scholarly journals Appraisal of linear load effect on non-linear distortion coefficient from rectifier

2021 ◽  
Vol 3 (397) ◽  
pp. 92-96
Author(s):  
G. Tsitsikyan ◽  
◽  
S. Kunaev ◽  
Keyword(s):  
Harmonic Analysis ◽  
Direct Current ◽  
Single Phase ◽  
Harmonic Coefficient ◽  
Air Cooling ◽  
Load Effect ◽  
Distortion Coefficient ◽  
Linear Load ◽  
Non Linear ◽  
Numerical Estimations

Object and purpose of research. The object of research is the rectifier (transducer) OPED-12,5-115 (О – single phase; P – direct current; Е – natural air cooling; D – on diodes with an example of document record; 12.5 – current rating; 115 – voltage rating). Materials and methods. Methods of power electronics and harmonic analysis are applied. Main results. Ways of appraisal and restriction for the harmonic coefficient (non-linear distortion coefficient from transducer) are worked out taking account of an active load of higher frequencies generator (400 Hz). Conclusion. Numerical estimations for the attenuation coefficient of harmonics 3, 5 and 7 are obtained using basic values Xd and Xq of generator АТО-20.

The Effects of Total Harmonics Distortion for Power Factor Correction at Non-Linear Load

2016 ◽  
Vol 7 (2) ◽  
pp. 551 ◽  
Author(s):  
R. A. Rani ◽  
Shakir Saat ◽  
Yusmarnita Yusop ◽  
Huzaimah Husin ◽  
F. K. Abdul Rahman ◽  
...  
Keyword(s):  
Power Factor ◽  
Single Phase ◽  
Power Factor Correction ◽  
Harmonic Distortion ◽  
The Other ◽  
Linear Load ◽  
Non Linear ◽  
Sinusoidal Waveform ◽  
Non Linear Load ◽  
The Relationship

This paper presents the effect of total harmonic distortion (THD) in power factor correction (PFC) at non-linear load. This study focuses on the relationship between THD and PFC. This is beacuse,the power factor affects THD. This occurs in power system as we have variety of loads, i. e linear load or non-linear load. The variety of loads will influence the sinusoidal waveform, which comes out from harmonic distortion. Thus, based on this study, we can compare the effective method in improving the power factor as it will not disturb the performance of THD. The focus of study is on the single phase load, where the voltage restriction is 240 V.  The analysis will  only focus on the consumer, which depends on the variety of non-linear load. Besides, the parameters for analysis are based on the percentage of THD and the value of power factor. The instrument for measuring the parameter is based on power factor correction device or technique. On the other hand, the method that was used for this study is based on simulation which incorporated the Multisim software. At the end of ths study, we can choose the most effective method that can be used to improve the power factor correction without disturbing the THD.

scholarly journals Advanced power transformer with improved parameters for rural electrical networks

2021 ◽  
Vol 59 (3) ◽  
pp. 366-377
Author(s):  
M. A. Prishchepov ◽  
A. I. Zelenkevich ◽  
V. M. Zbrodyga
Keyword(s):  
Power Supply System ◽  
Single Phase ◽  
Power Transformer ◽  
Electrical Equipment ◽  
Electrical Networks ◽  
Power Losses ◽  
Linear Load ◽  
Non Linear ◽  
Harmonic Components ◽  
Non Linear Load

