The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Shuo Zhang - One of the best experts on this subject based on the ideXlab platform.
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A Pilot DC Line Protection Scheme for Multi-Terminal HVDC Grid
2019 IEEE Power & Energy Society General Meeting (PESGM), 2019Co-Authors: Qiang Huang, Bin Xu, Jun Li, Shuo ZhangAbstract:Pilot protection is indispensable in multi-terminal HVDC grid to ensure its safe operation. This paper proposes a pilot protection method based on voltage polarities of Current-Limiting Reactors at the ends of DC lines. Analysis shows that the voltage polarities of terminal Reactors at the two ends of DC lines are both positive when internal fault occurs, while they are opposite for external faults. Based on the aforementioned characteristic difference, a pilot protection criterion is built to distinguish internal fault from external fault. To avoid mal operation of the healthy pole generated by the coupling effect, the fault voltage of Current-Limiting reactor is integrated, and its polarity can be identified based on the integration value. At last, a four-terminal modular multilevel converter (MMC)-based HVDC grid simulation model is built in PSCAD/EMTDC, and the simulation results verified the effectiveness of the protection method.
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Fast single-end line protection method for the meshed multi-terminal HVDC grid
The Journal of Engineering, 2019Co-Authors: Qiang Huang, Jie Zhang, Chunhua Xu, Shuo ZhangAbstract:In view of the short-circuit fault characteristics, the protection technique of the dc lines limits the development of the modular multi-level converter (MMC)-based HVDC grid in a large extent. This study derives the calculation formulas of the transient voltages of internal and external faults and proposes a single-end protection scheme based on the transition period (TP) from the abrupt changing point to the first extreme point of the fault voltage. Due to the Current-Limiting Reactors, the TP of the internal fault is much shorter than that of the external fault, which is used to discriminate internal fault from external fault. A four-terminal symmetrical bipolar HVDC grid based on MMC is modelled using PSCAD/EMTDC, and simulation results demonstrate the validity of the new proposed dc transmission line protection method.
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A Pilot Protection Scheme of DC Lines for Multi-Terminal HVDC Grid
IEEE Transactions on Power Delivery, 2019Co-Authors: Qiang Huang, Shuo ZhangAbstract:Multi-terminal HVDC grid has extremely high demand for protection speed of DC lines, consequently, the sampling time window of the main protection is very short, which affects its selectivity and reliability. To make up for the insufficiency of the non-unit main protection, this paper proposes a pilot protection scheme based on the voltage polarities of Current-Limiting Reactors at the ends of DC lines. Analysis shows that the voltage polarities of terminal Reactors at the two ends of the DC lines are both positive when internal fault occurs, while they are opposite for external faults. Based on the aforementioned characteristic difference, a pilot protection criterion is built to discriminate between internal and external faults. To avoid mal-operation of the protection on healthy pole generated by the coupling effect, the polarity mutation of reactor voltage on healthy pole due to coupling effect is analyzed when single-pole-to-ground fault occurs. Based on the analysis, the fault voltage of Current-Limiting reactor is integrated, and its polarity can be identified based on the integration value. At last, a four-terminal modular multilevel converter (MMC)-based HVDC grid model is built in PSCAD/EMTDC, and the effectiveness of the protection scheme is verified by extensive simulations.
Qiang Huang - One of the best experts on this subject based on the ideXlab platform.
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A Pilot DC Line Protection Scheme for Multi-Terminal HVDC Grid
2019 IEEE Power & Energy Society General Meeting (PESGM), 2019Co-Authors: Qiang Huang, Bin Xu, Jun Li, Shuo ZhangAbstract:Pilot protection is indispensable in multi-terminal HVDC grid to ensure its safe operation. This paper proposes a pilot protection method based on voltage polarities of Current-Limiting Reactors at the ends of DC lines. Analysis shows that the voltage polarities of terminal Reactors at the two ends of DC lines are both positive when internal fault occurs, while they are opposite for external faults. Based on the aforementioned characteristic difference, a pilot protection criterion is built to distinguish internal fault from external fault. To avoid mal operation of the healthy pole generated by the coupling effect, the fault voltage of Current-Limiting reactor is integrated, and its polarity can be identified based on the integration value. At last, a four-terminal modular multilevel converter (MMC)-based HVDC grid simulation model is built in PSCAD/EMTDC, and the simulation results verified the effectiveness of the protection method.
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Fast single-end line protection method for the meshed multi-terminal HVDC grid
The Journal of Engineering, 2019Co-Authors: Qiang Huang, Jie Zhang, Chunhua Xu, Shuo ZhangAbstract:In view of the short-circuit fault characteristics, the protection technique of the dc lines limits the development of the modular multi-level converter (MMC)-based HVDC grid in a large extent. This study derives the calculation formulas of the transient voltages of internal and external faults and proposes a single-end protection scheme based on the transition period (TP) from the abrupt changing point to the first extreme point of the fault voltage. Due to the Current-Limiting Reactors, the TP of the internal fault is much shorter than that of the external fault, which is used to discriminate internal fault from external fault. A four-terminal symmetrical bipolar HVDC grid based on MMC is modelled using PSCAD/EMTDC, and simulation results demonstrate the validity of the new proposed dc transmission line protection method.
