scholarly journals Selection of C-Type Filters for Reactive Power Compensation and Filtration of Higher Harmonics Injected into the Transmission System by Arc Furnaces

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2330
Author(s):  
Andrzej Grzegorz Lange ◽  
Grzegorz Redlarski
Keyword(s):  
Reactive Power ◽  
Second Harmonic ◽  
Transmission System ◽  
Operating Conditions ◽  
Arc Furnace ◽  
Steel Mill ◽  
Nonlinear Loads ◽  
Higher Harmonics ◽  
Current Harmonics ◽  
Arc Furnaces

This article presents a method for selecting the elements of a C-type filter working with a conventional LC-type filter for compensating reactive power and filtering out higher harmonics generated by arc furnaces and ladle furnaces. The study was conducted in a steel mill supplied by a 110 kV transmission system, where higher harmonic currents and nonlinear loads were measured. A series of computer simulations were performed under various operating conditions, and an algorithm for selecting the parameters of a third-order C-type filter (for suppressing the second harmonic) and two second-order LC-type filters (for suppressing the third harmonic) was proposed. The filtering system was tested in an arc furnace with the highest rated power, and harmonics in the current spectrum were evaluated. The results of the measurements were used to analyze the effectiveness of the compensation system comprising two passive C-type and LC-type filters at different system configurations. C-type filters significantly influenced current harmonics. The influence of the changes in the number of arc furnace transformers on the true Root Mean Square (RMS) of the currents injected into the 110 kV transmission system and on the voltages of the 110 kV busbars was discussed.

scholarly journals PI Regulator with Tracking Anti-Windup Based Modified Power Balance Theory for SAPF under Unbalanced Grid Voltage Unbalance Non Linear Loads

2019 ◽  
Vol 23 (2) ◽  
Author(s):  
Zellouma Laid ◽  
Khechiba Kamel ◽  
Benaissa Amar
Keyword(s):  
Reactive Power ◽  
Power Balance ◽  
Balance Theory ◽  
Nonlinear Loads ◽  
Shunt Active Power Filter ◽  
Current Harmonics ◽  
Voltage Unbalance ◽  
Pi Regulator ◽  
Power Filter ◽  
Unbalanced Grid

This paper presents a modified power balance theory for extracting the reference compensating currents to shunt active power filter (SAPF) which is applied to illuminate current harmonics and compensate reactive power under unbalanced voltages and unbalancing Nonlinear loads. A new method has been proposed based proportional-integrator (PI) controller with tracking anti-windup protection is presented. The power balance theory is used to establish suitable current reference signals. The studied is carried out with Matlab/Simulink and power system tools to verify the performance of the proposed technique. The filtering method of the SAPF can achieve the THD% limit specified by the IEEE-519 standard.

scholarly journals IMPROVE THE EFFICIENCY OF THE POWER TRANSMISSION SYSTEM USING THE GENETIC ALGORITHM TO DETERMINE THE OPTIMUM LOCATION AND FACTS DEVICES

2020 ◽  
Vol 21 (2) ◽  
pp. 133-142
Author(s):  
Husam Hasan Mohammed ◽  
Hiba Zuhair Abdul Kareem ◽  
Wafaa Mohammed Ridha Ridha
Keyword(s):  
Genetic Algorithm ◽  
Reactive Power ◽  
Rapid Development ◽  
Energy System ◽  
Transmission System ◽  
Operating Conditions ◽  
Transmission Capacity ◽  
Optimal Placement ◽  
Reactive Control ◽  
Facts Devices

