Transient Analysis and Modelling of 2nd- and 4th-Order LCLC Filter under Non-Symmetrical Control

1970 ◽  
Vol 111 (5) ◽  
pp. 89-94 ◽  
Author(s):  
B. Dobrucky ◽  
M. Benova ◽  
S. Kascak
Keyword(s):  
Transient Analysis ◽  
Harmonic Distortion ◽  
Harmonic Component ◽  
Switching Frequency ◽  
Sinusoidal Voltage ◽  
Higher Harmonic ◽  
Simulation Results ◽  
Harmonic Components ◽  
Lc Filter

The paper shows how it is possible to obtain the harmonic sinusoidal voltage on the load side at non-harmonic periodical supplying from the converters. It can be used either LCLC resonant filter for frequency of fundamental harmonic component, or LC filter tuned for switching frequency. Both filters have to remove higher harmonic components from the supplying voltage to reach the harmonic distortion roughly 5 %. The paper deals mainly with analysis and modelling of 4th order LCLC filter (of the first type) under non-symmetrical supply and with comparing to the other types of filtering. Simulation results as well as experimental verification confirm good quality of output quantities of the filter. Ill. 19, bibl. 10 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.111.5.364

scholarly journals Induction Motor Drives Fed by an NPC Inverter with Unbalanced DC-Link

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1379 ◽  
Author(s):  
Umberto Abronzini ◽  
Ciro Attaianese ◽  
Matilde D’Arpino ◽  
Mauro Di Monaco ◽  
Giuseppe Tomasso
Keyword(s):  
Output Voltage ◽  
Harmonic Distortion ◽  
Voltage Regulation ◽  
Motor Drives ◽  
Operating Conditions ◽  
Switching Frequency ◽  
Voltage Level ◽  
Voltage Quality ◽  
Vector Modulation

Neutral Point Clamped (NPC) converters with n levels are traditionally controlled in such a way that the DC-link capacitors operate at 1/( n - 1) of the total DC-link voltage level. The voltage level across the DC-link capacitors has to be properly regulated by the capacitor unbalance control to contain the harmonic distortion of the converter output voltages. State-of-the-art modulation techniques address the problem of the DC-link voltage regulation for NPC inverters. However, they highly show reduced performance when unbalanced DC-link voltages are considered. In this paper, a novel Space Vector Modulation (SVM) is proposed for NPC converters with an unbalanced DC-link. At every modulation interval, the technique defines the optimal switching pattern by considering the actual unbalanced DC-link conditions. The proposed modulation allows improving the harmonic content of the NPC converter output voltage with respect to a traditional ML-SVM, when the same operating conditions are considered. As an extension, the proposed modulation technique will guarantee the same output voltage quality of a traditional ML-SVM with unbalanced DC-link, while improving the conversion efficiency thanks to a reduction of switching frequency.

Consideration of Nonsinusoidal/Unbalanced Operating Conditions of a Municipal Electric Network for Calculating the Current Level through the Neutral Conductor

2021 ◽  
Vol 1 (1) ◽  
pp. 35-43
Author(s):  
Mukhammadzhon М. KAMOLOV ◽  
◽  
Sagid A. АBDULKERIMOV ◽  
Khurshed B. NAZIROV ◽  
Shokhin D. DZHURAEV ◽  
...  
Keyword(s):  
Harmonic Component ◽  
Operating Conditions ◽  
Electric Networks ◽  
Electric Network ◽  
Three Phase ◽  
Zero Sequence ◽  
Flow Through ◽  
Higher Harmonic ◽  
Harmonic Components ◽  
Electric Loads

