Advanced Materials Research Vols. 986-987

Abstract: Grid technology can provide electricity market bidding to achieve the ability to provide large-scale computing. Agent technology has the autonomy, interoperability, and self-learning, can effectively solve the grid resource discovery and management, computing task allocation and scheduling problems, shared grid environment of heterogeneous computing resources. Introduction grid technology related content, Agent technology and proposes a use of Agent technology in the electricity market bidding model grid environment. Bidding able to provide the technology platform the parties a fair trade.

Abstract: This paper focuses on proper grounding practices and grounding fault protection for low voltage generators in island mode. The paper presents the fundamentals of power system grounding and requirements of IEEE with respect to grounding, the need for low voltage ground fault protection and implement is execution. The paper outlines the solid grounding method is used and necessary grounding fault protection for multiple generators in low voltage system.

Abstract: The overvoltage calculation of 750kV transmission line with series compensation has great significance on the design, insulation coordination and protection of the line. In this paper, a transient model of 750kV power transmission system with series compensation is established. Effects of different capacity on no-load capacitive rise overvoltage, single-phase grounding overvoltage, two-phase grounding overvoltage are calculated. Secondary arc current and recovery voltage of different series compensation capacity in single-phase grounding is also calculated.

Abstract: The nuclear safety became the more important after the Fukushima accident. The development of nuclear safety culture is one of the most effective methods to improve the safety. Also the assessment shows the level of the nuclear safety culture. The nuclear safety assessment model is described. The assessment model was described from its time and space, and it was also discussed from macro and micro levels. The internal and external environment parameters are considered and the assessment of different levels of safety culture is described. According to established principles of nuclear safety culture, the selection rules of the different levels evaluation indicators of nuclear safety culture are discussed too. And it is pointed that the assessment of nuclear safety culture is a long time project and an integrated system.

Abstract: For the actual situation in Liaoning Power Grid, analyzed the problems the wind power interconnection brought. Involving power quality, power fluctuations, power peaking, power delivery and so on. Proposed related coping strategies. Strengthen wind power connection management, plan the power structure scientifically and rationally, carry out multi-channel consumer of wind power actively, improve the security and stability level of the power grid.

Abstract: External insulation design of UHV power project is important. The lightning impulse (LI) voltage is one of the main factors that determine the air gap distance. Based on existing LI voltage results of power project typical gap, impact of gap structure and distance on LI discharge correction is analyzed. And from a theoretical aspect, existing LI discharge correction methods are summarized. Furthermore, by the use of common correction methods, LI voltage correction factors of rod - plane were calculated and analyzed. Results show no significant impact of gap type or gap distance on LI voltage correction is found out. Average atmospheric conditions are effective when atmospheric parameters method is used for LI voltage correction. DL/T 620, IEC 60060-1 and IEC 60071-2 can be used for LI voltage correction at areas with altitudes of 1000-5000m. While GB311.3-improvement method can be used for LI voltage correction at areas with altitudes blow 4000m.

Abstract: To study the mechanism of cascading failures in a power grid and find out the key vulnerable lines propagating cascading failures, entropy theory and analysis hierarchy process were applied in entropy-weighted fuzzy comprehensive evaluation model, and information of objective data and the subjective opinion of experts were combined in the model to implement effective evaluation and sorting of line vulnerability. The article builds a index system that contains voltage deviation, power flow coefficient and electric betweenness in considering the network structure and real-time running state of the system, and then the lines vulnerability assessment method is proposed .This method can be used to help power grid designers and operators spot the lines prone to black-out. Numerical example results show that the proposed indicators can overcome the deficiency of existing indicators not taking the state of the grid structure and operation into account which proves the assessment method is feasible.

Abstract: For long time span, the impact of many factors, uncertainties and other characteristics of mid-long term load forecasting, as well as the over-estimation of interval arithmetic, a mid-long term load forecasting method based on interval Taylor model algorithm was presented. In order to avoid misjudgment of the relationship between variables, reducing over-estimation problem, a global variable named Taylor model ID was presented to identify the independent variables and the dependent variable. The same independent variables construct the interval Taylor model only once. Use Maclaurin formula to derive the interval Taylor model of correlation function formula, and then get a quadratic exponential smoothing method based on interval the Taylor model. The proposed method has been tested on a provincial calculation. The results demonstrated the effectiveness and practical value of the approach by comparing with the results of Monte Carlo simulation and interval method.

Abstract: For Receiving-end AC system, DC location selection depends on its role in supporting the DC system and economy. This paper proposes a method based on multi-attribute decision making of receiving-end power grid DC location selection. First, the balance of power DC location selected by region; then select the optimal placement through multi-attribute decision making; finally checked by calculating the feasibility of the selected placement. Zha Lute DC Shandong receiving-end power grid placement choice proved the effectiveness of the proposed method.

Abstract: Micro grid can minish the impact from fluctuation of distributed generator by control and management system as a new type of power system. But micro-grid also brings disadvantages on power attemperation, function and relay protection. Firstly the inverter’s electric model is built and the fault transient is simulated. Inverter interfaced distributed generator shows evident non-linear characteristic for the limits on power and current from control system. In this paper, according to the fault transient simulation results, analysis of the problems faced by the existing relay protection and corresponding solutions is given respectively.