• Title/Summary/Keyword: Power theory

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A Study on Commercial Power of Traditional Market

  • Baik, Key-Young;Youn, Myoung-Kil
    • East Asian Journal of Business Economics (EAJBE)
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    • v.4 no.2
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    • pp.1-11
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    • 2016
  • This study investigated commercial power theory of traditional market through the analysis of literature review. Consumers' store selection models are made up a theory based on normative hypothesis, theory of mutual reaction, utility function estimation model, and cognitive-behavioral model. Detailed models are as follows. Normative hypothesis based theory is divided into Reilly's retail gratification theory and Converse's revised retail g ratification theory. Interaction theory is composed of Huff's probability gratification theory, MCI model and Multi-nominal Logit Model (MNL model). There are four models in retail organization position theory such as central place theories, single store position theory, multi store position - assign model, and retail growth potential model. In case of single store position theory, theoretical and empirical techniques have developed for a decision to optimum single store position. Those are like these, a check list, the most simple and systematic method, analogy, and microanalysis technique. Aforementioned models are theoretical and mathematical commercial power measurement and/or model. The study has rather limitations because the variation factors included in formula are only a part of actual commercial power. Therefore, further study shall be made continuously to commercial power areas and variables.

Improvement of Dynamic Behavior of Shunt Active Power Filter Using Fuzzy Instantaneous Power Theory

  • Eskandarian, Nasser;Beromi, Yousef Alinejad;Farhangi, Shahrokh
    • Journal of Power Electronics
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    • v.14 no.6
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    • pp.1303-1313
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    • 2014
  • Dynamic behavior of the harmonic detection part of an active power filter (APF) has an essential role in filter compensation performances during transient conditions. Instantaneous power (p-q) theory is extensively used to design harmonic detectors for active filters. Large overshoot of p-q theory method deteriorates filter response at a large and rapid load change. In this study the harmonic estimation of an APF during transient conditions for balanced three-phase nonlinear loads is conducted. A novel fuzzy instantaneous power (FIP) theory is proposed to improve conventional p-q theory dynamic performances during transient conditions to adapt automatically to any random and rapid nonlinear load change. Adding fuzzy rules in p-q theory improves the decomposition of the alternating current components of active and reactive power signals and develops correct reference during rapid and random current variation. Modifying p-q theory internal high-pass filter performance using fuzzy rules without any drawback is a prospect. In the simulated system using MATLAB/SIMULINK, the shunt active filter is connected to a rapidly time-varying nonlinear load. The harmonic detection parts of the shunt active filter are developed for FIP theory-based and p-q theory-based algorithms. The harmonic detector hardware is also developed using the TMS320F28335 digital signal processor and connected to a laboratory nonlinear load. The software is developed for FIP theory-based and p-q theory-based algorithms. The simulation and experimental tests results verify the ability of the new technique in harmonic detection of rapid changing nonlinear loads.

Algorithm of Extended Current Synchronous Detection for Active Power Filters (능동전력필터를 위한 확장된 전류 동기 검출 알고리즘)

  • 정영국
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.111-114
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    • 2000
  • Harmonics and fundamental reactive power of nonlinear loads in serious unbalanced power condition are compensated by current synchronous detection(CSD) theory which is also acceptable for single phase power system, but the CSD theory is not suitable any more in case of controlled independently harmonics and reactive component. Therefore a new algorithm the extended current synchronous detection (ECSD)theory for a three phase active power filter based on decomposition of fundamental reactive distorted components is proposed in this paper. The proposed ECSD theory is simulated and tested comparison with a few power theories under asymmtrical condition in power system.

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A DSP Based Active Power Filter with Instantaneous Correlation Power Theory (상관함수에 의한 순시전력이론을 이용한 DSP 능동전력필터)

  • 정영국;임영철
    • The Transactions of the Korean Institute of Power Electronics
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    • v.4 no.1
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    • pp.50-56
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    • 1999
  • This paper presents consideration on validity of instantaneous correlation power theory. The proposed power theory is defined and analyzed by time domain approach, thus it is easy to understand and instrument. The power is decomposed into active, fundamental reactive and harmonics components based on the autocorrelation and crosscorrelation signal techniques between voltage and current waveforms. On the compensation property, active power filter deal with three components only. Also, for real time control of active power filter, the power models with difficult concept are not cost effective. To verify the validity of the instantaneous correlation power theory, experimental work for voltage type DSP based active power filter is achieved. The power of thyristor controlled motor drives is decomposed into three orthogonal components by proposed power theory. From compensation results, validity of proposed theory is confirmed. feedback controller needs the information on some motor parameters. New recursive adaptation algorithms for rotor resistance and mutual inductance which can be applied to our nonlinear feedback controller are also presented in this paper. The recursive adaptation algorithms make the estimated values of rotor resistance and mutual inductance track their real values. Some simulation and experimental results show that the adaptation algorithms are robust against the variation of stator resistance and stator inductance.