During the operation of 0.4 kV electric networks, asymmetry of currents and voltages is unavoidable. As is known, unbalanced operation of 0.4 kV networks is stemming from nonuniform distribution of loads between the phases. This results in that a fundamental frequency zero-sequence current will flow through the neutral conductor in a four-wire three-phase electric network. On the other hand, during balanced operation of a four-wire electric network containing loads with a nonlinear volt-ampere characteristic, higher harmonic currents multiple to three are summed in the neutral conductor. Therefore, it is of relevance to analyze unbalanced operating conditions of a four-wire electric network containing loads with a nonlinear volt-ampere characteristic. The article presents the characteristics of a municipal load for analyzing unbalanced/nonsinusoidal conditions of its operation. For carrying out full-valued assessment of unbalanced operating conditions of a four-wire electric network, a simulation model of a 0.4 kV network section containing a nonsinusoidal load is developed. It is shown that during unbalanced operation of an electric network containing electric loads with a nonlinear volt-ampere characteristic it is recommended to take into account zero-sequence current higher harmonic components that are not multiple to three. An algorithm for calculating the neutral conductor current harmonic component for determining the cable temperature rating is developed.

Switching Angles Optimization of Single Phase PWM DC-AC Inverter by Particle Swarm Optimizations

2014 ◽  
Vol 18 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Takuya Shindo ◽  
◽  
Kenya Jin’no
Keyword(s):  
Single Phase ◽  
Particle Swarm Optimization Algorithm ◽  
Harmonic Distortion ◽  
Particle Swarm ◽  
Design Procedure ◽  
Pso Algorithm ◽  
Evaluation Function ◽  
Swarm Optimization ◽  
Simulation Results ◽  
Harmonic Components

We consider the design procedure for a single-phase PWM DC-AC inverter using a particle swarm optimization algorithm. The switching operation is the most important component of the single-phase PWM DC-AC inverter. The PSO algorithm optimizes the switching angle effectively. The design procedure of the switching angle evaluates total harmonic distortion and the effective value of output. The proposed evaluation function restricts the scope to evaluating harmonic components. Based on numerical simulation results, we confirmed that the performance of the proposed design procedure was improved compared to the conventional sinusoidal PWM procedure. We develop an implementation circuit for our PWM DCAC inverter. By using the implemented circuit, we confirmed that results for implementation circuits are consistent with results for numerical simulations, indicating that the proposed algorithm exhibits better performance than the conventional sinusoidal PWM DC-AC inverter.

scholarly journals The impact of the larger number of non-linear consumers on the quality of electricity

2019 ◽  
Vol 32 (3) ◽  
pp. 369-385
Author(s):  
Enver Agic ◽  
Damir Sljivac ◽  
Bakir Agic
Keyword(s):  
Total Duration ◽  
Harmonic Component ◽  
Simulation Models ◽  
Voltage Level ◽  
Harmonic Content ◽  
Three Phase ◽  
Harmonic Components ◽  
Parallel Filter ◽  
The Impact

Theoretically this paper will explain the formation of higher harmonic components in the electricity network, their causes, consequences on consumers and the ways of their elimination. Transformer role in the Dyg connection will be explained on the concrete example. For a specific example the waveform of primary (R) phase at 10 kV voltage level, the current of the secondary (r) phase and the neutral conductor at the 0.4 kV voltage level will be determined as shown in the concrete example in the work. Harmonic content will be determined up to 15 harmonics and the effective value of all these currents (phases R and r). THD for current of primary (R) phase and secondary (r) fase will be calculated. In this paper, the dimensional three-phase filter is set to eliminate the maximum harmonic component of current of the primary (R) phase on the 10 kV side of the transformer. The waveform, the corresponding harmonic content for the current and THD of primary (R) phase will be determined. Additional measures have been proposed to reduce the THD. Another parallel filter has been realized to eliminate the second by size harmonic components of primary (R) phase current. It will also compare THD for primary (R) phase as in the previous cases. For the total duration of the simulation, the used time is Tstop = 0.1 sec. All of the above simulations will be realized in the MATLAB/PSB program package and simulation models will be displayed.

scholarly journals Gap resonance and higher harmonics driven by focused transient wave groups

