A Hybrid Active Filter Using the Backstepping Controller for Harmonic Current Compensation

This document presents a new hybrid combination of filters using passive and active elements because of the generalization in the use of non-linear loads that generate harmonics directly affecting the symmetry of energy transmission systems that influence the functioning of the electricity grid and, consequently, the deterioration of power quality. In this context, active power filters represent one of the best solutions for improving power quality and compensating harmonic currents to get a symmetrical waveform. In addition, given the importance and occupation of the transmission network, it is necessary to control the stability of the system. Traditionally, passive filters were used to improve energy quality, but they have endured problems such as resonance, fixed remuneration, etc. In order to mitigate these problems, a hybrid HAPF active power filter is proposed combining a parallel active filter and a passive filter controlled by a backstepping algorithm strategy. This control strategy is compared with two other methods, namely the classical PI control, and the fuzzy logic control in order to verify the effectiveness and the level of symmetry of the backstepping controller proposed for the HAPF. The proposed backstepping controller inspires the notion of stability in Lyapunov’s sense. This work is carried out to improve the performance of the HAPF by the backstepping command. It perfectly compensates the harmonics according to standards. The results of simulations performed under the Matlab/Simulink environment show the efficiency and robustness of the proposed backstepping controller applied on HAPF, compared to other control methods. The HAPF with the backstepping controller shows a significant decrease in the THD harmonic distortion rate

Adaptive hysteresis based fuzzy controlled shunt active power filter for mitigation of harmonics

Active filters are widely employed in distribution system to reduce the harmonics produced by non-linear loads result in voltage distortion and leads to various power quality problems. In this work the simulation study of a Adaptive hysteresis based fuzzy logic controlled shunt active power filter capable of reducing the total harmonic distortion is presented. The advantage of fuzzy control is that it is based on a linguistic description and does not require a mathematical model of the system and it can adapt its gain according to the changes in load. The instantaneous p-q theory is used for calculating the compensating current. Fuzzy-adaptive hysteresis band technique is adopted for the current control to derive the switching signals for the voltage source inverter. The fuzzy-adaptive hysteresis band current controller changes the hysteresis bandwidth according to the supply voltage and slope of the reference compensator current wave. A fuzzy logic-based controller is developed to control the voltage of the DC Capacitor. This work presents and compares the performance of the fuzzy-adaptive controller with a conventional fuzzy and PI controller under constant load. The total Harmonic Distortion, Individual harmonic content with respect to % of fundamental in Supply current, source voltage have been analyzed. Various simulation results are presented. And also the performance of two current control techniques namely adaptive hysteresis current control and fixed hysteresis control techniques are compared with respect to average switching frequency. A neural network control method for regulating the DC Voltage across the capacitor connected to the inverter for harmonic suppression is proposed. The THD of the source current after compensation is well below 5%, the harmonic limit imposed by the IEEE-519 standard

Adaptive-Fuzzy Controller Based Shunt Active Filter for Power Line Conditioners

This paper presents a novel Fuzzy Logic Controller (FLC) in conjunction with Phase Locked Loop (PLL) based shunt active filter for Power Line Conditioners (PLCs) to improve the power quality in the distribution system. The active filter is implemented with current controlled Voltage Source Inverter (VSI) for compensating current harmonics and reactive power at the point of common coupling. The VSI gate control switching pulses are derived from proposed Adaptive-Fuzzy-Hysteresis Current Controller (HCC) and this method calculates the hysteresis bandwidth effectively using fuzzy logic.  The bandwidth can be adjusted based on compensation current variation, which is used to optimize the required switching frequency and improves active filter substantially. These shunt active power filter system is investigated and verified under steady and transient-state with non-linear load conditions. This shunt active filter is in compliance with IEEE 519 and IEC 61000-3 recommended harmonic standards

Interleaved Buck Converter Based Shunt Active Power Filter with Shoot-through Elimination for Power Quality Improvement

