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Ma J.,North China Electrical Power University | Peng M.-F.,Jiaxing Power Supply Company | Li Y.-N.,North China Electrical Power University | Wang S.-X.,North China Electrical Power University | And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2014

A novel method is proposed to analyze the stability of fault power system based on time-varying state matrix, since the energy function method cannot analyze the relationship between the time-varying state matrix and the system stability. First, through the state and operation mode of the system at the failure vanishing point, the real-time state matrix after the fault is calculated gradually. Then, the solution of the differential equation is calculated, and the stability of the fault system can be judged based on the stability criterion of the time-varying system. Finally, simulation results of the equivalent two-generator and sixteen-generator system illustrate that the method can accurately analyze the stability of the system when the fault occurs at different position and with different duration time.

Yan L.,Huzhou Power Supply Company
China International Conference on Electricity Distribution, CICED | Year: 2016

Considering energy security and environmental protection, electric vehicles will become a major choice for developing China's automobile industry. The popularization of electric vehicles depends on convenient charging. As the theoretical basis for charging stations, a dynamic traffic network method is used to build a multi-objective optimization model with hard-time-window constraint to obtain the optimal layout and scale of these charging stations. In this model, a minimum capital and charging cost is considered as the optimal objective, and a two-phase heuristic algorithm is proposed to solve this model. Finally, a case study on a simple example verifies the correctness and effectiveness of the proposed model. Results show that the layout of electric vehicle charging stations is determined by the charging demand of different locations and charging time constraints, and that the scale of charging stations is related to the number of electric vehicles, layout of charging stations and duration of charging at peak hours. © 2016 IEEE.

Yan L.,Huzhou Power Supply Company
China International Conference on Electricity Distribution, CICED | Year: 2014

The author analyzed the evolution process and compensation modes of restrictive land at home and abroad, and presented an easement-based compensation mod e of restricted land for grid construction under China's existing legal framework. The author set forth the concept and legal nature of easement of restricted land for grid construction, proposed a concept of easement royalty and the principle and idea of determining its compensation ratio, and gave engineering examples. Practice has proven that this mode can solve, to a certain extent, the problem of rising compensation expense, and contributes to relieving the stress from external conflicts of grid construction. © 2014 IEEE.

Yan L.,Huzhou Power Supply Company
China International Conference on Electricity Distribution, CICED | Year: 2014

This paper simulated the game in the policy-processing of grid construction based on the Rubinstein game ideology of bargaining, studied the interaction among main interest groups. The paper also introduced the stakeholder theory to the design of the compensation mechanism, and confirmed the compensation mechanism efficiency through the economic simulation method. This paper points out that in the compensation mechanism based on the stakeholder theory the grid company may use limited fund effectively, balance the profit among interest groups, expand t he negotiating space, reach the agreement more quickly among different interest groups in policy-processing of grid construction, so as to reduce the contradictions and conflicts, and thus contribute to the smooth development of grid construction. © 2014 IEEE.

Zhang C.,Zhejiang University | Lin Z.,Zhejiang University | Wen F.,Zhejiang University | Xue Y.,NARI Group | And 2 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2014

First, a modified method for evaluating the importance of each node is presented, and a multi-objective bi-level optimization model for the network reconfiguration is proposed. In the upper-level optimization model, the start-up sequence of generating units is determined by maximizing the restored generation capacity. While in the lower-level, the restoration path is optimized by maximizing the average importance of the candidate restoration path and minimizing the charging capacitance of the same path, and in the formulation the impacts of the restoration path on the restoration of generating units are taken into account. A continuous dynamic Pareto multi-step apoptosis optimization strategy (MSAOP) is next proposed to solve the multi-objective optimization problem of the network reconfiguration problem with multi-step restoration by simulating the physiological characteristics of the cell, and in this way the scale and difficult degree of the optimization problem to be solved can be reduced, and the possible curse of dimensionality avoided as well. This optimization strategy focuses on the stage-wise optimal solution in the restoration path of the generating units, while the global optimality is also taken into account. In addition, the set of network reconfiguration strategies obtained in the restoration procedure can be depicted in the form of a branch graph. Then, a fuzzy decision-making (FDM) method is employed to determine the final network reconfiguration strategy. Finally, the New England 10-unit 39-bus power system and Guangzhou power system are employed to demonstrate the feasibility and efficiency of the developed model and method. © 2014 State Grid Electric Power Research Institute Press.

Cheng J.,Zhejiang University | Guan M.,Huzhou Power Supply Company | Tang L.,Hangzhou Electric Power | Huang H.,Zhejiang University | And 2 more authors.
IET Generation, Transmission and Distribution | Year: 2014

This study presents a novel protection criterion of fault locating in multi-terminal DC (MTDC) transmission systems. When a fault occurs on the DC transmission line of the MTDC system, the traditional protection cannot locate the fault because there is no smoothing reactor (equipped at the converter output) in the transmission lines. In the circumstance of AC/DC conductor contact (ADCC) fault, the varieties of the transient voltage and current components are given based on the symmetrical fault analysis. According to the Bergeron equation, the travelling wave characteristic is analysed. A new criterion of fault locating using the change rate of the current travelling wave is presented which can reduce the impacts of the related fault on the AC system. Finally, simulation results verify the effectiveness of the proposed protection criterion. © The Institution of Engineering and Technology 2014.

Yue L.,Huzhou Power Supply Company | Lu L.,Huzhou Power Supply Company | Zhang X.,Huzhou Power Supply Company | Dai J.,Huzhou Power Supply Company
Dianwang Jishu/Power System Technology | Year: 2012

In view of distinctive features of ±500 kV DC power transmission line from Yichang to Shanghai such as its high tower height, easy to be lightning-stricken and wider lightning-induced area, it is necessary to assess lightning protection performance of this DC transmission line. Using the improved electro-geometric model the flashover rate due to shielding failure was calculated and a model to analyze lightning resisting level of this transmission was built on EMTP platform. Calculation results showed that there were differences among the influences of various arrangements of polar line on lightning resisting levels of shielding failure and flashback, and there were evident influences of polar line arrangement, ground slope angle, protection angle, height and structure of tower on lightning performance of the transmission line.

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