C. Gouveia

Coordinating Storage and Demand Response for Microgrid Emergency Operation

Microgrids are assumed to be established at the low voltage distribution level, where distributed energy sources, storage devices, controllable loads and electric vehicles are integrated in the system and need to be properly managed. The microgrid system is a flexible cell that can be operated connected to the main power network or autonomously, in a controlled and coordinated way. The use of storage devices in microgrids is related to the provision of some form of energy buffering during autonomous operating conditions, in order to balance load and generation. However, frequency variations and limited storage capacity might compromise microgrid autonomous operation. In order to improve microgrid resilience in the moments subsequent to islanding, this paper presents innovative functionalities to run online, which are able to manage microgrid storage considering the integration of electric vehicles and load responsiveness. The effectiveness of the proposed algorithms is validated through extensive numerical simulations.

Microgrid Service Restoration: The Role of Plugged-in Electric Vehicles

The development of the microgrid (MG) concept endows distribution networks with increased reliability and resilience and offers an adequate management and control solution for massive deployment of microgeneration and electric vehicles (EVs). Within an MG, local generation can be exploited to launch a local restoration procedure following a blackout. EVs are flexible resources that can also be actively included in the restoration procedure, thus contributing to the improvement of MG operating conditions. The feasibility of MG service restoration, including the active participation of EVs, is demonstrated in this article through extensive numerical simulation and experimentation in a laboratorial setup.

Coordinated management of distributed energy resources in electrical distribution systems

Current electrical distribution systems are facing significant challenges due to the widespread deployment of Distributed Energy Resources (DER), particularly the integration of variable Renewable Energy Sources (RES). This requires a change in the paradigm of distribution grids from a purely passive perspective into fully active networks within the smart grid vision. This new paradigm involves new control and management architectures as well as advanced planning methods and operational tools for distribution systems exploiting a smart metering infrastructure. This infrastructure will enable leveraging data from smart meters and short-term forecasts of load demand and RES in order to manage the distribution system in a more efficient and cost-effective way, thus enabling large scale integration of RES. Future tests to be carried out in a new, state of the art laboratory environment will bring additional added-value to the validation of the proposed concepts and tools.

INESC Porto experimental Smart Grid: Enabling the deployment of EV and DER

The feasibility of the MicroGrid (MG) concept, as the pathway for integrating Electric Vehicles (EV) and other Distributed energy Resources (DER), has been the focus of several research projects around the world. However, developments have been mainly demonstrated through numerical simulation. Regarding effective smart grid deployment, strong effort is required in demonstration activities, addressing the feasibility of innovative control solutions and the need of specific communication requirements. Therefore, the main objective of this paper is to provide an integrated overview of the laboratorial infrastructure under development at INESC Porto, where it will be possible to conceptualize, implement and test the performance of new control and management concepts for Smart Grid cells. The laboratorial infrastructure integrates two experimental MG, including advanced prototypes for power conditioning units to be used in micro generation applications, batteries for energy storage and a fully controlled bidirectional power converter. Preliminary experimental results and organization of the infrastructure are presented.

Optimizing PV self-consumption through electric water heater modeling and scheduling

This paper aims at presenting a Home Energy Management System (HEMS) module capable of scheduling electric water heater (EWH) appliances in order to optimize the PV self-consumption. A multi-period optimization model is presented. Laboratory tests were conducted to validate the model and to demonstrate the capability of this HEMS module to address recent challenges of self-consumption in a domestic environment. A commercial EWH device developed by Bosch communicating with the HEMS module is used to perform the tests.

Microgrids emergency management exploiting EV, demand response and energy storage units

Within the Smart Grid paradigm, the MicroGrid concept (MG) presents an adequate framework to monitor and manage the low voltage network and coordinate the resources connected to it, including the smart grid new players, namely the consumers, prosumers and the Electric Vehicles (EV). The coordinated management and control of the MG resources, enables the operation both connected to the main power network or autonomously, due to planned or unplanned outages. In order to operate autonomously, the MG relies in its storage capacity to provide some form of energy buffering capabilities to balance load and generation. This paper presents innovative methodology to coordinate the microgrid storage capacity with EV smart charging strategies and demand response schemes, in order to improve microgrid resilience in the moments subsequent to islanding and reduce the non-served load. The effectiveness of the proposed algorithms are validated though extensive numerical simulations.

