scholarly journals Optimization of Control Processes of Digital Electrical Drive Systems

2010 ◽  
Vol 47 (2) ◽  
pp. 16-24
Author(s):  
J. Dochviri

Optimization of Control Processes of Digital Electrical Drive Systems The aim of the work is solution of the problems associated with synthesis of the digital speed regulators both for DC and AC thyristor electrical drives. The investigation is realized based on the parameters of continuous technological equipment (e.g. paper-making machine) by taking into account elastic transmission links of the drive systems. Appropriate frequency characteristics and transient processes are described.

Author(s):  
Horst Ecker ◽  
Thomas Pumhössel

Drive systems may experience torsional vibrations due to various kinds of excitation mechanisms. In many engineering systems, however, such vibrations may have a negative impact on the performance and must be avoided or reduced to an acceptable level by all means. Self-excited vibrations are especially unwanted, since they may grow rapidly and not only degrade the performance but even damage machinery. In this contribution it is suggested to employ parametric stiffness excitation to suppress self-excited vibrations. In the first part of the article we study the basic energy transfer mechanism that is initiated by parametric excitation, and some general conclusions are drawn. In the second part, a hypothetic drivetrain, consisting of an electrical motor, a drive shaft and working rolls is investigated. A self-excitation mechanism is assumed to destabilize the drive system. Parametric excitation is introduced via the speed control of the electrical drive, and the capability of stabilizing the system by this measure is investigated. It is shown that the damping available in the system can be used much more effectively if parametric stiffness excitation is employed.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1440
Author(s):  
Jianping Wu ◽  
Bin Jiang ◽  
Hongtian Chen ◽  
Jianwei Liu

Electrical drive systems play an increasingly important role in high-speed trains. The whole system is equipped with sensors that support complicated information fusion, which means the performance around this system ought to be monitored especially during incipient changes. In such situation, it is crucial to distinguish faulty state from observed normal state because of the dire consequences closed-loop faults might bring. In this research, an optimal neighborhood preserving embedding (NPE) method called multi-manifold regularization NPE (MMRNPE) is proposed to detect various faults in an electrical drive sensor information fusion system. By taking locality preserving embedding into account, the proposed methodology extends the united application of Euclidean distance of both designated points and paired points, which guarantees the access to both local and global sensor information. Meanwhile, this structure fuses several manifolds to extract their own features. In addition, parameters are allocated in diverse manifolds to seek an optimal combination of manifolds while entropy of information with parameters is also selected to avoid the overweight of single manifold. Moreover, an experimental test based on the platform was built to validate the MMRNPE approach and demonstrate the effectiveness of the fault detection. Results and observations show that the proposed MMRNPE offers a better fault detection representation in comparison with NPE.


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