An Improved ip-iq Harmonic Detection Algorithm

2012 ◽  
Vol 588-589 ◽  
pp. 864-867
Author(s):  
Xue Hai Cui

This paper introduces the the basic principle of ip-iq harmonic detection algorithm and puts forward a method of harmonic detection for the single-phase circuit. This method eliminates the three-phase to two-phase and two-phase to the three-phase coordinate transformation, thus effectively reduces the computation ; moreover it has the advantages of good real-time performance and makes the digital control easy. Matlab simulation results show that this method can detect the harmonic component of single-phase and three-phase current accurately and in real-time.

2012 ◽  
Vol 241-244 ◽  
pp. 1889-1895
Author(s):  
Jin Yu Wang ◽  
Zhi Hui Shen ◽  
Yu Long Zhou ◽  
Pei Jiang Zhang

Although Active Power Filter can achieve good filtering effect and accurately compensate harmonic current, it dependents on the proposed current detection algorithm. The paper first discusses the method which is based on transient reactive power theory; the detection method is based on coordinate transformation. After the coordinate transformation is analyzed, the paper advances an harmonic method, this method can remove three-phase to two-phase and two-phase to three-phase coordinate transformation, and effectively reduce the computation, improve the detection speed. At last, the feasibility and validity of the new algorithm have been showed by MATLAB simulation


2014 ◽  
Vol 596 ◽  
pp. 511-518
Author(s):  
Lin Qi ◽  
Hai Peng Wang ◽  
Yu Liu ◽  
Cong Wang

To achieve fast and accurate association for AIS and radar tracks, provide associated track-pairs for subsequent sensor bias registration and situational fusion, this paper presents an anti-bias association algorithm for AIS and radar tracks according to centroid reference topological characteristics (CRT). The algorithm describes the topological characteristics of track-points set on the basis of targets position relative to the centroid of the set to achieve AIS and radar tracks fine association in the presence of radar bias. The proposed algorithm outperforms the traditional tracks association algorithms based on image matching principle (IM) or targets reference topology feature (TRT) in terms of real-time performance, simultaneously has high correctly associated rate. Simulation results show that the falsely associated rate of this algorithm maintains 0, the correctly associated rate maintains above 85%. It can provide reliable associated track-pairs for system errors registration; while the average time-consuming of the algorithm is 1/4 and 1/417 of TRT and IM algorithm, the practicality has been significantly improved.


2013 ◽  
Vol 341-342 ◽  
pp. 1308-1312
Author(s):  
Chao Wang

Microcomputer relay is a kind of intelligent devices used for detecting and protecting power system. Whenever, it quickly calculate whether the power system is wrong or not on the basis of the fundamental and harmonics detected from power system, And according to the calculating results to obviate the troubles, among them, the fundamental and harmonics acquired accurately in time is the most important part of the power system protection process. The basic principle of d-q fundamental and harmonics voltage detection is presented and on this basis a fundamental and harmonics detection method of presumption the transformation frequency is put forward. The results of the theoretical analysis and MATLAB simulation indicate that the d-q method in this paper can precisely detect the voltage and frequency change of the power system in time, whether the distortion voltage or not in three-phase power system .


2013 ◽  
Vol 373-375 ◽  
pp. 992-995
Author(s):  
Jun Li Wan ◽  
Wen Jie Chen

This paper arrives at a method of harmonic and reactive current real-time detection applied on active power filter based on the three-phase circuit instantaneous reactive power theory. With Matlab simulation software, a research on simulation of harmonic detection means is carried out, and an analysis of the simulation result is presented. The result indicates: the harmonic detection means based on instantaneous reactive power theory can detect harmonic and reactive component in three-phase current precisely and real-time, to supply reliable harmonic and reactive current for harmonic restraint and reactive power compensation. It could provide reliable indicator parameters for research and development of active power filter.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 871
Author(s):  
Yun Zhao ◽  
Li-Bin Liu ◽  
Li-Gang Zhang ◽  
Jia-Jun Yang ◽  
Patrick J. Masset

The polythermal section of Ti-22Al-xNb (30–78 at.% Ti) in the Ti-Al-Nb system was studied using X-ray diffraction analysis (XRD), differential thermal analysis (DSC), and electron probe micro-analysis (EPMA). No new ternary compounds were found in this work. The polythermal section has five three-phase regions, nine two-phase regions, and three single-phase regions. The O phase transition is confirmed to occur below 1000 °C. A four-phase invariant reaction β + σ → O + δ was found at 931 °C.


