Abstract
The development of the Smart Grid concept is the pathway for assuring high reliability, control and management requirements in future electric power distribution systems. The Smart Grid can be defined as an electricity network supported by an intelligent infrastructure, both hardware and software, capable of accommodating high shares of Distributed Energy Resources. Within this line, a Smart Grid laboratorial infrastructure was developed, being dedicated to advanced research and demonstration activities. The adopted laboratorial architecture was developed according to the Microgrid concept, where Electric Vehicles are regarded as active and flexible players. Following the laboratory implementation, this paper provides a detailed description of its infrastructure and experimental capabilities, presenting and discussing different experimental set-ups and associated results.

Abstract
A distinctive characteristic of a Microgrid (MG) system is related to the ability of operating autonomously. However, the stability of the system relies in storage and generation availability, providing frequency and voltage regulation. Considering the deployment of distributed storage units in the Low Voltage network and of smart metering infrastructures, this paper presents an online tool for promoting an effective coordination of MG flexible resources in order ensure a secure autonomous operation and maximize the time that the MG is able to operate islanded from the main grid. The tool determines a priori an emergency operation plan for the next hours, based on load and microgeneration forecasting. The limited energy capacity of the distributed storage units participating in MG control is also considered.

Abstract
Renewable energy sources are environmentally appealing in electrical power grids. However, distributed energy resources (DER) are typically connected to the grid through converters that do not have the same properties as synchronous generators which have high participation in power generation. Some of these properties like inertial response are important and must not be lost with higher DER penetration. The present paper analyses two converter control algorithms that are capable of emulating inertial response in DER: the Virtual Synchronous Generator control (VSG) and the Synchronverter. Both algorithms are described, implemented and tested in a practical experiment and a comparison of both algorithms is assessed in terms of frequency nadir achieved, settling time and implementation complexity. The findings can give useful insights to help decide which algorithm should be implemented in a future real application.

Abstract
The large scale integration of Distributed Energy Resources (DER) at the Low Voltage (LV) distribution network offers new opportunities for the improvement of power quality and network reliability. Currently, the occurrence of large disturbances at the transmission network causing severe voltage sags at the distribution level could lead to the disconnection of a large share of DER units connected to the LV network, causing a more severe disturbance. In this paper, Low-Voltage-Ride Through (LVRT) requirements and current support strategies are proposed to mitigate the impact of severe voltage sag at the distribution level for DER units connected to LV network. The impact of adopting the proposed LVRT strategies will be analyzed through simulation and experimentally. A developed in house ESS prototype incorporating the developed LVRT strategies is also presented, and its capacity to comply with the proposed LVRT requirements is demonstrated using an experimental Power Hardware-in-the-Loop (PHIL) setup.

Abstract
Using power-hardware-in-the-loop is a solution for testing the behavior of devices on an emulated grid, with greater flexibility and avoiding the introduction of disturbances or critical operating conditions in the utility grid. This paper highlights the implementation of such a setup, its challenges and the solutions to cope with its limitations. The emulated grid is then used for the experimental validation of a 10kVA converter, regarding fault-ride-through, dynamic reactive current support and frequency and voltage based droop control, leading to the identification of design improvement recommendations.

Abstract
The progressive decommissioning of large synchronous generators that should take place in face of increasing penetration ratios of Distributed Generation (DG) will demand additional control mechanisms for inertia provision and frequency and voltage regulation in the power system. The need to cope with increasing penetration ratios of DG in distribution grids, added to the necessity to integrate an expected massification of EV and distributed ESS, and to the necessity to enhance Power System resilience and controllability, makes the Smart-Transformer (ST) a suitable solution. In this paper it is demonstrated the feasibility of the ST to contribute to frequency control through the control of the resources available in the distribution AC/DC hybrid networks created from the ST. The feasibility of local droop controllers, acting on frequency and voltage magnitude of the AC/DC hybrid networks created from the ST, to achieve the aforementioned goal, is demonstrated through computational simulation.