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A Novel Procedure for Protection Setting in an HVDC System Based on Fault Quantities
Gao, Benfeng,Zhang, Ruixue,Zhang, Xuewei The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2
HVDC protection setting is difficult to be calculated analytically because of its strong nonlinearity. The currently used setting method is based on the empirical setting of previous projects and then verified by digital simulation. It entails a huge workload and low efficiency. To facilitate protection setting, this paper systematically summarizes the HVDC protection characteristics and then presents a classification of HVDC protections according to the protection principles. On the basis of the fault quantities, a novel setting procedure suitable for travelling wave protection, derivative and level protection, and differential protection is proposed. The proposed procedure is illustrated and verified in detail with the example of travelling wave protection. An HVDC protection setting system that has the functions of automatic protection setting and data management is developed utilizing the C# programming language.
A Novel Procedure for Protection Setting in an HVDC System Based on Fault Quantities
Benfeng Gao,Ruixue Zhang,Xuewei Zhang 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2
HVDC protection setting is difficult to be calculated analytically because of its strong nonlinearity. The currently used setting method is based on the empirical setting of previous projects and then verified by digital simulation. It entails a huge workload and low efficiency. To facilitate protection setting, this paper systematically summarizes the HVDC protection characteristics and then presents a classification of HVDC protections according to the protection principles. On the basis of the fault quantities, a novel setting procedure suitable for travelling wave protection, derivative and level protection, and differential protection is proposed. The proposed procedure is illustrated and verified in detail with the example of travelling wave protection. An HVDC protection setting system that has the functions of automatic protection setting and data management is developed utilizing the C# programming language.
Design of Direct-Current Fuzzy Controller for Mitigating Commutation Failure in HVDC System
Benfeng Gao,Kewei Yuan,Peiyi Dong,Chao Luo,Shuqiang Zhao 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.4
Commutation failures can deteriorate the availability of high-voltage direct current (HVDC) links and may lead to outage of the HVDC system. Most commutation failures are caused by voltage reduction due to ac system faults on inverter side. The commutation failure process can be divided into two stages. The first stage, from the occurrence to the clearing of faults, is called ‘Deterioration Stage’. The second stage, from the faults clearing to restoring the power system stability, is called ‘Recovery Stage’. Based on the analysis of the commutation failure process, this paper proposes a direct-current fuzzy controller including prevention and recovery controller. The prevention controller reduces the direct current to prevent Commutation failures in the ‘Deterioration Stage’ according to the variation of ac voltage. The recovery controller magnifies the direct current to speed up the recovery of power system in the ‘Recovery Stage’, based on the recovery of direct voltage. The validity of this proposed fuzzy controller is further proved by simulation with CIGRE HVDC benchmark model in PSCAD/EMTDC. The results show the commutation failures can be mitigated by the proposed direct-current fuzzy controller.
Design of Direct-Current Fuzzy Controller for Mitigating Commutation Failure in HVDC System
Gao, Benfeng,Yuan, Kewei,Dong, Peiyi,Luo, Chao,Zhao, Shuqiang The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.4
Commutation failures can deteriorate the availability of high-voltage direct current (HVDC) links and may lead to outage of the HVDC system. Most commutation failures are caused by voltage reduction due to ac system faults on inverter side. The commutation failure process can be divided into two stages. The first stage, from the occurrence to the clearing of faults, is called 'Deterioration Stage'. The second stage, from the faults clearing to restoring the power system stability, is called 'Recovery Stage'. Based on the analysis of the commutation failure process, this paper proposes a direct-current fuzzy controller including prevention and recovery controller. The prevention controller reduces the direct current to prevent Commutation failures in the 'Deterioration Stage' according to the variation of ac voltage. The recovery controller magnifies the direct current to speed up the recovery of power system in the 'Recovery Stage', based on the recovery of direct voltage. The validity of this proposed fuzzy controller is further proved by simulation with CIGRE HVDC benchmark model in PSCAD/EMTDC. The results show the commutation failures can be mitigated by the proposed direct-current fuzzy controller.