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1

Self-adaptive fault-tolerant control strategy of shunt active power filter based on multicellular converter

Bouhafs Ali, Rouabah Boubakeur, Kafi Mohamed Redouane, Louazene Lakhdar

Diagnostyka

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2023

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Vol. 24, No. 4

art. no. 2023411

EN

The use of multicellular topology in power quality enhancement can reduce the power loss and also dv/dt of power switches, minimize the electromagnetic interference. However, the failure of flying capacitors can reduce the active filtering efficiency and affect the power quality by injecting currents with wave-form distortion (harmonics, notching, noises etc.) in power distribution grid. Therefore, this study presents a faulttolerant control strategy (FTC) allowing to keep the normal operation conditions of a multicellular converter even under failure mode. The obtained results show that the proposed FTC strategy enhances the power quality of power distribution grid when a fault in flying capacitors occurs.

2

SRF control strategy based on STFIS controllers for single-stage four-leg transformerless inverter for grid-connected pv system

Chaouch Djamel Eddine, Azzeddine Hocine Abdelhak, Larbaoui Ahmed, Ahmed-Foitih Zoubir

Przegląd Elektrotechniczny

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2021

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R. 97, nr 7

42--47

EN

In this paper synchronous reference frame (SRF) control strategy based on a self-tunable fuzzy inference system (STFIS) is proposed to control a four-leg transformerless inverter, is presented. The single-stage inverter is controlled to achieve high performance from the PV system without using any maximum power point technique (MPPT), to inject power into the grid, and to improve the power quality, simultaneously. A Fuzzy controller based on an on-line optimization of a zero-order Takagi-Sugeno fuzzy inference system (FIS) by a back propagation-like algorithm is applied to minimize a cost function that is made up of a quadratic error term and a weight decay term that prevents excessive growth of DC-link and PCC. A detailed design of the STFIS controller parameters is given in detail. Furthermore, a comparison between classical PI and STFIS controllers is provided. The performance test of the proposed single-phase configuration and its control strategies are realized under the presence of severe conditions using Matlab/Simulink.

PL

W artykule przedstawiono strategię sterowania synchroniczną ramką odniesienia (SRF) w oparciu o samostrajalny system wnioskowania rozmytego (STFIS) do sterowania falownikiem beztransformatorowym. Falownik jednostopniowy jest sterowany w celu uzyskania wysokiej wydajności systemu fotowoltaicznego bez stosowania techniki maksymalnego punktu mocy (MPPT), jednoczesnego wprowadzania mocy do sieci i poprawy jakości energii. Sterownik Fuzzy oparty na optymalizacji on-line systemu wnioskowania rozmytego Takagi-Sugeno (FIS) zerowego rzędu za pomocą algorytmu przypominającego propagację wsteczną jest stosowany w celu zminimalizowania funkcji kosztu, która składa się z kwadratowego składnika błędu i wagi zaniku, który zapobiega nadmiernemu wzrostowi łącza DC i PCC. Szczegółowo podano projekt parametrów sterownika STFIS. Ponadto przedstawiono porównanie między klasycznymi sterownikami PI i STFIS.

3

A novel source side power quality improved soft starting of three-phase induction motor using a symmetrical angle controller through pic microcontroller

Selvaperumal S., Krishnamoorthy N., Prabhakar G.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 2

art. no. e136746

EN

PIC microcontroller has a vital role in various types of controllers and nowadays the presence of PIC microcontroller is unavoidable in most control applications. This paper describes the enhancement of soft starting of induction motors using PIC microcontroller. Soft starting is required for the induction motors with reduced applied voltages so that the peak starting current is reduced and the startup of the motor is smooth with controlled torque and reduced mechanical vibrations, reduced starting current with correspondingly reduced bus voltage drops. While many of the available schemes of soft starting offer better results in view of smooth starting process, the proposed methodology offers soft starting as well as it cares about the source current quality. In contrast to the conventional multistep starting scheme, in this work a continuously controlled starting scheme is proposed. The three phase AC voltage controller topology is used as the core controller. In each of the half cycles, instead of a single conduction period with a single delay angle, the proposed AC voltage controller is switched symmetrically in each half cycle with multiple pulses in each quarter cycle. Symmetrically placed fixed numbers of switching pulses are used. The paper also describes the various time ratio controls namely the phase angle controller, the extinction angle controller and the symmetrical angle controller. The design aspects of the proposed soft starting scheme and the validation of the proposed system in the MATLAB SIMULINK environment are presented in this paper.

