scholarly journals Accelerating the charge inversion algorithm with hierarchical matrices for gas insulated systems

2021 ◽  
Vol 2090 (1) ◽  
pp. 012136
Author(s):  
F Lucchini ◽  
N Marconato
Keyword(s):  
Industrial Applications ◽  
Hierarchical Matrices ◽  
Stable Operation ◽  
Dense Matrix ◽  
Memory Requirement ◽  
Inversion Algorithm ◽  
Surface Charges ◽  
Charge Inversion ◽  
Electrostatic Problem ◽  
Time Operation

Abstract Surface charges accumulating on dielectrics during long-time operation of Gas Insulated High Voltage Direct Current (HVDC-GIS) equipments may affect the stable operation and could possibly trigger surface flashovers. In industrial applications, to quantify and identify the location of the surface charge accumulation from experimental measurements, the surface potential distribution is evaluated using, e.g., electrostatic probes, then the charge density is determined by solving an electrostatic problem based on an inversion procedure known as Charge Inversion Algorithm. The major practical limitation of such procedure is the inversion and the storage of the fully dense matrix arising from the representation via Integral Equations of the electrostatic phenomenon, resulting in O(N 3) computational complexity and O(N 2) memory requirement. In this paper it is shown how hierarchical matrices can be efficiently used to accelerate the charge inversion algorithm and, more importantly, reduce the overall memory requirement.

Chaos control of permanent magnet synchronous motor using simple controllers

2018 ◽  
Vol 41 (8) ◽  
pp. 2352-2364 ◽  
Author(s):  
Arif Iqbal ◽  
Girish Kumar Singh
Keyword(s):  
Permanent Magnet ◽  
Chaos Control ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Industrial Applications ◽  
Stable Operation ◽  
Comparative Performance ◽  
Experimental Implementation ◽  
Chaotic Characteristic ◽  
The Stability

Owing to the superior properties and stable operation, the Permanent Magnet Synchronous Motor (PMSM) is preferably used in wide industrial applications. But, the stability of motor is found to be dependent on its initial operating condition, showing the chaotic characteristic. Therefore, this paper addresses the chaos control of PMSM by developing four simple but effective controllers, which are mathematically designed by using the principle of Lyapunov’s method for asymptotic global stability. A comparative performance assessment has been carried out for the developed controllers in terms of settling time and peak over shoot. Furthermore, the concept of conventional proportional-integration type controller has been extended to develop two more controllers for chaos control of PMSM. Numerical simulation has been carried out in Matlab environment for performance evaluation of developed controllers. The obtained analytical results have been validated through experimental implementation in real time environment on Multisim/Ultiboard platform.

scholarly journals Empirical Mode Decomposition and Neural Networks on FPGA for Fault Diagnosis in Induction Motors

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
David Camarena-Martinez ◽  
Martin Valtierra-Rodriguez ◽  
Arturo Garcia-Perez ◽  
Roque Alfredo Osornio-Rios ◽  
Rene de Jesus Romero-Troncoso
Keyword(s):  
Empirical Mode Decomposition ◽  
High Performance ◽  
Induction Motors ◽  
Industrial Applications ◽  
Feed Forward Neural Network ◽  
Linear Network ◽  
Multiple Faults ◽  
Online Systems ◽  
Time Operation ◽  
Mode Decomposition

Nowadays, many industrial applications require online systems that combine several processing techniques in order to offer solutions to complex problems as the case of detection and classification of multiple faults in induction motors. In this work, a novel digital structure to implement the empirical mode decomposition (EMD) for processing nonstationary and nonlinear signals using the full spline-cubic function is presented; besides, it is combined with an adaptive linear network (ADALINE)-based frequency estimator and a feed forward neural network (FFNN)-based classifier to provide an intelligent methodology for the automatic diagnosis during the startup transient of motor faults such as: one and two broken rotor bars, bearing defects, and unbalance. Moreover, the overall methodology implementation into a field-programmable gate array (FPGA) allows an online and real-time operation, thanks to its parallelism and high-performance capabilities as a system-on-a-chip (SoC) solution. The detection and classification results show the effectiveness of the proposed fused techniques; besides, the high precision and minimum resource usage of the developed digital structures make them a suitable and low-cost solution for this and many other industrial applications.

