Modeling Of Secondary Distribution Network Based On Metering Data

For a long time, due to various reasons, power utilities don't have full or accurate mastering of the information of the secondary distribution network and the accurate parameters of circuit are those we have not fully understood. The accurate parameters of circuit in the secondary distribution network are the basis of power flow calculation, loss analysis and monitor of electrical theft. The accurate parameters are important, but research on them is far from sufficient, which is mainly because of the absence of measured data in secondary distribution network.Smart Grid has become the major strategic to solve the energy, environment and sustainable development problem, and advanced metering infrastructure(AMI) is regarded as the first step to turn Smart Grid into reality. AMI is comprised of smart meters, meter data management system, home area networks and the communication system, and can provide large amount of data. This thesis researches on the calculation of the accurate parameters of circuit in the secondary distribution network, then we can obtain the accurate model of secondary distribution network.First of all, this thesis introduces the background of the research, the significance of research on modeling of secondary distribution network, the current situation, the difficulties and the meaning of implementation of AMI. And then, this thesis introduces the present development and state of model of distribution network based on metering data.The innovative works of this thesis are as follows.1. This thesis introduces a method of accurately estimating the impedance of branch circuit in distribution secondary network under the mathematical model of electric power circuit. Provided the distribution network topology is known, the method leverages a series of smart meter measurements at end nodes of the distribution network, mainly voltage, active power and reactive power at customer sites. It calculates the voltage of the most upstream node or source node in the radial network through bottom up approach and build an optimization model to minimize the source node voltage variance derived from different meter node measurements, or the differences of the estimated source node voltage from different smart meter measurements with actual voltage measurement in the source node over a period of times. Then the best estimates for branch impedances are obtained.2. This thesis chooses active-set algorithm of quadratic programming problem for the method of accurately estimating the impedance of branch circuit in distribution secondary network. The proposed optimization method is tested with a practical distribution network. The results achieved confirm its effectiveness of the proposed method.