 As the world's energy consumption increases, the expansion of the energy system becomes increasingly important. However, the creation of new transmission lines requires excessive costs and time if the same transmission capacity is to be added to the existing network. Today's electrical networks are faced with high risks of voltage instability and real power losses. This development tends to occur due to the lack of reactive control power (RPL) in heavily stressed operating conditions caused by increased demand for loads and the rapid development of power systems worldwide. This paper has adopted the setting of FACTS (flexible AC transmission system) devices as additional control parameters for reducing transmission losses in power system static types of two FACTS devices consisting of SVC (static VAR compensators) while the TCSC (thermistor controlled series compensator) is included in the issue formulation. During this paper, the proposed algorithm was to determine the optimal placement of power network devices by genetic algorithm to manage reactive power, reduce losses, increase the transmission capacity and power lines, and help simulate the IEEE 24 bus control system and also the position of FACTS devices. ABSTRAK: Apabila penggunaan tenaga dunia semakin meningkat, penambahan sistem tenaga sangat penting. Walau bagaimanapun, penciptaan talian penghantaran terkini memerlukan kos yang berlebihan dan had masa jika kapasiti penghantaran yang sama digunakan dengan lebih tinggi. Dalam rangkaian elektrik hari ini, unit ini berhadapan dengan risiko ketidakstabilan voltan dan putus bekalan tenaga. Penambahan sistem tenaga ini cenderung berlaku disebabkan kekurangan kuasa kawalan reaktif (RPL) dalam keadaan beban operasi yang besar disebabkan oleh peningkatan beban permintaan dan perkembangan pesat sistem kuasa di seluruh dunia. Kertas ini telah mengguna pakai peranti FACTS (sistem penghantaran AC fleksibel) sebagai parameter kawalan tambahan bagi mengurangkan kehilangan penghantaran dalam sistem kuasa statik dua peranti FACTS yang terdiri daripada SVC (pemampas VAR statik) manakala TCSC (pemampas siri termistor kawalan) adalah termasuk dalam perumusan isu. Dalam kertas kerja ini, algoritma yang dicadangkan adalah penempatan optimum peranti rangkaian kuasa oleh algoritma genetik bagi mengurus kuasa reaktif juga mengurangkan kerugian dan meningkatkan kapasiti penghantaran dan kabel elektrik dan membantu menyerupai sistem kawalan bas IEEE 24 dan juga kedudukan peranti FACTS di mana ia terbukti berkesan.

scholarly journals Nonlinear load modeling for analysis of non-sinusoidal conditions in electrical networks based on measurements of harmonic parameters

2021 ◽  
pp. 5-20
Author(s):  
L. Kovernikova ◽  
V.C. Luong
Keyword(s):  
Electrical Equipment ◽  
Distribution Functions ◽  
Operating Conditions ◽  
Electrical Network ◽  
Electrical Networks ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Current Harmonics ◽  
Load Models ◽  
Nonlinear Devices

Non-sinusoidal conditions in electrical networks need to be calculated for their control and development of technical measures to maintain harmonic parameters according to the requirements of regulatory documents. These calculations are impossible without electrical network and nonlinear load models that adequately reflect them in computational programs. Nonlinear load models have been developed for a long time. Some studies present general modeling principles and models of various nonlinear devices. Others consider some nonlinear devices as equivalent nonlinear loads connected to low and medium voltage networks. A whole host of high-power nonlinear electrical equipment is connected to high voltage networks. Modeling nonlinear loads connected to these networks is a problem. Research of measured parameters of harmonic conditions in electrical networks has shown that they are random values. The probabilistic nature is determined by the network configuration, a range of network components, the number of nonlinear loads, wave and frequency properties of the network, harmonic source phase currents, voltage at terminals of nonlinear electrical equipment, changes in operating conditions and load power, and many other factors. Nonlinear loads can only be modeled based on the measurements of parameters of harmonic conditions due to their unpredictability. The paper presents an overview of existing methods for modeling nonlinear loads, a methodological approach to modeling nonlinear loads based on measured parameters, an algorithm for modeling harmonics of active and reactive currents, a computational program algorithm designed to identify distribution functions of measured current harmonics, and modeling results for current harmonics of railway transformers supplying power to electric locomotives.

scholarly journals ANN Current Controller Based on PI-Fuzzy Adaptive System for Shunt Power Active Filter

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Moulay Tahar Lamchich
Keyword(s):  
Reactive Power ◽  
Adaptive System ◽  
Control Method ◽  
Average Power ◽  
Active Filter ◽  
Voltage Source ◽  
Nonlinear Loads ◽  
Shunt Active Filter ◽  
Current Harmonics ◽  
Fuzzy Adaptive