The “shoot-through” phenomenon defined as the rush of current that occurs while both the devices are ON at the same time of a particular limb is one of the most perilous failure modes encountered in conventional inverter circuits of active power filter (APF). Shoot-through phenomenon has few distinct disadvantages like; it introduces typical ringing, increases temperature rise in power switches, causes higher Electromagnetic Interference (EMI) and reduces the efficiency of the circuit. To avert the “shoot-through”, dead time control could be added, but it deteriorates the harmonic compensation level. This dissertation presents active power filters (APFs) based on interleaved buck (IB) converter. Compared to traditional shunt active power filters, the presented IB APFs have enhanced reliability with no shoot-through phenomenon. The instantaneous active and reactive power (p-q) scheme and instantaneous active and reactive current component (id-iq) control scheme has been implemented to mitigate the source current harmonics. Type-1 and Type-2 fuzzy logic controller with different membership functions (MFs) viz. Triangular, Trapezoidal and Gaussian have been implemented for the optimal harmonic compensation by controlling the dc-link voltage and minimizing the undesirable losses occurred inside the APF. Additionally, the adaptive hysteresis band current controller (AHBCC) is being implemented to get the nearly constant switching frequency. The performance of the control strategies and controllers for the presented IB APF topologies has been evaluated in terms of harmonic mitigation and dc-link voltage regulation under sinusoidal, unbalanced sinusoidal and non-sinusoidal voltage source condition. This dissertation is concerned with the different topologies of 3-phase 4-wire IB APFs viz. split capacitor (2C) topology, 4-leg (4L) topology, transformer based full-bridge IB APF or single capacitor based FB IB APF (1C 3 FB IB APF) and full-bridge IB APF (FB IB APF) for low to medium power application. Moreover, APF topology is now being expanded to multilevel VSIs for high power application. Thanks to flexible modular design, transformerless connection, extended voltage and power output, less maintenance and higher fault tolerance, the cascade inverters are good candidates for active power filters with the utility of high power application. The cascaded FB IB APF is modelled with no shoot-through phenomenon by using multicarrier phase shifted PWM scheme. Extensive simulations have been carried out in the MATLAB / Simulink environment and also verified in the OPAL-RT LAB using OP5142-Spartan 3 FPGA to support the feasibility of presented IB APF topologies, control strategies and controllers during steady and dynamic condition. The performance shows that IB-APF topologies bring the THD of the source current well below 5% adhering to IEEE-519 standard. A comparison has also been made, based on SDP (switch device power) between the IB-APF topologies

A hybrid fuzzy sliding-mode control for a three-phase shunt active power filter

This document is the Accepted Manuscript version of the following article: Mohamed Abdeldjabbar Kouadria, Tayeb Allaoui, and Mouloud Denai, ‘A hybrid fuzzy sliding-mode control for a three-phase shunt active power filter’, Energy Systems, Vol. 8 (2): 297-308, March 2016. The final publication is available at Springer via http://dx.doi.org/10.1007/s12667-016-0198-4.This paper describes the hybrid fuzzy sliding-mode control (HFSMC) for a three phase shunt active shunt filter for the power quality improvement. The Power Quality (PQ) problems in power distribution systems are not new but only recently the effects of these problems have gained public awareness. These non-linear loads are constructed by nonlinear devices in which the current is not proportional to the applied voltage. For the harmonic elimination different methods are used, but in this paper a novel fuzzy logic controller for a three-phase shunt active power filter for the power quality improvement such as reactive power and harmonic current compensation generated due to nonlinear loads. The hybrid fuzzy sliding-mode control (HFSMC) approach is proposed such that it can be applied with advantages to both fuzzy and sliding-mode controller. Simulation results are presented to demonstrate the effectiveness of the control strategy. The results are found to be quite satisfactory to mitigate harmonic distortions, reactive power compensation and power quality improvement.Peer reviewedFinal Accepted Versio

Fuzzy Logic Control For Three Phase Shunt Active Power Filter (Modeling And Simulation)

The main purpose of this project is to perform studied on fuzzy logic control for a three-phase Shunt Active Power Filter (SAPF) in order to reduce total harmonic distortion and power factor correction in a distribution system supplying non-linear loads. The project mainly focuses on the design of FLC to optimize the function of SAPF

Power Quality Enhancement of DFIG Based Wind Energy System Using Priority Control Strategies

A. BOUZEKRI T. ALLAOUI, M. DENAI, 'Power Quality Enhancement of DFIG Based Wind Energy System Using Priority Control Strategies', Journal of Electrical Engineering, Vol. 15 (4): 139-145, 2015.The integration of intermittent renewable energy sources into the electric grid presents some challenges in terms of power quality issues, voltage regulation and stability. Power quality relates to those factors which affect the variability of the voltage level and distortion of the voltage and current waveforms which can cause severe adverse effects to the electric grid. The paper focuses on the design and evaluation of a priority control strategy for improving the quality of energy of a grid-connected variable speed Doubly Fed Induction Generator (DFIG) wind energy conversion system. The aim of priority control is to manage the priority among three different controls: active stator power control; reactive stator power control and harmonic rotor current control by using the active shunt filter with SRF method harmonic compensation, and to have a high performance and robustness; an adaptive-fuzzy PI control are including for currents rotor control. The simulation model was developed in Matlab/Simulink environment. The results show that the proposed control scheme can effectively reduce the Total Harmonic Distortion (THD) in the grid currents.Peer reviewedFinal Published versio

