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Zhang F.,Fuzhou Electrical Power Industry Bureau | Guo B.-Y.,Fuzhou Electrical Power Industry Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011

The operation mode of sectionalized single bus is similar to that of internal bridge scheme. However, the present close-up device of stand-by power supply can't be directly used in sectionalized single bus scheme without busbar protection at the terminal substation, because there is a problem that automatic device won't be blocked due to the faults of any bus. For this reason, line protection with the inverse direction is suggested to be added to the logic for automatic close-up device of stand-by power supply which will make automatiionc device be reliably blocked. At the same time, in the mode of power line stand-by power supply, it can't judge which bus is at fault for line protection with the inverse direction, and automatic device will be blocked due to the fault of any bus, which results in non-selective action of automatic device, and it will come to the ending that all loads are lost. To solve the problem, the paper suggests that it needs to add a criterion judging whether there is fault current going through the bus sectionalizing breaker to the action logic of power line stand-by power supply, and the setting of fault current can adopt the method of over-current, or more sensitive method of current variation of fault phase.


Jiang N.,Fuzhou Electrical Power Industry Bureau | Xie Y.,Fuzhou Electrical Power Industry Bureau | Hou J.,State Grid Electric Power Research Institute of China | Xu L.,Fuzhou Electrical Power Industry Bureau | And 2 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

With more and more cable-overhead mixed lines in power grid, it brings out a difficult problem for the operation department whether the reclosing device of the mixed line should be put into operation or not. This paper analyzes the influence of power cable type, laying mode and operating status of cable line on the reclosing mode of mixed lines. An instructional summary of reclosing mode is made and it directly provides the service for safe operation of power system. © 2010 State Grid Electric Power Research Institute Press.


Zhou J.-P.,Fuzhou Electrical Power Industry Bureau | Zhou J.-P.,Fuzhou University | Lin H.,Fuzhou Electrical Power Industry Bureau | Lin H.,Fujian Electrical Power Co. | Wen B.-Y.,Fuzhou University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

Transmission network expansion planning is a complicated, multi-objective, nonlinear and combinatorial optimization issue. Aiming at the problem that genetic algorithm possesses the slow convergence speed and easily plunges in part convergence when solving the model of the transmission network expansion planning, this paper proposes a method of transmission network expansion planning based on improved quantum genetic algorithm. On the basis of the quantum genetic algorithm, the method proposes a strategy that the quantum chromosomes are directly compared with the current best solution to determine the rotating angle of the rotating gate. The strategy ensures every individual in population evolves with different convergence speed to complete both local and global search. Simultaneously, the whole interference crossover operation and negater mutation operation are put forward to prevent the algorithm plunging in part convergence. Three kinds of improvement strategies are targeted and can effectively improve the convergence function of quantum genetic algorithm in the planning for transmission network expansion. The transmission network expansion planning for Garver-6 system is performed by genetic algorithm, quantum genetic algorithm and the proposed method respectively. The result shows that the method has good global optimum capability, and the convergence speed is obviously improved.


Shu S.,Hubei Engineering University | Ruan J.,Hubei Engineering University | Huang D.,Hubei Engineering University | Wu G.,Hubei Engineering University | Liu C.,Fuzhou Electrical Power Industry Bureau
Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV | Year: 2012

Starting from a transient equivalent model of a triple-break 126 kV vacuum circuit breaker (VCB) containing a dielectric reignition criterion, the reignition current waveform of the vacuum interrupter (VI) which took over the higher part of the transient recovery voltage (TRV) was simulated. A series damped resistor was added in the grading capacitor branch to extinguish the reignition current as early as possible. The results show that the effect of the damped resistor is optimal when its value is threshold between oscillatory and non-oscillatory decay. Excessive TRV which appeared across other un-reignition VIs and power frequency recovery voltage (PFRV) which appeared across the reignition VI were simulated. A metal oxide arrester (MOA) was installed in parallel with each VI to ensure breaking successfully by limiting the excessive TRV and PFRV. It is shown that the voltage limiting effect is preferable when a MOA with the reference voltage of 50 kV is in parallel with a grading capacitor of 1000 pF, also the thermal limit can be satisfied. Research results are expected to provide a basis for choosing proper dynamic voltage sharing measures for a triple-break 126 kV VCB. © 2012 IEEE.


Zhang F.,Fuzhou Electrical Power Industry Bureau | Guo B.,Fuzhou Electrical Power Industry Bureau
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

The combination of substation operation order generating system with programmed operation scheme is introduced. For the centralized and hybrid schemes, the substation operation order generating system is easily combined in the programmed operation server, while a computer is added in substation level for the distributed scheme to combine these two systems. Three points should be noticed: measures should be taken to assure the correct programmed operations after combining with the substation operation order generating system, such as the integrated online misoperation prevention software; the combination pattern of representative operation order and intelligent operation order should be more rational and applicable; both should be under closed-loop control.


