In recent years, sinusoidal waveform of the current and voltage disturbs in the electrical distribution system because of the due to the increasing number of non-linear loads. Many standards of IEC and IEEE standards ...In recent years, sinusoidal waveform of the current and voltage disturbs in the electrical distribution system because of the due to the increasing number of non-linear loads. Many standards of IEC and IEEE standards have been published in order to limit the voltage and current waveform distortion. The operators of the electricity distribution network widely use the power quality monitoring systems at the point of common connection (PCC). It has been identified that there are substantial number of harmonic currents excess of the standards transferred to the grid according to the data obtained from power quality monitoring systems. In case of exceeding the limits specified in the standards, there is a need to determine the network and customer responsibilities for the implementation of required sanctions. In this study, using recorded data at the PCC of a medium voltage electrical distribution system, voltage and current harmonic distortion responsibilities of the network and customer are determined by the improved harmonic current vector method. Up-to-date load model based on field measurement which provides more accurate results has been used instead of the constant load impedance in the proposed method.展开更多
The widespread deployment of renewable energies and non-linear loads has led to serious harmonic pollution in electrical distribution networks.Evaluation of the harmonic contribution(HC)of each customer is a significa...The widespread deployment of renewable energies and non-linear loads has led to serious harmonic pollution in electrical distribution networks.Evaluation of the harmonic contribution(HC)of each customer is a significant task for power quality management.Most previous studies focus on periodic evaluation methods,where numerous data have to be collected in advance over a period(e.g.,one day).However,customer behaviors are time-varying and would lead to dynamic HCs,which can not be captured by traditional periodic evaluation methods.To address this issue,this paper presents a novel real-time HC evaluation method considering multiple dynamic customers.First,a two-stage iteration estimator is proposed based on the information fusion technique to quantify real-time HC of each customer.Then,to mitigate the negative effect of unknown background harmonics,a dominant index method is developed to determine credibility of the measurement data.On this basis,an adaptive gain selection strategy is proposed to improve accuracy of real-time HC evaluation.By doing so,the major harmonic contributor can be identified for implementing harmonic suppression and improving power quality.Finally,a typical IEEE system is utilized to verify the proposed methods.The results show that using the proposed method,evaluation errors can be reduced from about 10%to 2.5%.Moreover,the total harmonic distortion of voltage can be suppressed from 5.564%to 0.702%.Therefore,this research provides practical insights for addressing harmonic problems in power systems.展开更多
基金This study has been financially supported by TUBITAK with 110E134 project number.
文摘In recent years, sinusoidal waveform of the current and voltage disturbs in the electrical distribution system because of the due to the increasing number of non-linear loads. Many standards of IEC and IEEE standards have been published in order to limit the voltage and current waveform distortion. The operators of the electricity distribution network widely use the power quality monitoring systems at the point of common connection (PCC). It has been identified that there are substantial number of harmonic currents excess of the standards transferred to the grid according to the data obtained from power quality monitoring systems. In case of exceeding the limits specified in the standards, there is a need to determine the network and customer responsibilities for the implementation of required sanctions. In this study, using recorded data at the PCC of a medium voltage electrical distribution system, voltage and current harmonic distortion responsibilities of the network and customer are determined by the improved harmonic current vector method. Up-to-date load model based on field measurement which provides more accurate results has been used instead of the constant load impedance in the proposed method.
基金funded by The Science and Technology Development Fund,Macao SAR,China(File/Project no.SKL-IOTSC-2021-2023,0003/2020/AKP,FDCT/0022/2020/A1).
文摘The widespread deployment of renewable energies and non-linear loads has led to serious harmonic pollution in electrical distribution networks.Evaluation of the harmonic contribution(HC)of each customer is a significant task for power quality management.Most previous studies focus on periodic evaluation methods,where numerous data have to be collected in advance over a period(e.g.,one day).However,customer behaviors are time-varying and would lead to dynamic HCs,which can not be captured by traditional periodic evaluation methods.To address this issue,this paper presents a novel real-time HC evaluation method considering multiple dynamic customers.First,a two-stage iteration estimator is proposed based on the information fusion technique to quantify real-time HC of each customer.Then,to mitigate the negative effect of unknown background harmonics,a dominant index method is developed to determine credibility of the measurement data.On this basis,an adaptive gain selection strategy is proposed to improve accuracy of real-time HC evaluation.By doing so,the major harmonic contributor can be identified for implementing harmonic suppression and improving power quality.Finally,a typical IEEE system is utilized to verify the proposed methods.The results show that using the proposed method,evaluation errors can be reduced from about 10%to 2.5%.Moreover,the total harmonic distortion of voltage can be suppressed from 5.564%to 0.702%.Therefore,this research provides practical insights for addressing harmonic problems in power systems.
