Research on Segmented Belt Acceleration Curve Based on Automated Mechanical Transmission

An automated mechanical transmission (AMT) is proposed as a new soft starter for medium-scale belt conveyors in this paper. The AMT is used to start the belt conveyor and shift gears step by step to make the belt conveyor accelerate softly. Based on analyzing common soft-starting acceleration curves, a segmented belt acceleration curve is proposed as a new soft-starting acceleration curve. By analyzing the AMT soft-starting system, the system modeling is built and the AMT output shaft’s angular acceleration is proposed to be controlled to control the belt acceleration. The AMT soft-starting simulation model is established in the environment of AMESim, and simulation results of the soft-starting process from the first to eighth gear positions are given. The main parameter curves of the AMT soft-starting system including the belt, driving pulley, and AMT output shaft are analyzed. The simulation model can indicate the viscoelastic property of the belt. The simulation results prove that the segmented belt acceleration is appropriate for a medium-scale belt conveyor and provide a theoretical and reasonable basis for using an AMT as a soft starter.

Application of the soft starter for the asynchronous motor of the belt conveyor

The purpose of the work is to justify the need for a smooth start of the conveyor belt. Based on the technological features of the transportation process, the direct start of the conveyor with a loaded undercarriage entails an increase in inertial forces, overload of the traction chains and the drive. Due to the increased starting torque, there is a danger of slipping, the occurrence of an oscillatory transient of the escaping branch of the tape, slipping between the tape and the drive drum. This leads to significant wear of the tape and breakdowns of other equipment, which requires high repair costs. With a smooth start of the conveyor, the acceleration lasts longer, but the movement of the concentrated masses of the belt is more consistent, less oscillatory, which indicates less dynamic forces in the belt. Also, with a smooth start, energy losses in the engine and its heating are reduced. The main results of the work - the transients in the currents of the stator and rotor, in the speed of rotation of the motor and in the speed of movement of the conveyor belt were obtained. The developed model allows us to investigate the dynamic operating modes of the engine and the mechanical part of the conveyor, to analyze the forces arising in the belt during direct and smooth start of the conveyor, to evaluate the slip of the belt and the magnitude of the traction factor. Conclusions - the results of this work should be the basis for controlling the tension in the belt and maintaining the traction factor of the conveyor belt in the start-brake operating modes. In addition, the results obtained can be used in the development of a belt speed control system depending on the amount of random freight traffic entering the conveyor.

AMT Starting Control as a Soft Starter for Belt Conveyors Using a Data-Driven Method

Automated mechanical transmission (AMT) is used as a soft starter in this paper. To improve the soft starting quality, a novel data-driven method is studied. By analyzing and comparing five common soft-starting acceleration curves, a segmented acceleration curve is put forward to be used as the soft-starting acceleration curve for the AMT. Based on the prototype model free adaptive control (MFAC) method, a modified MFAC method with jerk compensation is given to control the AMT output shaft’s angular acceleration and reduce driveline shock. Compared with the methods of prototype MFAC and traditional proportion integration differentiation (PID), the modified MFAC method with jerk compensation can better control the AMT output shaft’s angular acceleration and has excellent characteristics in terms of small tracking error and smaller shock. The research results provide a novel data-driven method for AMT as a soft starter.

Automatic Asynchronous Drive Efficiency Control with Soft-Starter Function

Digital models of pulse-width voltage control system with step switching of power supply frequency and automatic control of induction motor are developed and built, the recommendations on the algorithm of their control and circuit solution for the implementation of smooth start modes, nominal and frequency-step control from low-power -variable load schedule are provided. The novelty of the work lies in the substantiated sequence and conditions of control and originality of the structure of the automatic system of smooth start-up and activation of the effective mode of the asynchronous drive. The introduction of the conversion system will create an automatic system of asynchronous drive, due to which it is possible to achieve energy conservation at all levels of the electromechanical system, with minimum capital investment.

ENERGY EFFICIENCY MEASURES IN ELETRIC MOTORS FOR WATER SUPPLY SYSTEMS

<p>The increase of water and electric consumption has caused concerns in relation to scarcity and water stress, while stimulating the development of energy efficiency techniques in water supply systems. However, these techniques can be considered costly and complex, since they use computational equipment and tools that make it difficult to implement into operational practice. In this regard, especially in developing countries, there is a need for progress in energy efficiency measures with low economic dependence on both equipment and tools, guaranteeing necessary environmental and social benefits. This study evaluated energy efficiency measures in a water supply system through the use of (i) a frequency inverter and (ii) replacing the electric motor with a more efficient motor. The first measure did not show economic attractiveness, revealing that frequency inverters do not always have applicability in reducing energy costs. However, the necessity of a soft starter should be noted, as well as suggested studies that have changes in the operating system that can make this measure attractive. The second measure demonstrated economic potential and reinforced the importance of commercial availability and technical regulation of high-efficiency motors, since the payback period was 4 years, with application potential throughout the water supply system.</p>

INVESTIGATION OF COMPRESSOR START-UP OF CONE DRILLING RIG WITH CURRENT LIMITING FUNCTION

The article deals with the problem of investigation of the system "soft starter- induction motor" for compressing equipment of cone drilling machine. Also refined mathematical model of the system, taking into account the behavior of compressor load, as well as existing working algorithm of the stator current control block is developed. The problems of choice of starting mode of compressing equipment are considered, the necessity of full research of the electric drive system with the methods of numerical modeling is determined. The basic parameters which have to be specified and corrected by the designer of the electromechanical system of the compressor during equipment commissioning are determined. Further, an algorithm for firing angle control of power thyristors, which used in modern soft starters, produced by WEG Company, is implemented. After that, the simulation of the procedure for starting the compressor induction motor using thyristors soft starter with the stator current limiting function is performed. As a result of modeling using application Simulink of software environment ATLAB, the graphs of transients for the most important working parameters, such as stator windings current, shaft rotation speed, load torque and firing angle for thyristors are obtained. The analysis of the obtained results, as a result of which formulated the conclusions on the possibility of using soft starters for the cone drill rig compressors is made. It has been determined that in the case of almost linear behavior of compressor load, the motor starts with a smooth change of speed without significant fluctuations of electric motor stator currents. It is proposed to use the current limiting function for easy starting modes and current control functions with an initial kick of torque.

AMT Starting Control as a Soft Starter Using a Novel Data-Driven Method

To improve the starting quality of automated mechanical transmission (AMT) as a soft starter for belt conveyors, a novel data-driven method is proposed. By analyzing the common soft-starting acceleration curves, a segmented acceleration curve is proposed as the soft-starting acceleration curve for AMT. A modified model free adaptive control (MFAC) method with jerk compensation is proposed as a data-driven method to control the AMT output shaft’s angular acceleration, which consists of a MFAC algorithm and a jerk compensation algorithm. Simulation comparisons are analyzed between the modified MFAC method with jerk compensation, the prototype MFAC method, and the proportion integration differentiation (PID) method. Results indicate better control of the modified MFAC method with jerk compensation on the AMT output shaft’s angular acceleration than the other two methods. It also has excellent properties of small tracking error and small shock, providing a novel approach for AMT as a soft starter.