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1

Grid-side current harmonic suppression based on Butterworth filter and quasi-proportional resonance controller

Zhao Feng, Zhang Jianing, Chen Xiaoqiang, Wang Ying

Archives of Electrical Engineering

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2022

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Vol. 71, nr 4

909--929

EN

In order to meet the lightweight requirements of high-speed trains, the inductancecapacitance (LC) resonance circuits are cancelled in the traction drive system of some high-speed electric multiple units (EMUs) in China, which will lead to large low-order current harmonics on the grid side in the traction drive system of EMUs, seriously affecting the power quality. Therefore, the low-order harmonic current of the traction drive system of an EMU is studied in this paper. Firstly, the working principle of a four-quadrant pulse rectifier in a traction drive system is analyzed, and then the generation mechanism of loworder current harmonics on the grid side is studied deeply. Secondly, the voltage outer loop and current inner loop control of a four-quadrant pulse rectifier are optimized respectively. In the voltage outer loop control, a Butterworth filter is designed to suppress the beat frequency voltage of the DC side voltage, so as to indirectly suppress the low-order current harmonics. In the current inner loop, a quasi-proportional resonance (PR) controller with harmonic compensation is used to suppress low-order current harmonics, and a novel loworder current harmonics suppression strategy based on the Butterworth filter and quasi-PR controller is proposed. Finally, the results of the simulated validation of the proposed control strategy show that compared with the existing method of the notch filter ₊ PR controller, the proposed optimal control strategy has a better effect on low-order current harmonic suppression, and improves the dynamic performance of the control system, further showing the correctness and effectiveness of the optimal control strategy.

2

Filtracja przebiegów elektrycznych : porównanie zastosowanych metod filtracji

Stawicki W.

Zeszyty Naukowe Wyższej Szkoły Informatyki

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2016

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Vol. 15, Nr 1

88--102

PL

W trakcie wykonywania pomiarów elektrycznych, każdy badacz narażony jest na niespodziewane trudności na które, może natrafić, takie jak np. zakłócenia mierzonych sygnałów. Zakłócenia mogą mieć wiele przyczyn, takich jak: konstrukcja układu pomiarowego, wpływ warunków atmosferycznych, obecność innych urządzeń elektrycznych pracujących w pobliżu oraz wiele innych. Do wykonania pomiarów autor wykorzystał układ Single Sheet Tester. Podczas wykonywania pomiarów, właściwości blach elektrotechnicznych stosowanych do budowy transformatorów i silników elektrycznych, autor otrzymał zniekształcone (zakłócone) przebiegi rejestrowanego prądu oraz indukowanego napięcia. W celu poprawnej interpretacji otrzymanych wyników należało więc skutecznie je odfiltrować. W artykule opisane są metody komputerowej filtracji przebiegów jakie autor zastosował, wraz z porównaniem wyników otrzymanych bezpośrednio z oscyloskopu pomiarowego oraz po zastosowaniu komputerowej filtracji.

EN

To perform research author has used Single Sheet Tester. While taking electrical measurements an error could appear caused by signal interference. Those errors could be caused by several factors like instrumental error, presence of other devices, or environmental factors and also many others. Author performed the research of magnetic properties steel sheets used to create transformers and electrical engines. The researcher observed disordered waveforms for recorded current and induced voltage. Author performed filtration of those waveforms in order to proper interpret obtained data. This paper contains description of a few computer filter methods, which have been used during the research. This article also describes comparison of filtered waveforms and unfiltered results obtained from oscilloscope.

3

Modelling of the seat suspension system for the vibration control system

Koszewnik A., Gosiewski Z.

Mechanics and Control

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2013

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Vol. 32, no. 3

97--101

EN

In this paper, a model of the passive seat suspension system is designed. To verify the model the excitation signals are modelled by using generator embedded to Simulink software. Additionally, the excitation signal is filtered with the use of the Butterworth filters. The vibroisolation properties of the system are calculated on the basis of the ratio transmissibility of the vibration. The investigations proved that the designed system is correctly modelled and the system damps the vibration speciously in the most dangerous frequency range up to 20 Hz.

XX

W artykule przedstawiono model pasywnego układu zawieszenia siedziska operatora autobusu na przykładzie siedziska firmy ISRI. Na potrzeby badań losowe sygnały wymuszenia zostały zamodelowane w środowisku Matlab/Simulink. Dodatkowo,na potrzeby badań, sygnały wymuszenia zostały przefiltrowane z wykorzystaniem filtru Butterworth. Właściwości wibroizolacyjne układu zostały wyznaczone na podstawie kryterium współczynnika przenoszenia drgań. Badania symulacyjne wykazały tłumienie drgań przez układ szczególnie w najbardziej niebezpiecznym zakresie częstotliwości do 20 Hz.

4

Frequency analysis of the 2004 Sumatra-Andaman earthquake using spectral seismograms

Wilde-Piórko M., Duda S., Grad M.

Acta Geophysica

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2011

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Vol. 59, no. 3

483-501

EN

Frequency analysis of the Sumatra-Andaman earthquake of 2004, one of the most significant and best-recorded earthquakes, is based on spectral seismograms obtained from their broadband seismograms. The Sumatra-Andaman earthquake is found to have a wide-range frequency content of P-wave radiation during the rupturing process. On the basis of stacking spectral seismograms we distinguished four time events of the rupturing process of a total length of about 540 s. The frequency, fmax, is the highest for the first event (0.163 Hz in time interval 0-88 s), lowest for the second - which is the strongest (0.075 Hz in time interval 88-204 s). For third and fourth events frequencies are similar (0.089 and 0.082 Hz in time intervals 204-452 and 452-537 s, respectively). The frequency also shows an azimuthal dependence (±0.02 Hz). Azimuths for which the frequency, fmax, has maximum and minimum values are 203-222° and 23-42°, respectively. These observations are discussed in relation to previously published papers on this topic.

5

Stability analysis of nonlinear a fourth order PLL with Butterworth lowpass filter

Kiełtyka G., Walczak J.

Poznan University of Technology Academic Journals. Electrical Engineering

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2010

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No. 61

35-42

EN

The paper presents continuation of work [14]. In the paper a stability analysis of nonlinear analog phase-locked loop with the fourth order Butterworth lowpass filter has been made. The stability analysis of the loop has been done using the first Lyapunov method. Presented results were illustrated by example.