Xu B.,Shanghai JiaoTong University |
Xu B.,Jinshan Power Supply Company |
Xu B.,Shinan Power Supply Company |
Xu B.,Inner Mongolia University of Technology |
And 16 more authors.
Australian Journal of Electrical and Electronics Engineering | Year: 2013
One of the most difficult problems in compensated distribution networks is the grounded fault location. This paper proposes a new method for locating single-line-to-ground SLG faults in compensated distribution networks. The grounded fault location system is made up of the host, the controller, the signal generator and the grounded fault indicator (GFI). When a SLG fault occurs, the fault phase is identified firstly, and then a signal generator paralleled with the arc suppression coil injects a special current into the system. Subsequently, GFIs along the fault phase are activated to sample the fault phase current and send it back. The fault phase current is computed by the host with a fast Fourier transform algorithm. By comparing these frequency components of the fault phase current, the fault section is identified based on the significant difference of the second harmonic of two adjacent GFIs. Due to the short length of feeders, the distance between two adjacent GFIs is short enough for line patrol personnel to find and repair the fault easily. Finally, a modified IEEE 13-node feeder test is constructed in PSCAD/EMTDC to evaluate this method. The simulations results confirm the validity of the proposed approach. © Institution of Engineers Australia 2013.
Luo Z.,Nanjing Southeast University |
Xie J.,Nanjing Southeast University |
Xie J.,Wuxi Information Security Engineering Technology Research Center |
Gu W.,Nanjing Southeast University |
And 3 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2015
Currently, the RAS algorithm is adopted as the public key algorithm of most existing security systems, which cannot ensure the security of message transmission in digital substation communications. In order to solve this problem, an implementation scheme for authentication mechanisms based on IEC 62351 combined with SM2 cryptosystem is proposed. For situations in which a bus fault occurs in the unified star network, ring network and ring network with redundant loop network in the whole D2-1 substation, respectively. The digital signing time for generic object oriented substation/sample value (GOOSE/SMV) messages is calculated quantitatively while the communication delay is obtained through OPNET simulation, and the different maximum transmission delay times of three kinds of network structures with 100 Mbit/s and 10 Mbit/s bandwidths are obtained. Simulation results have proved the effectiveness of the proposed design in meeting the demand of security and real-time in substation communication message. ©, 2015, Automation of Electric Power Systems Press. All right reserved.