Advanced Materials Research Vols. 860-863

Abstract: Probability box (P-box) and interval probability (IP) were used to express both variability and imprecision of wind speed and output power of WTGs. The p-box of WTG's output power was constructed by empirical cumulative distribution function and K.S. confidence limits. The discrete IP distribution of WTG's output power was elicited from the p-box. The optimization model of imprecise generating capacity adequacy assessment incorporating wind power was established and solved by genetic algorithm (GA). Case study on RBTSW system shows the rationality of presented method.

Abstract: Close attention has been paid to the power generation using renewable energy such as the widespread energy and solar energy. After the integration of large-scale renewable energy, more uncertain factors are brought to the power system, which badly influences systems planning and operation. The wind power, photovoltaic power and load are random but correlative, therefore, it is more logical to study the influence exerted by the integration of renewable energy when considering the uncertainty and it is meaningful to the power systems planning and operation. Based on the summary and survey of previous studies, the technical route of power system analysis concerning the correlation of wind power, photovoltaic power and load is proposed in this paper and some key technologies are discussed. The study of correlation offers valuable analysis and recommendations to the connection of large-scale wind and solar power base.

Abstract: Dispatchers dispatch power system with real-time data, but big data causes inconvenience to them. The paper introduces risk theory into dispatching operation quantitative assessment, and proposes a real-time risk analysis method for dispatching operation. Fault Tree theory is used to simulate practical operation process and to analysis the risk under successful and failure state of dispatching operation. The paper proposes some power system dispatching risk indices to help dispatchers to learn dispatching effects from different aspects pre-operation. Finally, the method is validated by IEEE 118-bus testing system.

Abstract: This paper proposed an improved ant colony optimization(ACO), to solve the economical operating dispatch of automatic generation control(AGC) units in hydropower station. The improved ant colony algorithm PSO-ACO imported particle swarm optimization is put forward. Both of the global convergence performance and the effectiveness of this algorithm is improved by using self-adaptive parameters and importing PSO to optimize the current ant paths. The mathematical description and procedure of the PSO-ACO are given with the maximum plant generating efficiency model as an example. Finally the superiority of the PSO-ACO is demonstrated by the application of AGC units on right bank of Three Gorges hydropower station. The optimal solution is more accurate and the calculation speed is higher than other methods.

Abstract: The reliability of UHVDC (ultra-high voltage direct current) transmission system is significant to the development of power grid. The paper selects dual 12-pulse converters on each pole to model and analyze the UHVDC transmission system. Firstly, the system is divided into six subsystems to evaluate the reliability by the fault tree analysis method. Then based on the fault frequency and the repair time of each subsystems bottom components, the paper calculates the fault frequency and the repair time of each subsystem. Using the frequency and duration method, the paper calculates the fault probability, fault frequency and repair time of the whole system. Finally, it is validated by the actual data of typical lines.

Abstract: The paper is devoted to the stability and feasibility boundary evaluation. New technique for evaluating shortest distance to feasibility boundary is described and tested. The technique is based on analysis of Jacobi matrix form the power flow routine. Described technique can be applied together with PMU-based identification procedures leading to new opportunities for on-line power system stability monitoring.

Abstract: This paper presents the result of identification of low-frequency oscillations in 9-bus test model of power system. The identification is achieved by novel technique developed by authors. The technique is described in detail in [1. It is based on treating synchronized phasor measurements. Applicability of identified state matrix for electromechanical oscillations monitoring is demonstrated in the paper.

Abstract: As the using quality of power grid asset becomes the focus of concern, the reasonable power grid asset utilization index is needed. The paper discusses the researching level of domestic and foreign power grid assets utilization and gives a brief analysis of the typical factors which have great influential on the utilization of power grid asset. According to safety and network structure requirements during the operation, the traditional power grid asset utilization indices were improved. Finally, the paper selects the typical 10kV distribution lines to conduct the calculation of utilization, and gives some analysis and advice according to the results.

Abstract: GIS is the most important equipment in power grid. Partial discharge is the main cause leading to insulation breakdown. UHF detection is an effective method for PD detection in GIS. It is significant to obtain the electromagnetic propagation characteristics for the accurate analysis of detection results. The FDTD algorithm is present in this paper to study the electromagnetic signal in GIS. The amplitude and frequency characteristics are studied in this paper.

Abstract: This paper addresses the problems, connected with distributed generation integration into distribution network systems. Due to the large amount of technical impacts associated with distributed generation operation, the list of criteria, illustrating the feasibility of network connection is investigated. The paper also provides the detailed description and practical implementation results of multi-criteria optimization tool, developed for siting and sizing of small-scaled power generation with subsequent technical feasibility analysis.