Analysis of Current Optimization Method on Compensation

2014 ◽  
Vol 668-669 ◽  
pp. 665-668
Author(s):  
Bin Su ◽  
Shun Tao ◽  
Xiang Ning Xiao ◽  
Tian Cai Wei

Nowadays, with the rapid development of industrial technology especially the power electronic technology, harmonic and reactive power problems are becoming severer. In sinusoidal conditions, there are no controversies on the definition of power quantities. In nonsinusoidal circuits, the traditional definition of active power is still applicable while the definitions of reactive power and apparent power are in controversy. Based on an optimization current decomposing method, this paper derives the expressions of optimal current and compensating current in a single-phase and a three-phase circuit by constructing a Lagrange functions. Based on simulation studies, the compensating effect of the optimization method is analyzed and shown; it can noticeably improve the efficiency of energy transfer in circuit. The paper presents all mathematical derivation of the method and verifies the results based on simulation.

2014 ◽  
Vol 635-637 ◽  
pp. 1404-1407
Author(s):  
Yuan Xing Zhang ◽  
Fei Li ◽  
Ya Li Shen ◽  
Lei Juan Yang ◽  
Jie Li ◽  
...  

Problems of power quality have been increasingly concerned by the researchers, as the domestic appliances we are usually used are single-phase load, which mainly causes the unbalance of three-phase voltage of power supply. If the induction motor is supplied by three-phase unbalanced voltage, the currents, active and reactive power, efficiency, and losses are affected as the negative-sequence current appears, this paper is emphasized on the induction motor’s characteristics when its’ power supply is three-phase unbalanced voltage by experimental research.


Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 880
Author(s):  
Martynas Šapurov ◽  
Vytautas Bleizgys ◽  
Algirdas Baskys ◽  
Aldas Dervinis ◽  
Edvardas Bielskis ◽  
...  

The thyristor-controlled reactor (TCR) compensator for smooth asymmetric compensation of reactive power in a low-voltage utility grid is proposed in this work. Two different topologies of compensator were investigated: topology based on a single-cored three-phase reactor and topology with separate reactors for every phase. The investigation of the proposed TCR compensator was performed experimentally using a developed experimental test bench for 12 kVAr total reactive power. The obtained results show that employment of separate reactors for every phase allows us to control the reactive power in every phase independently, and that the TCR compensator with three single-phase reactors is suitable for smooth and asymmetric compensation of reactive power in a low-voltage utility grid.


2021 ◽  
Author(s):  
Iosu Marzo ◽  
Jon Andoni Barrena ◽  
Alain Sanchez-Ruiz ◽  
Gonzalo Abad ◽  
Ignacio Muguruza

Author(s):  
EDUARDO ANTONIO CANO PLATA ◽  
HERNÁN EMILIO TACCA

This paper discusses the definition of active and reactive power in wavelet domain. Different definitions for three-phase power may cause significant changes in the measurement equipment topology. The simple phase shift using the Akagi method between current and voltage for reactive power measurement is discussed. A new power quality analysis technique (pqAT) is proposed.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4814
Author(s):  
Nickolay I. Shchurov ◽  
Sergey V. Myatezh ◽  
Boris V. Malozyomov ◽  
Alexander A. Shtang ◽  
Nikita V. Martyushev ◽  
...  

Based on the development of the theory of reactive power and distortion power, starting with the works of Fryze and Budeanu, it has been found that the contradictions in the definition of the components of inactive powers are caused by errors in the introduced intermediate concepts and corresponding calculations when switching to nonlinear and non-sinusoidal AC circuits. The materials of the works of modern researchers and the numerical calculations carried out made it possible to trace the differences between reactive power and distortion power, to confirm the orthogonality properties of the active, reactive power, and distortion power components. The paper defines the conditions for achieving a power balance in an AC network with nonlinear loads, compiled and tested criteria leading to the absence of distortion power in a single-phase AC network. Using the time base of the projection of the generalized vectors in vector diagrams, it is shown that compliance with the criteria for the absence of distortion power does not determine the mutual similarity of the voltage curve with the current curve for a nonlinear load. It has been found that the well-known term “distortion power” has an unfortunate wording, since this power, although it characterizes the interaction of harmonics of currents and voltages with different ordinal numbers, is not determined by the visual similarity or the degree of distortion of the load current waveforms relative to the supply voltage curve.


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