Design and Characterization of a Stand-Alone Merging Unit

Giuliano Cipolletta, Antonio Delle Femine, Daniele Gallo, Carmine Landi, Mario Luiso


Merging Units (MUs) play a key role in enhancing the levels of security and the reliability of power systems, allowing for advanced remote diagnostics. Some of the benefits are a more efficient transmission of electricity and a better integration with renewable energy systems. In this article, an implementation of a Stand-Alone Merging Unit (SAMU), compliant with the IECĀ 61850-9-2 standard and based on a low-cost ARM microcontroller, is described. It acquires two signals, one voltage and one current, and it sends the samples over the ethernet connection. A high-resolution Analogue-to-Digital Converter (ADC), synchronised to the Universal Time Coordinated (UTC) through a Global Positioning System (GPS) disciplined oscillator, is used. The opportune insulation and conditioning stage have been designed. Several tests have been performed, varying amplitude, frequency, and phase of the input signals, in order to evaluate the metrological performance of the proposed SAMU and they are here discussed.

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