2017 ◽  
Vol 812 ◽  
pp. 905-939 ◽  
Author(s):  
W. Zhao ◽  
H. A. Wolgamot ◽  
P. H. Taylor ◽  
R. Eatock Taylor
Keyword(s):  
Incident Wave ◽  
Second Harmonic ◽  
Harmonic Component ◽  
Transient Wave ◽  
Sea State ◽  
Wave Groups ◽  
Wave Basin ◽  
Higher Harmonic ◽  
Harmonic Components ◽  
Quadratic Coupling

The first and higher harmonic components of the resonant fluid response in the gap between two identical fixed rectangular boxes are experimentally investigated in a wave basin. Gap response is excited by transient wave groups (being based on scaled versions of the autocorrelation function of sea-state spectra, representing NewWaves, the average shape of large waves in a sea state). Several different wave groups with different maximum surface elevations, spectral peak frequencies and bandwidths are used, while the bilge shape of the boxes and approach angle of the waves are also varied. Unlike a simple regular wave, it is complicated to separate the harmonic components for a transient wave group due to nonlinear wave–wave and wave–structure interactions. A four-phase combination methodology is used to separate the first four harmonic components, and this also allows higher harmonic components to be isolated with simple digital frequency filtering. Harmonic components up to 14th order in the incident wave amplitude have been extracted. It is shown that for an incident group with appropriate frequency content, the linear gap response may be substantially smaller than the second harmonic component, which is strongly driven via quadratic coupling of the linear terms from the incident wave and occurs in the gap resonant modes. Double frequency excitation may have important practical implications for offshore operations. Fourth and zeroth (long-wave) harmonics in the gap are further driven via quadratic coupling of the second harmonic itself. Linear damping coefficients for the first few modes of the gap resonant response are derived from measured time series using a numerical fit and shown to be higher than those from linear diffraction calculations.

Effects of Switching Frequency Modulation on Input Power Quality of Boost Power Factor Correction Converter

2017 ◽  
Vol 8 (2) ◽  
pp. 882 ◽  
Author(s):  
Deniss Stepins ◽  
Jin Huang
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Frequency Modulation ◽  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Power Factor Correction ◽  
Harmonic Distortion ◽  
Input Power ◽  
Switching Frequency

Switching frequency modulation (SFM) as spread-spectrum technique has been used for electromagnetic interference reduction in switching power converters. In this paper, a switching-frequency-modulated boost power factor correction (PFC) converter operating in continuous conduction mode is analysed in detail in terms of its input power quality. Initially, the effect of SFM on the input current total harmonic distortion, power factor and low-frequency harmonics of the PFC converter are studied by using computer simulations. Some advices on choosing parameters of SFM are given. Then the theoretical results are verified experimentally. It is shown that, from a power quality point of view, SFM can be harmful (it can significantly worsen the power quality of the PFC converter) or almost harmless. The results depend on how properly the modulation parameters are selected.

Effect of Higher-Harmonic Deflection Components on the Creep Buckling of Columns

1957 ◽  
Vol 8 (3) ◽  
pp. 215-225 ◽  
Author(s):  
Sharad A. Patel ◽  
Joseph Kempner
Keyword(s):  
Power Function ◽  
Second Harmonic ◽  
Harmonic Component ◽  
Initial Amplitude ◽  
Creep Properties ◽  
Third Harmonic ◽  
Creep Buckling ◽  
Higher Harmonic ◽  
Harmonic Components ◽  
Simple Power Function

SummaryThe influence of higher-harmonic deflection components on the creep-buckling characteristics of an idealised H-section column is investigated. The creep properties of the material of the column are defined by a simple power-function creep law. The results show that higher-harmonic deflection components reduce the column lifetime significantly only when their initial amplitudes, as well as the initial amplitude of the first harmonic component, are very large. Furthermore, it is shown that second-harmonic components have a much smaller effect on the column behaviour than do third-harmonic components.