This paper deals with the use of triphase shunt active filter which is able to compensate current harmonics, reactive power, and current unbalance produced by nonlinear loads. To perform the identification of disturbing currents, a very simple control method is introduced. It’s formed by a DC voltage regulator and a balance between the average power of load and the active power supplied by the grid. The output current of the voltage source inverter (VSI) must track the reference current. This is done by a neural controller based on a PI-Fuzzy adaptive system as reference corrector. Also to regulate the DC link capacitor voltage a fuzzy logic adaptive PI controller is used.

scholarly journals Reactive Power and Current Harmonic Control Using a Dual Hybrid Power Filter for Unbalanced Non-Linear Loads

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1392 ◽  
Author(s):  
Leonardo Rodrigues Limongi ◽  
Fabricio Bradaschia ◽  
Calebe Hermann de Oliveira Lima ◽  
Marcelo Cabral Cavalcanti
Keyword(s):  
Reactive Power ◽  
Active Filters ◽  
Nonlinear Loads ◽  
Harmonic Compensation ◽  
Current Harmonics ◽  
Current Harmonic ◽  
Electrical Grid ◽  
Hybrid Power ◽  
Quality Issue ◽  
Non Linear

An important power quality issue is related to current harmonic components demanded by non-linear loads. A solution to mitigate this issue is to use hybrid power filters (HPFs), that apply low power active filters with passive filters. Some dual-converter topologies have been shown to be attractive due to a better compensation performance compared with single filters, where the HPFs give a reactive power support (an extra feature) together with harmonic compensation. On the other hand, the drawback of dual converters is the high number of active switches. Besides that, due to the high number of unbalanced non-linear loads connected to the electrical grid, triplen harmonics can appear. However, traditional HPFs do not compensate triplen harmonics, which usually have considerable values. Therefore, in this paper, a dual HPF based on the nine-switch inverter (DHPF-NSI) is proposed to compensate current harmonics and to provide reactive power support. The NSI presents a reduced number of switches when compared with classical dual topologies. The compensation of the third harmonic caused by unbalanced nonlinear loads was also inserted in the control system. Experimental results are presented for the DHPF-NSI in order to demonstrate the reactive power and harmonic compensation performances.

scholarly journals Reactive power and harmonic compensation: A case study for the coal-mining industry

2019 ◽  
Vol 30 (1) ◽  
pp. 34-48 ◽  
Author(s):  
F. Roos ◽  
R.C. Bansal
Keyword(s):  
Reactive Power ◽  
Mining Industry ◽  
Load Flow ◽  
Nonlinear Loads ◽  
Network Growth ◽  
Harmonic Compensation ◽  
Current Harmonics ◽  
Technology Advancement ◽  
Network Simulations

This study reports on a case study in Grootegeluk Mine: Exxaro Coal, Lephalale, South Africa, in terms of power factor correction (PFC), load flow, harmonic frequency scans and harmonic voltage distortion analyses. The DIgSilent PowerFactory software was used for network simulations. Harmonic and reactive power compensation techniques were compared in terms of filter type evolution and technology advancement, with the use of simple trade-off criteria such as cost-effectiveness versus performance. It was found that both passive and hybrid filters were more favourable and could effectively compensate all voltage and current harmonics and reactive power for large nonlinear loads. The installation of switched PFC filter banks tuned at the fifth harmonic order accommodates future network growth and this solution can be rolled out to any mining industry as a benchmark to lower energy cost and maximise savings achievable on the electricity bill.  

scholarly journals DSTATCOM for Harmonic Mitigation in Distribution Lines using Two-Level Inverter

2019 ◽  
Vol 9 (2) ◽  
pp. 4475-4478
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Distribution Systems ◽  
Reactive Power ◽  
Nonlinear Loads ◽  
Load Current ◽  
Current Harmonics ◽  
Side Load ◽  
Non Linear ◽  
Power Quality Improvement

Distribution systems have been facing serious problems of harmonics load current mainly due to advancement in power electronic based and other non-linear loads. The DSTATCOM has been widely used to mitigate the load current harmonics problems in distribution system. The power quality improvement is one of the major problems when the distribution side load increases with non-linear loads like electric vehicles, laptops, PCs etc., There are some power quality mitigation technique available at the load side where the electronic chargers works with unity power factor (UPC) control. But many DC loads are connected without the UPC. So, it is a need for a device which corrects the real and reactive power at the distribution level. The DSTATCOM is connected to the Indian distribution system with 415V, 50Hz. In this paper the linear loads and nonlinear loads are coupled to the system and analysis with DSTATCOM and without DSTATCOM cases are presented.

