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Zhang Z.-H.,China University of Petroleum - East China | Zhang Z.-H.,Shandong University | Xu B.-Y.,Shandong University | Xu B.-Y.,Shandong Kehui Electrical Co. | And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

The closed loop distribution network of double sources is the basis of realizing the seamless fault self-healing of distribution network fault, but the power flow has the characteristic of natural distribution and is lack of effective control means. We adopt united power flow controller (UPFC) to research the power flow control methods. Based on analyzing the power flow distribution and control regularity with the normally closed loop distribution, and taking the load node voltage deviation and closed loop feeder power output limit as constraints, we deduce the optimal power flow control scheme in the condition of minimum active power output by UPFC when the power regulation variables are fixed. The control method can ensure the economy of UPFC application while meeting the flexible regulation of power flow. Considering the issue of unequal output at two sides, we establish a simulation model for the closed loop distribution network of double sources. Simulation results show that the method is effective.


Duan J.-J.,Shandong University of Technology | Xue Y.-D.,Shandong Kehui Electrical Co Ltd | Xu B.-Y.,Shandong Kehui Electrical Co Ltd
IET Conference Publications | Year: 2010

In view of the special structural characteristics of traction power supply system, the paper proposed a new method based on the principle of double-ended voltage travelling waves to make fault location. Double-ended travelling waves fault location avoids the drawbacks of impedance method, and it makes huge significance to the high-speed electrified railway of China. Application system of this method has been put into trial operation and the results are good.


Huang Z.,Southwest Jiaotong University | Jiang T.,Sichuan Bazhong Electrical Power Bureau | Zhang W.,Sichuan Bazhong Electrical Power Bureau | Wu S.,Sichuan Bazhong Electrical Power Bureau | And 5 more authors.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

The design of traveling-wave-based fault locating card is proposed for high voltage lines, which is added on the microcomputer based line protection or fault recorder. With the concept of highly independent operation, it has own functional circuits: CPU, high speed data acquisition, high precision clock, digital inputs, digital outputs, communication interfaces, voltage converter, etc., and applies an embedded operating system to coordinately dispatch various functional software tasks. A type of microcomputer based line protection is slightly reconstructed and a matched card is developed. The card fetches DC power from the mother board of the protection and communicates with the HMI unit via the mother board. Its application realizes the integration of fault locating and line protection or fault recording.


Ma L.,Shandong University | Xu B.,Shandong University of Technology | Xu B.,Shandong Kehui Electrical Co. | Gao H.,Shandong University | And 3 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

It is very important to simulate transmission lines accurately in power system simulation. Now all kinds of real-time simulation tools have limitations to some extent. This paper presents the principle of electronic simulation of transmission lines and introduces the solutions of electronic simulation of lumped components, low-loss transmission lines and frequency-dependent transmission lines. The technology builds the equivalent model of transmission lines based on the mathematical model of electromagnetic interaction between conductors. In the model, those components of which values can be determined by the history record of sampled quantities are simulated by digital signal processors and the conversion between physical quantities and digital quantities is accomplished by A/D and D/A conversion units. Those components of which values are independent on the history record of sampled quantities and that reflect the relationship of instantaneous voltage and current are realized by themselves. An example simulation system for low-loss transmission lines verifies the feasibility of the proposed principle. The technology establishes the foundation for further exploration of power system simulation methods with space efficiency, low investment and convenient operation. ©2010 State Grid Electric Power Research Institute Press.


Huang Z.,Southwest Jiaotong University | Jiang T.,Sichuan Bazhong Electrical Power Bureau | Zhang W.,Sichuan Bazhong Electrical Power Bureau | Wu C.,Sichuan Bazhong Electrical Power Bureau | And 3 more authors.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

The basic principle of adaptive instantaneous current protection for distribution line is analyzed, based on which a protection and supervisory control device with adaptive instantaneous current protection function is developed for distribution lines. It mainly includes the CPU, transformer card, trip relay card, power card and human machine interface module. The CPU card integrates MCU, DSP, FPGA, SRAM and Flash RAM, as well as the data acquisition circuit, digital input/output circuit and communication interface circuit. Its software aggregates the functions of adaptive instantaneous current protection, traditional three-stage current protection, three-phase reclose, low frequency shedder, event alarm, SCAD A and fault recorder. Test shows that, the developed device has reliable functions and flexible configuration, and its protective performance is automatically adjusted to an optimal state according to the system operating mode, fault type and load conditions.


