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Zhou X.,Nanjing SAC Power Grid Automation Co. | Wang S.,Nanjing SAC Power Grid Automation Co. | Wu Z.,Jiangsu Electric Power Company | Tang Z.,Nanjing SAC Power Grid Automation Co. | And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2015

According to the requirement of the protection equipment's local placing in the hierarchical relay protection control system and because of the problems, such as large power supply, complex link, etc., the centralized busbar protection cannot be directly placed locally. This paper puts forward a distributed busbar protection locally placing implementation scheme based on HSR ring network. In this scheme, at each interval it locally places the corresponding independent submachine to get the interval's sampling value and digital data. Using dual redundant HSR ring network to interconnect each submachine and share each data, each submachine owns whole busbar protection function and judges independently. The new interpolation synchronization technology makes the busbar protection not rely on the external clock, at the moment the bypass technology designed can reduce the complexity of operation. This busbar protection model machine has been successfully passed the professional institute's test and trial work in the substation, which verify the feasibility of this scheme. ©, 2015, Power System Protection and Control Press. All right reserved.


Xu L.,Nanjing SAC Power Grid Automation Co. | Chen X.,Nanjing SAC Power Grid Automation Co. | Yu H.,Nanjing SAC Power Grid Automation Co. | Xie K.,Nanjing SAC Power Grid Automation Co. | Xu F.,Nanjing SAC Power Grid Automation Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2014

To solve the problems in EMC (electromagnetic compatibility) test of IMUIT (integrated merging unit and intelligent terminal)equipment, the authors analyze the characteristics of the fast transient impulses, such as electrical fast transient/burst (EFT/B), surge, and electro-static discharge (ESD), and propose the following anti-interference methods to enhance EMC for IMUIT equipment. The AC filter circuit, digital output filter circuit, and LED filter circuit are modified with capacitors, magnetic bead or transient voltage suppressor(TVS)to enhance the interference suppression. The inter-coupling among different circuits can be reduced by optimizing the wiring and layout of PCB and keeping reliable grounding. Test results show that the proposed methods for suppressing electromagnetic interference in the hardware system design of IMUIT equipment are effective. ©, 2014, Xi'an High Voltage Apparatus Research Institute. All right reserved.


Zhang X.-J.,Nanjing SAC Power Grid Automation Co. | Liu Y.,Nanjing SAC Power Grid Automation Co. | Yu H.-W.,Nanjing SAC Power Grid Automation Co. | Chen X.-Z.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2014

Smart substation GOOSE, SV, MMS three-in-one network achieves full information sharing, the double star network reliability is high, the corresponding power device needs to support efficient and robust redundancy discarding algorithm. According to the PRP recommended double window drop algorithm is complex, disordered packet has low efficiency, timing considerations are not rigorous, restarting exception handling is not included, this paper summarizes the basic needs of discard algorithm, analyzes reliable discarded and safe receiving timing principle, proposes the sequence number state HASH algorithm and a single fixed sliding window method. A detailed analysis of the starting and ending points are or not in the sliding window, the receiving sequence number before or in or after the window situations, and gives the algorithm pseudo code for reference use. Robustness that exceeds specific interval, for the same sequence number, the content of the packet may not be the same; within specific interval, different packets may have the same FCS (frame check sequence). This method can assert and discard received duplicate packet quickly and accurately, which lays a solid basis for the power device of smart substation to realize PRP/HSR algorithm. ©, 2014, Power System Protection and Control Press. All right reserved.


Bei D.,Nanjing SAC Power Grid Automation CO. | Xiang Z.,Nanjing SAC Power Grid Automation CO. | Shi C.,Nanjing SAC Power Grid Automation CO. | Shizhen S.,Nanjing SAC Power Grid Automation CO. | And 2 more authors.
POWERCON 2014 - 2014 International Conference on Power System Technology: Towards Green, Efficient and Smart Power System, Proceedings | Year: 2014

This paper use the platform technology to present a scheme of a full-featured relay protection devices simulation system, using the program as same as in the actual device, ensured the simulation result is exactly same as actual device, then according to this design, developed a digital simulation system. Depend on this platform, we can study the protection algorithm or perform the source code level debugging, simulation devices can exchange data with a simulation software like PSCAD and a server via protocol 61850 at the same time. It can monitor the fault, analysis the protection action behavior and upload the data to backend server, Develop protection devices by using this platform technology will greatly improve the development efficiency and shorten the development cycle, reduce the development investment and costs, at the same time, the system is suitable for off-line training and simulation test for all power system users. © 2014 IEEE.


