Adaptive estimation of sequence components for three-phase unbalanced system using fractional LMS/F algorithm

2021 ◽  
Author(s):  
Umamani Subudhi ◽  
Harish Kumar Sahoo
Keyword(s):  
Adaptive Estimation ◽  
Three Phase ◽  
Sequence Components

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.

Power Invariance Transformation in Power Systems

2000 ◽  
Vol 37 (2) ◽  
pp. 180-189
Author(s):  
J. Heydeman ◽  
W. W. Schongs
Keyword(s):  
Power Systems ◽  
Single Phase ◽  
Positive Sequence ◽  
Equivalent Representation ◽  
Symmetrical Components ◽  
Three Phase ◽  
Sequence Components ◽  
Invariance Transformation

Many textbooks describe a balanced three-phase circuit by a single-phase equivalent representation. Confusion may arise amongst students regarding per-unit values of line-to-line voltages and phase voltages and, therefore, about the magnitudes of currents and powers. This paper proposes that students must first be taught symmetrical components based on power invariance transformation. A balanced three-phase circuit is to be described only in terms of positive sequence components. In the authors' experience, students understand this approach better and make fewer errors in per-unit calculation than when they use the single-phase equivalent representation.

Three-Phase Harmonic and Sequence Components Measurement Method Based on mSDFT and Variable Sampling Period Technique

2016 ◽  
Vol 65 (8) ◽  
pp. 1761-1772 ◽  
Author(s):  
Ignacio Carugati ◽  
Carlos M. Orallo ◽  
Patricio G. Donato ◽  
Sebastian Maestri ◽  
Jorge L. Strack ◽  
...  
Keyword(s):  
Measurement Method ◽  
Sampling Period ◽  
Variable Sampling ◽  
Three Phase ◽  
Sequence Components

Torque Improvement of Dual Three-Phase Permanent Magnet Machine Using Zero Sequence Components

2017 ◽  
Vol 53 (11) ◽  
pp. 1-4 ◽  
Author(s):  
K. Wang ◽  
J. Y. Zhang ◽  
Z. Y. Gu ◽  
H. Y. Sun ◽  
Z. Q. Zhu
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnet Machine ◽  
Three Phase ◽  
Sequence Components ◽  
Zero Sequence

scholarly journals Research on the Nonlinear Control Strategy of Three-Phase Bridgeless Rectifier under Unbalanced Grids

Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3090
Author(s):  
Hong Cheng ◽  
Daokuan Yang ◽  
Cong Wang
Keyword(s):  
Mathematical Model ◽  
Nonlinear Control ◽  
Control Strategy ◽  
Dynamic Performance ◽  
Power Grids ◽  
Current Loop ◽  
State Variables ◽  
Three Phase ◽  
Sequence Components ◽  
Practical Engineering

The three-phase Y-connected bridgeless rectifier is essentially a nonlinear system, and it is difficult to obtain superior dynamic performance under the action of traditional linear controller. Under the condition of unbalanced power grids, this paper has established a mathematical model based on Euler–Lagrange (EL) equations with line voltage and line current as state variables. Furthermore, it then designed a passivity-based controller in inner current loop based on the mathematical model. The hybrid nonlinear control strategy consisting of active disturbance rejection controller (ADRC) in the outer voltage loop and passivity-based controller (PBC) in the inner current loop is adopted to control the system, which does not need to consider the positive and negative sequence components. The control structure is simple and can improve the steady-state accuracy, dynamic performance and anti-interference ability. The feasibility of the proposed control strategy is verified by computer simulation, which has a guiding significance for the application of three-phase bridgeless rectifier in practical engineering.

A Three-phase to Seven-phase Energy Transformation under Unbalanced Supply Voltage

2018 ◽  
Author(s):  
Md Tabrez ◽  
Pradip Kumar Sadhu ◽  
Atif Iqbal ◽  
Farhad Ilahi Baksh
Keyword(s):  
Power Transmission ◽  
Supply Voltage ◽  
Power Input ◽  
Phase System ◽  
Ac Power ◽  
Three Phase ◽  
Sequence Components ◽  
Definition Of ◽  
And Control ◽  
Generation Power

In the recent past, multiphase power generation, power transmission, and electrical drive system are the main focus of research due to their several advantages over three phase. Multiphase drives have better performance over three-phase drives. A multiphase transformer is required at the input of a fixed frequency multiphase drive, rectifier circuit for HVDC applications and multiphase generation and transmission systems. This paper investigates a static three to seven phase conversion technique and presents a design of transformer and control strategy to analyze the effect of unbalanced supply on a three phase to seven phase transformer. The transformer so designed takes three phase as input and seven phase output is obtained at the secondary terminals. The paper also discusses input-output unbalancing. A complete design, analysis, simulation of the proposed technique and experimental validation is presented in this paper. Experimental and simulation results prove that the presented design produced a seven-phase from a tree-phase ac power. Input unbalance is reflected to output but is less than the input unbalance. A seven phase output is not produced if one phase of input is open and the transformer has more than three limbs for flux to flow. A balanced seven phase output in steady state is produced even in one phase open condition for a three limb core type transformer. A new definition of sequence components of an unbalanced seven phase system is defined in this paper.

scholarly journals A Novel Fast Voltage Sequence Component Detector of Unbalanced Three-Phase System

2018 ◽  
Vol 173 ◽  
pp. 01036
Author(s):  
Baohong Jiang ◽  
Xinian Li
Keyword(s):  
Reference Frame ◽  
Traditional Method ◽  
Phase System ◽  
Detection Time ◽  
Continuous Processing ◽  
Synchronous Reference Frame ◽  
Three Phase ◽  
Rotating Reference Frame ◽  
Sequence Components ◽  
Simulation Results

The fast and accurate voltage sequence component detection of unbalanced three-phase system is of major importance for the industrial continuous processing. The traditional method is to calculate the voltage in dq synchronous reference frame. This results in low order harmonics and long detection time. A novel fast voltage sequence components detector is proposed in this paper. It is to calculate the sequence component projection on dq rotating reference frame with h times the fundamental angular velocity. Simulation results demonstrate the validity of the algorithm.

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