easy grid analysis method (egam)
TRANSCRIPT
Easy Grid Analysis Method (EGAM) for a central observing and controlling system in the low voltage grid for E-Mobility and Renewable Integration
Methods
In this case a DC load flow analysis method including elec-
tric current iteration with following adoptions is chosen:
Demand of consumers and sources are stated.
All loads are symmetric and therefore the positive-
sequence polyphase system can be used.
Radial grid systems without intermeshing.
Project KOFLA This easy grid analysis method is developed in the project
KOFLA, which is funded by the program “ways2go“ of the
Austrian Federal Ministry for Transport, Innovation and Tech-
nology.
Centralized broker mediates between the moving electric
vehicles (EV) requesting service and the recharging sta-
tions offering recharge capacity.
Find the best match for each user and balance the electric
grid load between recharg-
ing stations.
Abstract: DC load flow analysis method including electric current iteration for calculation the available power of each charging station in the low voltage grid. EGAM is imple-mented in a routing and charging system, which avoid grid overloads by scheduling EV charging loads.
Figure 1: Model grid of a radial system
Methods and Equations
Electric Current Iteration:
Results (1)
Low voltage grid in the city of Bregenz, Vorarlberg -
Austria, with households, companies and several offices.
Simulation software NEPLAN with an extended Newton
Raphson calculation.
Figure 3: Compari-son results of the load calculation with correction values
Results (2)
Node Voltage failure between –0.22% and 0.14%
72% of all calculations have a max. grid losses failure
±5%, but the total failure can be up to –25%
Figure 4: Comparison results of the reactive power
Conclusions and Outlook
Calculation results of the load flow are exact and compu-
tation times are fast enough.
Grid losses computations get only recommendations for
saving energy in the grid and no exact values.
Grid Losses:
Figure 5: Overall grid losses over the charging power of two charging stations
“Kooperative Fahrerunterstützung für Lademanagement von elektrischen Fahrzeugen”
Figure 2: Flow chart of the Easy Grid Analysis Method
DC-LF:
Institute of Energy Systems and Electrical Drives
Vienna University of Technology
Gusshausstr. 25 / 370-1, 1040 Vienna, Austria
http://www.ea.tuwien.ac.at
Andreas SCHUSTER, MSc
Project assistant
T: +43 1 58801 370134