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A Pilot Protection Scheme of DC Lines for Multi-Terminal HVDC Grid
IEEE Transactions on Power Delivery, 2019Co-Authors: Qiang Huang, Shuo ZhangAbstract:Multi-terminal HVDC grid has extremely high demand for protection speed of DC lines, consequently, the sampling time window of the main protection is very short, which affects its selectivity and reliability. To make up for the insufficiency of the non-unit main protection, this paper proposes a pilot protection scheme based on the voltage polarities of Current-Limiting Reactors at the ends of DC lines. Analysis shows that the voltage polarities of terminal Reactors at the two ends of the DC lines are both positive when internal fault occurs, while they are opposite for external faults. Based on the aforementioned characteristic difference, a pilot protection criterion is built to discriminate between internal and external faults. To avoid mal-operation of the protection on healthy pole generated by the coupling effect, the polarity mutation of reactor voltage on healthy pole due to coupling effect is analyzed when single-pole-to-ground fault occurs. Based on the analysis, the fault voltage of Current-Limiting reactor is integrated, and its polarity can be identified based on the integration value. At last, a four-terminal modular multilevel converter (MMC)-based HVDC grid model is built in PSCAD/EMTDC, and the effectiveness of the protection scheme is verified by extensive simulations.
Bingbing Wang - One of the best experts on this subject based on the ideXlab platform.
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Research on Coordination and Optimal Configuration of Current Limiting Devices in HVDC Grids
IEEE Access, 2019Co-Authors: Rui Ge, Bingbing WangAbstract:This paper proposes a collaborative optimal configuration method of Current Limiting Reactors (CLRs) and fault Current limiters (FCLs) in the modular multilevel converter (MMC)-based high voltage direct Current (HVDC) grids. The calculation methods of dc line fault Currents and bridge arm fault Currents considering the collaboration of CLRs and FCLs have high accuracy. The multi-objective optimization configuration model is established, in which the fault Current Limiting effect, the total inductances of CLRs and the number of FCLs are used as objective functions while the DCCBs Current breaking capacity, the converter valves overCurrent protection, the boundary of the dc line protection area, the dynamic performance of the dc system and the converter station outlet dc voltage are used as constraints. In this paper, the multi-objective optimization algorithm is used to solve multi-objective optimal configuration problem for the CLRs and FCLs. Finally, the proposed method is tested with a symmetrical monopole four-terminal MMC-HVDC grid in PSCAD/EMTDC. The simulation results verify that the proposed optimal configuration method can ensure the continuous and reliable operation of the dc grid under dc faults.
Wei Wang - One of the best experts on this subject based on the ideXlab platform.
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side effects of Current Limiting Reactors on power system
International Journal of Electrical Power & Energy Systems, 2013Co-Authors: Shuiming Chen, Pengcheng Yang, Wei Xu, Xiao Bian, Wei WangAbstract:Abstract Air-cored Current-Limiting Reactor (CLR) has already been widely applied to limit the magnitude of fault Current in power systems in many countries, Brazil for example, and meanwhile the CLR has made a significant contribution to the severity of transient overvoltages in power systems, such as transient recovery voltage (TRV), switching overvoltage (SOV), and temporary overvoltage (TOV). The present paper here did a lot of simulations on the application of CLR for a real-life transmission line, suggesting that with equipment parameters of originally draft, TRV would have exceeded the circuit breakers’ TRV ratings and necessary measures should be taken to decrease TRV. Digital simulations were made with PSCAD/EMTDC software and the results implied that the magnitude of the SOV and the TOV increased up to or even exceeded the safe limits with the CLR installed. Relevant studies are strongly recommended before the CLR is applied to ensure the safety of equipment and transmission system.
Rui Ge - One of the best experts on this subject based on the ideXlab platform.
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Research on Coordination and Optimal Configuration of Current Limiting Devices in HVDC Grids
IEEE Access, 2019Co-Authors: Rui Ge, Bingbing WangAbstract:This paper proposes a collaborative optimal configuration method of Current Limiting Reactors (CLRs) and fault Current limiters (FCLs) in the modular multilevel converter (MMC)-based high voltage direct Current (HVDC) grids. The calculation methods of dc line fault Currents and bridge arm fault Currents considering the collaboration of CLRs and FCLs have high accuracy. The multi-objective optimization configuration model is established, in which the fault Current Limiting effect, the total inductances of CLRs and the number of FCLs are used as objective functions while the DCCBs Current breaking capacity, the converter valves overCurrent protection, the boundary of the dc line protection area, the dynamic performance of the dc system and the converter station outlet dc voltage are used as constraints. In this paper, the multi-objective optimization algorithm is used to solve multi-objective optimal configuration problem for the CLRs and FCLs. Finally, the proposed method is tested with a symmetrical monopole four-terminal MMC-HVDC grid in PSCAD/EMTDC. The simulation results verify that the proposed optimal configuration method can ensure the continuous and reliable operation of the dc grid under dc faults.
