scholarly journals Intelligent Hybrid-Fuzzy Controller using VLLMS Based Shunt Active Filter

Author(s):  
Shaik Nagul Sharif and Sri Latha Veerla

The power quality problem in the power system is increased with the use of non-linear devices. Due to the use of non-linear devices like power electronic converters, there is an increase in harmonic content in the source current. Due to this there is an increase in the losses, instability and poor voltage waveform. To mitigate the harmonics and provide the reactive power compensation, we use filters. There are different filters used in the power system. Passive filters provide limited compensation, so active filters can be used for variable compensation. In this work, a shunt active filter has been made adaptive using a Variable Leaky Least Mean Square (VLLMS) based controller. Proposed adaptive controller can be able to compensate for harmonic currents, power factor and nonlinear load unbalance. DC capacitor voltage has been regulated at a desired level using a PI controller and a self-charging circuit technique. But, this scheme as two disadvantages such as, tuning issues of current controller pre-requisites the traditional PI controller, which is controlled by intelligent based Hybrid-Fuzzy-Logic controller for achieving good performance features. The design concept of proposed intelligent Hybrid-Fuzzy controller for shunt active filter has been verified through simulation analysis and results are presented with proper comparisons.

2020 ◽  
Vol 8 (6) ◽  
pp. 1004-1012

The power quality problem in the power system is increased with the use of non-linear devices. Due to the use of non-linear devices like power electronic converters, there is an increase in harmonic content in the source current. Due to this there is an increase in the losses, instability and poor voltage waveform. To mitigate the harmonics and provide the reactive power compensation, we use filters. There are different filters used in the power system. Passive filters provide limited compensation, so active filters can be used for variable compensation. In this paper, a shunt active filter has been made adaptive using a Variable Leaky Least Mean Square (VLLMS) based controller. Proposed adaptive controller can be able to compensate for harmonic currents, power factor and nonlinear load unbalance. DC capacitor voltage has been regulated at a desired level using a PI controller and a self-charging circuit technique. But, this scheme has two disadvantages such as, tuning issues of current controller pre-requisites the traditional PI controller, which is controlled by intelligent based Fuzzy-Logic controller for achieving good performance features. The design concept of proposed intelligent Fuzzy controller for shunt active filter has been verified through simulation analysis and results are presented with proper comparisons.


2014 ◽  
Vol 23 (09) ◽  
pp. 1450132 ◽  
Author(s):  
G. VIJAYAKUMAR ◽  
R. ANITA

This paper presents an operation of photovoltaic (PV)-based shunt active filter (SAF) for significant energy conservation, harmonic mitigation and reactive power compensation. When the PV system generates excessive or equal power required to the load demand, then the coordinating logic disconnects the service grid from the load and with a consequent reduction of panel tariff and global warming gasses. The PV module is connected to the DC side of SAF through the DC–DC converter. Converter switch is controlled by fuzzy-based perturb & observe (P&O) maximum power point tracking (MPPT) algorithm and it eliminates the drawback in the conventional PV system. The reference currents are extracted by the fuzzy logic controller-based ICos Φ control strategy. This proposed PV-SAF, if connected at the terminals of a small industry or a home or a small enlightening institution can avoid the use of interruptible power supply and individual stabilizer. An emulation using MATLAB Simulink is presented to validate the advantage of the proposed system.


2020 ◽  
Vol 184 ◽  
pp. 01041
Author(s):  
Krishna S. Patel ◽  
Vijay H. Makwana

This paper presents the modified grid side converter control (GSC) technique which enable the GSC to work as a shunt active filter to mitigate the grid current harmonics produced by the nonlinear load, as well as to transfer power from the grid to the rotor of doubly fed induction generator (DFIG) or vice versa. The main contribution of this proposed technique is an addition of a shunt active filter with space vector pulse width modulation (SVPWM) controller in GSC control itself in order to achieve a better grid current %THD profile, and simultaneously to control active power for variable wind speed. The reactive power supply to the DFIG and extraction of maximum power is achieved using RSC. The comparison of the modified GSC control technique using hysteresis current control (HCC), and SVPWM controller used to mitigate the harmonics is presented with different wind speeds. The proposed modified GSC control technique is simulated for grid-connected 2.6 MW DFIG based wind energy conversion system (WECS) in MATLAB Simulink environment.