2018 ◽  
Vol 160 ◽  
pp. 01007
Author(s):  
Wu Xiaobin ◽  
Xu Shihua ◽  
Zhao Hui ◽  
Zhang Wei

In order to solve the problem of single-phase grounding fault judgment in non-solid-earthed distribution network, the power flow in non-solid-earthed distribution is analyzed. A single-phase grounding fault judgment method based on mutation current logic matrix is proposed. The minimum fault judgment area model is constructed by the parent and child nodes. The feeder mutation current matrix is generated by the feeder real-time current matrix and the feeder history current matrix. The feeder mutation current matrix is transformed into the feeder mutation current logic matrix by the capacitance current threshold, and the non-zero elements of the feeder mutation current logic matrix are extracted into the mutation current logic sequence list. Then the single-phase grounding fault can be determined in the minimum fault judgment area of the last element of the mutation current logic sequence list as the parent node. The detailed calculation formulas are given. This method is also applicable to the non-solid-earthed distribution network containing distributed generation. The simulation results show that the method proposed in this paper has a good adaptability to the permanent grounding fault and it is worth popularizing.


Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3166 ◽  
Author(s):  
Cao ◽  
Song ◽  
Song ◽  
Xiao ◽  
Peng

Lane detection is an important foundation in the development of intelligent vehicles. To address problems such as low detection accuracy of traditional methods and poor real-time performance of deep learning-based methodologies, a lane detection algorithm for intelligent vehicles in complex road conditions and dynamic environments was proposed. Firstly, converting the distorted image and using the superposition threshold algorithm for edge detection, an aerial view of the lane was obtained via region of interest extraction and inverse perspective transformation. Secondly, the random sample consensus algorithm was adopted to fit the curves of lane lines based on the third-order B-spline curve model, and fitting evaluation and curvature radius calculation were then carried out on the curve. Lastly, by using the road driving video under complex road conditions and the Tusimple dataset, simulation test experiments for lane detection algorithm were performed. The experimental results show that the average detection accuracy based on road driving video reached 98.49%, and the average processing time reached 21.5 ms. The average detection accuracy based on the Tusimple dataset reached 98.42%, and the average processing time reached 22.2 ms. Compared with traditional methods and deep learning-based methodologies, this lane detection algorithm had excellent accuracy and real-time performance, a high detection efficiency and a strong anti-interference ability. The accurate recognition rate and average processing time were significantly improved. The proposed algorithm is crucial in promoting the technological level of intelligent vehicle driving assistance and conducive to the further improvement of the driving safety of intelligent vehicles.


2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Yali Xue ◽  
Hu Chen ◽  
Jie Chen ◽  
Jiahui Wang

This paper based on the Gaussian particle filter (GPF) deals with the attitude estimation of UAV. GPF algorithm has better estimation accuracy than the general nonlinear non-Gaussian state estimation and is usually used to improve the system’s real-time performance whose noise is specific such as Gaussian noise during the mini UAV positioning and navigation. The attitude estimation algorithm is implemented on FPGA to verify the effectiveness of the Gaussian particle filter. Simulation results have illustrated that the GPF algorithm is effective and has better real-time performance than that of the particle filter.


2013 ◽  
Vol 418 ◽  
pp. 269-272
Author(s):  
Rong Hui Liu ◽  
Ai Qang Pan ◽  
Hai Bo Wang ◽  
Xiu Yang

In this paper, the characteristics of AC/DC converter under single-phase voltage sags and three-phase voltage sags are simulated with Matlab emulator. The simulation results show that effects on rectifier equipment under three-phase voltage sags are more serious than those under single-phase voltage sags. The flat wave capacitance plays an important role in voltage sensitivity of sensitive loads. In practice, the capacitance of flat wave capacitor is chosen according to the power supply and load requirements so as to realize the best balance of performance and price.


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