scholarly journals Power factor correction using capacitors & filters

2018 ◽  
Vol 7 (2.12) ◽  
pp. 234
Author(s):  
Karthik Subramanian ◽  
Shantam Tandon
Keyword(s):  
Root Mean Square ◽  
Phase Difference ◽  
Power Factor ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Active Filters ◽  
Minimum Amount ◽  
Mean Square ◽  
The Real ◽  
Electrical Consumption

Power factor is the ratio of the real current or voltage received by a load to the root mean square (rms) value of the current or voltage that was supposed to be acquired by the same load. The fact that the two become different is due to the presence of reactive power in the circuit which gets dissipated.Improving the power factor means reducing the phase difference between voltage and current. Since majority of the loads are of inductive nature, they require some amount of reactive power for them to function. Therefore, for the better use of electrical appliances with minimum amount of electrical consumption, the power factor should necessarily be increased and should be brought near to 1. This can be easily done by the help of Automatic Power Factor Correction Capacitors and Active filters.  

scholarly journals A fractional order epidemic model for the simulation of outbreaks of Ebola

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Weiqiu Pan ◽  
Tianzeng Li ◽  
Safdar Ali
Keyword(s):  
Numerical Solution ◽  
Root Mean Square ◽  
Fractional Order ◽  
Relative Error ◽  
Numerical Solutions ◽  
Real Data ◽  
Mean Square ◽  
Order Model ◽  
The Real ◽  
Fractional Orders

AbstractThe Ebola outbreak in 2014 caused many infections and deaths. Some literature works have proposed some models to study Ebola virus, such as SIR, SIS, SEIR, etc. It is proved that the fractional order model can describe epidemic dynamics better than the integer order model. In this paper, we propose a fractional order Ebola system and analyze the nonnegative solution, the basic reproduction number $R_{0}$ R 0 , and the stabilities of equilibrium points for the system firstly. In many studies, the numerical solutions of some models cannot fit very well with the real data. Thus, to show the dynamics of the Ebola epidemic, the Gorenflo–Mainardi–Moretti–Paradisi scheme (GMMP) is taken to get the numerical solution of the SEIR fractional order Ebola system and the modified grid approximation method (MGAM) is used to acquire the parameters of the SEIR fractional order Ebola system. We consider that the GMMP method may lead to absurd numerical solutions, so its stability and convergence are given. Then, the new fractional orders, parameters, and the root-mean-square relative error $g(U^{*})=0.4146$ g ( U ∗ ) = 0.4146 are obtained. With the new fractional orders and parameters, the numerical solution of the SEIR fractional order Ebola system is closer to the real data than those models in other literature works. Meanwhile, we find that most of the fractional order Ebola systems have the same order. Hence, the fractional order Ebola system with different orders using the Caputo derivatives is also studied. We also adopt the MGAM algorithm to obtain the new orders, parameters, and the root-mean-square relative error which is $g(U^{*})=0.2744$ g ( U ∗ ) = 0.2744 . With the new parameters and orders, the fractional order Ebola systems with different orders fit very well with the real data.

scholarly journals Unfavourable Reactive Power in a Rolling Mill

2021 ◽  
Vol 19 ◽  
pp. 413-417
Author(s):  
Stanislav Nowak ◽  
◽  
Stanislav Kocman
Keyword(s):  
Energy Efficiency ◽  
Rolling Mill ◽  
Reactive Power ◽  
Rolling Process ◽  
The Real ◽  
Compensating Devices ◽  
Electrical Consumption ◽  
Very High ◽  
Inductive Power

The electrical consumption of the rolling mill is usually very high, above 10MW, and significantly changes during the rolling process. The rolling mill drives consume not only active but also reactive inductive power. This reactive consumption is directly compensated in the rolling mill. In order to achieve feasible energy efficiency, it is necessary to maintain balance between the instantaneous reactive inductive consumption of the drives and the instantaneous capacitive consumption of the compensating devices. The results of the consumption measurements in the real working rolling mill are presented and discussed in this paper.

