Multivariable Regression Equivalent Model of Interconnected Active Distribution Networks Based on Boundary Measurement

Zhang Zhang,Li Li,Huang Huang,Yang Yang

doi:10.3390/en12122339

Abstract

With the increasing complexity of the active distribution network (ADN) due to distributed generation (DG) integration, together with the electricity market evolution, the traditional ADN is divided into multiple areas to operate independently. Due to technical problems or business privacy, the internal network regional control center cannot grasp the changes of the external regional network in time. In order to accurately reflect the distribution network operation state, a multivariable regression equivalent model is proposed in this paper. Firstly, the external network is made equivalent to a multi-port Norton model. The multivariable linear regression model is then derived based on the equivalent distribution network, and the regression model variables are constructed using boundary node information collected by the measurement equipment. Finally, the maximum likelihood estimation (MLE) is used to estimate the parameters of the multivariable linear regression model. Furthermore, case studies demonstrate the effectiveness and robustness of the proposed method, and detailed information of external ADN is unnecessary, except for the boundary node information. The proposed method can also be applied for three-phase unbalanced ADN efficiently.

Highlights

Due to the penetration of a large number of distributed generation (DG) in the distribution system, together with demand-side interaction enhancement, the traditional distribution network is gradually evolving into an active distribution network (ADN), and its topology and power flow are moving towards complexity and diversification [1]
The voltage amplitude obtained by the method proposed in this paper is closer to the voltage using the original model, which indicates that the equivalent method proposed in this paper can reveal the actual voltage better than the other three methods, when large numbers of DGs are connected to the distribution networks
A multivariable regression equivalent method for interconnected active distribution networks is proposed in this paper

Summary

Introduction

Due to the penetration of a large number of distributed generation (DG) in the distribution system, together with demand-side interaction enhancement, the traditional distribution network is gradually evolving into an active distribution network (ADN), and its topology and power flow are moving towards complexity and diversification [1]. In order to give the regional management centers the required responsiveness, it is necessary to establish an equivalent method for the three-phase unbalanced interconnected distribution network. The multi-microgrid (MMG), defined as multiple interconnected small-scale power grid that is comprised of distributed energy resource systems, storage devices, and local demands, has similar characteristics as the interconnected ADN [4,5]. The established equivalent method of the interconnection ADN could be applicable for MMG

Methods

Results

Conclusion