Xu L.,Nanjing SAC Power Grid Automation Co. | Ding Q.,Nanjing SAC Power Grid Automation Co. | Shi Z.,Nanjing SAC Power Grid Automation Co. | Yu H.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2014

According to the problem of merging unit during the test on electrical fast transient/burst (EFT/B), the characteristics of the EFT/B are analyzed and the anti-interference methods for solving the EFT/B problem of the merging unit are proposed. The improved filter structure with metalized polyester film capacitors and transient voltage suppressor (TVS) is proposed to enhance high-frequency interference suppression. The wiring and layout of the mother PCB is optimized to reduce the impact of coupling between different circuits. The results of the test show that the improved merging unit is able to meet the requirements of EFT/B of grade 4. ©2014 State Grid Electric Power Research Institute Press


Xie K.,Nanjing SAC Power Grid Automation Co. | Yu H.,Nanjing SAC Power Grid Automation Co. | Chen F.,Nanjing SAC Power Grid Automation Co. | Xu L.,Nanjing SAC Power Grid Automation Co. | Li S.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2016

For current 110 kV voltage level system or above, the secondary fault and fault analysis mainly relies on the tester for off-line analysis system. The results of this analysis are difficult to achieve the same on-line test effect as the operation of the system. A novel processing equipment is proposed, which can transfer Comtrade file to IEC 61850 and send generic object oriented substation event (GOOSE) and sampling value (SV) message based on transfer results, so that the operator and maintainer are enabled to make on-line fault analysis on site. The device hardware, mapping between IEC 61850 and Comtrade, synchronous output function design of SV and GOOSE are described. © 2016 Automation of Electric Power Systems Press.


Xing W.,Nanjing SAC Power Grid Automation Co. | Guo X.,Nanjing SAC Power Grid Automation Co. | Hu B.,Nanjing SAC Power Grid Automation Co. | Han X.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2016

The DC filter is an indispensable equipment in the HVDC transmission system. At present, DC filter protections only use the current protection, and most of which use the tuning frequency current. When the earth fault is close to the head end of filter, there is a greater shift of tuning frequency, and the harmonic current is reduced, so the differential current of filter is reduced, and the protection is lack of sensitivity, and the protection may not operate. In this paper, the harmonic impedance protection is proposed, and the protection makes use of voltage and current, and uses smaller tuning frequency harmonic impedance magnitude as the protection criterion. When the earth fault is close to the head end of filter, the protection with high sensitivity can respond many kinds of faults, but also as a filter detuning monitoring criterion. The simulation using PSCAD verifies the feasibility and reliability of protection, and the harmonic impedance protection will protect the DC filter more reliably. © 2016 Power System Protection and Control Press.


Wei Y.,Guodian Nanjing Automation Co. | Wei Y.,Nanjing SAC Power Grid Automation Co. | Xue M.,Guodian Nanjing Automation Co. | Xue M.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2016

When the high voltage transmission line is non-full-phases operation, the asymmetric element will be closed. While the healthy phases of the line have faults under such circumstances, if the voltage of swing center continuous low is the only criterion for fault detection, it needs long time-delay and will impact the speed of distance protection trip. Moreover, this scheme is not suitable for single-phase earth fault. The paper proposes a combining scheme that, single-phase fault can be detected through partition changes of phase selection by zero-sequence current and negative-sequence current phase selector, and phase-to-phase fault can be detected through the delta voltage of swing center, when power system is non-full-phases and swing operation. The simulation results show the effectiveness of the scheme. © 2016 Power System Protection and Control Press.


Liu Y.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2015

Plug and play of the smart substation's life cycle is the main line, which includes three stages, i.e. the design, construction and operation. It introduces the method of virtual terminator auto-mapping and network architecture of distributed local protection in the design stage, refers the precast cabin of the new material and the innovation of standard precast optical cable in the construction stage, and studies the advanced application of panoramic simulation closed loop test, no-setting protection of auto-identification system of and smart tripping, etc. in the operation stage. Last it forecasts the future trend of the smart substation combined with its application. © 2015, Power System Protection and Control Press. All right reserved.


Zhang X.,Nanjing SAC Power Grid Automation Co. | Liu Y.,Nanjing SAC Power Grid Automation Co. | Yu H.,Nanjing SAC Power Grid Automation Co. | Chen X.,Nanjing SAC Power Grid Automation Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2015

Making full use of existing equipment under the new conditions, and trying to reduce the cost, this paper proposes the isolation and control strategy for smart substation MMS, GOOSE, SV three-in-one communication network overload fatal fault. Combined with the use of the simplified topology, dynamic layer two protocol (IEC62439, PrivateLoop, LoopDetection, STP/RSTP/MSTP, GMRP, IGMPSnooping), static configuration (VLAN, multicast, layer three routing, policy routing, ACL), overload monitoring and overload control, the reliability of network is improved. The combined VLAN, layer three switching, policy routing isolated topology, policy routing support core switch load balance is analyzed, the communication design and configuration of measuring and protective device are simplified. The communication equipment innovation overload monitoring and blocking solution is developed, which changes the traditional single means of suppression. The problems and advantages of dynamic and static configuration in three in one network are analyzed, and according to the levels and reliability requirements of smart substation, the different isolation strategies are selected. If the overload is monitored by communication equipment, first overload self recovery treatment is made, and by using hard wiring alarm and local log, the alarm information is sent to the monitoring host via MMS network simutaneously. If self recovery is failed, overload isolation is adopted to try to reduce the influence range of overload, waitting for the timely treatment of administrator. © 2015, Power System Protection and Control Press. All right reserved.

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