The integration of numerous distributed energy resources and power electronic devices introduces a wide spectrum of frequency disturbances,which significantly challenge the stability of modern power systems.Therefore,...The integration of numerous distributed energy resources and power electronic devices introduces a wide spectrum of frequency disturbances,which significantly challenge the stability of modern power systems.Therefore,there is an urgent need to enhance the current monitoring level of modern power systems.This paper proposes a novel busbar current inversion scheme based on an elliptical magnetic sensor array.By establishing a simulation model,the effect of structural parameters of the elliptical array on its current measurement accuracy was analysed.The anti-interference capability of the elliptical array in complex environments such as busbar displacement and crosstalk was studied,and principles for designing array parameters under different current sensor standards were established.Experiments conducted on the proposed current sensing scheme demon-strated that the designed current array has a range of 0-150 A,with a current mea-surement error below 0.1% without external interference and not exceeding 1%during busbar displacement.Under conditions of crosstalk,the measurement accuracy achieved was class 0.5.The sensor array possesses high measurement accuracy,robust anti-interference capability,low power consumption,compact size and a noncontact nature.It exhibits significant potential for extensive application in novel business scenarios within the power system.展开更多
Busbar differential relaying method based on combined amplitude and phase information of high frequency transient currents is put forward in this paper for the speed and reliability problems of busbar protection based...Busbar differential relaying method based on combined amplitude and phase information of high frequency transient currents is put forward in this paper for the speed and reliability problems of busbar protection based on fundamental frequency. Under the analysis of features of bus high frequency differential currents, complex wavelet analysis is used to extract the amplitude and phase features of 1/4 period high frequency differential currents, and amplitude and phase information are used to form the polar coordinates. Bus fault is identified intuitively and precisely according to polar locus differences. This polar coordinates represented busbar differential protection scheme based on high frequency transient signals can not only avoid TA saturation, realizing quick protection, lots of PSCAD/EMTDC simulations also show that this busbar differential protection scheme works well under different fault conditions.展开更多
In response to the current imbalance phenomenon and its harmfulness, a current sharing circuit model is built up, which reveals the underlying causes for the current imbalance through a quantitative analysis. Then, a ...In response to the current imbalance phenomenon and its harmfulness, a current sharing circuit model is built up, which reveals the underlying causes for the current imbalance through a quantitative analysis. Then, a feasible approach of improvement, namely enlargement of the length of connection busbars, is proposed. After the amendment, it can be seen that the current sharing coefficient is ahnost unity under rated or fault current conditions.展开更多
随着光伏组串式逆变器功率的不断提升,对最大功率点跟踪(Maximum Power Point Tracking,MPPT)侧电流传感器的热设计提出了更高要求。为了解决铜排在MPPT侧电流传感器中的发热问题,文章基于传热学原理和铜排的电热耦合特性,建立了精确的...随着光伏组串式逆变器功率的不断提升,对最大功率点跟踪(Maximum Power Point Tracking,MPPT)侧电流传感器的热设计提出了更高要求。为了解决铜排在MPPT侧电流传感器中的发热问题,文章基于传热学原理和铜排的电热耦合特性,建立了精确的数学模型,并提出了一种铜排温升的理论计算方法。首先,利用ANSYS有限元分析软件,建立了铜排的热仿真模型,对铜排温升进行了数值模拟;然后,搭建了实验平台,对铜排实际温升进行了测量。通过对比理论计算结果、仿真结果和实验数据,发现三者具有良好的一致性,最大误差控制在3%以内。这表明本文提出的热模型和理论计算方法是准确、可靠的,可为大量程电流传感器的热设计提供重要参考。展开更多
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB2402900Science and Technology Project of State Grid,Grant/Award Number:52060023001T。
文摘The integration of numerous distributed energy resources and power electronic devices introduces a wide spectrum of frequency disturbances,which significantly challenge the stability of modern power systems.Therefore,there is an urgent need to enhance the current monitoring level of modern power systems.This paper proposes a novel busbar current inversion scheme based on an elliptical magnetic sensor array.By establishing a simulation model,the effect of structural parameters of the elliptical array on its current measurement accuracy was analysed.The anti-interference capability of the elliptical array in complex environments such as busbar displacement and crosstalk was studied,and principles for designing array parameters under different current sensor standards were established.Experiments conducted on the proposed current sensing scheme demon-strated that the designed current array has a range of 0-150 A,with a current mea-surement error below 0.1% without external interference and not exceeding 1%during busbar displacement.Under conditions of crosstalk,the measurement accuracy achieved was class 0.5.The sensor array possesses high measurement accuracy,robust anti-interference capability,low power consumption,compact size and a noncontact nature.It exhibits significant potential for extensive application in novel business scenarios within the power system.
文摘Busbar differential relaying method based on combined amplitude and phase information of high frequency transient currents is put forward in this paper for the speed and reliability problems of busbar protection based on fundamental frequency. Under the analysis of features of bus high frequency differential currents, complex wavelet analysis is used to extract the amplitude and phase features of 1/4 period high frequency differential currents, and amplitude and phase information are used to form the polar coordinates. Bus fault is identified intuitively and precisely according to polar locus differences. This polar coordinates represented busbar differential protection scheme based on high frequency transient signals can not only avoid TA saturation, realizing quick protection, lots of PSCAD/EMTDC simulations also show that this busbar differential protection scheme works well under different fault conditions.
文摘In response to the current imbalance phenomenon and its harmfulness, a current sharing circuit model is built up, which reveals the underlying causes for the current imbalance through a quantitative analysis. Then, a feasible approach of improvement, namely enlargement of the length of connection busbars, is proposed. After the amendment, it can be seen that the current sharing coefficient is ahnost unity under rated or fault current conditions.
文摘随着光伏组串式逆变器功率的不断提升,对最大功率点跟踪(Maximum Power Point Tracking,MPPT)侧电流传感器的热设计提出了更高要求。为了解决铜排在MPPT侧电流传感器中的发热问题,文章基于传热学原理和铜排的电热耦合特性,建立了精确的数学模型,并提出了一种铜排温升的理论计算方法。首先,利用ANSYS有限元分析软件,建立了铜排的热仿真模型,对铜排温升进行了数值模拟;然后,搭建了实验平台,对铜排实际温升进行了测量。通过对比理论计算结果、仿真结果和实验数据,发现三者具有良好的一致性,最大误差控制在3%以内。这表明本文提出的热模型和理论计算方法是准确、可靠的,可为大量程电流传感器的热设计提供重要参考。