Author(s):  
Mohamed M. El-sotouhy ◽  
Ahmed A. Mansour ◽  
Mostafa I. Marei ◽  
Aziza M. Zaki ◽  
Ahmed A. EL-Sattar

<span>Four-leg active power filter is considered one of the greatest vital active filters that are frequently used in industrial applications, especially those that need to be controlled in each individual phase. Also, to control the neutral current that created because of a lot of unbalanced and non-linear loads. In this paper, the used active filter was controlled by a proposed control method which can achieve simplicity and intelligence at the same time. The novelty of this paper is using the proposed controller with Four-leg active power filter. This controller relies on instantaneous reactive power theory, which used to create the required currents that are injected into the network via the used active filter to remove the problems created by unbalanced and non-linear loads. It is also maintained that the current source a pure sinusoidal wave. The system is implemented on MATLAB/Simulink. The simulation results proved the preference of the proposed controller than the conventional proportional-integration controller, where it reduced the percentage of total harmonic distortion for the current source<em><span lang="AR-SA" dir="RTL">.</span></em></span>


2019 ◽  
Vol 6 (2) ◽  
pp. 24
Author(s):  
G. A. M. Dwi Ade Saputra ◽  
I Wayan Rinas ◽  
I Made Suartika

Electrical equipment categorized as the nonlinear load will cause harmonics. Harmonic is a periodic distortion of the sine wave that can cause a negative impact on electronic equipment components. One way to improve power quality is to reduce harmonics using harmonic filters. In this study, an analysis of the system was carried out before adding a filter and after adding an active filter based on a fuzzy logic controller. The application of the fuzzy logic method on filters functions to reduce over switching in the inverter so that it can reach the lowest THDi value. THDi simulation results when the existing conditions are in phase R, S, T; at 14%, 17%, 14%. When the active filter condition is without control, the THDi percentage at the R phase is 6%, the S phase is 6%, the T phase is 4%. In the active filter conditions based on the fuzzy logic controller the percentage of THDi in phase R, S, T; is 0.9%, 0.9, 1%. Based on the simulation results introduced in the active filter based fuzzy logic controller is able to reduce harmonic distortion to the lowest value, so the use of fuzzy logic in active filters can be used in the harmonic filtering process in the electrical system.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 545
Author(s):  
R Sriranjani ◽  
S Jayalalitha

This paper deals with the harmonic mitigation and reactive power compensation using Shunt Active filter. The performance of the Shunt active filter depends on the design and current control technique for generating a reference current. The design of the filter involves the iterative procedure for choosing the filter components so that it compensates the harmonics and reactive power for maximum load condition. The current controller method adopted for indirect current control technique where the reference signal is similar to the supply current signal. The Adaptive filter used in current controller mitigates harmonics and reactive power and voltage control loop of SAF balancing the active power between the load and supply unit. The learning rate is fixed by repeated simulation. The SAF active filter is tested in four load condition ie., nonlinear load(37% Total Harmonic Distortion(THD)),highly nonlinear load(>100% THD), linear load(<8% THD, power factor(pf) <0.5) and both nonlinear and linear load(37% THD and 0.7 pf). The study is carried out in MATLAB Simulink and the results are presented.  


2014 ◽  
Vol 573 ◽  
pp. 40-45
Author(s):  
S.S. Lalitha Maheswari ◽  
V. Revathi ◽  
S. Muralidharan

This paper presents a comparative study on performance of conventional PI controller and fuzzy controller on three phase, three wire voltage source inverter based shunt active filter that is used to compensate the harmonics currents drawn by non-linear loads in distribution systems. Hysteresis PWM method is used to generate the pulses to the switches used in active filter. The compensation is based on PLL method of fundamental current extraction. The nonlinear load taken into account is a three phase diode bridge rectifier.


Author(s):  
Kundeti Krishna Rao , M Sonia

Generally, one of the custom power device in FACTS called unified power quality conditioner, which is used to compensate the voltage and current-related Power Quality issues in the distribution systems. The proposed UPQC technology have an advantage of reduced dc-link voltage without compromising its compensation capability. This new method also helps to meet the requirement of dc-link voltage for the shunt and series active filters of the UPQC. This type of topology has a capacitor in series with the interfacing inductor across the shunt active filter for filtering purpose, and the system neutral is also considered and directly connected to neutral of distribution system avoid the requirement of the fourth leg in the voltage source inverter. This paper also presents a concept for improving power quality of a power distribution system such as an FUZZY logic controller along with the UPQC control strategy. The simulation results are compared for both conventional PI controller and FUZZY controller.


Sign in / Sign up

Export Citation Format

Share Document