Owing to the advantages, such as high speed, low cost, high safety, easy implementation and non-intrusive sensing, electrical capacitance tomography (ECT) is considered as a promising process tomography technology. Su...
详细信息
ISBN:
(纸本)9780853163220
Owing to the advantages, such as high speed, low cost, high safety, easy implementation and non-intrusive sensing, electrical capacitance tomography (ECT) is considered as a promising process tomography technology. Successful applications of ECT depend on the speed and precision of the image reconstruction algorithms. In essence, ECT image reconstruction process belongs to a typical ill-posed problem. Methods that ensure a stable numerical solution while enhancing the quality of the reconstructed images should be employed. In this paper, based on the semiparametric model, a generalized objective functional that considers the inaccuracy nature in the measured capacitance data and the model error, which has been developed using the combination estimation and a novel stabilizing functional, is created. An efficient algorithm, which integrates the beneficial advantages of the homotopy method where the homotopy equation is designed by the fixed point homotopy and solved using the fixed point iteration algorithm based on the alternate iteration scheme, the self organizing migration algorithm and the harmony search algorithm, is proposed for searching a possible global optimal solution. This algorithm is tested by the noise-free capacitance data and the noise-contaminated capacitance data, and excellent numerical performances and encouraging results are observed. Numerical simulation results reveal that the proposed algorithm is very successful in solving the ECT image reconstruction problem. In the cases considered in this paper, the reconstructed results by the proposed algorithm show salient improvement in the spatial resolution and accuracy. The spatial resolution of the reconstructed images by the proposed algorithm is enhanced, and the artifacts in the reconstructed images can be removed effectively. Furthermore, the reconstructed results under the noise-contaminated capacitance data indicate that the proposed algorithm is very competent to deal with the inaccuracy i
For digital distance relays, in order to get the correct measuring impedance, phase selector is widely used to identify the fault phases first. However, when a fault occurs at the line during powersystem swings, the ...
详细信息
DSR (dynamic security region) is one of the direct methods focusing on the transient stability of powersystem. This paper focuses on the DSRs of powersystem with different load models, and explores the characteristi...
详细信息
The faults in electric powersystem can not be completely avoided. When powersystem operates from normal state to failure or abnormal operates, its electric quantities may change significantly. Our researches indicat...
详细信息
In load model verification process, the accuracy of model and its parameters makes the actual operating conditions unable to reappear in simulation. The information deviation between measured data and verifiable simul...
详细信息
Synchronous generator excitation controlsystem is one of the most important parts of powersystemcontrol. And as PID control is one of the first developed and the most widely used control schemes in excitation syste...
详细信息
Load model has great impacts on the powersystem simulation results, while in transient stability analysis the traditional load models have some disadvantages which can't describe the load shedding characteristic ...
详细信息
ISBN:
(纸本)9788986510119
Load model has great impacts on the powersystem simulation results, while in transient stability analysis the traditional load models have some disadvantages which can't describe the load shedding characteristic when low voltage disturbances happened. Thus, a new load model is proposed in this paper after the investigation of the field measurement data and the load characteristics of some equipment under low voltage. Several new parameters describing the load shedding characteristic are provided in the new load model which can be derived by identifying the field data. With these new parameters, the load difference caused by the load shedding during the low voltage disturbances can be well illustrated. The improved load model has larger application ranges and better properties in describing the nature of the load dynamic behaviors during the transient stability analysis which also improves the reliability of the simulation. The field measurement data illustrate its efficiency.
This paper theoretically analyzes the compound control apparatus for current quality compensation which is designed as differentiation cascaded H bridge type with two modules: fundamental-frequency module and high-fre...
详细信息
The structure of Static Var Compensator (SVC) controlsystem and compensation principle is briefly analyzed in this paper. Based on the control method of nonlinear norm transformation PID, a novel method for SVC using...
详细信息
A new self-shunt excitation control method has been brought in this paper, which is about how to use DC chopper that is composed with full controlled switch device IGBT to regulate exciting voltage. This new method re...
详细信息
暂无评论