Implementation of an online state estimator in an edge computing device for European-type industrial lv grids

Abstract

The pervasive use of communication technologies in industrial facilities puts them in an excellent position to pioneer the active management of distribution grids. In this context, only a decentralized online state estimator can allow for a proper flexibility management, and thus, for an adequate use of distributed generation and energy storage systems. Due to the lack of current solutions tailored for 4-wire unbalanced LV grids, i.e., European type, this proposal presents the implementation of an edge computing device, aimed at the terminal transformer level, which can perform distribution state estimation at a low cost. The state estimator which is designed to be run in a compute module with a compact form factor for deeply embedded applications, solves the state estimation problem by minimizing an objective function formulated using the modified augmented weighted least squares method. Additionally, this contribution presents a testbed for the evaluation of the proposed solution: (1) an external device is used to carry out an online emulation of the distribution grid and to generate the corresponding field measurements including Gaussian noise, and (2), the embedded device obtains the measurements via Modbus TCP/IP and performs the state estimation making these results available for higher-layer applications. To confirm the effectiveness of this implementation, a comprehensive set of tests are conducted using the model and data of a real LV grid in Spain. The results show good accuracy and an acceptable execution time for a cost-effective embedded solution.