This paper describes the control algorithm of a utility connected microgrid, based on independent control of active and reactive power and operating in centralized and distributed operation mode. The microgrid is composed of several (three in the experimental tests conducted) configurable units, including generation, storage, and load units. These units are interfaced with the microgrid through a voltage source converter and are controlled by the nodes of the communication system by means of IEC 61850. The proposed control strategy is validated by simulation in MATLAB/Simulink and with experimental tests.
The technological leap of smart technologies and the Internet of Things has advanced the conventional model of the electrical power and energy systems into a new digital era, widely known as the Smart Grid. The advent of Smart Grids provides multiple benefits, such as self-monitoring, self-healing and pervasive control. However, it also raises crucial cybersecurity and privacy concerns that can lead to devastating consequences, including cascading effects with other critical infrastructures or even fatal accidents. This paper introduces a novel architecture, which will increase the Smart Grid resiliency, taking full advantage of the Software-Defined Networking (SDN) technology. The proposed architecture called SDN-microSENSE architecture consists of three main tiers: (a) Risk assessment, (b) intrusion detection and correlation and (c) self-healing. The first tier is responsible for evaluating dynamically the risk level of each Smart Grid asset. The second tier undertakes to detect and correlate security events and, finally, the last tier mitigates the potential threats, ensuring in parallel the normal operation of the Smart Grid. It is noteworthy that all tiers of the SDN-microSENSE architecture interact with the SDN controller either for detecting or mitigating intrusions.
The electricity sector foresees a significant change in the way energy is generated and distributed in the coming years. With the increasing penetration of renewable energy sources, smart algorithms can determine the difference about how and when energy is produced or consumed by residential districts. However, managing and implementing energy demand response, in particular energy flexibility activations, in real case studies still presents issues to be solved. This study, within the framework of the European project “SABINA H2020”, addresses the development of a multi-level optimization algorithm that has been tested in a semi-virtual real-time configuration. Results from a two-day test show the potential of building’s flexibility and highlight its complexity. Results show how the first level algorithm goal to reduce the energy injected to the grid is accomplished as well as the energy consumption shift from nighttime to daytime hours. As conclusion, the study demonstrates the feasibility of such kind of configurations and puts the basis for real test site implementation.
The high-penetration of Distributed Energy Resources (DER) in low voltage distribution grids, mainly photovoltaics (PV), might lead to overvoltage in the point of common coupling, thus, limiting the entrance of renewable sources to fulfill the requirements from the network operator. Volt-var is a common control function for DER power converters that is used to enhance the stability and reliability of the voltage in the distribution system. In this study, a centralized algorithm provides local volt-var control parameters to each PV inverter, which are based on the electrical grid characteristics. Because accurate information of grid characteristics is typically not available, the parametrization of the electrical grid is done using a local power meter data and a voltage sensitivity matrix. The algorithm has different optimization modes that take into account the minimization of voltage deviation and line current. To validate the effectiveness of the algorithm and its deployment in a real infrastructure, the solution has been tested in an experimental setup with PV emulators under laboratory conditions. The volt-var control algorithm successfully adapted its parameters based on grid topology and PV inverter characteristics, achieving a voltage reduction of up to 25% of the allowed voltage deviation.
This paper describes the control algorithm of a utility connected microgrid, based on independent control of active and reactive power (PQ control) and working in centralized operation mode. The microgrid under investigation is composed of three configurable units: a generation unit, a storage unit and a load. These units are interfaced with the microgrid through a Voltage Source Converter (VSC) and are controlled by the nodes of the communication system by means of IEC 61850. A set of tests have been conducted to evaluate the microgrid behavior.
This paper presents an approach to microgrid automation. The microgrid is composed of three different nodes connected to the public electric grid, which are hardware emulated with back-to-back converters. The microgrid is a flexible and weather independent test bed for testing different control algorithms. The intelligence of the automation system is split in three hierarchical layers: the RMU layer, the iNode layer and the iSocket layer. Communications among iNode and iSockets are according IEC 61850 standard. The aims of the project is to comission a set of technologies and acquire experience in microgrid automation, IEC 61850 communications and power control algorithms in DER systems.