Тhe features of using synchronous electric machines in high-power electric drives of critical technological installations are Considered. The main types of synchronous motors with different excitation systems are presented, as well as a mathematical description based on vector diagrams. The obtained static characteristics of the network of the synchronous motor in asynchronous modes, the start and entry into synchronism when the automatic excitation control.
Тhe system of high-voltage motors, which are expressed with different granularity characteristics as their functional units, operating parameters, thermal and vibrational state, the external connection diagram and internal connections). It is shown that the most appropriate model for monitoring electric motors is a functional diagnostic model, when using which the input effects are determined in advance by the working algorithm of the object's operation based on four operational factors. Methods of formalization of processes for each of them are given.
Issue of commissioning reactive power compensators that were disconnected during the reconstruction of refinery process units is considered in the article. Influence of the level of harmonic components from variable-frequency drives in electric motors and powerful industrial uninterruptible power supplies in the supply main is analyzed.
The work is devoted to the analysis of efficiency of the developed and implemented high-precision devices for determining fault locations on 10 kV overhead lines. Due to introduction of digital devices, operating and repair costs in the 10 kV power supply network are reduced, which allows significant cost savings.
The article deals with the system of measurement and control of technological parameters of the main units and equipment of air separation units of the AK 40/32 type.
The article discusses production activities of an enterprise, suggests methods for the efficient operation of the equipment. Operators directly working with it are responsible for the serviceability and maintenance of machinery and equipment; they also perform a minimum of daily maintenance operations. Faults are eliminated together with the instrumentation technician. All newcomers undergo introductory briefing with a corresponding mark in the personal file; they are instructed in the workplace with a note in the journal «with the signatures» of the person receiving instructions and the person who gives instructions. Calculation of electrical load of the facility, which amounted to 213.8 kVA, was carried out. Distribution cabinets of the «ShR-11» type are used to connect equipment, they are powered through the incoming switchgear with wires receiving power from the transformer substation via two cables, and calculations for the grounding device of the transformer substation were performed. Lighting calculations were made for all rooms, power and lighting networks were protected from short circuits by circuit breakers.
The article describes in detail the accident, provides comments by a specialist in the field of labor protection. The source of information about the accident, as well as its causes identified during the investigation, is Rostekhnadzor.
The article considers the effectiveness of using silicone transformer fluid as a cooling and dielectric liquid for filling oil transformers and other equipment for operation at very low and very high temperatures, and especially in cases where high thermal stability and the lowest value of heat generated during combustion are required. The directions of using this type of dielectric are given. The operational properties of silicone transformer fluid are considered. The conclusion is made about the feasibility of using a liquid dielectric based on the advantages of silicone transformer fluid in comparison with other types of dielectrics used in power transformers.
Multicore cables and round wires, the problem of ice forming on such wires are considered in the article. Technical design solution is proposed in this article, it consists in breaking the ice crust by increasing the diameter of the wire due to the protrusions forming from the inner layers during movement. A study of the proposed design and the results are presented.
