ldn sce symposium poster jb
DESCRIPTION
Poster Presented at SCE symposium October 2015TRANSCRIPT
Project Sponsors:ADVANCED POWER & ENERGY PROGRAM
www.apep.uci.edu
GOALS
1. Characterize the dynamic behavior of an advanced nanogrid comprised of solar PV, battery energy
storage system, and electric vehicle charging.
2. Assess the impact of the nanogrid on the connected primary microgrid circuit power quality.
3. Determine preferred battery dispatch strategies.
RESULTS
Four different BESS control modes were tested: (1) Peak-load-shifting (PLS), (2) Minimize Peak
Period Impact (MPPI), (3) Cap-demand, and (4) PV-capture (Fig.2).
A power quality survey combined with a harmonic load flow model allowed total harmonic
distortions (THD) to be calculated (Fig.3).
All voltage THD remained below the 5% threshold (IEEE 519 -1992). Transformers T1 and T2
delta/wye grounding scheme trapped 3rd harmonics. Harmonic cancellation also occurred due to the
effect of 20 EVs charging simultaneously.
OVERVIEW
Microgrids with distributed assets including renewable energy sources and Zero Emission Vehicles
(ZEV) are emerging to play a key role in offsetting greenhouse gas emissions and fossil fuel reliance.
Given this trend, it is expected that the integration of these new components will affect the power quality,
stability, integrity, and also reliability of the power distribution system.
As part of the Irvine Smart Grid Demonstration (ISGD) project, a unique distributed energy
resource has been deployed in a primary circuit of University of California, Irvine (UCI) Microgrid. On the
roof of a parking structure, 48kW of PV panels are installed to power 20 monitored EV chargers. The
system is integrated with a 100kW/100kWh battery energy storage system (BESS) (Fig.1).
Figure 1 – The Car Shade System
An Integrated PV/Battery for EV Charging in a Microgrid Topology
RESULTS (continued)
October, 2015
U.S. Department of Energy
Southern California Edison
Figure 2 – BESS modes daily dynamics
Figure 3 –Car Shade nanogrid voltage THD
0.92 %
1.51 %
3.08 %
1.47 %
1.54 %
1.52 %
PCC
Peak Load Shifting Minimize Peak Period ImpactMinimize Peak Period Impact
CAP demand – 20 kW PV Capture
A steady state load flow model calculated daily voltage profiles under different BESS operation
modes. Preferred modes have voltage profiles above 95% p.u. within the nanogrid. CAP 20 mode
showed such low voltages (Fig.4)
Table 1 ranks BESS dispatch modes in under-voltage occurrences, ability to increase PV contribution
to EV charging, and ability to zero-net charging demand.
Figure 4 – CAP demand 20 KW voltage profile
Table 1 – BESS modes ranking per category
PERSONNEL
Graduate Student: Laura Novoa
Principal Investigators: J. Brouwer, G.S Samuelsen
Advanced Power and Energy Program
University of California, Irvine
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