Multi-period modeling of behind-the-meter flexibility

Reliable and smart information on the flexibility provision of Home Energy Management Systems (HEMS) represents great value for Distribution System Operators and Demand/flexibility Aggregators while market agents. However, efficiently delimiting the HEMS multi-temporal flexibility feasible domain is a complex task. The algorithm proposed in this work is able to efficiently learn and define the feasibility search space endowing DSOs and aggregators with a tool that, in a reliable and time efficient faction, provides them valuable information. That information is essential for those agents to comprehend the fully grid operation and economic benefits that can arise from the smart management of their flexible assets. House load profile, photovoltaic (PV) generation forecast, storage equipment and flexible loads as well as pre-defined costumer preferences are accounted when formulating the problem. Support Vector Data Description (SVDD) is used to build a model capable of identifying feasible HEMS flexibility offers. The proposed algorithm performs efficiently when identifying the feasibility of multi-temporal flexibility offers.

Electric Vehicles Charging Management and Control Strategies

In this article, we present a holistic framework for the integration of electric vehicles (EVs) in electric power systems. Their charging management and control methodologies must be optimized to minimize the negative impact of the charging process on the grid and maximize the benefits that charging controllability may bring to their owners, energy retailers, and system operators. We have assessed the performance of these methods initially through steady-state computational simulations, and then we validated them in a microgrid (MG) laboratory environment.

Coordinating Distributed Energy Resources During Microgrid Emergency Operation

The development of the Smart Grid (SG) concept is the pathway for assuring flexible, reliable and efficient distribution networks while integrating high shares of Distributed Energy Resources (DER): renewable energy based generation, distributed storage and controllable loads such as Electric Vehicles (EV). Within the SG paradigm, the Microgrid (MG) can be regarded as a highly flexible and controllable Low Voltage (LV) cell, which is able to decentralize the distribution management and control system while providing additional controllability and observability. A network of controllers interconnected by a communication system ensures the management and control of the LV microgrid, enabling both interconnected and autonomous operation modes. This new distribution operation philosophy is in line with the SG paradigm, since it improves the security and reliability of the system, being able to tackle the technical challenges resulting from the large scale integration of DER and provide the adequate framework to fully integrate SG new players such as the EV. By exploiting the MG operational flexibility and controllability, this chapter aims to provide an extended overview on MG self-healing capabilities, namely on its ability of operating autonomously from the main grid and perform local service restoration. The MG hierarchical management and control structure is revisited and adapted in order to exploit the flexibility of SG new players, like the EV and flexible loads and integrate smart metering infrastructures. The implementation of the MG architecture and communication infrastructure in a laboratorial facility is also presented and used to validate the MG self-healing capabilities.

Operational characteristics of microgrids with electric vehicles

Microgrids are the basic building cells of a smart grid. They are assumed to be established at the low voltage distribution level, where distributed energy sources, storage devices, controllable loads, and electric vehicles are integrated and need to be properly managed. The microgrid cell is a very flexible system that can be operated connected to the main power network or autonomously, in a controlled and coordinated way. When operating in islanded mode, the MG relies on local energy storage to ensure the balance between generations and loads. However, when operating isolated from the main grid, the MG is more sensitive to power quality issues such as voltage unbalance, caused by the connection of single-phase loads and sources. In order to improve the MG emergency operation conditions, the EV should be envisaged as an active and flexible entity, providing to the MG additional distributed load or storage capacity under the vehicle-to-grid (V2G) concept. This chapter reviews the MG architecture considering EV and focuses on the impact of their active participation on the MG frequency regulation in emergency conditions (namely in islanding operating mode). Voltage unbalance issues during MG autonomous operation and the need for adopting voltage balancing mechanisms in specific power electronic interfaces are also discussed.