Wang W.,Hunan University | Luo A.,Hunan University | Li Y.,Central South University | Xu X.,Hunan Electrical Power Research Institute | And 3 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012

The basic control rule applied to three-phase four-switch inverters (TFSI) for outputting three-phase balanced voltages is revealed. Based on this rule, a novel space vector pulse width modulation (SVPWM) algorithm is proposed in order to control the three-phase four-switch shunt active power filter (TFSSAPF). By introducing an advanced coordinate transform method, the proposed algorithm makes sure the basic voltage vectors to be on the coordinate axes in the two-phase stationary coordinate system, so that it only needs the four arithmetic operations of two line voltages to accomplish the selection of the basic voltage vector and the calculation of its function time. The proposed algorithm has the advantages of less detection units, less computation and higher accuracy than the traditional ones. As the output voltage vectors of the TFSSAPF have no zero-vectors, a so-called 'five segment type' algorithm is presented to synthesize the zero-vectors by forcing the durations of the voltage vectors which are equal in extent and opposite in phase equal to each other, which has the advantages of simply control logic and low harmonic contents of the output voltages. Simulation and experiment results show the validity and feasibility of the proposed algorithm. © 2012 Chin. Soc. for Elec. Eng.


Wang Y.-M.,Fuzhou Electrical Power Industry Bureau | Guo B.-Y.,Fuzhou Electrical Power Industry Bureau | Zhang F.,Fuzhou Electrical Power Industry Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

The paper proposes the distributed scheme. The scheme implements programmed operation in cell devices, establishes the communication system with the standard of IEC61850, achieves the locking information transmission between the cell devices by the application of GOOSE. It also takes the measures, such as on-line system that keeps people from misoperating, duality criterion to ensure the final state of primary equipment after operated, to assure the reliability and correctness of programmed operation. The system provides a graphical management functionality and friendly human-machine interface, and possesses the features of a graphical simulation of the operation of ticket preview and validation.


Guo B.-Y.,Fuzhou Electrical Power Industry Bureau | Zhang F.,Fuzhou Electrical Power Industry Bureau | Luo S.,Fujian Provincial Electrical Power Training Center
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

In earth neutral system, zero-sequence protection of 220 kV transformer acts as earth-fault backup protection of bus and adjacent line, and considers internal earth-fault backup protection of transformer. For the fault of single phase high-resistance grounding occuring between current transformer and isolating switch laying aboard transformer, the motion analysis of transformer protection is conducted considering the case of circuit breaker refusal. The deficiency of trip setting is found that there is no protection to segregate faultless equipments with the fault. For the problem, a suggestion of adding another time to trip bus tie circuit breaker for zero-sequence protection of transformer II is put forward, which provides reference for trip setting of zero-sequence protection of 110 kV side of 220 kV transformer.


Wang H.-R.,Fuzhou Electrical Power Industry Bureau | Wang K.,Fuzhou Electrical Power Industry Bureau | Chen H.-S.,Fuzhou Electrical Power Industry Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

According to the experiences from the scene debug of the integrated automation system over the years and characteristic of neutral point effectively earthing, this paper simply introduces the principles about the microcomputer-based zero sequence current directional protection from positive-earth fault and the negative earth fault. In addition, it discusses the debug way and characteristics about microcomputer-based zero sequence current directional protection. Meanwhile, it sums up the points worth paid attention to during the process of scene debug relying on the specialties of devices produced by different factories and concludes the alarming terms in the practical test and debug.


Guo B.-Y.,Fuzhou Electrical Power Industry Bureau | Zhang F.,Fuzhou Electrical Power Industry Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010

Enlarging bridge main connection is widely used in 110 kV terminal substations. However, traditional logic conditions of back-up switching equipment are unable to meet its operation. First of all, the paper introduces the logic conditions of 110 kV back-up switching equipment, then presents a solution of configuration of 110 kV enlarging internal bridge back-up switching equipment after analysing main modes in 110 kV enlarging internal bridge main connection, and discusses the logic conditions by considering its cooperation with main transformer protection and the case that circuit breakers refuse trip. The logic conditions discussed in the paper provide reference for its design. At last, the paper indicates the insufficiency of logic conditions widely used in incoming-line back-up switching equipment, i.e. after the action of main transformer protection, circuit breaker of back-up power is put into operation without judging the position of sectional circuit breaker. A solution of adding the logical condition of judging the position of sectional circuit breaker is put forward.

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