4

Improving power quality by application of active filter - case study

Pniewski M.

Prace Naukowe Politechniki Śląskiej. Elektryka

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2016

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z. 3-4

7--21

EN

The paper presents methods for improving power supply quality with properly selected active filter, obtaining better power factor and lower levels of voltage and current harmonics. Real case of active filter application in industry has been analysed. Measurement results of quality indicators of energy are given for active filter in use and filter switched off. Analysis of the cost-effectiveness of its use has been conducted.

PL

W artykule przedstawiono sposoby poprawy jakości zasilania uzyskując poprawę współczynnika mocy oraz obniżenie poziomu harmonicznych napięcia i prądu, wykorzystując do tego celu odpowiednio dobrany filtr aktywny. Przenalizowano rzeczywisty przypadek zastosowania filtra aktywnego w zakładzie przemysłowym. Przedstawiono wyniki pomiarów wskaźników jakości energii – zarówno przed zastosowaniem filtra aktywnego jak i po jego zastosowaniu. Dokonano analizy opłacalności ekonomicznej jego zastosowania.

5

Wpływ tolerancji parametrów elektrycznych dławika sprzęgającego na czułość równoległego filtra aktywnego

Grugel P.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2013

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nr 78

7--22

PL

W artykule przedstawiono wpływ rezystancji i indukcyjności dławika sprzęgającego równoległy filtr aktywny z siecią zasilającą na czułość filtra oraz dokładność kompensacji harmonicznych. Badania dotyczyły dwóch różnych mocy zwarciowych sieci. Eksperymenty symulacyjne przeprowadzono dla typowego układu filtra trójfazowego, sterowanego z zastosowaniem predykcyjnego algorytmu wektorowego, dołączonego do sieci nn (400 V, 50 Hz).

EN

The article shows the influence of resistance and inductance of a choke connecting a shunt active power filter with a network on the filter's sensitivity and accuracy of harmonics' compensations. The research has been conducted for two different network's short-circuit powers. The simulation experiments have been done for a typical three-phase filter connected to the low-voltage network (400 V, 50 Hz), controlled with the use of predictive, vector algorithm.

6

New Control Algorithms for Three-Phase Four-Wire Unified Power Quality Conditioner - a simulation study

Pal Y., Swarup A., Singh B.

Electrical Power Quality and Utilisation. Journal

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2013

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Vol. 16, iss. 1

1--10

EN

In this paper, some new control algorithms are proposed for a three-phase four-wire Unified Power Quality Conditioner. These control algorithms are based on the combination of Unit Vector Template Generation (UVTG) with Power Balance Theory (PBT), single phase d-q theory, Synchronous Current Detection (CSD) technique, and I CosΦ theory. The performance of each control algorithm of UPQC is evaluated in terms of power factor correction, load balancing and source neutral current mitigation, and voltage and current harmonic mitigation. The performance of proposed control algorithms are compared with synchronous reference frame (SRF) based control algorithm. In each proposed control scheme of the three-phase four-wire UPQC, the current/voltage control is applied over the fundamental supply currents/ load voltages instead of fast changing APFs currents/ voltages, thereby reducing the effects of computational delay. Moreover, the load neutral or shunt APF neutral currents are not sensed hence the required current sensors are reduced. MATLAB/ Simulink based simulations are obtained, which support the functionality of the UPQC.