Adaptive Detecting Method for Fundamental Positive Sequence, Negative Sequence Components and Harmonic Component Based on Space Vector

2006 ◽  
Author(s):  
Hairong Chen ◽  
Zheng Xu ◽  
Fan Zhang
Keyword(s):  
Harmonic Component ◽  
Positive Sequence ◽  
Space Vector ◽  
Negative Sequence ◽  
Sequence Components ◽  
Detecting Method ◽  
Adaptive Detecting

Grid Information Synchronous Monitoring Algorithm under Unbalanced and Distorted Condition

2014 ◽  
Vol 898 ◽  
pp. 867-872
Author(s):  
Wei Li ◽  
Li Sun
Keyword(s):  
Harmonic Component ◽  
Angular Frequency ◽  
Negative Sequence ◽  
Grid Voltage ◽  
Voltage Vector ◽  
Distorted Grid ◽  
Sequence Components ◽  
Synchronization Phase ◽  
Monitoring Algorithm ◽  
Synchronous Monitoring

The Amplitude and angular frequency of grid voltage vector fluctuate with the positive and negative sequence components and harmonic component under unbalance and distortion grid model, the conventional grid information synchronous algorithm is not suitable. A novel grid information synchronous algorithm based on AC amplitude integral is proposed, which can obtain the information of phase angle, frequency and amplitude of the fundamental positive and negative sequence components of fundamental grid voltage using the synchronization phase locked technique. Experimental results show that the proposed algorithm is suitable to the unbalanced and distorted grid condition and can restrain the harmonic interference and achieve the grid information synchronous monitoring.

scholarly journals Induction Motor Stator Interturn Short Circuit Fault Detection in Accordance with Line Current Sequence Components Using Artificial Neural Network

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Gayatridevi Rajamany ◽  
Sekar Srinivasan ◽  
Krishnan Rajamany ◽  
Ramesh K. Natarajan
Keyword(s):  
Neural Network ◽  
Fault Detection ◽  
Induction Motor ◽  
Short Circuit ◽  
Positive Sequence ◽  
Negative Sequence ◽  
Three Phase ◽  
Sequence Components ◽  
Negative Sequence Current ◽  
Short Circuit Fault

The intention of fault detection is to detect the fault at the beginning stage and shut off the machine immediately to avoid motor failure due to the large fault current. In this work, an online fault diagnosis of stator interturn fault of a three-phase induction motor based on the concept of symmetrical components is presented. A mathematical model of an induction motor with turn fault is developed to interpret machine performance under fault. A Simulink model of a three-phase induction motor with stator interturn fault is created for extraction of sequence components of current and voltage. The negative sequence current can provide a decisive and rapid monitoring technique to detect stator interturn short circuit fault of the induction motor. The per unit change in negative sequence current with positive sequence current is the main fault indicator which is imported to neural network architecture. The output of the feedforward backpropagation neural network classifies the short circuit fault level of stator winding.

Three-phase phase-locked loop algorithms for the detection of positive-sequence and negative-sequence components

2021 ◽  
Vol 126 ◽  
pp. 106570
Author(s):  
Jean Marcos Lobo da Fonseca ◽  
Francisco Kleber de Araújo Lima ◽  
Fernando Lessa Tofoli ◽  
Carlos Gustavo Castelo Branco
Keyword(s):  
Phase Locked Loop ◽  
Positive Sequence ◽  
Negative Sequence ◽  
Three Phase ◽  
Sequence Components ◽  
Phase Phase

scholarly journals Modeling of three-phase electric motor operation by the MATLAB system with deteriorated power quality in the 0.38 kV distribution networks

2018 ◽  
Vol 58 ◽  
pp. 03016 ◽  
Author(s):  
I.V Naumov ◽  
N.V. Savina ◽  
M.V. Shevchenko
Keyword(s):  
Induction Motor ◽  
Power Quality ◽  
Electric Motor ◽  
Distribution Networks ◽  
Negative Sequence ◽  
Operation Modes ◽  
Three Phase ◽  
Sequence Components ◽  
Motor Operation ◽  
The Impact

One of the main operation modes that characterizes power quality in distribution networks is asymmetry of three-phase voltage system. Operation of an induction motor (IM) with disturbed voltage symmetry in the supply network can not be considered as a rated one. The system of voltages applied to the stator winding of IM under these conditions contains positive- and negative-sequence components. This worsens the performance characteristics of IM essentially. In order to balance the 0.38 kV network operation and enhance the efficiency of the three-phase electric motor operation it is suggested to use a special balancing unit (BU) that minimizes the negative-sequence components of current and voltage. The operation modes of the obtained system “supply source – induction motor – balancing unit” are simulated within the MATLAB software package of applied programs, which allows one to assess the impact of low quality of power on the operating characteristics of the electric motor and the efficiency of the balancing unit to increase the “durability” of the motor under the asymmetrical power consumption.

