In order to eliminate the influence of frequency change on real-time voltage acquisition,a low-cost solution of voltage monitoring was proposed using the multi-channel DMA synchronous frequency trace-sampling techniqu...In order to eliminate the influence of frequency change on real-time voltage acquisition,a low-cost solution of voltage monitoring was proposed using the multi-channel DMA synchronous frequency trace-sampling technique.In-chip resources of the designed voltage monitor were fully utilized in hardware design to reduce external devices.The MQX RTOS was used to perform the functional tasks flexibly and efficiently;especially the Ethernet communication applications and USB device connection were realized using its TCP/IP protocol stack and USB driver.In addition,to ensure the safety of electrical records,data statistics and alarm information management were also implemented through the management of the storage in FLASH.The test results show that the voltage monitor designed in this paper has the advantages of accurate measurement,strong resistance to frequency interference and low cost,and can be widely applied in the field of voltage monitoring in distribution networks.展开更多
Power grid is an indispensable infrastructure in modern society,in order to ensure the normal operation of the grid,online non-contact monitoring of high-voltage lines is essential.In this work,a‘capacitor-laser diod...Power grid is an indispensable infrastructure in modern society,in order to ensure the normal operation of the grid,online non-contact monitoring of high-voltage lines is essential.In this work,a‘capacitor-laser diode(LD)-capacitor’structure,namely,laser diode in capacitors(LDIC),that can be used for non-contact monitoring of high-voltage(HV)line status by directly transferring the status information of the HV line to modulated laser pulses is proposed.The proposed LDIC can accurately extract the real-time voltage changes on the HV line with an accuracy level of 0.959%.Because the LDIC is sensitive to high-frequency electromagnetic field,the LDIC is successfully utilised to detect the external electromagnetic interference(EMI)to obtain the intensity and frequency of the external EMI.Additionally,the amplitude and frequency of the HV line vibration can be accurately monitored by using the LDIC.For the third-order curve fitting of vibration amplitude,the average error is only 0.00867,and the average error of linear fitting of vibration frequency is as low as 0.00655.This work provides a novel approach for the online monitoring of the HV line status and a new supplement for the development of power grid technology.展开更多
The increase in the number of sensitive loads in power systems has made power quality,particularly voltage sag,a prominent problem due to its effects on consumers from both the utility and customer perspectives.Thus,t...The increase in the number of sensitive loads in power systems has made power quality,particularly voltage sag,a prominent problem due to its effects on consumers from both the utility and customer perspectives.Thus,to evaluate the effects of voltage sag caused by short circuits,it is necessary to determine the areas of vulnerability(AOVs).In this paper,a new method is proposed for the AOV determination that is applicable to large-scale networks.The false position method(FPM)is proposed for the precise calculation of the critical points of the system lines.Furthermore,a new method is proposed for the voltage sag monitor(VSM)placement to detect the fault locations.A systematic placement scheme is used to provide the highest fault location detection(FLD)index at buses and lines for various short-circuit fault types.To assess the efficiency of the proposed methods for AOV determination and VSM placement,simulations are conducted in IEEE standard systems.The results demonstrate the accuracy of the proposed method for AOV determination.In addition,through VSM placement,the fault locations at buses and lines are detected.展开更多
文摘In order to eliminate the influence of frequency change on real-time voltage acquisition,a low-cost solution of voltage monitoring was proposed using the multi-channel DMA synchronous frequency trace-sampling technique.In-chip resources of the designed voltage monitor were fully utilized in hardware design to reduce external devices.The MQX RTOS was used to perform the functional tasks flexibly and efficiently;especially the Ethernet communication applications and USB device connection were realized using its TCP/IP protocol stack and USB driver.In addition,to ensure the safety of electrical records,data statistics and alarm information management were also implemented through the management of the storage in FLASH.The test results show that the voltage monitor designed in this paper has the advantages of accurate measurement,strong resistance to frequency interference and low cost,and can be widely applied in the field of voltage monitoring in distribution networks.
基金supported by National Key R&D Program of China under Grant No.2021YFB3600400Mindu Innovation Laboratory Project under Grant No.2020ZZ113.
文摘Power grid is an indispensable infrastructure in modern society,in order to ensure the normal operation of the grid,online non-contact monitoring of high-voltage lines is essential.In this work,a‘capacitor-laser diode(LD)-capacitor’structure,namely,laser diode in capacitors(LDIC),that can be used for non-contact monitoring of high-voltage(HV)line status by directly transferring the status information of the HV line to modulated laser pulses is proposed.The proposed LDIC can accurately extract the real-time voltage changes on the HV line with an accuracy level of 0.959%.Because the LDIC is sensitive to high-frequency electromagnetic field,the LDIC is successfully utilised to detect the external electromagnetic interference(EMI)to obtain the intensity and frequency of the external EMI.Additionally,the amplitude and frequency of the HV line vibration can be accurately monitored by using the LDIC.For the third-order curve fitting of vibration amplitude,the average error is only 0.00867,and the average error of linear fitting of vibration frequency is as low as 0.00655.This work provides a novel approach for the online monitoring of the HV line status and a new supplement for the development of power grid technology.
文摘The increase in the number of sensitive loads in power systems has made power quality,particularly voltage sag,a prominent problem due to its effects on consumers from both the utility and customer perspectives.Thus,to evaluate the effects of voltage sag caused by short circuits,it is necessary to determine the areas of vulnerability(AOVs).In this paper,a new method is proposed for the AOV determination that is applicable to large-scale networks.The false position method(FPM)is proposed for the precise calculation of the critical points of the system lines.Furthermore,a new method is proposed for the voltage sag monitor(VSM)placement to detect the fault locations.A systematic placement scheme is used to provide the highest fault location detection(FLD)index at buses and lines for various short-circuit fault types.To assess the efficiency of the proposed methods for AOV determination and VSM placement,simulations are conducted in IEEE standard systems.The results demonstrate the accuracy of the proposed method for AOV determination.In addition,through VSM placement,the fault locations at buses and lines are detected.
