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Date submitted1975-07-20
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Date accepted1975-09-15
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Date published1976-01-01
Problems of electrification and automation of mining machinery and installations
- Authors:
- V. V. Rudakov
The main directions of development of the national economy of the USSR in 1976-1980, as approved by the XXV Congress of the CPSU, envisage a broad scope of work aimed at improving efficiency and quality. …
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Date submitted1975-07-04
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Date accepted1975-09-12
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Date published1976-01-01
Complete thyristor electric drive of an excavator
- Authors:
- V. N. Batitsky
- R. P. Martikaynen
- V. V. Rudakov
The development of the excavator drive using a thyristor converter - motor (TC-M) system was carried out jointly by researchers from VNIIElectromash and the Leningrad Mining Institute named after Plekhanov. The design and manufacture of the power section of the thyristor converters were undertaken by the Tallinn Electrotechnical Plant named after Kalinin. The reconstruction of the EKG-4.6 excavator, involving the replacement of the generator - motor system with the thyristor converter - motor system, was performed by the Apatit Combine. ...
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Date submitted1975-07-23
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Date accepted1975-09-16
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Date published1976-01-01
Algebraic method for synthesising control systems for electric drives with subordinate regulation under elastic mechanical connections
- Authors:
- A. S. Solovev
The generation of accelerations and dynamic torques in electric drives with subordinate control leads to elastic deformations in transmission elements significantly affecting the motion law of the output (actuating) shaft. Therefore, in-depth study of the dynamics of electromechanical systems incorporating elastic connections receives particular attention. The dynamics of such electric drives are investigated using logarithmic frequency characteristics, based on which the feedback (FB) coefficients and transfer functions of corrective elements are determined to optimise transient processes. ...
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Date submitted1975-07-10
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Date accepted1975-09-12
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Date published1976-01-01
Dynamics of roller-cone drilling rig drives
- Authors:
- I. M. Stolyarov
Operational experience with drilling rigs of the SBSh and BASh types demonstrates that during operation, vibrations occur in the drill string, which are transmitted to the rig platform. These vibrations limit the permissible level of technological parameters and ultimately reduce the rig's productivity. The vibration level can be reduced by adjusting technological parameters, as well as by improving the design of the rig's rotation-feed mechanism. Vibrations of the rig's centre of mass are caused by disturbance introduced into this system by the drill string. ...
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Date submitted1975-07-12
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Date accepted1975-09-10
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Date published1976-01-01
Thyristor DC regulator for the rotary drive of a drilling rig
- Authors:
- I. M. Stolyarov
- V. O. Chashnikov
Thyristor DC regulators, or, as they are called, DC pulse converters, in control systems containing electrical machines, prove to be more convenient than adjustable thyristor rectifiers in a number of cases. The use of controlled rectifiers is often complicated by distortion of the supply voltage waveform. ...
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Date submitted1975-07-28
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Date accepted1975-09-17
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Date published1976-01-01
On the improvement of unregulated electric drives for mining combines
- Authors:
- Ya. P. Grinberg
- V. S. Solovev
- A. S. Solovev
There is no consensus on the optimal dynamic parameters of electric motors used to drive coal and tunnelling combines. It is known that the operating mode graphs of these machines are characterised by extreme irregularity and obey only probabilistic laws. ...
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Date submitted1975-07-14
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Date accepted1975-09-23
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Date published1976-01-01
Asynchronous motor with series capacitors under periodic loading
- Authors:
- O. V. Ivanov
- B. I. Komarov
- A. D. Sigarreta
The loads of mining machine drives are characterised by significant irregularity and, as correlation analysis of the operating modes of extraction and tunnelling combines demonstrates, contain periodic components with a frequency range of 0.5–20 Hz. In extensive mine networks, cutter-loader electric motors often cannot stably sustain a load equal to their rated power. ...
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Date submitted1975-07-15
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Date accepted1975-09-03
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Date published1976-01-01
Study of capacitor braking of squirrel-cage induction motors using an analogue computer
- Authors:
- O. V. Ivanov
- B. I. Komarov
In electric drive systems, capacitive braking of squirrel-cage induction motors is employed either autonomously or in combination with other operating modes. The braking torque on the motor shaft, depending on the circuit configuration and initial conditions, arises either from machine self-excitation, capacitor discharge, or a combination of both effects simultaneously. ...
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Date submitted1975-07-04
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Date accepted1975-09-06
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Date published1976-01-01
Vector control of AC machines
- Authors:
- V. A. Dartau
- V. V. Rudakov
Vector control of AC machines differs from conventional frequency drive control systems in that the mutual position of generalised electromagnetic quantity vectors is taken into account when generating control signals (the voltage vector). The rationale for such consideration becomes apparent upon analysing the expressions for electromagnetic torque. ...
