Synchronized profiles of power quality parameters in assessment of disturbances in power systems with distributed generation

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.

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Fast-training feedforward neural network for multi-scale power quality monitoring in power systems with distributed generation sources

Measurement ◽

10.1016/j.measurement.2020.108690 ◽

2021 ◽

Vol 170 ◽

pp. 108690

Author(s):

O. Cortes-Robles ◽

Emilio Barocio ◽

Artjoms Obushevs ◽

Petr Korba ◽

Felix Rafael Segundo Sevilla

Keyword(s):

Neural Network ◽

Power Systems ◽

Power Quality ◽

Distributed Generation ◽

Feedforward Neural Network ◽

Quality Monitoring ◽

Multi Scale ◽

Power Quality Monitoring ◽

Fast Training

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Power Quality Issues on Distribution System : A Survey

SMART MOVES JOURNAL IJOSCIENCE ◽

10.24113/ijoscience.v6i9.328 ◽

2020 ◽

Vol 6 (9) ◽

pp. 11-14

Author(s):

MD Shahabuddin Alam ◽

Jyoti Bansal

Keyword(s):

Power Quality ◽

Distributed Generation ◽

Distribution System ◽

Power Flow ◽

Reactive Power ◽

Quality Parameters ◽

Active Filters ◽

Photovoltaic System ◽

Dynamic Voltage Restorer ◽

Wide Range

Improving the quality of energy in distributed generation is a rapidly growing, challenging, and interesting area of modern times. In recent decades, a large number of techniques have been developed to improve energy quality. This article attempts to comprehensively examine a wide range of methods for improving power quality in distributed generation. This includes the use of active filters, Dynamic Voltage Restorer, DSTATCOM, reactive power compensation techniques, and an unmodified power quality conditioner. In this test, all of these methods are examined with power quality parameters such as reverse power flow, voltage stability, and current harmonics. This document describes energy quality problems and possible effects on the distribution system due to a grid-connected photovoltaic system.

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

URBAN CONSTRUCTION AND ARCHITECTURE ◽

10.17673/vestnik.2017.01.23 ◽

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.

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

Electronics ◽

10.3390/electronics8111259 ◽

2019 ◽

Vol 8 (11) ◽

pp. 1259 ◽

Cited By ~ 15

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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