Gao M.,Shandong University | Xu B.,Shandong University of Technology | Xu B.,Shandong Kehui Electrical Co.
2010 China International Conference on Electricity Distribution, CICED 2010 | Year: 2010

A new overcurrent fault isolation technology in distribution line based on network is presented. The FTU detects fault and exchanges fault data with the adjacent FTUs by peer-to-peer communication technology. The FTUs at both ends of the faulted section will trip the circuit breakers to isolate the fault. Then FTU at the tie breaker will close the tie breaker to restore supply. © 2010 Chinese Soc for Elec Eng.


Zhang Z.,Shandong University | Xu B.,Shandong University of Technology | Xu B.,Shandong Kehui Electrical Co. | Chen Q.,Shandong University
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2012

Aiming at the power output unbalance of interlinked distribution system with dual sources, the UPFC (United Power Flow Controller) is applied to adjust the power flow. The power flow control law of interlinked distribution system with dual sources is analyzed and the optimal power flow control is derived, which takes the voltage deviation limitation of load node and the power flow limitation of tie feeder as the constraints and the minimal series compensating voltage as the objective. Simulative results show that, under the control of the proposed strategy, the power outputs of two sources are balanced by a certain degree while satisfying the constraints.


Xue Y.,China University of Petroleum - East China | Li T.,State Grid Corporation of China | Li W.,State Grid Corporation of China | Hu A.,Shandong Kehui Electrical Co. | And 2 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2014

In the non-effectively earthed distribution network, the fault location method based on transient current similarity between upstream and downstream fault points lacks rigorous theoretical proof and suffers definite blind area in principle, which may lead to the failure of location. A transient model applied to single-phase earth fault location is built, and the relationship of transient current's dominant resonant frequency between upstream and downstream fault points is analyzed. A novel fault location method based on transient current comparison which synthesizes the similarity and polarity relationship of transient current is proposed. The fault is located in the section on whose two sides the transient currents are similar but have opposite polarity, or located in the first section with dissimilar transient currents on the two sides. In the resonant earthed system, the consistency of polarity relationship between power frequency current and transient current at detecting points can exclude the effect of the anti-polarity current transformer. This method can eliminate the blind location area, while improving the reliability and adaptability of the transient-fault-location principle. The effectiveness of this method is verified by simulation and field data. ©, 2014 State Grid Electric Power Research Institute Press.


Xue Y.-D.,Shandong Kehui Electrical Co Ltd | Sun B.,Shandong University | Xu B.-Y.,Shandong Kehui Electrical Co Ltd | Duan J.-J.,Shandong Kehui Electrical Co Ltd
IET Conference Publications | Year: 2010

A new approach using transient signals for earth fault location in non-solidly earthed overhead lines is presented. The characteristics of zero module network are analyzed in detail. Also, the product of zero-module voltage after Hilbert transform and zero-module current in selected frequency band is determined the direction of the fault. The earth fault can be located in accordance with the difference of fault directions before and after fault. The paper proposes to use electromagnetic field induction to acquire fault signals.


Sun B.,Shandong University | Sun T.-J.,Shandong University | Xue Y.-D.,China University of Petroleum - East China | Xu B.-Y.,Shandong Kehui Electrical Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

A new transient direction protection principle using zero-module combination admittance is presented for non-solidly earth fault. In selected frequency band (SFB), ratio of algebraic addition of single frequency zero-module reactive power to that of the reactive power caused by zero-module voltage and zero-module current of same frequency in the whole frequency band is taken as weighted coefficient of zero-module addimitance, and the weighted integral of single frequency zero module admittance in the whole frequency band is considered as transient combination admittance. The fault direction is determined by calculating zero-module combination admittance angle. According to the different fault directions, the fault line selection and earth fault location can be realized. In the end, simulation results and field data demonstrate the feasibility of the approach.

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