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Date submitted1975-07-02
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Date accepted1975-09-19
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Date published1976-01-01
Principles of constructing control systems for thyristor frequency converters in drives with block vector regulation
- Authors:
- Yu. P. Pavlov
When employing thyristor frequency converters (TFCs) in block control systems of AC variable frequency drives, the converter is controlled by a two-phase AC signal modulated in magnitude, frequency, and phase. …
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Date submitted1975-07-28
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Date accepted1975-09-18
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Date published1976-01-01
Control of direct frequency conversions from AC signals in block vector regulation systems for induction drives
Based on the principle of output voltage formation, direct frequency converters are divided into two main types: thyristor-based direct frequency converters with natural commutation (DFC-NC) and thyristor-based direct frequency converters with forced commutation (DFC-FC). In DFC-NC, the output frequency is formed through natural commutation within a half-cycle of the output voltage. ...
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Date submitted1975-07-13
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Date accepted1975-09-02
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Date published1976-01-01
Energy characteristics of the frequency converter–motor system in frequency-controlled drives of mining machinery
For the analysis of the spectral composition of the output voltage in the previously proposed thyristor-based direct frequency converter with forced commutation (DFC-FC), we shall employ the following expression…
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Date submitted1975-07-12
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Date accepted1975-09-17
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Date published1976-01-01
Block frequency-controlled drive of a mine hoisting installation
- Authors:
- V. A. Dartau
- A. E. Maksimov
The application of variable frequency drives in medium-power hoisting installations enables significant improvement in reliability indicators and enhancement of the system's dynamic characteristics. …
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Date submitted1975-07-20
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Date accepted1975-09-17
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Date published1976-01-01
Adjustable main drive system for coal shearers using the DFC-IM (Direct Frequency Converter - Induction Motor) configuration
The increase in labour productivity in mines and the improvement of miners' working conditions have led to the widespread implementation of mining complexes with coal-cutting machines. To ensure high operational efficiency under various conditions, coal-cutting machines must incorporate regulation of both feed and cutting speeds. ...
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Date submitted1975-07-02
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Date accepted1975-09-04
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Date published1976-01-01
Structural diagrams of frequency-controlled electric drives based on synchronous machines with vector control
- Authors:
- V. A. Dartau
The control of electromagnetic transients in variable frequency drives based on synchronous machines can be achieved by applying vector control principles. The fundamental concept of vector control involves transitioning from natural electromagnetic stator variables - components of the generalised stator current and voltage vectors in stationary stator coordinates - to new variables representing components of these same vectors in rotating coordinate systems. ...
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Date submitted1975-07-12
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Date accepted1975-09-30
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Date published1976-01-01
Control of a thyristor converter for a synchronous motor in main ventilation fan drives
- Authors:
- V. N. Yazev
Main ventilation fan installations at mining enterprises represent the most energy-intensive consumers. Significant energy wastage and low efficiency of ventilation systems are attributed to substantial deviations between actual ventilation regimes and design parameters. This occurs because main ventilation fans are selected for the entire operational lifespan of the enterprise based on ultimate maximum design values of gas emission, explosive quantity, production volume, workforce numbers, etc. Consequently, the determination of fan operating modes for mine ventilation networks often proves insufficiently precise. ...
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Date submitted1975-07-23
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Date accepted1975-09-15
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Date published1976-01-01
Rotation drive system for ball mills using the DFC-SM (Direct Frequency Converter - Synchronous Motor) configuration
- Authors:
- I. M. Stolyarov
- Z. B. Sleptsova
In certain cases involving the mechanisation of maintenance and auxiliary operations related to ball mills, direct frequency converters with a limited output frequency range are employed. These operate in short-term duty modes that do not require optimal converter output voltage waveform or high precision in maintaining thyristor firing angles. On the other hand, such devices typically must meet enhanced requirements regarding noise immunity and reliability, as they are installed in industrial premises with high levels of electromagnetic interference. ...
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Date submitted1975-07-20
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Date accepted1975-09-16
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Date published1976-01-01
Analysis of commutation methods for synchronous motors in step mode
- Authors:
- Z. B. Sleptsova
The slow-turning device for a ball mill drum, implemented via a thyristor-based direct frequency converter-synchronous motor (DFC-SM) system with a simplified noise-resistant pulse distribution system, accomplishes sequential energisation of the mill motor's stator windings from a DC voltage source in a specific sequence. ...
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Date submitted1975-07-29
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Date accepted1975-09-06
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Date published1976-01-01
Radioisotope method for measuring the average density of slurry flow
- Authors:
- K. L. Korbel
Nuclear engineering provides particularly suitable conditions for implementing measurement systems capable of continuous monitoring of average fluid density without disrupting flow patterns. Depending on pipeline parameters and fluid type, such measurements can be based either on scattering phenomena or on absorption of ionising radiation. ...