Regulatori struje aktivnih filtara snage za poboljšanje kvalitete snage: Tehnička analiza

Non-linear load deteriorates the quality of current waveforms at the point of common coupling of various consumers. Active power filter (APFs) is used to mitigate the most concern harmonic pollution in an electrical network. The controller part is the nucleus of an active power filter configuration. Active power filter performance is affected significantly by the selection of current control techniques. The active filter and its current control must have the capability to track sudden slope variations in the current reference to compensate the distorted current drawn by the voltage source inverter. Therefore, the choice and implementation of the current regulator is more important for the achievement of a satisfactory performance level. In this survey, technical reviews of various types of controllers covering a wide range have been presented. This work also reveals the advantages and disadvantages of the practiced control strategies. The effectiveness of the study will help the researchers to choose the proper control methods for various applicationsof active power filter.Nelinearni tereti pogoršavaju kvalitetu strujnih valova u točki u kojoj se spaja više potrošača. Aktivni filtar snage se koristi za ublažavanje najvažnijeg harmoničkog onečišćenja strujne mreže. Jezgra aktivnog filtra snage je regulator. Na performanse aktivnog filtra snage značajno utječe odabir upravljačke tehnike. Aktivni filtar i njegova tehnika upravljanja strujom moraju imati mogućnost pratiti nagle skokove u referentnoj vrijednosti struje kako bi mogli kompenzirati izobličenja struje koju vuče inverter naponskog izvora. Zato su izbor i implementacija regulatora struje iznimno važni za postizanje zadovoljavajuće razine performansi. U ovom pregledu su predstavljene tehničke recenzije koje pokrivaju širok raspon regulatora. Ovaj rad također otkriva prednosti i mane korištenih strategija upravljanja. Efektivnost ovog pregleda pomoći će istraživačima da izaberu ispravnu metodu upravljanja za različite aplikacije aktivnog filtra snage

Regulatori struje aktivnih filtara snage za poboljšanje kvalitete snage: Tehnička analiza

Non-linear load deteriorates the quality of current waveforms at the point of common coupling of various consumers. Active power filter (APFs) is used to mitigate the most concern harmonic pollution in an electrical network. The controller part is the nucleus of an active power filter configuration. Active power filter performance is affected significantly by the selection of current control techniques. The active filter and its current control must have the capability to track sudden slope variations in the current reference to compensate the distorted current drawn by the voltage source inverter. Therefore, the choice and implementation of the current regulator is more important for the achievement of a satisfactory performance level. In this survey, technical reviews of various types of controllers covering a wide range have been presented. This work also reveals the advantages and disadvantages of the practiced control strategies. The effectiveness of the study will help the researchers to choose the proper control methods for various applicationsof active power filter.Nelinearni tereti pogoršavaju kvalitetu strujnih valova u točki u kojoj se spaja više potrošača. Aktivni filtar snage se koristi za ublažavanje najvažnijeg harmoničkog onečišćenja strujne mreže. Jezgra aktivnog filtra snage je regulator. Na performanse aktivnog filtra snage značajno utječe odabir upravljačke tehnike. Aktivni filtar i njegova tehnika upravljanja strujom moraju imati mogućnost pratiti nagle skokove u referentnoj vrijednosti struje kako bi mogli kompenzirati izobličenja struje koju vuče inverter naponskog izvora. Zato su izbor i implementacija regulatora struje iznimno važni za postizanje zadovoljavajuće razine performansi. U ovom pregledu su predstavljene tehničke recenzije koje pokrivaju širok raspon regulatora. Ovaj rad također otkriva prednosti i mane korištenih strategija upravljanja. Efektivnost ovog pregleda pomoći će istraživačima da izaberu ispravnu metodu upravljanja za različite aplikacije aktivnog filtra snage

Fuzzy Hysteresis Controller Based Unified Power Quality Conditioner for Voltage Fluctuations and Harmonic Isolation

Power quality problem makes the consumer un satisfy.  FACTS devices such as UPQC are such devices to avoid power quality problems. This paper proposed an efficient hysteresis controller and fuzzy controller for unified power quality conditioner. In this harmonics and voltage fluctuations were dealed by UPQC with hysteresis control strategy. The performance of the control strategy applied unified power quality conditioner on distribution system checked with and without UPQC. And the performances of these two controllers of UPQC are compared. This strategy makes the industries to get pure power and to avoid the disturbances from polluted distribution system. The proposed dynamic model was developed in MATLAB/SIMULINK. Keywords: power quality, voltage fluctuations, harmonics, hysteresis controller, fuzzy controller