A method of improving the quality of the current in the system “network – controlled bridge thyristor compensator of reactive power”

Author(s):  
A.I. Chyzhenko ◽  
◽  
I.V. Trach ◽  
Keyword(s):  
2015 ◽  
Vol 9 (1) ◽  
pp. 553-559
Author(s):  
HU Xin-xin ◽  
Chen Chun-lan

In order to optimize the electric energy quality of HVDC access point, a modular multilevel selective harmonic elimination pulse-width modulation (MSHE-PWM) method is proposed. On the basis of keeping the minimum action frequency of the power device, MSHE-PWM method can meet the requirement for accurately eliminating low-order harmonics in the output PWM waveform. Firstly, establish the basic mathematical model of MMC topology and point out the voltage balance control principle of single modules; then, analyze offline gaining principle and realization way of MSHEPWM switching angle; finally, verify MSHE-PWM control performance on the basis of MMC reactive power compensation experimental prototype. The experimental result shows that the proposed MSHE-PWM method can meet such performance indexes as low switching frequency and no lower-order harmonics, and has verified the feasibility and effectiveness thereof for optimizing the electric energy quality of HVDC access point.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1527
Author(s):  
R. Senthil Kumar ◽  
K. Mohana Sundaram ◽  
K. S. Tamilselvan

The extensive usage of power electronic components creates harmonics in the voltage and current, because of which, the quality of delivered power gets affected. Therefore, it is essential to improve the quality of power, as we reveal in this paper. The problems of load voltage, source current, and power factors are mitigated by utilizing the unified power flow controller (UPFC), in which a combination of series and shunt converters are combined through a DC-link capacitor. To retain the link voltage and to maximize the delivered power, a PV module is introduced with a high gain converter, named the switched clamped diode boost (SCDB) converter, in which the grey wolf optimization (GWO) algorithm is instigated for tracking the maximum power. To retain the link-voltage of the capacitor, the artificial neural network (ANN) is implemented. A proper control of UPFC is highly essential, which is achieved by the reference current generation with the aid of a hybrid algorithm. A genetic algorithm, hybridized with the radial basis function neural network (RBFNN), is utilized for the generation of a switching sequence, and the generated pulse has been given to both the series and shunt converters through the PWM generator. Thus, the source current and load voltage harmonics are mitigated with reactive power compensation, which results in attaining a unity power factor. The projected methodology is simulated by MATLAB and it is perceived that the total harmonic distortion (THD) of 0.84% is attained, with almost a unity power factor, and this is validated with FPGA Spartan 6E hardware.


2012 ◽  
Vol 479-481 ◽  
pp. 1476-1480
Author(s):  
Qing He Chu ◽  
Wen Si Cao ◽  
Zhen Nie

In the present rural power grid reconstruction project ,according to the problems of capacitor reactive power compensation in rural small substation. Take a small substation for instance, according to its operation and control method, set the criterion of the capacitor bank switching. A new high reliability, flexible reactive power compensation control device based on s7-200 PLC is designed. It plays an important role in improving the power supply , guaranteeing the quality of voltage, reducing the loss of rural power gid.


2020 ◽  
Vol 22 (1-2) ◽  
pp. 137-144
Author(s):  
Hidajet Salkić ◽  
Amir Softić ◽  
Amer Salkić

The electric power system, as an integrated system for transmission, distribution and consumption of electricity, is one of the most complex technical and economic systems today. Customers affect on the voltage quality of power network, but the network also has an impact on customers. All disturbances in the network can disrupt operation of the network and affect on operation of the customers, as well as reduce the level of efficiency and operation life or even seriously damage network. Number of customers is increasing every day, as well as proportion of customers who generate disturbances in the network and, at the same time, are sensitive to them. These circumstances impose the need for frequent monitoring of the network, so the analysis of power quality is not unjustified cost but extremely important and profitable investment. The quality of electricity, as part of the overall quality supply of electricity customers in deregulated conditions of liberal electricity market becomes significant regulatory parameter for network operators and a significant contracting parameter on the electricity market. Network operators are obliged to establish a system of individual measurements and a system of permanent monitoring of power quality parameters to determine the state and improve the parameters to the standardized level. Technical parameters are determined by the recommendations made at the international level and may, but do not need, be legally binding. Maintaining a certain level of voltage quality at some point of the network is the responsibility of electricity distributor. This task distributor executes by limiting of negative effects of producer/customer to the network. Therefore, each electricity producer/customer is obliged to reduce own negative feedback effects (injection of higher harmonics, taking of reactive power, emissions of flickers and loads unbalances) to a prescribed, prearranged, limited values. There are many norms that describe the quality of electricity, but in Europe the best known is EN50160 (issued by CENLEC). This paper presents the approach to measuring the voltage quality at the point of electricity delivery from distributed source into distribution network from the aspect of limiting the negative feedback of distributed source on the voltage quality.


2019 ◽  
Vol 4 (9) ◽  
pp. 1-8
Author(s):  
Montaser Abd El Sattar ◽  
Adel A. Elbaset ◽  
Ali H. KasemAlaboudy ◽  
Wessam Arafa Hafez

Wind energy system is lately receiving a lot of attention, because they are cost inexpensive, environmental safe and clean renewable energy source, as compared with nuclear and fossil fuel power generation. The operational characteristics of wind electric turbines has considerable dissatisfaction and stress on the quality of electric power system. Harmonics, variations of voltage and reactive power are most of power quality issues for grid connected with wind turbine. This paper introduces a design and simulation of unified power quality conditioner using a fuzzy controller to improve the power quality for Egyptian power grid connected to Zafarana Egypt wind system. The proposed performance of the unified power quality conditioner system is verified by simulating the model using MATLAB/SIMULINK environment. The simulation results showed that the proposed unified power quality conditioner provide efficient cancellation of both load current  harmonics  and supply voltage sag in addition to compensation of reactive power, and thus making the electrical grid connected wind energy system more efficient by improving the quality of power.