The problem of power quality supply is relevant for rural electrical networks, due to long distance and branching, as well as connection of a large number of single-phase and non-linear loads. Asymmetry of electrical loads causes voltage asymmetry, which adversely affects the operation of all elements of the electrical system, causing additional power losses, reducing the service life of electrical equipment and its economic performance, as well as reliability of operation of individual electrical equipment and power supply system as a whole. Reduction of voltage asymmetry can be ensured by rational construction of electrical network circuit and use of special correcting devices. The authors consider it reasonable to use relatively simple and reliable by design and inexpensive power transformers with a “star - double zigzag with a zero wire” (Y/2Zн) winding connection circuit with a neutral winding connection group. The paper deals with design and processes of converting electrical energy in a transformer. It has been proved that phase EMF of the secondary winding coincides in phase with the same EMF of the primary winding, i.e. the proposed circuit has a neutral windings’ connection group. Results of theoretical studies of transformer operation with an asymmetric and non-linear load are presented. Decrease in voltage asymmetry is due to the neutral sequence components compensation. Decrease of the higher harmonic voltage components level occurs due to the compensation of the higher harmonics multiplied three times. It is theoretically substantiated that transformer will not emit higher harmonic components of zero sequence voltages into the supply network. Experimental studies have confirmed the theoretical conclusions that a transformer with Y/2Zн winding connection circuit allows obtaining the highest level of voltage symmetry with an asymmetric load. In single-phase load mode, the values of voltage unbalance factor in reverse sequence do not exceed 1.7 %, in neutral sequence - 2.9 %. The transformer allows obtaining 1.2-1.5 times lower value of total harmonic components factor at non-linear load, which is the best result among circuits studied. This power transformer is resistant to load effects that distort voltage quality and is capable to provide a high level of symmetry and sinusoidal voltage as well as parallel operation with commercially available transformers. This makes it possible to use it in rural electrical networks to reduce power losses, increase service life and efficiency of electrical equipment, and increase reliability of the power supply system.

Digital-Controlled Single-Phase Transformer-Based Inverter for Non-Linear Load Applications

2013 ◽  
Vol 9 (2) ◽  
pp. 1084-1093 ◽  
Author(s):  
Ming-Shi Huang ◽  
Po-Yi Yeh ◽  
U-Ting Yeh ◽  
Meng-Gu Huang
Keyword(s):  
Single Phase ◽  
Linear Load ◽  
Non Linear ◽  
Non Linear Load

scholarly journals Feedforward control method for single‐phase inverters with non‐linear load

2019 ◽  
Vol 12 (12) ◽  
pp. 3131-3140 ◽  
Author(s):  
Jiang You ◽  
Mahinda Vilathgamuwa ◽  
Negareh Ghasemi ◽  
Fanrong Meng
Keyword(s):  
Single Phase ◽  
Control Method ◽  
Feedforward Control ◽  
Linear Load ◽  
Non Linear ◽  
Non Linear Load

scholarly journals Analysis of loss on single-phase dry transformers with non-linear load

2021 ◽  
Vol 5 (8 (113)) ◽  
pp. 17-22
Author(s):  
Harrij Mukti Khristiana ◽  
Sudjito Soeparman ◽  
Slamet Wahyudi ◽  
Rini Nur Hasanah
Keyword(s):  
Power Supply ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Constant Input ◽  
Loading Test ◽  
Linear Load ◽  
Half Wave ◽  
Non Linear ◽  
Non Linear Load

The paper studies power losses in transformers due to non-linear loads. The research aims to analyze the power loss in a single-phase dry transformer under a non-linear load. The research uses an SW43W Power supply type, FlukeView Power Quality Analyzer as a DC or AC power supply on the primary side of the transformer. The non-linear load is connected to the secondary side. The loading test of the dry transformer was carried out at non-linear loads. The load variations used 0 %; 12.5 %; 25 %; 37.5 %; 50 %; 62.5 %; 75 %; 87.5 % and 100 %, as well as variations in the THD value by adjusting the ignition angle (α). The non-linear loads used are Half-Wave Rectifier and Controlled Half-Wave Rectifier with resistive loads with variations in THD values. The results showed that the transformer losses comprised Pno load and Pload. The operation of the transformer with constant input voltage and frequency with THDv<5 % resulted in a constant Pno load value at all load values. The greater the percentage of the load, the higher the load. The increase in THD because of non-linear load will increase the load on the transformer. The value of the derating factor is obtained by connecting the increase in losses (∆PLosses), which is influenced by THD and the increase in temperature T(°C) in dry transformers. When the transformer is loaded with a non-linear load, the derating factor<1. THD and derating factor form a linear relationship, when THD increases, the derating factor value decreases. Linear load on the transformer causes a decrease in its capacity, but if it gets a non-linear load with THD=39.1 %, it can withstand a load of 84.294 %, besides the increase in total harmonic distortion will increase losses and reduce transformer capacity

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