Using Positive and Negative Sequence Components of Currents and Voltages for High Impedance Fault Analysis via ANFIS

2012 ◽  
Vol 1 (4) ◽  
pp. 132-157 ◽  
Author(s):  
Mohamed M. Ismail ◽  
M. A. Moustafa Hassan
Keyword(s):  
Distribution System ◽  
Electrical Contact ◽  
Design Procedure ◽  
Fault Analysis ◽  
Foreign Object ◽  
Inference System ◽  
Negative Sequence ◽  
High Impedance ◽  
Sequence Components ◽  
High Impedance Faults

High Impedance Faults are defined as unwanted electrical contact between an energized conductor and a non-conducting foreign object. Non-conducting foreign object present high impedances to current flow due to their material, so a fault of this type will not appear to the classical protection equipment as abnormal conditions. Presented is an approach for detection, classification, and location of high impedance faults in a distribution system using Adaptive Neuro Fuzzy Inference System (ANFIS) based on positive and negative sequence components of voltages and currents. The proposed scheme was trained by data from simulation of a distribution system under different faults conditions and different distances in a short and long transmission lines. Details of the design procedure and the results of performance using the proposed method are discussed in this paper.

Calculation of Spectrum Characteristics for Braking Modes of Linear Induction Motors

2010 ◽  
Vol 164 ◽  
pp. 41-46 ◽  
Author(s):  
Bronius Karaliunas ◽  
Edvardas Matkevicius
Keyword(s):  
Magnetic Field ◽  
Continuous Spectrum ◽  
Spectral Characteristics ◽  
Positive Sequence ◽  
Linear Induction ◽  
Linear Induction Motor ◽  
Sequence Components ◽  
The Moment ◽  
Main Component ◽  
Analytical Expressions

The purpose of the wok is to derive analytical expressions of spectral characteristics at electrical braking of linear induction motor with diverse number of poles as well as to provide results of calculations. The major task in the analysis of braking modes is to determine spectral characteristics of braking current, primary magnetic field and braking force. To this aim Maxwell equations were solved together with Fourier and Laplace integral transformations. The obtained results indicate that in addition to the main component of the magnetic field, when the space frequency is , in the process of braking there appears continuous spectrum of elementary components with the frequencies occupying the infinite sector from - to + . Due to that fact, during the process of energy conversion at the moment of braking, there participate positive – sequence, negative – sequence components and elementary components of the continuous spectrum, motionless in the space.

Unbalanced Control Strategy for DFIG Used in Wind Turbines

2013 ◽  
Vol 805-806 ◽  
pp. 430-435
Author(s):  
Chang Xi Huang ◽  
Shu Ying Yang ◽  
Liu Wei Chen
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Power Grid ◽  
Current Control ◽  
Doubly Fed Induction Generator ◽  
Test Bed ◽  
Negative Sequence ◽  
Synchronous Reference Frame ◽  
Sequence Components ◽  
Doubly Fed

Unbalanced input voltages would make doubly fed induction generator (DFIG)-based wind turbine operating performance deteriorate, such as shaft tremble, temperature increasing, and so on, even make it cut out of the power grid. Meanwhile, without proper control the power ripples generated from wind turbines may further aggravate power grid. Considering the unbalanced conditions, DFIG was modeled in dual synchronous reference frame (SRF), namely the positive one and the negative one, based on which the dual PI current controllers were designed. To implement the dual current control, the sensing variables were divided into positive and negative sequence components, which were controlled in positive and negative SRF respectively. At the same time, to synchronize with the positive and negative sequence voltage components, a phase latch loop (PLL) control was designed. Experimental results on 11kW DFIG wind turbine test bed validated the designed control system.

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