To: “The use and misuse of apparent resistivity in electromagnetic methods,” by B. R. Spies and D. E. Eggers which appeared in the July 1986 issue of GEOPHYSICS, p. 1462–1471.

Geophysics ◽  
1988 ◽  
Vol 53 (12) ◽  
pp. 1637-1637 ◽  
Keyword(s):  
Root Mean Square ◽  
Apparent Resistivity ◽  
Simple Relation ◽  
Mean Square ◽  
The Real ◽  
Electromagnetic Methods

Of the list of possible definitions of magnetotelluric apparent resistivity, equation (18) is equivalent to the conventional Cagniard definition given by equation (14). Equation (21) is in error; there is no simple relation in terms of impedance for the root‐mean‐square average of the apparent resistivities from the real and imaginary parts of the impedance.

scholarly journals Performance of Three Level H-Bridge Inverter in Grid Connected Solar PV for Multifunctional Operations using Different Control Techniques

2020 ◽  
Vol 9 (4) ◽  
pp. 1942-1950
Keyword(s):  
Power System ◽  
Power Factor ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Solar Pv ◽  
Distribution Grid ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Control Techniques ◽  
Active And Reactive Power

This paper presents multifunctional operation capability of three level cascade H bridge inverter for grid connected solar pv application. The solar panel and inverter are modelled for unbalance and nonlinear loads with three control techniques (pq,dq,cpt) and its performance is simulated in the MATLAB environment using SIMULINK and Sim Power System (SPS) toolboxes. The performance of inverter is evaluated for harmonics elimination, power factor correction apart from active and reactive power support to grid and nonlinear load .Performance of three level H bridge inverter is evaluated for both PV mode and STATCOM mode using three control techniques for distribution grid.

scholarly journals Simulating and Building an Appliance Clustering Fuzzified SVC for Single Phase System

2021 ◽  
Vol 20 (1) ◽  
pp. 34-42
Author(s):  
Osama Ahmed ◽  
Abdul Wali Abdul Ali
Keyword(s):  
Power System ◽  
Power Factor ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Fast Response ◽  
Reactive Power Compensation ◽  
Phase System ◽  
Smart Meter ◽  
Power Monitoring ◽  
Compensating Devices

A power system suffers from losses that can cause tragic consequences. Reactive power presence in the power system increases system losses delivered power quality and distorted the voltage. As a result, many studies are concerned with reactive power compensation. The necessity of balancing resistive power generation and absorption throughout a power system gave birth to many devices used for reactive power compensation. Static Var Compensators are hunt devices used for the generation or absorption of reactive power as desired. SVCs provide fast and smooth compensation and power factor correction. In this paper, a Fuzzified Static Var Compensator consists of Thyristor Controlled Reactor (TCR) branch and Thyristor Switched Capacitors branches for reactive power compensation and power factor correction at the load side is presented. The system is simulated using Simulink using a group of blocks and equations for measuring power factor, determining the weightage by which the power factor is improved, determining the firing angle of TCR branch, and capacitor configuration of TSC branches. Furthermore, a hardware prototype is designed and implemented with its associated software; it includes a smart meter build-up for power monitoring, which displays voltage, current, real power, reactive power and power factor and SVC branches with TRIAC as the power switching device. Lastly, static and dynamic loads are used to test the system's capability in providing fast response and compensation. The simulation results illustrated the proposed system's capability and responsiveness in compensating the reactive power and correcting the power factor. It also highlighted the proportional relation between reactive power presence and the increased cost in electricity bills. The proposed smart meter and SVC prototypes proved their capabilities in giving accurate measurement and monitoring and sending the data to the graphical user interface through ZigBee communication and power factor correction. Reactive power presence is an undesired event that affects the equipment and connected consumers of a power system. Therefore, fast and smooth compensation for reactive power became a matter of concern to utility companies, power consumers and manufacturers. Therefore, the use of compensating devices is of much importance as they can increase power capacity, regulate the voltage and improve the power system performance.

