Fabio D'Agostino

Distributed Energy Resources Management in a Low-Voltage Test Facility

The electric energy demand will increase in the future, and the will to exploit larger amounts of generation from renewable resources requires the development of new strategies to manage a more complex electrical system. Different techniques allow the smart management of distribution networks such as load shifting, peak shaving, and short-term optimization. This work aims to test, in a real low-voltage (LV) active network (LV test facility of Strathclyde University of Glasgow), a Microgrid Smart Energy Management System, which adopts a two-stage strategy. The two levels of the proposed energy control system are composed of: 1) midterm controller that, according to weather, load, and generation forecasts, computes the profile of the controllable resources (generation, load, and storage), the dispatch problem is then solved through an optimization process; and through 2) short-term controller, which controls the power absorption of the active network. This procedure is hierarchically designed to dispatch the resources/loads, according to priority signals with the objective to contain the energy consumption below predetermined thresholds. The scalability and effectiveness of the architecture, which is validated in a real test bed, demonstrates the feasibility of implementing such a type of controller directly connected to the LV breakers, delivering a part of a real smart grid.

Dynamic Modeling of a Supply Vessel Power System for DP3 Protection System

The work is focused on modeling and simulation of a supply vessel from a static and dynamic perspective in an integrated way. Modern marine vessels with electric propulsion are becoming more and more complex systems. Therefore, there is a strong necessity to develop models capable to integrate different subsystems in order to evaluate the overall performance under faults conditions, harsh weather and other critical situations. In particular, the focus of the work is to highlight the need to implement zonal protection scheme to respect DP3 (Dynamic Position 3) constraints in case of severe busbar faults, operating the system with the main tie breaker closed. The model developed is characterized with a complete representation of a Platform Supply Vessel (PSV). The model represents also the full protection system (static and dynamic) in accordance to fine-tuning conducted on the real system. In this work, the innovative contribution is the investigation of the short-term dynamics after a busbar faults with a detailed electric model of the full network taking into account zonal power system protections and load shedding actions. The work is also focused on representing the electromechanical model of the propulsion power converters.

Dynamic modeling of a supply vessel electrical grid for DP3 protection system

The work is focused on modeling and simulation of a supply vessel from a static and dynamic perspective. The aim of the work is to highlight the necessity to implement zonal protection scheme to respect DP3 (Dynamic Position 3) constrains in case of severe busbar faults, operating the system with the tie breaker closed. The model developed is characterized with a complete representation of a ship for Platform Supply - Vessel (PSV). The model represents also the full protection system (static and dynamic) in accordance to the fine tuning conducted on the real system. The work is also focused on the representation of electromechanical model the propulsion power converters. The main objective and the innovation of the work is to demonstrate the ability to sustain severe busbar faults, respecting the DP3 requirement using zonal protection, using a full dynamic model of all the ship electrical system.

Low voltage microgrid islanding through adaptive load shedding

The aim of this work is to propose an adaptive load shedding procedure for Microgrid application, designed for blackout prevention and frequency transient containment in case of Microgrid islanding. The goal of the adaptive load shedding algorithm is to define the minimal set of loads to be shed, able to maintain the electrical variables within defined performance thresholds, while ensuring the Microgrid system stability.

Implementation of a distribution state estimation algorithm on a low voltage test facility with distributed energy resources

The paper illustrates the development and the implementation of a Distribution State Estimation (DSE) algorithm for the Low Voltage Test Facility with Distributed Energy Resources of the Italian Research center RSE. The algorithm is integrated into a Distribution Management System within the control system of the Test Site organized as a microgrid. The Test Facility is equipped with conventional and renewable generation plants, storage systems and programmable loads. Switching boxes allow to obtain a very high number of different topology configurations. The paper shows details of the methodologies and theoretical bases adopted for the algorithm design, implementation and testing of a two level state estimation procedure. Simulation and comparison with field results allow the evaluation of the power contributions to total nodal injections, in all the possible grid configurations.

Smart management of demand in naval application: Prospects and technologies for distributed control of loads

The paper aims to introduce an interesting concept of Power Management System, which adopts a full distributed architecture for achieving Smart Management of loads. An effective way to prepare and manage electric network with the increased demand, is to apply all the different techniques available in smart grids, such as load balancing, load shifting and peak shaving through the intelligent management of the load (ILM). This approach can be also used on vessel in order to perform different specific objectives in accordance to the PMS (Power Management System) or as a back-up solution of this component.

Mixed-integer algorithm for optimal dispatch of integrated PV-storage systems

The exploitation of combined photovoltaic (PV) plants and storage systems is nowadays assuming growing importance, due to the technical, environmental, and economical benefits which can derive from an optimal integration. In this paper, a mixed-integer algorithm for the optimal dispatch of a storage system, based on the day-ahead PV forecasting is developed. The optimization objective is the maximization of the total production of the integrated system, according to a requested active power profile, which can be defined by the operator. The study case of an existing distribution management system, which operates on the low-voltage microgrid at University of Genova is analyzed. The procedure is validated by field results with particular attention to the storage round-trip efficiency.

Real time control of a low voltage microgrid through a Distribution Management System

The technological, economical and social changes of the last years had an impressive impact in the electrical energy world. The improvement in information and communication technologies, the liberalization of the energy market, the appearance of active customers and the growing spread of renewables have required to systems operators to recognize and manage new scenarios. Nowadays, it is globally accepted that distribution systems are the core of this change, which will lead to the realization of the smartgrid concept. As the key field of the transition is represented by the distribution system, the main role is played by Distribution System Operators (DSOs). They are asked to modernize their medium and low voltage networks and to adopt advanced control and management systems. Modern Distribution Management Systems (DMSs) answer this request, by providing a valuable and effective support to system operators, thanks to advanced functionalities, embedded on board, which support the exploitation of unpredictable resources (as renewable generation), controllable devices (distributed generators and storage systems) or active customers. In this context this paper aims to describe the implementation of a DMS for the real time control of a low voltage microgrid, focusing on the communication architecture and on the routine of the embedded advanced functionalities.

Reliability assessment of distribution systems incorporating feeder restoration actions

This paper proposes a computational methodology for the evaluation of the IEEE reliability indices for distribution systems considering distribution system restoration. The goal of the proposed methodology is to move from a reliability assessment based on historical data to a computational approach. The developed tool allows the evaluation of the Service Restoration benefits, in terms of customers interruption duration in case of fault occurrences. Distribution System Restoration (DSR) is aimed at restoring loads after a fault by altering the topological structure of the distribution network while meeting electrical and operational constraints. The Spanning Tree Search algorithm is used to identify a post-outage topology that will restore the maximal amount of load with a minimal number of switching operations. The goal of the proposed tool is to determine the optimal switching sequences for the restoration process. The reliability indices incorporates contributions of all possible faults effects.

Intentional islanding of Microgrid by frequency support with building HVAC system

The paper proposes a control strategy for managing the load associated to the HVAC system of a building. The idea is to use the thermal energy stored into the building to contribute to frequency response during emergency conditions and improve islanding transition. The frequency dynamics of a Microgrid, following a disturbance on the main grid, can be improved using load response. A test network model of a commercial microgrid has been implemented in a dedicated simulation environment, in order to evaluate the performance of the microgrid frequency response and the effectiveness of the proposed technique. A comparative study against a dynamic response using a BESS (Battery Energy Storage System) is also investigated.