With the integration of electric vehicle (EV) charging and uncertain renewable generation, maintaining stability in the electric distribution grid becomes a critical challenge. To this end, there exists a need for a dedicated software framework to simulate the active distribution grid operation with flexible loads and battery energy storage systems (BESSs). The Flexible Distribution Grid Demonstrator (FLEDGE) is being developed by TUMCREATE as a simulation tool which integrates active distribution grid operation with classic power flow studies.
Approach and Methodology
The Flexible Distribution Grid Demonstrator (FLEDGE) is a software framework for the integration of distributed energy resources into the distribution grid. Equipped with power-flow solvers and optimal scheduling algorithms, the tool is suitable for classical studies as well as for designing optimal operation strategies.
With a focus on the distribution grid, FLEDGE enables realistic modelling of unbalanced multi-phase distribution grids and a range of distributed energy resources. The power flow and optimisation algorithms are bundled into three modules:
Planning: Utilisation of publicly available data on load points and grid parameters to generate a technically-feasible synthetic grid with optimal configuration
Operation: Simulation of a local distribution grid market on a day-ahead basis, which considers technical (grid) constraints as well as optimal economical (cost) preferences of the market participants (e.g. flexible loads)
Control: Setup of an online optimisation scheme which rejects any disturbances experienced by the grid in real-time.
The area of Hougang was selected as a test case for FLEDGE. From available load and substation data, a realistic grid layout was generated through the planning module. Two scenarios were then designed to answer the following questions:
What is the impact of electrified transport on the distribution grid?
How can optimal scheduling algorithms for flexible loads mitigate the impact?
Scenario 1 considers a high penetration of private vehicles as well as electric public buses, but no flexible loads. This results in high-peak voltage drop during midday and evenings. In Scenario 2, the flexible loads are optimally scheduled to improve the voltage stability. While maintaining a similar average maximum voltage drop, the peak voltage drop is reduced with this strategy.
FLEDGE can perform classical power flow analysis and power quality analysis, but it also includes state-of-the-art features for cost-effective and optimal integration of flexible loads, BESSs, EV charging and renewable generation into distribution grids. The main goal of this FLEDGE is to analyse, optimise and visualise distribution grids in the presence contemporary distributed energy resources.