The design of intelligent strategies for grid management is a cost-effective solution to increase the hosting capacity of distribution grids without investing in the reinforcement of the grid assets. This paper presents a distributed voltage control algorithm to coordinate Energy Storage Systems (ESSs) and Distributed Generation (DG) in a scenario of high renewable penetration. The proposed control algorithm relies on a dual decomposition approach and aims at mitigating possible voltage rise events occurring in the Low Voltage (LV) grid by solving an optimization problem of power minimization. Instead of using local control strategies, in the proposed solution, the voltage control burden is distributed among all the available resources in the grid, which cooperate to resolve the existing voltage violations. The performance of the developed voltage control has been tested under realistic distribution grid scenarios, using stochastic load profiles together with photovoltaic generation profiles obtained in the presence of both clear sky and cloudy sky conditions. The algorithm is also compared to a strategy that considers only DG management, highlighting the benefits associated to the proposed coordination of DG and Energy Storage Systems (ESSs).

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This paper investigates two control approaches to stabilize MVDC microgrids under large perturbations. The control approaches compared here are a 2 Degree of Freedom (2DoF) linear control and a synergetic control for voltage stability of DC microgrids, where loads and generators are interfaced through power electronic converters. The stabilizing control of the bus voltage resides in the converters on the generation side. The stability is challenged by Constant Power Loads (CPLs) that are tightly regulated within their control bandwidth exhibiting incremental negative impedance characteristic. In the scenario of a microgrid the two control approaches are compared in their centralized and decentralized formulation

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The development of strategies for distribution network management is an essential element for increasing network performance and reducing the upgrade of physical assets. This paper analyzes a multi-timescale framework to control the voltage of distribution grids characterized by a high penetration of renewables. The multi-timescale solution is based on three levels that coordinate Distributed Generation (DG) and Energy Storage Systems (ESSs), but differs in terms of the timescales and objectives of the control levels. Realistic load and photovoltaic generation profiles were created for cloudy and clean sky conditions to evaluate the performance features of the multi-timescale framework. The proposed solution was also compared with different frameworks featuring two of the three levels, to highlight the contribution of the combination of the three levels in achieving the best performance.

Abstract-The distributed control of islanded AC microgrids is based on the local measurements of the electrical variables at some nodes of the system to perform the secondary control. The Phasor Measurement Units (PMUs) guarantee accurate synchronized measurements that can be used as input signals for such distributed controllers. This paper analyzes the effect of one of the characteristic parameters of the PMU, the reporting rate, on the control performance. Verifying that could allow the use of low cost measurement devices with the aim of implementing the monitoring and control of low voltage microgrids.

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