in this paper, an electromechanically coupled mathematic model of multi-roller driving system for belt conveyor is set up, and the computing equations for dynamic displacement and dynamic tension of the conveyor are a...in this paper, an electromechanically coupled mathematic model of multi-roller driving system for belt conveyor is set up, and the computing equations for dynamic displacement and dynamic tension of the conveyor are also formulated when the hoister is used for straining. Based on the belt conveyor of main inclined shaft in Chengzhuang coal mine, the driving torque, driving power and starting-speed characteristic of each electric motor are studied and measured when multi-roller variable-frequency drive (power distribution 2∶1) is used. The optimal control and the optimal starting-acceleration of the multi-roller variable-frequency drive are determined by a large number of industrial experiments and theoretical calculations.展开更多
Electromagnetic interference （EMI） causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive （VFD） systems. Unlike fundamental frequency components in motor drive syste...Electromagnetic interference （EMI） causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive （VFD） systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifierinverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifierinverter systems are also summarized. EMI noise suppres- sion techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.展开更多
In order to strengthen the production efficiency and quality of underground coal mine, the application of variable frequency drive control system of scraper conveyor is analyzed. Firstly, the performance of the equipm...In order to strengthen the production efficiency and quality of underground coal mine, the application of variable frequency drive control system of scraper conveyor is analyzed. Firstly, the performance of the equipment is introduced, and the necessity of the design and application of frequency conversion drive control system is clarified, which is beneficial to strengthen the informatization and digitization of underground coal mine production. Secondly, it describes the construction of variable frequency drive control system, grasps the system structure and the selection requirements of various components. Finally analyzes the application of variable frequency drive control system, and summarizes the suggestions on optimizing the application effect of scraper conveyor, which is conducive to improving the stability and efficiency of the equipment operation, and provides modern system support for future underground coal mine production.展开更多
文摘in this paper, an electromechanically coupled mathematic model of multi-roller driving system for belt conveyor is set up, and the computing equations for dynamic displacement and dynamic tension of the conveyor are also formulated when the hoister is used for straining. Based on the belt conveyor of main inclined shaft in Chengzhuang coal mine, the driving torque, driving power and starting-speed characteristic of each electric motor are studied and measured when multi-roller variable-frequency drive (power distribution 2∶1) is used. The optimal control and the optimal starting-acceleration of the multi-roller variable-frequency drive are determined by a large number of industrial experiments and theoretical calculations.
文摘Electromagnetic interference （EMI） causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive （VFD） systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifierinverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifierinverter systems are also summarized. EMI noise suppres- sion techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.
文摘In order to strengthen the production efficiency and quality of underground coal mine, the application of variable frequency drive control system of scraper conveyor is analyzed. Firstly, the performance of the equipment is introduced, and the necessity of the design and application of frequency conversion drive control system is clarified, which is beneficial to strengthen the informatization and digitization of underground coal mine production. Secondly, it describes the construction of variable frequency drive control system, grasps the system structure and the selection requirements of various components. Finally analyzes the application of variable frequency drive control system, and summarizes the suggestions on optimizing the application effect of scraper conveyor, which is conducive to improving the stability and efficiency of the equipment operation, and provides modern system support for future underground coal mine production.