Author(s):  
Liu Yang ◽  
Qinyue Tan ◽  
Di Xiong ◽  
Zhengguang Liu

The overrun of transient power quality index caused by the large-capacity electric arc furnace (EAF) has become a prominent problem affecting the safe and stable operation of the power system. (1) In this paper, the relationship between arc furnace volt-age and current is derived based on the different stages of arc combustion, and the random variation of chaotic phenomenon of the arc voltage are simulated. Established an EAF model suitable for the study of transient power quality problems. (2) Take 50t AC EAF as an example to analyze the reactive power impact and the influence on the point of common coupling (PCC) voltage caused by the three-phase short circuit of the electrode. The results show that the experimental results are consistent with the theoretical analysis, verifying the correctness and effectiveness of the model. (3) When the three-phase short-circuit occurs, the reactive power impact is nearly 6 times that of normal operation, the short-circuit current is 2.66 times that of normal operation, and the effective value of the PCC voltage has dropped by 40.37%, which provides a theoretical basis for real-time compensation of impulsive reactive power and improvement of the transient power quality of the EAF.


2021 ◽  
Vol 1 (42) ◽  
pp. 23-28
Author(s):  
Irina Pospelova ◽  
◽  
Tatiana A. Shirobokova ◽  
Vyacheslav Kuzmin ◽  
Tatiana Sterkhova ◽  
...  

Currently, 50-60 percents of power consumption in oil fields falls on mechanized oil production. The specificity of the operation of a submersible electric centrifugal pump (ESP), powered by a submersible electric motor (SEM) as consumers of electricity, is due to their operation at a considerable distance from the earth’s surface, the variable nature of the load, the aggressiveness of the produced fluid, and the presence of an extended cable line. (Research objective) To study devices for improving the quality of electricity in the oil industry. (Materials and methods) The results of the survey of the parameters of power consumption of the Novoportovskoe oil and gas condensate field of the PREO «Yamal» Network district No. 1 Kust 18 KTP 10 / 0.4 kV No. 1 input-2. (Results and discussion) The results of studies of the parameters of electricity at the Novoportovskoye oil and gas condensate field have shown that it is advisable to use devices that improve the quality of electricity. Devices can be different, both in design and in scope. Such as voltage stabilizers, phase voltage balancing devices, reactive power compensation devices, filter compensating devices, active mains filters. (Conclusions) Having considered the variety of devices on the market that improve the quality of electricity, as well as devices that compensate for reactive power, it is advisable to use static thyristor reactive power compensators manufactured by JSC Electrointer, Serpukhov.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2021 ◽  
Author(s):  
Yuehui Chen ◽  
Zhao Huang ◽  
Zhenfeng Duan ◽  
Pengwu Fu ◽  
Guandong Zhou ◽  
...  

This paper solves the problem of reactive power and harmonics compensation in a high-voltage (HV) distribution network supplying nonlinear loads. An inductive filtering (IF) approach where passive filters connect to the filtering winding of a four-winding inductive filtering transformer (FW-IFT) is presented to enhance the power quality of the public grid. This method can not only greatly suppress harmonic currents of the medium and/or low-voltage (LV) side, but also prevent them from flowing into the public grid. The new main circuit topology, where the FW-IFT has specific filtering winding by adopting the ampere-turn balance of the transformer, is presented. On the basis of the structure of the FW-IFT, the magnetic potential balanced equation and inductive filtering technology, its equivalent circuit and mathematical model are established, and the filtering performances are analyzed in detail. Simulation and experimental results rated at SN-10/0.38 of the FW-IFT are presented to prove the efficacy of the comprehensive enhancement of power quality on the grid side.


2014 ◽  
Vol 484-485 ◽  
pp. 343-347
Author(s):  
Da Peng Liu

This paper takes DSP2812 as the core to develop the new reactive power compensation controller, realized the reactive power compensation, detection of the electricity distribution network information, and through mobile phone short message module TC35 to send mobile phone SMS information, remote control compensation capacitor, configuration parameters. The design has the characteristics of flexible and reliable, convenient and practical. This paper analyses the software and hardware structure of controller in detail, and the hardware principle and circuit and the software block diagram of the controller. Controller adopts the integrated control, to maximize the use of compensation equipment to improve the power quality of power grid.


2013 ◽  
Vol 347-350 ◽  
pp. 1501-1505
Author(s):  
Xiao Bo Sun ◽  
Da Wei Meng

Static var Compensator (SVC) can suppress the voltage fluctuation, flicker and rapidly compensate the reactive power and the quality of electric power can be improved. In this paper, a new calculation method of reactive susceptances based on balance principle was proposed, which only uses the fundamental positive reactive and negative active & reactive components, and was analyzed and verified by simulation and dynamic test. The results of simulation and experiment show that the method can achieve the dynamic compensation of reactive power of the unbalanced load, and it is accurate, rapid and efficient.


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