$\alpha$-$\beta$Current and Power Components Analysis of Instantaneous Power Theory Using MATLAB/SIMULINK (MATLAB/SIMULIN에 의한 순시전력이론의 $\alpha$-$\beta$ 전류 및 전력성분 해석)

  • 정영국;임영철
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.3
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    • pp.88-96
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    • 2000
  • The instantaneous power theory have been considered as efficient theory in recent years, because it is easier to understand numerical representation and more soft to control PWM power converter on $\alpha$-$\beta$ stationary reference frame. From the forgoing theory, with regard to the calculating process of compensating reference current, there are many induced components of current/ power, and these components have consequently influence on physical interpretation of instantaneous power theory. Especially, beginners for studing the instantaneous power theory don't have enough informations for standard waveform of induced $\alpha$-$\beta$ components. Therefore, this paper describes simulation works using MATLAB/SIMULINK for $\alpha$-$\beta$ space trajectories and waveforms of $\alpha$-$\beta$ current and power components, induced from the instantaneous power theory. It is respected that the results in this paper are serviceable as basic information to assist beginner for studing the instantaneous power theory.

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Instantaneous Power Compensation Theory in Three-phase Four-wire Systems (3상 4선 계통에서의 순시전력 보상이론)

  • Kim, Hyo-Sung
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.2
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    • pp.172-183
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    • 2006
  • This paper analyzes instantaneous power compensation theory through comparing p-q theory and cross-vector theory which were proposed by Akagi and Nabae respectively in three-phase four-wire systems. The two compensation theories are identical when there is no zero-sequence voltage component in three-phase three-wire systems, However, when the zero-sequence voltage and/or current components exist in three-phase four-wire systems, the two compensation theories we different in definition on instantaneous real power and instantaneous imaginary power. Based on the analysis, this paper presents instantaneous power compensation method that can eliminate neutral current completely without using energy storage element when the zero-sequence current and voltage components exist in three-phase four-wire systems.

The Expanded Current Synchronous Detection for Active Power Filters (능동전력필터를 위한 확장된 전류 동기 검출법)

  • 정영국;김우용;임영철
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.4
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    • pp.341-347
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    • 2001
  • Harmonics and fundamental reactive current of nonlinear loads in serious unbalanced power condition, are compensated by current synchronous detection(CSD) theory which is also acceptable for single phase power system. But, the CSD theory is not suitable any more, in case of controlled independently harmonics and reactive component. Therefore, a new algorithm, the expanded current synchronous detection(ECSD) theory for a three phase active power filter based on decomposition of fundamental reactive, distorted components, is proposed in this paper. The proposed ECSD theory is experimented and tested comparison with a few power theories under asymmetrical condition in power system.

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New Concept of Apparent Power with Non-Sinusoidal Waveforms (고조파를 함유한 계통에서의 새로운 겉보기전력 개념에 관한 연구)

  • Kim Joo Rak;Shin Chang Ki;Kim Jung Hoon;Lee Byung Ha
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.220-223
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    • 2004
  • This paper presents the new concept in ac power theory with non-sinusoidal waveform. It will be shown that there is discrepancy in the definition of active and complex power in the time and frequency domains when the conventional power theory is considered It will also be shown that the new power theory consistently defines the power quantifies in the time domains.

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A Non-Linearity Compensation Method for Matrix Converter Drives Using PQR Power Theory (PQR 전력이론을 이용한 Matrix Converter 구동 시스템의 비선형특성 보상)

  • Lee Kyo-Beum
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.12
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    • pp.751-758
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    • 2004
  • This paper presents a new method to compensate the non-linearity for matrix converter drives using PQR instantaneous Power theory. The non-linearity of matrix converter drives such as commutation delay, turn-on and turn-off time of switching device, and on-state switching device voltage drop is modelled by PQR power theory and compensated using a reference current control scheme. The proposed method does not need any additional hardware and off-line experimental measurements. The proposed compensation method is applied for high performance induction motor drives using a 3 kW matrix converter system without a speed sensor. Simulation and experimental results show the proposed method using PQR power theory Provides good compensating characteristic.

Radial Basis Function Neural Networks (RBFNN) and p-q Power Theory Based Harmonic Identification in Converter Waveforms

  • Almaita, Eyad K.;Asumadu, Johnson A.
    • Journal of Power Electronics
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    • v.11 no.6
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    • pp.922-930
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    • 2011
  • In this paper, two radial basis function neural networks (RBFNNs) are used to dynamically identify harmonics content in converter waveforms based on the p-q (real power-imaginary power) theory. The converter waveforms are analyzed and the types of harmonic content are identified over a wide operating range. Constant power and sinusoidal current compensation strategies are investigated in this paper. The RBFNN filtering training algorithm is based on a systematic and computationally efficient training method called the hybrid learning method. In this new methodology, the RBFNN is combined with the p-q theory to extract the harmonics content in converter waveforms. The small size and the robustness of the resulting network models reflect the effectiveness of the algorithm. The analysis is verified using MATLAB simulations.