One of the challenges faced by Brazilian distribution utilities to enable the connection and operation of microgrids (MGs) is the absence of a solid set of technical standards in the country. An alternative has been to use and adapt existing standards applied to micro- and mini-distributed generation. In this context, this paper presents an analysis of the development status of norms, standards, and general requirements for the connection and operation of microgrids, as well as a proposal for the regulation and structuring of technical and operational requirements related to the implementation of microgrid projects. Some critical points highlighted in the paper include: the modes of operation, the minimum requirements for the different modes of operation, interoperability of systems, a conceptual model with attribution of responsible actors for the decentralized management of microgrids adapted to the institutional standards of the Brazilian sectorial model, a proposal for a standard connection structure considering the point of connection (PoC) implanted using multifunctional relay and recloser, procedures for technical feasibility assessment (operational studies) of MGs connection, and, finally, a discussion of operational issues of storage systems in a microgrid environment.

The Monte Carlo method (MCM) is the most widely used statistical approach to evaluate the lightning performance (LP) of overhead transmission lines (OTLs). However, the MCM has a very high computational burden, making LP studies time consuming. To overcome this difficulty, this letter proposes a new alternative approach for calculating the the lightning overvoltages (LOs) using the unscented transform method (UTM). This letter compares the UTM and MCM for calculating LO in insulator strings of OTLs through extensive tests carried out using the Alternative Transients Program (ATP). Such LO evaluation is an essential requirement for LP evaluation of a transmission line. The results indicate that the UTM significantly reduces the processing time to generate LOs while its accuracy is similar to that of the MCM.