scholarly journals Finding the Best Programmable PWM Pattern for Three-Level Active Front-Ends at 18-Pulse Connection

Machines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 127
Author(s):  
Alexander S. Maklakov ◽  
Tao Jing ◽  
Andrey A. Radionov ◽  
Vadim R. Gasiyarov ◽  
Tatyana A. Lisovskaya
Keyword(s):  
Phase Shift ◽  
Power Systems ◽  
Power Quality ◽  
Electromagnetic Compatibility ◽  
Work Roll ◽  
Quality Parameters ◽  
Power Circuit ◽  
Electric Power Supply ◽  
Positive Effects ◽  
Harmonic Distortions

The existing publications on the analysis of power quality indicators in modern electric power supply systems are void of a comprehensive approach to improving these indicators in power systems by implementing multipulse connections. To the authors’ knowledge, this paper is the first to analyze current harmonic distortions in an 18-pulse connection of three-level active front-ends (AFE) featuring a programmed PWM. Raw data were obtained from, and current quality was analyzed for the power circuit of the main electric drive actuating the rolls in the rolling stand of a plate mill. The key feature of such circuitry is that the synchronous motor of each work roll is connected to the grid with an 18-pulse connection that uses three phase-shift transformers, where the phase shifts are 0° (delta/delta), 20° (delta/polygon) and −20° (delta/polygon). The circuitry connects three frequency converters (FC) with the AFEs in parallel. Phase-shift transformers were found to periodically overheat in the process. When overheating occurred, a programmed PWM voltage waveform was applied where harmonics 17 and 19 were eliminated. The goal and objectives were to analyze why the transformer would overheat and to find out how the issue could be addressed. The authors developed a simulation model of the research object in order to assess power quality parameters. Simulation results obtained in Matlab/Simulink were used to estimate the total harmonic distortions (THD) and individual harmonic factors for up to the 50th secondary transformer winding and grid harmonic with four different programmed AFE PWM voltage waveforms. The results helped find the best such waveform to prevent phase-shift transformers from overheating; one with harmonics 5, 7, 17 and 19 eliminated. The experimental and mathematical modeling results in the paper were confirmed by positive effects after industrial implementation of the system. Research performed directly on the operating equipment has been classified by the company and is not publicly available. These results are highly versatile and could be used in similar research on other circuitries to ensure the electromagnetic compatibility of nonlinear power-consuming devices.

scholarly journals Improving the technology of operating electric locomotives using electric power storage device

2019 ◽  
Vol 110 ◽  
pp. 01033 ◽  
Author(s):  
Kirill Domanov ◽  
Andrei Shatohin ◽  
Vladislav Nezevak ◽  
Vasily Cheremisin
Keyword(s):  
Electric Energy ◽  
Economic Assessment ◽  
Quality Parameters ◽  
Storage Device ◽  
Railway Transportation ◽  
Storage Unit ◽  
Power Circuit ◽  
Positive Effects ◽  
Transportation Process ◽  
Transportation Organization

The article discussed the questions of the railway transportation organization along the transport corridors passing through the territory of Russia using the innovative locomotives of new generation with the polygon’s structure of the transportation process’ organization. There was carried out an analysis of the railway car standing at the docking stations of the single-phase alternating and direct current. The results of simulation modeling of the transportation process on the railway sections, which have a docking station, are given. There are shown the positive effects of the perfection of the polygon’s exploitation technology of the locomotive fleet due to introduction of the double feed electric locomotives to the transport corridors, manifesting in the cargo delivery’s time reduction due to reduction of the ready train’s standing time at docking stations twice, in comparison with the time during exploitation of the only single-system electric locomotives, and also in increasing of the area’s speed of trains in the all polygon of the heavy trains’ turnover. The usage of the double feed electric locomotives in areas, which contains different kinds of the current, allows increasing the quality parameters of the traction electric rolling stock’s exploitation. There were considered the ways to increase the energy efficiency of the double feed electric locomotives, particularly by applying the electric energy storage unit for connection to the DC link of the electric locomotive’s power circuit. The economic assessment of exploitation of the two-systems electric locomotives was carried out.

ELECTRIC POWER QUALITY IN ELECTRIC POWER SYSTEMS OF BOILER STATIONS AND HEATING SUBSTATIONS USING PUMPS OPERATED BY VARIABLE-FREQUENCY DRIVE

2017 ◽  
Vol 7 (1) ◽  
pp. 138-144
Author(s):  
Ivan I. ARTYUKHOV ◽  
Svetlana V. MOLOT
Keyword(s):  
Power Systems ◽  
Electric Power ◽  
Power Quality ◽  
Energy Savings ◽  
Quality Parameters ◽  
Electric Power System ◽  
Variable Frequency ◽  
Variable Frequency Drive ◽  
Electric Power Quality ◽  
Negative Impacts

Power electronics devices are widespread in diff erent engineering systems for housing and public utilities. But they have negative impacts on the power source. A typical example is using of the pumps, operated by variable frequency drive, in boiler stations and heating substations. The using helps both the energy savings and the electric power quality declination. If boiler station is supplied by emergency generator the electric power quality declination signifi cantly increases. Electric power quality parameters are analyzed using a simulation model, built in MATLAB/Simulink, in diff erent situations. The recommendations to ensure the specifi ed electric power quality in the electric power system are created.

scholarly journals High Accuracy Power Quality Evaluation under a Colored Noisy Condition by Filter Bank ESPRIT

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1259 ◽  
Author(s):  
Elaine Santos ◽  
Mahdi Khosravy ◽  
Marcelo A. A. Lima ◽  
Augusto S. Cerqueira ◽  
Carlos A. Duque ◽  
...  
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Filter Bank ◽  
Colored Noise ◽  
Renewable Energy Sources ◽  
Quality Parameters ◽  
Computational Effort ◽  
Parameters Estimation ◽  
Quality Analysis ◽  
High Level

Due to the highly increasing integration of renewable energy sources with the power grid and their fluctuations, besides the recent growth of new power electronics equipment, the noise in power systems has become colored. The colored noise affects the methodologies for power quality parameters’ estimation, such as harmonic and interharmonic components. Estimation of signal parameters via rotational invariance techniques (ESPRIT) as a parametric technique with high resolution has proven its efficiency in the estimation of power signal components’ frequencies, amplitudes, and phases for quality analysis, under the assumption of white Gaussian noise. Since ESPRIT suffers from high computational effort, filter bank ESPRIT (FB-ESPRIT) was suggested for mitigation of the complexity. This manuscript suggests FB-ESPRIT as well for accurate and robust estimation of power signal components’ parameters in the presence of the colored noise. Even though the parametric techniques depend on the Gaussianity of contaminating noise to perform properly, FB-ESPRIT performs well in colored noise. The FB-ESPRIT superiority compared with the conventional ESPRIT and MUSIC techniques was demonstrated through many simulations runs on synthetic power signals with multiple harmonics, interharmonics, and subharmonic components in the presence of noises of different colors and different SNR levels. FB-ESPRIT had a significant efficiency superiority in power quality analysis with a wide gap distance from the other estimators, especially under the high level of colored noise.

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