Multiarea Distribution System State Estimation

Abstract

This paper presents a new approach to the distribution system state estimation in wide-area networks. The main goal of this paper is to present a two-step procedure designed to accurately estimate the status of a large-scale distribution network, relying on a distributed measurement system in a multiarea framework. First of all, the network is divided into subareas, according to geographical and/or topological constraints and depending on the available measurement system. Then, in the first step of the estimation process, for each area, a dedicated estimator is used, exploiting all the measurement devices available on the field. In the second step, data provided by local estimators are further processed to refine the knowledge on the operating conditions of the network. To improve the accuracy of the estimation results, correlation arising in the first step estimations has to be suitably evaluated and considered during the second step. Performed analysis shows that existing correlations can be included in the estimation process with very low data exchange among areas, thus involving minimum communication costs. Both first and second steps can be performed in a decentralized way and with parallel processing, thus leading to reduced overall execution times. Test results, obtained on the 123-bus IEEE test network and proving the goodness of the proposed method, are presented and discussed

Performance Assessment of Linear State Estimators Using Synchrophasor Measurements

“…They solve the resulting unobservability by complementing the PMU data with pseudo-measurements and zero-injection information. Finally, Muscas et al [38] have presented a twostep procedure in order to estimate the state of a large-scale distribution network by dividing it into subareas. For each area, they first use a dedicated estimator, and then, data provided by local estimators are further processed to refine the knowledge of the operating conditions of the network.…”

Distribution system state estimation-A step towards smart grid

“…This improves convergence speed and reduces the data exchanges between the neighboring areas [88]. A decentralized-MASE is proposed in [89], which undertakes a two-step estimation process to determine the state of a large DS. A large DN is first divided into manageable local-area networks based on geography, various topological-constraints and available metering infrastructure.…”

Decentralized Dynamic State Estimation in Microgrids

“…Therefore, the communication delay can be neglected. In addition, the state vector size here is just four as expressed in (10). Thus, the local estimation can have a sampling rate that is as high as possible with respect to the sensors.…”