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Manipulating the magnetization of nanomagnets by local electric current has been widely studied in the past few years because of its promise in non-volatile magnetic memory and logic devices.1–3
This paper presents a novel algorithm, named adaptive morphological lifting wavelet (AMLW). It is the first time to be applied for the detection of power quality disturbances (PQD). AMLW is a nonlinear wavelet transform which is based on morphological operation and the lifting scheme. The adaptability of AMLW lies in that the algorithm can select between two filters, the morphological gradient filter...
In this paper, a dual-band CPW-fed MIMO antenna is designed and analyzed. Fundamental resonance of the coplanar stepped impedance resonator (CSIR) produces the 1st operating band, while its harmonic resonance and the resonance of the rectangular slot line resonator (RSLR) construct the 2nd band. The port-to-port isolation within the 2nd band is high since it works at the harmonic resonant frequency...
When a power system is contaminated by power quality problems, a short transition will appear before power system restoring to a new stability state. The short transitions of various power disturbances correspond to different principal component characteristics. According to these characteristics, in this paper, a scheme based on transient behaviors using morphological max-lifting scheme (MMLS) and...
This paper presents a new algorithm which employs morphological filter and instantaneous reactive power theory for phasor measurement. A preprocessor is proposed to removes the decaying DC component from the input signal with a delay of two samples. The effects of sampling rate, time constant, frequency shift, harmonics and fault inception angle on the performance of the proposed algorithm have been...
Sympathetic interaction between transformers would lead to mal-operation of transformer differential protection. Based on the fact that the waveform of internal fault current has the sinusoidal features while the sympathetic inrush has not, a weighted mathematical morphological method is proposed for the identification of sympathetic inrush. In the simulation studies, the identification results have...
The accurate detection and location of a fault is crucial for power systems applications such as protective relaying and phasor measurement. As fault signals have unique mathematical expressions, this paper proposes a computational intelligence based method to estimate the parameters of the fault signal towards the minimum difference between the input signal and the reconstructed one. The optimization...
This paper presents a novel method to solve the estimation of the amplitudes and phases of different harmonic components contained in a power electrical signal, based on Particle Swarm Optimizer with Natural Selection (PSONS). PSONS is an Evolutionary Algorithm (EA) with the natural selection mechanism. The proposed method utilizes PSONS to estimate the phases of the harmonics and a standard least-square...
The Hefei Light Source upgrade project (HLS-II) contains 8 dipoles, 32 quadrupoles (2 spares), and 32 sextupoles (2 spares) for the storage ring. Magnets were manufactured and magnetic measurements were performed in collaboration with the Institute of High Energy Physics (IHEP), China. Magnet production and validation measurements were finished in December of 2012. Measurements for all quadrupole...
This paper proposes an approach using weighted mathematical morphology (WMM) to effectively identify inrush current. The identification is based on the feature that the waveform of inrush current is quite different from sinusoid whereas internal fault current is nearly sinusoidal. Compared with the traditional method based on the second harmonic, the proposed approach reduces the data window from...
This paper presents a morphological max-lifting scheme for the detection and classification of low-frequency power disturbances. In order to extract waveform features of low-frequency disturbances, the proposed scheme employs mathematical morphology (MM) for its advantage in noise removing and max-lifting for its ability of information preserving. Afterwards, two aided variables are constructed to...
To reduce harmonics in the AC voltage signal, a precise bound-pass RC filter named `waveform purer' is designed with a double-T network in the negative feedback loop. This filter keeps fundamental frequency unvaried, in both phase and amplitude, but greatly reducing harmonics. Related principles are discussed, including the `bridge balance principle' of double-T network and the `three time constants...
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