Distribution network state estimation method based on hierarchical solution

Abstract

The invention discloses a distribution network state estimation method based on hierarchical solution. The method comprises the steps of 1) performing hierarchical partitioning based on a network topological structure of a distribution network and the configuration of measurement points to form a sub-partition set, and determining the current and voltage relationship between tree branch circuits; 2) traversing and extracting a sub-partition from the tree root in the sub-partition set, and deleting the extracted sub-partition in the sub-partition set; 3) based on the SCADA and AMI measurement data, performing state estimation of hybrid measurement information based on the time-scale hierarchical solution on the extracted sub-partition; and 4) repeating the steps 2) and 3) to determine whether the sub-partition set is empty, if so, integrating and outputting the estimation result of each sub-partition at the current time, and otherwise, executing the step 2). The method of the invention improves the redundancy of the state estimation based on the added AMI real-time measurement data, realizes the hierarchical state estimation of the distribution network through a hybrid strategy of the AMI and the SCADA measurement data, and can improve the accuracy of the three-phase state estimation of the distribution network.

Description

technical field [0001] The invention relates to the field of distribution network, in particular to a distribution network state estimation method based on hierarchical solution. Background technique [0002] With the development of smart grid and information, communication and other technologies, the distribution network can obtain SCADA (Supervisory Control And Data Acquisition, data acquisition and monitoring) data through the distribution automation system, and through the advanced measurement system (Advanced Metering Infrastructure, AMI) Obtain real-time power consumption data of users, combined with network data provided by Geographic Information System (Geographic Information System) and Management Information System (Management Information System), etc., to provide a basis for the realization of measurable, observable and controllable power distribution system operation . Domestic and foreign studies on distribution network state estimation mainly rely on SCADA dat...

AI Technical Summary

Problems solved by technology

[0003] The development of the power system promotes the wider use of flexible equipment such as distributed power and electric vehicles in the distribution network, which makes the operating range of the distribution network expand, and the two-way flow of the power flow is frequent, which leads to the complex active distribution network when performing state estimation. Unavoidable problems such as slow calculation speed, large number of iterations and low calculation accuracy

The node scale of the distribution network is becoming larger and larger, and the scale of the prefecture-level distribution network reaches tens of thousands. At the same time, the types of dynamic components such as distributed power sources, electric vehicles and other flexible sources and loads and their controllers are becoming more and more complex. The traditional overall state estimation method is adopted The method is used to solve the state estimation under the condition of three-phase unbalanced load in the distribution network. The calculation amount of the nonlinear equations involved is super-linear compared with the dimension, which makes the state estimation unable to obtain both the calculation speed and the solution accuracy. Improve, limit the popularization practice of online fast state estimation

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