal relay is one in which its main contacts are connected to the «delta» phases, and the thermal relay must be three-pole.

Research of current distribution by phases in asynchronous electric motor with a combined winding

THE PURPOSE. To consider the features of power supply system of oil and gas production complex, variety of layout of electrical complexes of producing wells. To develop a universal methodology for determining optimal voltage value in power supply center, that is, on substation power bus.METHODS. When calculating voltage in power supply center, which provides a certain amount of voltage on stator of most remote electric motor, method of equalizing potentials in nodes of outgoing line was used when calculating loads of elements of electrical complexes of producing wells. The development of a methodology for calculating optimal voltage of power supply center was carried out using the method of cognition, which was called ascent from simple to complex. The search for optimal voltage value of power supply center must be carried out by numerical methods with involvement of a software product that allows use of search algorithms.RESULTS. The article proposes a method for calculating optimal voltage of power supply center of outgoing line of an oil and gas producing enterprise. The developed technique can be applied under a wide range of energy optimization criteria and for any configuration of outgoing line circuit, takes into account technological features of the process of mechanized oil production and ensures a reduction in electricity consumption.CONCLUSION. The calculation method considered in article makes it possible to develop an optimal list of organizational and technical measures for voltage regulation in distribution network in order to reduce power consumption.