A robust synchronization method for centralized microgrids

Abstract

Microgrids represent one of the best candidates to redesign the architecture of the future distribution network. Such a model, in fact, promises to be able to properly manage a larger penetration of Distributed Energy Resources while improving the local production and utilization of energy. On the other hand, the control of a Microgrid is quite challenging, since the system has to be particularly reliable and flexible, due to the requested multiple and concurrent tasks to be performed. In this scenario the present paper proposes a novel solution able to synchronize the phase and the frequency of all the devices connected to the Microgrid in many different and complex ways. The proposed method, in particular, is based on the combined use of Phase Locked Loops and the 1 Pulse Per Second signal provided by any GPS device

Evolution of Microgrids with Converter-Interfaced Generations: Challenges and Opportunities

“…This work is extended by designing a robust controller based on a µ synthesis analysis in [195]. An approach for synchronising the frequencies and phase angles of all DGs based on a combination of three distinctive phase-locked loops (PLLs) is demonstrated in [196]. In these methods, a central control unit used to make decisions sends information via communication channels that are vulnerable for a large system during communication failures.…”

Steady-State Linear Kalman Filter-Based PLLs for Power Applications: A Second Look

“…2, as mentioned before, illustrates the general structure of an SSLKF-PLL. In developing a two-state version of this PLL, it is assumed in [8] that the frequency of the PLL input signal does not experience large variations. Based on this assumption, the following two-state prediction model is considered [8] x(n) = Ax(n − 1)…”

“…Throughout this letter, T s = 0.0001 s (which corresponds to a sampling frequency equal to 10 kHz) is considered. Based on the model described in (1), the following steps are conducted by the prediction/correction filter to accurately estimate the state variables [8]:…”

“…The main aim of this letter is analysing these so-called new synchronization methods [8]- [11]. It is demonstrated here that they are equivalent with some well-known SRF-PLLs.…”

Distributed cooperative synchronization strategy for multi-bus microgrids

“…In the past researches, the main methods can be divided into two categories, either synchronizing one DG with the UG [9]- [10] or reconnecting microgrids to UG with a central controller [13]- [15], [19]- [22]. A single DG can be simply reconnected to the UG by the traditional synchronizer [9]- [10].…”