Dong Xuzhu

Research and implementation of outage analysis key technology based on information integration of power distribution and utilization

Based on multi-source data modeling and information integration of power distribution and utilization, outage analysis key technology under different time dimensions is studied. Implementation of several key techniques are also elaborated including consumer outage event alarm and reason analysis, consumer outage statistic and impact access, real-time consumer power recover analysis, consumer power reliability analysis and consumer outage simulation analysis. The study indicates that instant and correct outage information and recover information of consumers can be provided while power dispatching of distribution and utilization can be supported by outage analysis results published based on the unified model and information integration for power distribution and utilization.

Distribution network expansion planning considering comprehensive equipment utilization

An equipment comprehensive utilization index considering power system security and operating mode was provided, and a distribution system expansion planning method based on this index was proposed. The expansion planning method takes “effective use of existing and additional equipment resources” as the guiding ideology, and makes full use of the historical operation data to realize the distribution system expansion planning. The planning model and the solving process using improved particle swarm algorithm are provided in the paper. An actual case study is used to verify the effectiveness of the method.

An improved self-healing control method of intelligent distribution grid based on feeder group regional model

In this paper, by studying the actual operation characteristics of distribution network, taking into account of decoupled nature between the running distribution lines, the regional model of feeder group for distribution network is established. This model divides specific region for the distribution network. Based on it, the self-healing control problem of distribution network is studied. An improved self-healing control scheme is proposed. The scheme gathers the merit of distributed and centralized scheme, meanwhile, avoid their disadvantages. Therefore, the practicability of self-healing control scheme enhances greatly. It is a practical self-healing control scheme. Idea of this improved scheme is as follows.(l) the Distributed self-healing control scheme is used for the fault diagnosis, location, isolation and restoration to upstream load. (2) the centralized self-healing control scheme is used when there are multiple restoration schemes for downstream load. It is showed that the model and the scheme can deal with the fault well by the experiment.

Design of an improved feeder self-healing control scheme

The logic processing course of both distributed mode and centralized mode for trunk line is introduced, and the advantages and shortcomings of two modes are also summarized. Because of the advantages and shortcomings of two modes for trunk line, an improved self-healing control scheme is presented and the use of IEC61850 standard for feeders self-healing application is taken into account. This scheme adopts the same logic processing course of fault diagnosis, fault location and fault isolation as the distributed mode. For the load in the offside of fault location, which has multiple power supply restoration ways, the method of implementing the defined plans is used for the fault processing procedure. Fault processing plans are defined in the master station in advance, and they are transmitted to the appropriate intelligent distribution terminal unit by IEC61850 communication protocol. During power supply restoration the intelligent distribution terminal unit perform the appropriate fault processing plan to the power supply for the load in the offside after it determines the current state of power grid. The improved self-healing control scheme possesses the advantages of both distributed mode and centralized mode, while avoiding their weaknesses. Theoretical analysis and engineering application indicate that improved self-healing control scheme presented has strong practicality in engineering.

System stability and its influencing factors analysis of the isolated wind-solar-diesel- battery hybrid micro-grid

An isolated micro-grid system of wind-solar-diesel-battery hybrid power generation is suitable for remote areas and islands. Possessing qualities generally attributed to the isolated micro-grid are inadequate anti-disturbance ability and weak stability. Power system stability analysis is needed for providing some suggestions and advices to planning and design. This paper analyses system stability of an island isolated micro-grid at different operation modes. Based on the results, reasonable operation modes and system reserve demand are proposed for long-term, efficient, and stable operation of the isolated micro-grid. Sensitivity analysis has made to find critical factors which mostly affecting system ability, such as transformer selection, low voltage ride-through capability and so on.