Évora demonstrator site
Évora is a Portuguese Municipality located in the Alto Alentejo Region, around 130km from Lisbon, with a population of almost
60,000 inhabitants in an area of 1307,08 km2. Évora was also chosen as the first EDP Labelec smart city in the InovGrid project, a
project led by EDP Distribuição, the main Portuguese Distribution System Operator (DSO), aiming at promoting a better network
management and energy efficiency. The test bed itself is located in Valverde, a small rural village in the countryside of Évora, with
around 450 inhabitants and 238 clients connected to the Low Voltage (LV) grid.
Highlights
•
The demonstrator is mainly focused on testing solutions of energy
management and energy storage systems not only for final clients but also for
distribution grid management, both under normal and emergency operation
•
Located in Évora, Portugal, at the end of a MV feeder with no redundancy
•
3 secondary substations (SS): 2 DSO owned; 1client owned
•
Rural LV grid with 238 LV clients
•
Clients’ equipment: 25 clients are equipped with Smart Meter (SM); Home
Energy Management System (HEMS); 1,5 kWp PV systems; 2 kWh batteries,
water heaters
•
LV Grid Storage: 50 kVA battery; 3 X 30 kVA batteries; 125 kVA Flywheel
Power grid architecture
The power grid chosen for the Évora Demonstrator includes two grid secondary substations (Medium Voltage/LV
substations) and a client-owned secondary substation.
The main elements are:
•
A circuit breaker between the transformer’s LV side and the LV secondary substation switchgear. It will be installed in
one of the secondary substation to enable the creation of a microgrid;
•
Distribution Transformer controller (DTC) concentrates data collected by all smart meters and send it to the upstream
central systems. It is responsible for sending to smart meters DSM signals. It is also responsible for managing the storage
units installed in the grid.
•
Electrochemical storage units (one battery with 100 kVA) and an electromechanical storage unit (flywheel with
125kVA of rated power) will be integrated and connected at one of the SS LV busbar, aiming to test different functionalities
and capabilities of energy storage in grid operation. Electrochemical storage units (4 units with 30 kVA and 2 prototype units
with 10 kVA) will also be installed in other points of the LV grid, along the feeders, enabling different applications like
technical losses’ reduction, voltage control and renewable energy sources integration.
•
Smart meters that enable DSM functionalities and provide valuable data for the operation of LV systems by
characterizing the energy consumption and voltage in each node of the network. Smart meters also provide important
information to clients, through a Home Area Network (HAN) port where a HEMS can be connected.
At residential level, behind the meter, a set of devices will be installed:
•
Residential electrochemical storage units and thermal storage units (water heaters);
•
Photovoltaic (PV) Systems as a form of microgeneration;
•
Home Energy Management Systems (HEMS) and Smart Plugs
ICT
The architecture of all the systems and
devices and data flow between these
systems are defined in the image on the
right.
The components of the Évora architecture
can be grouped according to their
ownership/responsibility:
• Client/retailer infrastructure
• DSO infrastructure
• DSO Tools
• Independent actors
The information between blocks flows
through RTP – (Real Time integration
Platform) which is a middleware
communication infrastructure for real-time
data acquisition and processing, with the
ability to handle large volumes of
information at low latency.
Client/retailer infrastructure
The client/ retailer infrastructure represents the participation of residential/ services clients.
DSO infrastructure
The DSO infrastructure is responsible for managing and control the distribution network as well as concentrating and
processing the data collected from smart meters.
DSO Tools
DSO tools incorporate the main algorithms and systems required for the operation of MV and LV networks considering the
integration of storage, micro-generation and flexible loads.
Independent actors
This block comprises three tools: PV Production Forecast, Electric Demand Forecast and Residential Flexibly Aggregator. In
addition, the Residential Flexibility Aggregator is responsible to both aggregate clients’ flexibility and allocate the necessary
flexibility for each client.
Market Platform
The Market Platform includes both the EMSP (Energy Market Service Platform) and the Energy Markets components that
will emulate an energy market.
Use Cases
The objectives of the demonstration work are materialized into 5 use cases, of which 4 are mainly related with grid
management and the last one is focused on client flexibility and demand management
UC 1 - OPTIMIZING THE OPERATION OF STORAGE DEVICES IN THE MV NETWORK IN NORMAL AND EMERGENCY OPERATION
Normal operation: Manage MV storage devices in order to solve technical problems at the MV network level (e.g. degradation of voltage
profiles, losses). The storage devices are assumed to have two objectives: (a) reserve capacity to support continuity of service of an installation
(or building) and (b) the residual capacity is used for grid support;
Emergency operation: In case of MV failure, the MV grid will be operated in islanding operation and LV grid will contribute to MV stability,
through active and reactive power supply from LV DER. Main goal is to last islanding operation until main grid can be reconnected
Grid
UC 2 - OPTIMIZING THE OPERATION OF STORAGE DEVICES IN THE LV NETWORK
The main goal is to manage local distributed storage devices in order to solve technical problems in the LV grid (namely related to voltage
issues) and minimize technical losses. The storage devices are to be coordinated with renewable generation at the LV level as well as with
demand side management schemes, considering residential storage and controllable loads.
UC 3 - ISLANDING TRASIENT IN LOW VOLTAGE ISLANDING
The main goal is to enable the operation of LV networks in islanding mode, ensuring the secure transition to islanding operation and the system
stability, by providing adequate frequency and voltage regulation mechanisms.
UC 4 - MICROGRID EMERGENCY BALANCE
During islanding operation, the unbalance between LV generation and load will have to be minimized in order to avoid the system collapse. The
main objectives of this module are i) Minimize energy not supplied and time of service interruption; ii) Ensure that the MG has sufficient
Retail
capacity to ensure frequency regulation following islanding; iii) Maintain frequency excursions within admissible limits.
UC 5 - FLEXIBILITY AND DSM IN MARKET PARTICIPATION
The scope is about LV customer flexibility market participation (wholesale and retail) and also regarding grid assess management by application
of grid access dynamic tariffs or other types of flexibility award to clients