The Suppressing Effect of Voltage Distortion by the Fifth Harmonic Current at the Supply Point for Customers with a Middle Voltage Power Supply

2013 ◽  
Vol 133 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Kenji Yukihira ◽  
Naotaka Okada
DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 150-159 ◽  
Author(s):  
Ana Maria Blanco ◽  
Sergey Yanchenko ◽  
Jan Meyer ◽  
Peter Schegner

<p>Electronic devices have a non-linear characteristic and emit harmonics into the low voltage grid. Different harmonic studies analyze their impact on the grids based on different types of harmonic models. The most used model is the constant current source. Measurements have shown that the harmonic currents emitted by electronic devices depend on the circuit topology and the existing supply voltage distortion. This paper quantifies the impact of supply voltage distortion on the harmonic current emission of individual devices and the summation of multiple devices. After a classification of the commonly used circuit topologies a time-domain model is developed for each of them. Then the individual and combined impact of voltage harmonics on the harmonic current emission of the modeled devices is analyzed based on simulations. Finally the impact of voltage distortion on the summation of multiple devices is analyzed and the accuracy of constant current source models is evaluated.</p>


2013 ◽  
Vol 732-733 ◽  
pp. 1240-1246
Author(s):  
Wei Si Deng ◽  
Bu Han Zhang ◽  
Hong Fa Ding ◽  
Jian Shao ◽  
Bing Jie Jin

Distributed renewable energy connected to the power grid in the form of micro-grid, which makes a great impact on the power quality of the grid. Active Power Filter (APF) is a kind of effective device, which can improve the power supply quality and purify the power pollution. It‘s particularly significant to improve the APF’s performance. Based on the selective harmonic current control strategy, which is used to solve the problem, that the main times of the harmonic current is not sufficiently compensated, this paper considers to adopt the LCL filter on the grid-side to further improve the compensation performance of active power filter. This improvement can reduce the high frequency harmonics caused by the way of PWM high frequency modulation. Finally a case study simulated by PSIM software verifies the superiority of the proposed measure.


2021 ◽  
Vol 1 (161) ◽  
pp. 157-162
Author(s):  
D. Kalyuzhniy

Non-sinusoidal voltage in power supply systems leads to economic losses that need to be distributed and compensated. This problem is solved on the basis of the problem of identification and evaluation of the influence of voltage distortion sources. To date, existing methods for identifying and assessing the impact of harmonic voltage sources have significant limitations of practical implementation. This is due to their basic mathematical model and local approach to measuring the parameters of the network. In the given research the new mathematical model of identification and an estimation of harmonic voltage sources that is focused on the distributed measuring system is presented. The criterion for identifying harmonic voltage sources is the distorting nodal current. To adequately determine it, it is necessary not only to measure the parameters of the network mode in the base nodes by the currents of the higher harmonic components, but also to control the structure and parameters of the replacement circuit of the entire power supply system. To achieve this goal, it is proposed to use a distributed measuring system, which is based on vector measurement systems and control systems. The estimation of the influence of harmonic voltage sources is directly proportional to the distorting nodal current, where the coefficient of proportionality is either mutual or intrinsic resistance of power supply systems, that connects the location of the distortion source and the place for which its influence is estimated. In order to control the influence of measurement errors and determine the parameters of circuits for replacing elements of the power supply system, the method and algorithm for identifying and assessing the impact of harmonic voltage sources should be developed based on the principle of excluding one of the voltage distortion sources.


2013 ◽  
Vol 722 ◽  
pp. 112-115
Author(s):  
Zhan Zhang ◽  
Na Guo

This paper investigated the cause of the harmonic current amplification in nonlinear load in a 6kV substations power supply system. The paper proposed that reactors could be series connected in the capacitors by-pass to restrain the amplification. The result from field practice showed that this method could overcome the harmonic current amplification efficiently.


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