Optimal Placement of FACTS Devices for Voltage Stability Improvement with Economic Consideration Using Firefly Algorithm

2019 ◽  
Vol 14 (1) ◽  
pp. 5-11
Author(s):  
S. Rajasekaran ◽  
S. Muralidharan
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Firefly Algorithm ◽  
Transmission System ◽  
Operating Conditions ◽  
Optimal Placement ◽  
Voltage Collapse ◽  
Facts Devices ◽  
The Cost ◽  
Bus System

Background: Increasing power demand forces the power systems to operate at their maximum operating conditions. This leads the power system into voltage instability and causes voltage collapse. To avoid this problem, FACTS devices have been used in power systems to increase system stability with much reduced economical ratings. To achieve this, the FACTS devices must be placed in exact location. This paper presents Firefly Algorithm (FA) based optimization method to locate these devices of exact rating and least cost in the transmission system. Methods: Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) are the FACTS devices used in the proposed methodology to enhance the voltage stability of power systems. Considering two objectives of enhancing the voltage stability of the transmission system and minimizing the cost of the FACTS devices, the optimal ratings and cost were identified for the devices under consideration using Firefly algorithm as an optimization tool. Also, a model study had been done with four different cases such as normal case, line outage case, generator outage case and overloading case (140%) for IEEE 14,30,57 and 118 bus systems. Results: The optimal locations to install SVC and TCSC in IEEE 14, 30, 57 and 118 bus systems were evaluated with minimal L-indices and cost using the proposed Firefly algorithm. From the results, it could be inferred that the cost of installing TCSC in IEEE bus system is slightly higher than SVC.For showing the superiority of Firefly algorithm, the results were compared with the already published research finding where this problem was solved using Genetic algorithm and Particle Swarm Optimization. It was revealed that the proposed firefly algorithm gives better optimum solution in minimizing the L-index values for IEEE 30 Bus system. Conclusion: The optimal placement, rating and cost of installation of TCSC and SVC in standard IEEE bus systems which enhanced the voltage stability were evaluated in this work. The need of the FACTS devices was also tested during the abnormal cases such as line outage case, generator outage case and overloading case (140%) with the proposed Firefly algorithm. Outputs reveal that the recognized placement of SVC and TCSC reduces the probability of voltage collapse and cost of the devices in the transmission lines. The capability of Firefly algorithm was also ensured by comparing its results with the results of other algorithms.

Optimization Design on Power Filter of TCR Under Asymmetrical Voltage

2015 ◽  
Vol 9 (1) ◽  
pp. 591-599
Author(s):  
Ma Wenchuan ◽  
Zhitong Li ◽  
Chen Daochang ◽  
Qi Jiaming ◽  
Zhou Qiang ◽  
...  
Keyword(s):  
Optimization Design ◽  
Reactive Power ◽  
Estimation Method ◽  
Reactive Power Compensation ◽  
Harmonic Suppression ◽  
Matlab Simulation ◽  
Steel Mill ◽  
Harmonic Current ◽  
Third Harmonic ◽  
Power Filter

For resolving the problem that power filter cannot work normally because TCR (thyristor controlled reactor) generates extra third harmonic current under asymmetrical voltage, the paper proposes the estimation method of current capacity that TCR generates extra third harmonic current under asymmetrical voltage. Considering extra third harmonic current under asymmetrical voltage, Optimum method based on genetic algorithm is used to design the parameters of power filter. With reactive power compensation and harmonic suppression project of a steel mill as example, the proposed method is simulated by Matlab. Simulation results show optimized power filter can eliminate extra third harmonic current effects under asymmetrical voltage, meet the requirement of reactive power compensation, reduce harmonics current that load injects into system, and guarantee the power filter safe operation under asymmetrical voltage.

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