scholarly journals ANALISIS KUALITAS DAYA PADA SUPLAI DAYA LISTRIK PT. SOSRO

2020 ◽  
Vol 1 (1) ◽  
pp. 27-33
Author(s):  
Aceng Daud Energi
Keyword(s):  
Power Systems ◽  
Harmonic Distortion ◽  
Data Logger ◽  
Current Harmonics ◽  
Ac Power ◽  
Linear Load ◽  
Harmonic Components ◽  
Non Linear Load ◽  
Voltage Harmonics

In more than ten years, quality of electricity has growed from clearness to be an principal issue. One heavy problems from quality of power is harmonic distortion and its consequences. Particularly, the increasing of penetration of loads bases on power electronics (non-linear load) what creates a harmonic distortion in AC power systems. Then, quality of electricity becomes principal issue for utility and its consumer and both swiftly adopts philosophy and proposes limits in new international standard (IEC, EN, BS, IEEE). As consequence the equipments of power conditioning (converter) will become more important for electrical utility and its consumer. From the results with the data logger recording at PT SOSRO distribution feeder system found that there are several current and voltage harmonics are significant in the load and hence the supply side. Fifth and the seventh Harmonic are heaviest harmonic components in the current load. Installation of passive filters will be one solution to overcome the issue with the current harmonics. The recomendation proposed will be submitted to management for consideration PT SOSRO factory in determining which type of passive filter will be used.

scholarly journals VSI LC filter optimized by a genetic algorithm from connected to island microgrid operation

2021 ◽  
Author(s):  
Juan R. Lopez ◽  
Pedro Ponce Cruz ◽  
Arturo Molina Gutierrez
Keyword(s):  
Genetic Algorithm ◽  
Renewable Energy Sources ◽  
Cutoff Frequency ◽  
High Harmonic ◽  
Harmonic Distortion ◽  
Reference Value ◽  
Switching Frequency ◽  
Algorithm Optimization ◽  
Design Factor ◽  
Lc Filter

AbstractIn microgrids (MG) with a high penetration of renewable energy sources (RES) power converters are used to regulate the produced energy to a single voltage and frequency reference value across the MG. Adequate incorporation of an LC filter at the output of power electronic devices allows the attenuation of harmful harmonics that can be introduced to the MGs energy bus. By traditional methods, LC filter values can be calculated by means of the power rating, switching frequency, cutoff frequency, and using the bode frequency domain. Nonetheless, in the transition from a connected to an autonomous MG operation, the calculated LC filter can lead to high harmonic injection. As a result, a tuning methodology capable of obtaining the right set of parameters for the LC filter for a transition event can improve the performance of the MG. This work optimizes the LC output parameters with respect to the size of the filter components, the IEEE Std 519-2014, and bandwidth of the filter, within a bounded region of values subjected to performance conditions such as voltage output, and the produced total harmonic distortion (THD) measurements during the transition from a connected to an autonomous operation. In a case study, genetic algorithm optimization is used to obtain the LC filter parameters and compared to a conventional arithmetic methodology to obtain the values of the filter. The optimization results in a set of values that lead to a higher harmonic attenuation after the transition rather than a conventional method using the switching frequency as the main design factor.

SIMULATION OF DIRECT SPREAD SPECTRUM COMMUNICATION SYSTEM ON THE HARDWARE MODULE EMONA DATEX. EVALUATION OF THE EFFECT OF NOISE ON THE QUALITY OF DEMODULATION

2019 ◽  
Author(s):  
Maksim Zhmakin ◽  
Irina Chadyuk ◽  
Aleksey Nadymov
Keyword(s):  
Spread Spectrum ◽  
Communication System ◽  
Spread Spectrum Communication ◽  
Direct Spread ◽  
Simulation Results

A variant of implementation of a communication system with direct spread spectrum is presented in this article, simulation results are also presented, the main parameters of the system are taken, and conclusions are drawn.

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