scholarly journals Performance Analysis of Closed Loop Operation of BLDC Motor

2021 ◽  
Vol 11 (4) ◽  
pp. 4854-4867
Author(s):  
CH.N. Narasimharao ◽  
G. Durga Sukumar ◽  
Y. Sinivasarao
Keyword(s):  
Closed Loop ◽  
Pulse Width Modulation ◽  
Torque Ripple ◽  
Industrial Applications ◽  
Stable Operation ◽  
Bldc Motor ◽  
Motor Speed ◽  
Improved Performance ◽  
Modulation Methods ◽  
The Stability

Industrial applications requires the minimized torque ripple along with the motor stable operation. The Hysteresis and pulse width modulation methods are used to obtain improved performance of BLDC motor. The torque ripples, speed control and the stability of BLDC motor were observed. The proposed system is mainly focused on the parameters such as motor speed; Stator current and Back EMF are to increase the performance level. The MATLAB/SIMULINK models of closed loop and dynamic modeling for stability are also presented.

scholarly journals A New Direct Speed Estimation and Control of the Induction Machine Benchmark: Design and Experimental Validation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Hmidet ◽  
Rachid Dhifaoui ◽  
Othman Hasnaoui
Keyword(s):  
Real Time ◽  
Direct Torque Control ◽  
Induction Machine ◽  
Fast Response ◽  
Industrial Applications ◽  
Torque Control ◽  
Direct Control ◽  
Speed Sensorless ◽  
Time Operation ◽  
Estimation And Control

Speed sensorless control schemes have potential benefits for industrial applications because they contribute to reducing process cost and they avoid using fragile sensors as encoders or resolvers in hostile environment. In addition, simplicity, reliability, and fast response of control structures to signal commands are much-needed features. In this paper, a new Speed Sensorless Direct Control (SSDC) technique allowing the achievement of these objectives is proposed. This technique combines Field Oriented Control (FOC) and Direct Torque Control (DTC) properties in the same approach. The estimated speed is reached only according to the measured current and voltage of the stator. DTC is extended to speed sensorless direct control with any notable modification. The proposed scheme is implemented to the induction machine benchmark and evaluated in real time under various possible scenarios of use. Experimental results show that the proposed SSDC has interesting capabilities to conduct induction motor in real time operation with good accuracy.

scholarly journals A fast and easy-to-implement inversion algorithm for mobility particle size spectrometers considering particle number size distribution information outside of the detection range

2014 ◽  
Vol 7 (1) ◽  
pp. 95-105 ◽  
Author(s):  
S. Pfeifer ◽  
W. Birmili ◽  
A. Schladitz ◽  
T. Müller ◽  
A. Nowak ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Particle Number ◽  
Inversion Algorithm ◽  
Charge Inversion ◽  
Final Particle ◽  
Detection Range ◽  
Number Size Distribution ◽  
Particle Number Size Distribution ◽  
Multiple Charge

Abstract. Multiple-charge inversion is an essential procedure to convert the raw mobility distributions recorded by mobility particle size spectrometers, such as the DMPS or SMPS (differential or scanning mobility particle sizers), into true particle number size distributions. In this work, we present a fast and easy-to-implement multiple-charge inversion algorithm with sufficient precision for atmospheric conditions, but extended functionality. The algorithm can incorporate size distribution information from sensors that measure beyond the upper sizing limit of the mobility spectrometer, such as an aerodynamic particle sizer (APS) or an optical particle counter (OPC). This feature can considerably improve the multiple-charge inversion result in the upper size range of the mobility spectrometer, for example, when substantial numbers of coarse particles are present. The program also yields a continuous size distribution from both sensors as an output. The algorithm is able to calculate the propagation of measurement errors, such as those based on counting statistics, into on the final particle number size distribution. As an additional aspect, the algorithm can perform all inversion steps under the assumption of non-spherical particle shape, including constant or size-dependent shape factors.