scholarly journals Software Solutions for Harmonic Conditions Monitoring and Optimal Placing of Reactive Power Sources in Distributions Networks

2013 ◽  
Vol 8-9 ◽  
pp. 77-84
Author(s):  
Alexandru Baloi ◽  
Adrian Pana
Keyword(s):  
Mathematical Model ◽  
Power Factor ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Distribution Networks ◽  
Virtual Instruments ◽  
Equivalent Network ◽  
Power Sources ◽  
Risk Increase ◽  
Electrical Distribution Networks

Power factor correction in electrical distribution networks can lead to harmonic risk increase. The paper presents a method to anticipate the amplification of network harmonic conditions based on the equivalent network harmonic impedance which can be monitored using virtual instruments. Based on the values of the harmonic impedance and the required reactive power, a mathematical model is implemented through an algorithm and software classes are developed for the solution regarding the type of the reactive power sources (capacitor banks or filters) and the place where it will be installed.

Design of variable reactive power compensator to improve power factor correction of a static load

2019 ◽  
Author(s):  
Chico Hermanu B. A. ◽  
Rio Yuan Pallafine ◽  
Meiyanto Eko Sulistyo ◽  
Feri Andriyanto ◽  
Irwan Iftadi ◽  
...  
Keyword(s):  
Power Factor ◽  
Static Load ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Reactive Power Compensator

scholarly journals An EMG Patch for the Real-Time Monitoring of Muscle-Fatigue Conditions During Exercise

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3108 ◽  
Author(s):  
Shing-Hong Liu ◽  
Chuan-Bi Lin ◽  
Ying Chen ◽  
Wenxi Chen ◽  
Tai-Shen Huang ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Real Time ◽  
Root Mean Square ◽  
The Body ◽  
Median Frequency ◽  
Mean Square ◽  
Sport Injuries ◽  
Physiological Measurement ◽  
The Real ◽  
Emg Signal

In recent years, wearable monitoring devices have been very popular in the health care field and are being used to avoid sport injuries during exercise. They are usually worn on the wrist, the same as sport watches, or on the chest, like an electrocardiogram patch. Common functions of these wearable devices are that they use real time to display the state of health of the body, and they are all small sized. The electromyogram (EMG) signal is usually used to show muscle activity. Thus, the EMG signal could be used to determine the muscle-fatigue conditions. In this study, the goal is to develop an EMG patch which could be worn on the lower leg, the gastrocnemius muscle, to detect real-time muscle fatigue while exercising. A micro controller unit (MCU) in the EMG patch is part of an ARM Cortex-M4 processor, which is used to measure the median frequency (MF) of an EMG signal in real time. When the muscle starts showing tiredness, the median frequency will shift to a low frequency. In order to delete the noise of the isotonic EMG signal, the EMG patch has to run the empirical mode decomposition algorithm. A two-electrode circuit was designed to measure the EMG signal. The maximum power consumption of the EMG patch was about 39.5 mAh. In order to verify that the real-time MF values measured by the EMG patch were close to the off-line MF values measured by the computer system, we used the root-mean-square value to estimate the difference in the real-time MF values and the off-line MF values. There were 20 participants that rode an exercise bicycle at different speeds. Their EMG signals were recorded with an EMG patch and a physiological measurement system at the same time. Every participant rode the exercise bicycle twice. The averaged root-mean-square values were 2.86 ± 0.86 Hz and 2.56 ± 0.47 Hz for the first and second time, respectively. Moreover, we also developed an application program implemented on a smart phone to display the participants’ muscle-fatigue conditions and information while exercising. Therefore, the EMG patch designed in this study could monitor the muscle-fatigue conditions to avoid sport injuries while exercising.

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