Using CFD to Improve Stall Margin

1999 ◽  
Author(s):  
James R. Hardin ◽  
Charles F. Boal
Keyword(s):  
High Efficiency ◽  
Industrial Applications ◽  
Stable Operation ◽  
Test Results ◽  
Peak Efficiency ◽  
Centrifugal Compressors ◽  
Stall Margin ◽  
Operating Range ◽  
Multi Stage ◽  
Cfd Analyses

Abstract Centrifugal compressors for multi-stage industrial applications must have both high efficiency and stable operation over a wide flow range. CFD analyses were used to evaluate the stall margins of candidate impeller designs compared to a baseline semi-inducer design. With this guidance, a new full-inducer impeller was designed with predicted wider operating range and slightly higher peak efficiency. Prototype tests confirmed these predictions. This paper presents predictions from two CFD codes and test results, for both the original and the redesigned impeller, and discusses the application of CFD for predicting impeller stall.

A Model for System Instability Analysis in a Multi-Stage Intercooled Industrial Compressor

2019 ◽  
Author(s):  
Jiaye Gan ◽  
Ahmed Abdelwahab ◽  
Viktor Kilchyk
Keyword(s):  
Guide Vane ◽  
Transient Behavior ◽  
Industrial Applications ◽  
Operating Conditions ◽  
System Response ◽  
Stable Operation ◽  
System Behavior ◽  
Multi Stage ◽  
Performance Reduction ◽  
Inlet Conditions

Abstract Compression equipment used for industrial applications are typically comprised of multi-stage intercooled compressor stages. The presence of large volume intercoolers between individual stages adds a layer of complexity currently not present in publicly available surge models both in terms of system behavior and recovery analysis. In this work a compressible, temporal, and spatial model is developed in which the conservation equations are solved numerically for each of the system components, i.e. pipes, plenums and heat exchangers, valves, and individual compressor stages. The model can identify the onset of instability on an individual stage basis as well as the switching that can occur between the controlling stages of the instability onset when the operating conditions change, e.g. changes in inlet conditions, intercooler fouling or cooling tower performance reduction, and speed or guide vane changes. The model is therefore used both as a stage stacking model during the compressor stable operation as well as a model of the transient behavior of the system past the stable operation. An inertial model of the compressor drive train is also incorporated to analyze the effects of power transients, e.g. emergency shut down (ESD), on the system behavior. In this article details of the developed model are provided. Several test cases are presented. The model is then used to demonstrate the proper sizing of a vent valve of a base load compressor to meet the required system response specification in a surge event. The developed model represents an improvement over available transient system models in terms of predicting the post stable behavior of multi-stage intercooled compressors.

scholarly journals A novel inversion algorithm for mobility particle size spectrometers considering non-sphericity and additional aerodynamic/optical number size distributions

2013 ◽  
Vol 6 (3) ◽  
pp. 4735-4767 ◽  
Author(s):  
S. Pfeifer ◽  
W. Birmili ◽  
A. Schladitz ◽  
T. Müller ◽  
A. Nowak ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Measurement Errors ◽  
Particle Number ◽  
Size Distributions ◽  
Inversion Algorithm ◽  
Charge Inversion ◽  
Final Particle ◽  
Counting Statistics ◽  
Multiple Charge

Abstract. Multiple charge inversion is an essential procedure to convert the raw mobility distributions recorded by mobility particle size spectrometers, such as the DMPS or SMPS (Differential or Scanning Mobility Particle Sizers) into true particle number size distributions. In this work, we present a new multiple charge inversion algorithm with extended functionality. The algorithm can incorporate size distribution information from sensors that measure beyond the upper sizing limit of the mobility spectrometer, such as an aerodynamic particle sizer (APS), or an optical particle counter (OPC). This feature can considerably improve the multiple charge inversion result in the upper size range of the mobility spectrometer, for example, when substantial numbers of coarse particles are present. The program also yields a continuous size distribution from both sensors as an output. The algorithm is able to calculate the propagation of measurement errors, such as those based on counting statistics, into on the final particle number size distribution. As an additional aspect, the algorithm can perform all inversion steps under the assumption of non-spherical particle shape, including constant or size-dependent shape factor profiles.

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